The characteristics of rural properties and the landscape, including the type of land use, can be predictors of the degree of integrity of the remaining native vegetation. However, the interrelationships between productive activities and the conservation of forest remnants in the Amazon are still poorly understood. The aim of this study was to assess whether the type of land use and the specific characteristics of private rural properties influence the degree of integrity of forest remnants in the Guamá micro-region, in northeastern Pará, which has 13 municipalities. To do this, we mapped the areas of permanent crops and forests, integrating this data with information from the Annual Mapping of Land Use and Land Cover in Brazil Project (MapBiomas). We used three variables as proxies for the integrity of native forests: the Normalized Difference Infrared Index (NDII), calculated using Landsat images, and height and above-ground biomass calculated using information from the Global Ecosystem Dynamics Investigation (GEDI). Seven main predictors were included in the analysis: a) TPR - the size of the rural property; b) %AGRI - the proportion of the rural property occupied by permanent agriculture; c) FOR - the area of native vegetation on the rural property; d) %FOR - the proportion of the rural property occupied by native vegetation; e) %FP - percentage of forest in the landscape; f) FIRE - average number of times the forest fragment on the property was burned between 1985 and 2022; g) IVEG - average age of the fragments. The results indicated that four predictors were important for explaining the variation in above-ground biomass (Mg/ha) of the forest fragments on the properties (%FOR, FIRE, IVEG, log_TPR), explaining 10% of the observed variation (r² = 0.10; p<0.05). All the predictors were relevant to explaining the variation in height in the fragments, explaining 28% of these variables (r² = 0.28; p<0.05). In the case of NDII, all the predictors were also significant, explaining 13% of the variation in the data (r² = 0.03; p<0.05). These findings highlight the importance of considering the complexity of the interactions between land use and the characteristics of rural properties for the conservation of forest remnants in the Amazon. This research contributes to the understanding of environmental dynamics and provides subsidies for policies and practices aimed at the sustainability and preservation of the Eastern Amazon.

The Amazon holds vast potential for forest management. Scientific research plays a crucial role in overcoming challenges associated with conducting management activities in the region, enhancing the capacity for effective management and control. Forest managers need to gather information about forest dynamics to determine harvesting cycles, minimizing impact and aligning with the vegetation's growth rate. Permanent plots are the most effective tool for assessing dynamics and measuring forest growth, providing vital information to detect growth patterns in specific forest areas. Each area is subject to unique characteristics, resulting in a specific growth rate. Therefore, understanding or estimating forest growth rates is essential for effective management. Population models (or global models) emerge as an alternative for volume forecasting, considering forest dynamics based on dendrometric attributes of vegetation as predictor variables, aiming to estimate volumetrics in respective areas. This study aims to identify the average dendrometric variables of a forest area with the greatest capacity to describe volume growth per unit area. Additionally, it seeks to estimate the volumetric recovery time of the area after forest management in the Amazon region and compare it with the stipulated cutting cycle. The study's forest area information was obtained from Management Unit 3 of Caxiuanã National Forest. Continuous forest inventory measurements were conducted on trees with Diameter at Breast Height from 10 cm, totaling a sample of 66 measurements and remeasurements in permanent plots. Preliminary results, based on Pearson correlation coefficients, indicate a stronger relationship between the area's volume and variables obtained through the cross-sectional area of trees, such as basal area and mean quadratic diameter.

This research aims to analyze the measurement, monitoring, and estimation of biomass and
carbon using allometric equations and remote sensing estimation. The study will be conducted
with data collected at Fazenda Piave, located in the municipality of Igarapé-Açu. The property,
which spans 75 hectares, is dedicated the agricultural and forestry production, being mostly
composed of secondary forest. The research intends verify the estimates obtained by both
methods, seeking identify statistically significant differences. Initially, the biomass and carbon
quantities in the area will be analyzed using allometric equations with data collected in the field

and subsequently for remote sensing, the estimative will be conducted using scenes of Sentinel-
2 satellite on the Google Earth Engine platform in the Python programming language, with

applying distinct spectral indices, NDVI, EVI, SAVI and NPP. The study objective is achieving
the best biomass and carbon estimation using the allometric equations and spectral indices,
evaluating the differences between the estimates in terms of precision, accuracy, bias, temporal
monitoring and cost.

The expansion of secondary forests in tropical ecosystems due to post-shifting cultivation abandonment is a reality driven by decreasing productivity resulting from improper management practices. Natural regeneration often plays a key role in restoring these ecosystems, but its effectiveness is limited by various factors, including the degree of degradation, seed sources, and proximity to adjacent forests. The Water and Nutrient Manipulation in Secondary Forests in the Eastern Amazonia (MANFLORA) project was developed over eight years (1999-2007) to understand the factors influencing the dynamics of these ecosystems. The experiment took place in an ecosystem with a 40-year history of shifting cultivation and included irrigation during drier periods and the removal of nutrients through litter. Treatments consisted of irrigation, litter removal, and a control group. Sixteen years after the conclusion of MANFLORA, this dissertation is divided into three chapters aimed at understanding the overall context of shifting cultivation in the Amazonia and the long-term impacts of resource management on secondary forests in the region. In the first chapter, a literature review on shifting cultivation in the Amazonia was conducted, highlighting its importance for rural populations and emphasizing negative impacts such as reduced biota, soil fertility, and aggregation, as well as impacts on flora and fauna. The following two chapters assessed the long-term effects of the MANFLORA experiment. The second chapter examined indicators of vegetation composition and structure, showing differences in floristic composition between treatments but no significant impacts on vegetation structure. The third chapter focused on soil and litter nutrient dynamics, highlighting residual effects on nutrient availability such as K, Ca, Mg, and P. Irrigation positively influenced K availability, while litter removal negatively impacted pH and monthly production of Ca, Mg, and P. These results suggest that resource management can have lasting effects on nutrient dynamics in secondary forests. In summary, the study underscores the importance of shifting cultivation for Amazonian communities but emphasizes the need for sustainable practices to balance food production with forest conservation. The long-term results of MANFLORA provide valuable insights into post-shifting cultivation dynamics, highlighting the influence of water and nutrient manipulations over time. Therefore, this work contributes to understanding the role of these ecosystems and emphasizes the importance of management approaches that consider long-term resilience and sustainability.

The use of plants with phytoremediation potential is a practice used in soils contaminated by heavy metals, which are environmental pollutants and their toxicity is a problem of global importance. The objective of this work is to evaluate the carbon and nitrogen metabolism of the species Pau-pretinho (Cenostigma tocantinum Ducke) regarding its tolerance capabilities to this type of stress subjected to doses of the heavy metal nickel chloride (NiCl2) and with the attenuator of metal in the soil, biochar from açaí seeds (Euterpe oleracea Mart), this by-product is abundant after the extraction of the juice. The application of new technologies allows us to find efficient ways to reduce waste and prevent this waste from accumulating. The use of açaí seeds in the production of biochar is a promising approach, it is a carbonized material that can be incorporated into the soil to improve its quality, fertility and also acts to sequester carbon to reduce the emission of greenhouse gases. The growth and biochemical metabolism of carbon and nitrogen (reducing and non-reducing sugars, total soluble carbohydrates, sucrose, amino acids, proteins, proline, glycine betaine, free ammonium, nitrate reductase) in Pau-pretinho seedlings were evaluated. The experiment was conducted in a greenhouse, in an area of the Institute of Agricultural Sciences (ICA), belonging to the Federal Rural University of the Amazon – UFRA, Belém-PA campus. The design used was completely randomized in a 4 x 3 factorial scheme with 5 replications, the 1st factor corresponds to the doses of nickel chloride (0 NiCl2, NiCl2 70mg/kg; NiCl2 100mg/kg; NiCl2 130mg/kg) and the 2nd factor corresponds the doses of biochar (0%; 3.5%; 7%), using 60 seedlings in total. The data obtained were subjected to analysis of variance using the F test (p<0.05) and the means were compared by the minimum significant difference using the Tukey test (p<0.05) and subjected to the regression test using the AgroEstat program. For the growth variables (height, stem diameter, root length, number of leaves) and chlorophylls A and B. Nickel provided a decrease as the doses were increased, resulting in lower production of root diameter and length. And chlorophylls A and B showed a high degree of significance in statistical tests. Interactions with Biochar will also be significant, showing that the Cenostigma tocantinum DUCKE species has potential for phytoextraction.

The nutshell that surrounds the almonds of the Brazil nut (Bertholletia excelsa Humn. & Bonpl) has a lignocellulosic composition and can be used to produce domestic charcoal to improve the income of extractivist communities. To do this, it is necessary to propose carbonization systems that are low-cost, durable and low-polluting. The aim of this work was to develop a low environmental impact kiln and methodologies for preparing the hedgehog to produce charcoal for domestic use. A prototype kiln was built consisting of four parts: reactor, energy chamber, carbonization chamber and drying chamber. The biomass was placed in the reactor, which consists of a 200 L drum, which in turn is introduced into the carbonization chamber for heating to approximately 450°C using external energy generated in the energy chamber. The gases produced in the reactor were directed to the energy chamber to promote feedback in the production system and, at the end, all the remaining gases were directed to the drying chamber to reduce the humidity of the biomass. The kiln was subjected to pre-tests of carbonization with other biomass until it was time to harvest the nuts, which took place in the Paru State Forest (Flona) in Pará in April 2024. Thermocouples were used to record the temperatures inside and outside the reactor. The nutshell were divided into exocarp and mesocarp. The mesocarp was tested by cutting it in half by the Brazil nut growers of Flona Paru. The material was then carbonized in the proposed system. The system reached temperatures of 350 to over 800°C, due to the configuration of its layout and feedback system. The exocarp and mesocarp charcoal had different apparent densities (0.35 and 0.68) g/cm³, dry basis moistures (14.71 and 3.40%) and volatile material contents (38.5% and 24.9%), ash (13.42% and 3.91%) and fixed carbon (33.37 and 70.53%). There was no variation between the charcoal derived from the cutting of the chestnut trees in the Paru Flona and that broken in half. The carbonization system needs to be adjusted to avoid temperature peaks above 800°C, but it is promising for Brazil nut extraction communities, as it provides nutshell charcoals that can be marketed. To do so, the exocarp must first be removed. 

Technosol is an alternative for recovering areas degraded by mining, as the topography of the relief
is reconstructed with tailings from mining and processing, thus creating an environment for fauna
and flora and waste disposal. However, to fulfill the ecosystem services of natural soil, the
Technosol must be of good quality. With this in mind, the study aimed to assess whether the
chemical, physical, and biological indicators of a Technosol are altered by different methods of
recovering degraded areas after three years in a given site condition. The experiment was set up at
the IRCC mine in 2020 with the following treatments: nucleation (NU), dense planting (PA), forest
planting (PF), forest planting with liming (PFC), and a native forest (FN) as the reference
ecosystem. To carry out the sampling, the treatments and FN were divided into four plots (25 x 25
m), which were collected in July 2023 at depths of 0–10 cm and 10–20 cm. First chapter: in this
chapter, the following indicators were assessed: pH, organic matter (MO), potassium (K),
phosphorus (P), calcium (Ca), magnesium (Mg), aluminum (Al), potential acidity (PA), sum of
bases (SAB), cation exchange capacity (CTC), base saturation (V), and aluminum saturation (m).
The physical indicators were: soil density (DS), total porosity (PT), penetration resistance (RP),
sand, silt, and clay, and the soil quality index (IQS). The physical indicators were little altered in the
Technosol, except for RP, which was positively affected by PA, while the chemical indicators in the
PFC treatment showed higher pH, Ca, Mg, SB, and V values, and lower Al and m values. Higher
PT and lower DS and RP were observed in the FN. In addition, the FN had higher MO, AP, CTC,
P, K, Al, and m values. The IQS in the PFC was higher in the Technosol, but not lower when
compared to the FN. Therefore, the treatments hardly altered the physical quality of the Technosol,
while the chemical characteristics were positively changed by liming. However, the characteristics
studied in the third year of recovery are still not close to those of the FN. Second chapter: this
chapter covers oxidizable carbon (COx), organic carbon (CO), microbial biomass carbon (CBM),
basal respiration (RBS), organic carbon stock (E-CO), microbial quotient (QMIC), and metabolic
quotient (QCO). CO was not influenced by the treatments, while E-CO and COx were altered, with
NU and PA having the highest values. For CBM and RBS, the highest values were at a depth of
10–20 cm in NU and 10–20 cm in PA in CBM and PA=NU in RBS. For QMIC, at 0–10 cm, it was
highest in NU and PFC and 10–20 cm in PA. QCO was higher in PF at a depth of 10–20 cm. As a
result, the quality of the Technosol for the variables studied is not yet equal to that of the native
forest. However, nucleation stands out from the other treatments in Technosol.

One of the key recognized aspects for achieving sustainability in forest management, biodiversity conservation, and responsible use of natural resources in the Amazon is the improvement of botanical identification in forest inventories. In this context, this study aims to evaluate the efficiency of tree botanical determination using dendrological methods and tools, thereby contributing to the sustainable use of managed forests. The study area is the UMF V located in the Paru State Forest (FLOTA) in Monte Alegre municipality. Botanical material was collected from the most voluminous species known by their common names for commercial purposes in the area. Samples were collected from a minimum of 5 different trees per species. Based on the identification of collected species, the accuracy level of species determination commonly traded in the state of Pará was assessed, including cases where different species are grouped under the same common name, as well as morphological differences among these species. It was observed that errors in determination mostly occur at the species level, where common names group different species from the same genus and family that are not listed in the forestry inventory of the responsible management company. This reinforces the need for improvements in botanical identification in forest management based on the morphological characteristics of each species.

Logging is an activity with a high economic factor in the main states of the Amazonian biome, between the months of August 2019 and July 2021 alone, 464,000 hectares of forest for timber production in the Legal Amazon. The least predatory way to exploit forest resources is through sustainable forest management, where it is possible to meet the high demand for timber and non-timber forest products, in addition to mitigating the damage caused in the region. In the process of botanical identification of forest species in inventories, common nomenclature is used and this practice can lead to misunderstandings, since a species can have several vernacular names, as well as a common name can indicate several species, and for the correct identification in the field it is necessary the morphological knowledge of the species, however, not always the characteristics are available for viewing, thus, the wood anatomy of forest species is of fundamental importance in the process of identifying and differentiating species, because the qualitative and quantitative anatomical characters can influence the grouping and distinction of similar species. In this sense, the objective of the present study is to use the anatomy of wood as a tool for the correct scientific identification of wood species and thus contribute to improvements in management. The study area is located in forest management unit IV of Floresta Estadual (FLOTA) do Paru, in the municipality of Monte Alegre, state of Pará. The experimental design will be completely randomized (CRD), for that 19 common names most commercialized in the region will be selected in which for each name samples of 5 trees will be collected, totaling 95 samples. Macroscopic and microscopic anatomical characterizations (qualitative and quantitative) of the samples will be carried out, followed by scientific identification. With the development of the research, it is expected that the anatomy of the wood will be able to distinguish similar species that are being commercialized with the same common name, in addition to contributing to the conservation and correct commercialization of the analyzed woods.

The Brazil Nut is one of the main non-timber exports from the Amazon, with 85% of the fruit consisting of residues. The Amazon community harvesting these nuts could benefit from the sustainable use of such biomass. This work comprises of three stages: (i) to review current research and technologies for the sustainable potential of Brazil Nut residues, (ii) to design and produce a device capable of helping the local communities to debark the Brazil Nuts easily, and (iii) to evaluate the energy potential of biomass and charcoal from both fresh and degraded Brazil Nutshell (BNS) mesocarp. The literature review showed that Brazil Nut residues are suitable for conversion into many bioproducts and biofuels. However, carbonization is applied nowadays. The current method for carbonizing BNS residues leaves a lot of the residue partially carbonized, which decreases the market value. This undesired result is mainly because the shape of residues harms carbonization. Since Brazil nutshell has remarkable physical properties and strength, it is difficult to cut them into a suitable shape for traditional carbonization. Therefore, a device has been designed in this work for the quick, safe, and efficient cutting of the BNS for later carbonization without harming the edible nuts. The device itself is basically a modification for the Miter Saw Vonder Sev857 to hold and cut open Brazil nuts. The device is in the assembling stage for later testing. Fresh BNS mesocarp samples presented a higher calorific value of 4797 kcal/kg, while degraded BNS mesocarp samples showed a lower calorific value of 4600 kcal/kg. Thermogravimetric analysis indicated that fresh and degraded BNS mesocarp samples are suitable for carbonization and have energy potential, but they behave differently providing charcoals with different quality. Overall, degradation of the nutshells in the forest floor decreases their energy quality.

The large trees of tropical forests are critical to carbon stocks and essential for climate regulation. In this study, we used data from forest inventories of 10 sites with forest management for timber extraction in the western region of the state of Pará to achieve two objectives related to large trees in the Amazon: a) to evaluate the most suitable allometric equation for estimating the biomass of large trees in the Amazon, and b) to analyze the importance of species richness as a predictor of carbon and timber stocks based on the niche complementarity hypothesis. In each studied site, trees with a diameter at breast height greater than 50 cm (DBH≥50cm) were sampled, totaling a sample area of 20,449.95 hectares. The results showed that the equation by Réjou-Méchain et al. (2017) was the most appropriate for estimating biomass. Species richness was positively associated with biomass (R2= 0.53; p<0.01) and timber stocks (R²= 0.30; p<0.01). Our results indicate that species richness increases biomass and wood stocks, highlighting the importance of biodiversity conservation, and efficient allometric models and equations are crucial for estimating carbon stocks in natural areas.

Knowledge of the specific characteristics of each tree species is necessary to make decisions about the need to apply silvicultural treatments for their adequate favoring. With the aim of expanding knowledge regarding the effect of silvicultural treatments on tree species, in order to obtain information that may contribute to improving forest management in the Amazon, the present study evaluated the growth of 56 species of ecological importance in the dense forests of the Amazon. . The study was carried out at the Fazenda Rio Capim Forest Management Unit, belonging to the Keilla Florestal Group (CIKEL), located in the municipality of Paragominas, Brazilian Amazon. The experimental area consists of 700 ha, distributed in 14 Work Units. Of the total area, 600 hectares were logged in 2004 and 100 hectares were left untouched. In the exploited area, silvicultural treatments were applied in 2005, the year following exploration, consisting of cutting lianas and refinement by girdling trees. For the statistical analyses, assumptions of the analysis of variance (ANOVA) were verified, namely: a) normality with the Shapiro-Wilk test (p > 0.05) and visualization with the Q-Q plot graph, and b) homoscedasticity by Bartlett's test (p > 0.05). Once these assumptions were not met, the data were analyzed using analysis of repeated measures over time (ANOVA) non-parametric through the Kruskall-Wallis test (p < 0.05) and after significance, the measures were compared by the Dunn test (p < 0.05). Graphs were generated using the “ggplot2” package, and statistical analyzes and results using the “AgroR” package. All statistical analyzes were performed using the R version 4.2.1 program, at a significance level of p < 0.05. There was a significant effect (p = 0.001) of both the period and the silvicultural treatments in the group of 56 species. Considering the group of 56 species, all treatments showed a higher IPA, two years after the application of silvicultural treatments. T1 had the highest mean IPA, one year (0.48 cm yr-1), two years (0.62 cm yr-1) and four years (0.52 cm yr-1) after the application of silvicultural treatments, significantly differing from treatments T3 and T4 (p = 0.001).

The crisis linked to climate change and global warming, persisting for years and particularly at present, demands the implementation of measures that address societal concerns. Among these measures, there is a highlighted need to reassess the management of natural resources. In this context, the practice of Agriculture without Burning emerges as a crucial alternative to avoid the use of fire in family farming, where this practice still persists. The use of fire to improve soil properties in nutritional terms and prepare the area for cultivation is a harmful practice, both for farmers and the environment. The Tipitamba project engages in technical-scientific cooperation to conduct studies that make family farming area preparation in the Northeast region of Pará less environmentally aggressive, with a focus on sustainable management of the capoeira, using shredders. Thus, the aim of this work was to assess the performance of a medium-sized shredder in the crushing of capoeira biomass, evaluating the biomass crushing yield, material quality, and cultivation performance. Experiments were conducted in Igarapé-Açu, in the northeastern part of Pará, a municipality known for agricultural production and support for small producers and family farming. For capoeira shredding, the medium-sized Ecotritus HL240 tractor from Himev was used. The evaluation of crushing yield was obtained by collecting aerial biomass on family farmers' properties, varying in size and conditions. Material crushing quality was assessed through a screening system using three sieves: 7mm, 25mm, and 35mm. To evaluate agricultural cultivation performance, a crop of corn, cowpea, and cassava was analyzed, simulating the production of these crops in an area prepared with the medium-sized shredder. The crops were planted in an area of approximately 0.5 hectares, divided into 3 blocks with 9 plots measuring approximately 16x33m, with spacings of 1x0.5m for corn and cowpea, and 1x1m for cassava. Three treatments were applied: T1 - corn, T2 – corn + cassava, T3 – corn + cowpea + cassava. As a result, an average biomass aerial yield of approximately 19.79 tons per hectare and consumption of 79.89 liters per hectare were obtained. The results for material quality indicated that the total amount of dry shredded biomass was approximately 17.08 tons per hectare. When using sieves, larger quantities of material were found in the <7mm class, followed by material >35mm. Larger-sized materials are important as long-term nutrient sources, while smaller-sized materials (<7mm) are absorbed more quickly. Average results were obtained for corn: T1 - 2.02 tons/ha, T2 - 1.87 tons/ha, T3 - 2.14 tons/ha; for cowpea: 1.59 tons/ha; for cassava, T2 presented 10,065.28 tons/ha and T3: 8,081.389 tons/ha. With the presented results, we can conclude the efficient functioning of the Ecotritus HL240 shredder, good efficiency in crushing, and possibilities to serve family farmers with capoeiras up to 5 years old.

Most ecosystems and their forest communities are in a secondary stage of succession, resulting not only from stochastic natural events, but mainly related to land use which, at different levels, cause some disturbance and disrupt them. Burning an area for the implementation of swidden land causes the death of soil organisms and considerable loss of nutrients, compromising carbon sequestration and storage, an important function of these ecosystems for regulating the planet's climate. An alternative to replacing this action is cutting and crushing the capoeira, as it leaves a dense layer of phytomass on the surface of the land covering and protecting the soil against erosion. In this context, the work aims to evaluate the influence of area preparation methods in the Cutting and Grinding (CT) and Cutting and Burning (CQ) systems on capoeira regeneration and biomass production in an experimental fragment located in Igarapé-açu. For this, the sampled plots come from a long-term study of secondary vegetation management in family farming linked to the SHIFT-Capoeira Project, today called Tipitamba. In a 21-year-old secondary forest, divided into two adjacent areas of 2ha each, were prepared with the CT and CQ methods, and a 2-ha fragment of the successional forest was conserved as Reference (R). A survey of the phytosociological structure of tree regeneration was carried out. 10 plots were implemented in the areas of CQ, CT and R, with dimensions of 10 m x 10 m each, arranged systematically. The analyzes included all individuals with diameter at breast height – DBH≥2.0 cm and measured at total height (HT). The inventoried individuals were identified with their respective scientific names by two parabotanists in the field belonging to EMBRAPA ORIENTAL. In the years 2016 and 2022, respectively, an average diversity (H’) of 2.14 and 1.35 was found for the CT; 2.06 and 1.93 for CQ; and 2.09 and 2.20 for the R area, the average density was 32.2 and 29.5 ind. ha־¹ in CT; 25.5 and 39.9 ind. ha־¹ in CQ; and 28.8 and 24.6 for the R area, the estimated dry biomass for the CT was 3.40 and 4.15 ton ha־¹; 1.40 and 2.52 ton ha־¹ for CQ; and 5.27 and 4.93 ton ha־¹ for the R area. Statistical differences (ANOVA; P < 0.05) occurred in structural parameters and biomass, indicating that CT facilitates the development of the arboreal component of forests and greater stock of carbon.

The production and commercialization of the açaí fruit has contributed significantly to the agro-industrial development of the Amazon region. However, such progress has been accompanied by the exponential growth of post-processing waste generation, with potential for the generation of bioenergy. However, inadequate storage, which depreciates the biomass, is one of the main limitations for this purpose. Therefore, the objective of this work was to analyze the effect of the environment and storage time on the degree of modification of the quality of the açaí waste for pyrolysis and combustion. The seeds were stored under three different conditions: immersed in deionized water, under the ground and in plastic bags, stored in a covered greenhouse for nine months. Physical and chemical analyses of the fresh residue were performed at time 0 (zero) and after 30, 60, 180, and 270 days of storage. Analyzes of water-soluble extractives, Fourier transform infrared spectroscopy, thermogravimetric in inert atmosphere and thermogravimetric in oxidative atmosphere were performed for the fresh waste and at the end of the storage time. Storage in soil and plastic bag caused a significant decrease in the waste moisture, unlike storage in water. The density of the residue stored in water and in a plastic bag reduced after 30 days. For waste stored in soil, this property decreased up to 180 days, increasing again after 270 days of storage. Fixed carbon and ash content increased while volatile material content decreased proportionally for the three conditions in relation to the fresh residue. Soil and water storage decreased water-soluble materials. Soil storage increased the concentration of lignin and silica. All storage methods made the residue more stable for pyrolysis and combustion. The storage in water was the one that most depreciated the energetic properties of the açaí residue. Soil and plastic bag storage are beneficial for increasing fixed carbon content and decreasing moisture content, but adversely affect ash content and waste density.

Soil contamination by heavy metals represents a high potential for danger in the agricultural sector, in addition to bringing imminent risks to ecosystems and human health. Faced with the problems caused by excess nickel (Ni) and other metals, it is necessary to adopt eco-sustainable techniques that aim to remove or stabilize them in the soil, to help mitigate the effects of pollutants on ecosystems. Phytoremediation is a technique that has been used to recover areas contaminated by different groups, especially metals, through the planned introduction of plants with regenerative behavior, such as Paricá – Schizolobium amazonicum Huber ex Ducke. Therefore, the objective of this work was to evaluate the effect of nickel doses on the antioxidant system of young plants from Paricá. The experiment was carried out in a greenhouse from July to September 2019. Sowing was carried out in Leonard-type pots, adapted with pet bottles, containing sterilized sand (120 ºC for 40 min.), with a capacity of 4.6 L. After 15 days, the seedlings received Sarruge nutrient solution. After 60 days, the application of Ni concentrations in the form of hydrated nickel chloride (NiCl2.H2O) was started. The experimental design was completely randomized (DIC), with five treatments (0, 200, 400, 600 and 800 µM L-1 NiCl2), in six replications. Data were submitted to analysis of variance using the Tukey test (p<0.05). The results showed that the antioxidant defense system (SOD, CAT, APX and G-POD) of Paricá were activated mainly at high concentrations of nickel, as a response to avoid toxicity and deleterious effects to plants, as well as the metal caused an increase in peroxidation. lipid characterized by the variable Malonaldehyde. Regarding nickel concentrations, there was greater accumulation mainly in the roots, however there was also a translocation to the aerial part of this species. Therefore, it is suggested that Schizolobium amazonicum can be characterized as a phytoextractor.

Urban secondary forests play an important role in the maintenance and conservation of biodiversity in anthropic environments. In this sense, knowing the structure of the natural regeneration of these forests is essential to ensure their continuity over time. This study aimed to verify the ideal sample size to accurately and accurately estimate the horizontal structure of the natural regeneration of tree species in urban forests in the Eastern Amazon. The experiment was carried out in the secondary forest of the Universidade Federal Rural da Amazônia, in the city of Belém, Pará, where an area of 1 ha was delimited and a 100% inventory was carried out, which was considered as a parameter for comparison and evaluation of the estimates, having as Inclusion criterion for measuring the presence of live stem at a height of 1.30 meters in relation to the ground and DBH ≤ 10 cm. Information on diameter at breast height (DBH), geographic coordinates, scientific name and information on the phytosanitary of the individuals were collected. The parameters of the horizontal structure considered were the basal area, the number of individuals, the number of stems, the richness and the Shannon index. In a Geographic Information System – GIS environment, different sizes and shapes of sample units were simulated, with areas ranging from 2 m² to 100 m². For the resampling simulation, the individuals were divided into two diameter classes. Namely: Class 1 (DBH ≤ 5 cm) and Class 2 (5 cm > DAP ≤ 10 cm). The Bootstraping method was used with 1000 repetitions per sample unit size. In total, 4472 stems, 2800 individuals, 83 species and Shannon index (H') = 3.19 were recorded. The results showed that sampling units with an area between 25 m² and 100 m² are more effective in estimating the horizontal structure of natural regeneration.

The study aimed to evaluate the silvicultural characteristics of seedlings of Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby (paricá), produced in nurseries and planted in clearing areas of low impact logging, as an alternative to enriching the forest after the logging. The experiment area consists of 700 ha of dryland dense rain forest, in the municipality of Paragominas, in the State of Pará. Survival rates, Annual Periodic Height Increment (IPAH), Annual Periodic Diameter Increment (IPADAP), Annual Average Height Increment (IMAH) and Annual Average Diameter Increment (IMADAP) were evaluated and the correlation between clearing classes and their increments, to analyze the possibility of using the species in clearings enrichment. For data collection, 245 clearings were selected in the forest enterprise GRUPO KEILLA area, at the annual production units 7 and 8. 1.088 paricá seedlings were planted in 2005, the year in which the first evaluation of survival and growth rates were performed. Other evaluations were carried out in 2006, 2008, 2010 and 2018. The results showed that with increasing age there was a reduction in height and diameter increments of the species. The size of the clearing classes did not contribute to an increase in height and diameter increments, however, the volume had a higher yield in larger clearings. Thus, the results indicated that the species can be recommended for enrichment in clearings, if silvicultural treatments are applied.
Keywords: enrichment planting in clearings; seedlings growth of tree species; natural forests management; post-harvest forestry; seedlings survival in clearings.

Knowing the dynamics and structure of a forest population are fundamental factors to determine the minimum felling diameter of its trees and the timber cutting cycle, in addition to contributing to the current Brazilian Silvicultural System for terra firme forests in the Amazon. The population dynamics of Eschweilera amazonica R. Knuth was evaluated in an experimental area in the Tapajós National Forest, where a Reduced Impact Logging and silvicultural treatments were carried out, in order to answer the questions: (a) Logging and the application of silvicultural treatments alter the growth dynamics and population structure of E. amazonica? and (b) does the population of E. amazonica have characteristics that allow its inclusion in a polycyclic silvicultural system? Data were collected in 60 permanent plots of 0.25 ha comprising logged forest and unlogged forest, over a 31-year period. The structure, mortality, recruitment and growth of individuals with DBH ≥ 5.0 cm were evaluated.

The sustainability of an enterprise that uses natural resources involves the use of relevant instruments for the feasibility of managerial aspects that integrate economic, social and environmental responsibility policies. Voluntary forest certification, as an alternative environmental management tool, signals good forest management practices and, as a competitive advantage, generates an aspect of reliability, commitment and the socio-environmental responsibility of certified organizations. In Brazil, there are several types of environmental certification that are accredited nationally and by international institutions. Currently, it is possible to perceive a devaluation of the certification process within the domestic market, thus constituting barriers to the advancement of certification, in particular, in the northern region of the country. In this context, the objective of this work is to propose an Amazon Certification System (AMZ) based on the experiences of institutions and researchers working in the Amazon, as well as on the observance of the pillars of sustainability. The proposed certification system can be understood as a measurement instrument and focuses on measuring the maturity of companies in terms of adherence to the minimum requirements necessary for certification. The following hypotheses were raised: [1] the Amazon Certification System is an instrument capable of measuring this adherence and the adoption of good management practices by the evaluated organization; and [2] the Amazon Certification System is not an instrument capable of measuring this adherence and the adoption of good management practices by the evaluated organization. Thus, through a theoretical procedure and quantitative methods, we seek to clarify the context of decision, validation and determination of representativeness for each analysis item. Given that the latent trait of this study is maturity, it is expected that it can be expressed in observable terms and with appropriate magnitudes. Therefore, and based on the multi-criteria model, the instrument was operationalized, adequate and validated in terms of the representativeness of the items and, after the phase of defining and ranking the factors, an initial instrument is proposed with 5 steps, 32 requirements and 99 indicators fundamental to demonstrate the maturity of companies.

The varieties of Schizolobium parahyba present a wide distribution in Brazilian biomes. For this reason, it is possible that adaptations accumulated over time have caused variations that may interfere with the anatomical characteristics and basic density of the wood, making this variety more efficient for large-scale cultivation than the others. Information on the anatomical properties and basic density of Schizolobium parahyba wood are important because it allows identifying characteristics intrinsic to each variety. The objective of this study was to determine the differences and similarities in the anatomy and basic density of the wood of the two varieties of Schizolobium parahyba (paricá and guapuruvu) that can contribute to the knowledge at the species level. The material used in this study comes from the planting of paricá and guapuruvu propagules at the Agroecológica São Roque farm, located in Moju town, Pará state. To study the anatomy and basic density of Schizolobium parahyba varieties, five paricá trees and five guapuruvu trees, both aged 6 years, were harvested. Discs were removed at the base and DBH position of each tree, for longitudinal analysis of the stem. In the radial direction of the stem, wedges were removed from the disks to collect the specimens in three equidistant positions: close to the medulla, intermediate, and close to the bark. The results show that the variations in the dimensions of the anatomical elements of the paricá and guapuruvu wood were more consistent along the radial profile compared to the longitudinal. The length and thickness of the fiber wall were relevant to differentiate the varieties of Schizolobium parahyba, in which the values were higher for paricá. The other anatomical characteristics (length, diameter, and frequency of the vessels, width, height and frequency of the rays, and diameter of the lumen of the fibers) were similar for both varieties. The highest value of wood basic density was reported for paricá as opposed to guapuruvu. Thus, paricá differed from guapuruvu with the highest value of wood basic density, which is justified by the higher values of fiber length and the cell wall thickness of this variety.

The objective of the study was to compare the floristic diversity of two forest fragments: SAFs and capoeira, as a way of recovering degraded areas. The study was conducted at Fattoria Piave, a 125h property located in the city of Igarapé-Açu / PA. For floristic and structural analysis of the two forest fragments, two censuses were carried out, the first in 2018 and the second in 2020 in SAFs and in capoeira the two areas have a size of 1 ha. Which was broken up into 100 plots of 100 m2 (10x10 m2) or forest plot (PF), where all the arboreal individuals that had a chest height circumference (CAP)> 15.7 cm were inventoried, using a measuring tape that in diameter the height of the chest (DBH) is equivalent to 5 cm, the height (h) of all individuals was estimated. In both treatments, 20 sub-plots of 50 m2 (5x10 m2) were allocated within the forest plot for the sample of juvenile tree individuals, where individuals with CAP> 7.8 cm and <15.7 cm were measured, and estimated height, within of these 20 subplots, it has a further 10 m2 (1x10 m2) subplot to sample the seedlings of the tree individuals, in which all individuals that had height> 30 cm and CAP <7.8 cm were calculated, using a measure tape. In the second census in 2020, there was an incorporation of new species and an accounting of the species that died in both treatments. Based on the field data, phytosociological variables were calculated, such as: density, dominance, frequency and sociological position, relative and absolute values for the evaluation of the species expanded importance value index (IVIA), species coverage value index (IVC), Shannon-Weaver diversity index (H'), Simpson dominance index (C), Pielou equitability index (J') and Jaccard similarity index, the mean annual periodic increase (IPMA) was necessary and the mortality rate of capoeira and SAFs species. The two forest fragments diametric distribution in the form of an “inverted J”, the Shannon-Weaver index (H') varied from 3.08 in 2018 to 3.03 in 2020 in capoeira and from 2.91 in 2018 to 2.83 in 2020 at SAFs, in both treatments the index was considered low, showing a medium diversity, the most expressive species in capoeira were Myrcia sylvatica, Myrciaria tenella, Myrcia bracteata, Tapirira guianensis, Attalea maripa, no longer SAFs were Jacaranda copaia, Acacia mangium, Lacistema pubescens, Myrcia sylvatica, Vismia guianensis. The mortality rate of capoeira was 10.7% higher compared to that of SAFs. However, both treatments have a high coverage value index, which constitutes soil covered by biomass, plants mainly of the middle and upper strata and can correlate with superficial and deep roots, facilitating water infiltration and nutrient cycling and reducing erosion. therefore recovering a degraded area, nevertheless these two forest fragments are still far from reaching the recovery of biodiversity.

This study aims to estimate the carbon stock of the tree community in the dense alluvial ombrophilous forest of the Amazon Delta. In 6 municipalities in the region 42 plots of 50m x 100m were installed, where the DBH of all individuals whose variable was ≥ 10cm was identified and measured. The study area was delimited by filtering Alluvial Dense Rainforests from the IBGE Vegetation Map. That of the inventory data, the height of the tree individuals was estimated using the Henricksen model adjusted from the data from Chave (2014). From the estimated height, the dominant height per plot was determined, which was used in the correction factor (fc) to estimate fresh biomass (PF) with an Manaus equation. Subsequently, the amount of carbon was calculated through simple multiplication by the water and carbon contents acquired in the literature. The stratified forest inventory was processed based on the estimated amount of carbon per plot, where two types of stratification were considered: 1st. 6 strata, being the municipalities; 2nd. 2 strata, being the hydrographic regions of the mouth of the Amazon River and the hydrographic region Rio Pará / Foz do Tocantins River. In the first stratification, the analysis of variance concluded that there is an advantage in this stratification, since it reduces the variance and increases the accuracy of the straps. It was also concluded that there is a geographical relationship of site quality, in which the dominant height and the dominant diameter, average of the 10% thickest trees, is greater in the hydrographic region of the Amazon River than in the hydrographic region of the Pará / Tocantins River. It was estimated that the dense alluvial rain forest in the Amazon Delta has a total of 285 million tons of carbon stock and an average of 135.98 t.ha-1. In the second stratification, it was concluded that, statistically, the average carbon stock of the alluvial dense ombrophilous forest of the hydrographic regions of the Amazon Delta are the same.

The occurrence of hollows in trees in the Amazon rainforest, in many cases, can be expressive and has a negative impact on the production of timber in managed forests. In this context, the use of mathematical models to estimate the volume of hollows in standing tree boles in stock surveys, can help on estimating of the net standing volume. The aim of the study was to investigate and evaluate the feasibility of using mathematical models to estimate volume of tree hollows in a tropical rain forest in the western Pará State, Brazilian Amazon. Hollow volumes were calculated for 532 sample trees of 17 commercial species.  To estimate hollow volumes, three linear and three linearized mathematical models commonly used to estimate volumes of tree boles were tested by the Ordinary Least Squares Method (OLS). The models were tested for the set of all species thus generating a general equation, and one specific equation for Manilkara elata. Two strategies were applied to test the models: the hollow volume was estimated having as independent variables the diameter D of the hollow of the hollow and its corresponding length (h) - strategy (A), and the DBH and the length of the hollow – strategy B. The criteria used for selecting the best models were the highest determination coefficient (R²), the lowest standard error of the estimate percent (Syx%) the distribution of the residues. The best fit was achieved for the linearized models, and the Spurr in linear form. Similar results were to obtained to Manilkara elata. For all the tested models, the distribution of residues was not homogeneous. The research findings indicated that the Spurr and the Schumacher & Hall mathematical models which use the length of the hollow as independent variables can only be used for used to estimate bole volumes of fallen trees. As the main focus of the research was to estimate the volume of hollows in standing trees and due to the impossibility of estimating the length of the hollow in the field, is recommended using the equations only for fallen boles. It is also recommended the continuity of the study with a more robust data set, having more sample trees in the smaller and in the larger hollow sizes as an attempt to improve the precision.  The use of machine learning techniques such artificial neural networks could be a path to be followed.

Smaller and less sample units (SUs) is in general wanted in forest inventories. This because the number of trees measured in the plots is reduced, turning the fieldwork less costly. This research explores resampling techniques for a set of clusters standardized by the Brazilian National Forest Inventory (NFI). The aim was twofold: to identify (1) the smallest cluster and (2) the smallest sample size that provides the same accuracy and precision as the original sample.  Data from 22 0,80 ha clusters were installed in the National Forest of Bom Futuro, Brazil. Three products were considered: (1) volume of the trees with the diameter at breast height (DBH) ≥ 20 cm, (2) volume of the trees with DBH ≥ 50 cm, and (3) volume of the trees with DBH ≥ 50 cm, with stem quality 1 and 2. In Chapter 1, consecutive reductions from 0.80 to 0.08 ha were carried out in two directions (distal and proximal), giving rise to 20 scenarios. In Chapter 2, the sampling intensity with full-size (0.80 ha each) and small-size (0.56 ha each) clusters was reduced from 22 to 4 clusters. The Monte Carlo method was used as the resampling technique needed to compute the accuracy and precision of the wood volume for every scenario. In Chapter 1, for the three products, findings revealed that 0.56-ha clusters reduced in the proximal direction can accurately and accurately estimate the variable of interest. In Chapter 2, also for the three products, all sample size reductions yielded less accuracy and precision than the original sample (22 SUs). This survey presents two main scientific contributions. First, for a given sampling intensity, it is better to reduce size of SUs than the amount of SUs. This relation has been verified in many variable and sampling spaces, being reported in Cochran (1977). This research confirms, therefore, that same relation for the variable ‘wood volume’ in an Amazonian Forest remnant. The second scientific contribution is to prove statistically that clusters installed in the Amazon could be reduced in size, for volumetry purposes. This size reduction could, inclusive, become the NFI less expensive.

The diversification of species for bioenergy forests in the Amazon will help several local and/or regional industrial segments. Soon, the expansion of knowledge of silvicultural practices of Tachigali vulgaris will subsidize future plantations on a commercial scale. The objective of this research was to verify the effect of different levels of fertilization, soil texture, and age on the development of the Tachigali vulgaris species to compose energetic forests. The study was conducted in two experimental areas of 1.6 ha each, belonging to the company Jari Celulose S.A. in Monte Dourado district of the municipality of Almeirim – Pará. Independent analyzes were performed, in both experimental areas and ages. The experiments were implemented in a randomized block design in a factorial scheme, with four blocks, whose treatments are 4 levels of Phosphorus and 3 levels of Potassium combined with each other, totaling 12 treatments. The variables diameter at breast height (DAP), equivalent diameter (DAPeq), total height (Ht), percentage of single bole (Fu), total volume per hectare (Vt ha-1) and survival (Sobr.) were evaluated. For soil with a sandy texture, ANOVA revealed a significant effect for variable DAP and Fu, and no significant effect for DAPeq, Ht, Vt ha-1 and Sobr.. Mean Vt ha-¹ of 21.28 m³ ha^-1 was observed (CV%=18.95); 81.78 m³ ha^-1 (CV%=20.11); 107.57 m³ ha^-1 (CV%=21.28); 121.85 m³ ha^-1 (CV%=20.63); 171.02 m³ ha^-1 (CV%=27.47); 216.68 m³ ha^-1 (CV%=29.59) and 254.06 m³ ha^-1 (CV%=30.06) at 2, 4, 5, 6, 8, 9 and 10 years of age, respectively . For the clayey textured soil, there was a significant effect of planting fertilization on the variable Vt ha-1 and Sobr., with average volumes of 25.96 m³ ha^-1 (CV%=25.46); 85.07 m³ ha^-1 (CV%=18.18); 113.57 m³ ha^-1 (CV%=19.65); 132.01 m³ ha^-1 (CV%=22.80); 197.23 m³ ha^-1 (CV%=28.36); 243.21 m³ ha^-1 (CV%=32.10) and 257.79 m³ ha^-1 (CV%=35.68) at 2, 4, 5, 6, 8, 9 and 10 years of age, respectively. The results indicate that Tachigali vulgaris was not very demanding on nutrients and, under the conditions of this study, a nutritional dose of 0 kg ha^-1 of triplo superphosphate and 172 kg ha^-1 of potassium chloride is recommended in an area with textured yellow oxisol. sandy medium and 195 kg ha^-1 of triplo superphosphate and 343 kg ha^-1 of potassium chloride in an area with yellow latosol of medium clayey texture.

Litter is an important indicator of ecosystem restoration quality, where its physical properties, water storage capacity and litter stock vary from one ecosystem to another. In the Amazon, the Interfluvial Plateaus Forest Successional Ecosystems (ESFPI) and the Fluvial Plains Forest Successional Ecosystems (ESFPF) are examples that represent differences for the litter factor. Thus, the following question was proposed: Do the interfluvial plateau successional forest ecosystems have a litter stock and higher water storage capacity compared to the river plain? With the hypothesis that (h): If the interfluvial plateau ecosystem has a larger litter stock, then it will have a greater water storage capacity regardless of the collection period. The experiment was carried out at UFRA, Campus Belém. Each ecosystem was considered as a treatment and 12 plots of 10m x 100m were implanted and with the use of a metallic collector 36 samples were collected per ecosystem with an interval of 6 months between collections. For the study, a floristic analysis (CAP>15cm) of ecosystems was performed and litter samples were collected to determine its storage on the soil surface (Mg.ha-1) and water storage (%). The experimental design applied was completely randomized with 2x2. Euterpe oleraceae presented the most expressive values in both ecosystems and the Fabaceae family was the richest in species. From the analysis of the mean values collected from the physical properties of the litter, water storage capacity and stock, the hypothesis was considered as rejected (ANOVA, p < 0.05). With the ESFPI ecosystem showing the highest litter storage in the period with less rain (10.5 ± 3.75 Mg.ha-1) and the ESFPF ecosystem the highest average water storage in the period of more rain (349%), it was considered that the ecosystem with the largest litter stock does not have the greatest water storage capacity, leading to believe that these characteristics come from factors of the ecosystem itself.

The Amazon is the largest remnant of humid tropical forest on earth, representing about 40% of the world's tropical forests, and therefore plays a strategic role in the preservation, maintenance, and conservation of biodiversity. Logging causes disturbances to its horizontal structure and floristic composition. The exploitation of natural forests anthropized causes a reduction in the usable stock of commercial species for future harvests. The denomination used here, anthropized forest, is equivalent to the literature term degraded forest. The degraded forests suffered a reduction of the canopy, with no change in land use and in the remaining forest cover, providing the growth of forest species. The main source of degradation is from overexploitation of timber forest resources. The objective of this work is to characterize and determine the wood potential through dendrometric parameters of a degraded forest in southeastern Pará. The study area is in the municipality of Dom Eliseu, Southeast Paraense. Fifty permanent plots were inventoried. Phytosociological parameters, diversity and similarity indices, forest dynamics, classification of species by ecological groups, and basic density of the wood were obtained. A total of 15,959 individuals with DBH ≥ 5 cm were inventoried and 382 species were identified. 57.33% of the species belong to the shade tolerant and 39.01% to the shade intolerant ecological group, and 3.66% could not be classified. The study area showed high diversity (H' = 4.62) and equability of 0.78 for individuals with DBH ≥ 5 cm. The diametric distribution showed a concentration of 54.28% of the individuals in the diametric class 5 to 10 cm, 44.59% in the classes 10 to 50 cm, and only 1.13% in the classes above 50 cm DBH. The IVI is fundamental for the quantitative study of floristic composition, structure, function, dynamics, distribution, and environmental relationships of the plant community. The species that presented the highest IVI were Cecropia distachya, Schizolobium parahyba var. amazonicum, Sagotia racemosa, Inga alba and Protium altsonii. During the monitoring period an ingress rate of 3.8% was recorded, where the species Inga ssp and Sagotia racemosa showed the highest rate and ingress. The mortality rate observed was 5.5%, where the species Cecropia distachya and Inga ssp showed the highest mortality. The higher mortality rate than the ingress rate indicates a negative balance in the forest dynamics. The IPA in basal area was 0.85 m².ha^-1.year^-1 and in volume was 2.60 m³.ha^-1.year^-1, which shows that tropical forests can grow above the value indicated by the legislation. The average value of basic density found for the species inventoried was 0.648 g.cm^-3, being the wood density an important parameter in the technological definition and commercial use and an excellent indicator to determine the quality of the wood. The analysis of IPA's showed that degraded forests have timber potential, with many species with medium and heavy basic density wood.

The 2015-2016 El Niño-Southern Oscillation (ENSO), after the 1950s, was one of the most extreme events recorded. In the Amazon, ENSO is the cause of reduced rainfall, increased solar radiation and air temperature, consequently, soil moisture is reduced and the vapor pressure deficit is high. These variables that influence the development and production of oil palm. In this context, the objective of the thesis was to quantify the surface fluxes of CO₂ and energy, defining the physical variables that control these processes seasonally and interannually in an oil palm plantation with interspecific hybrid (HIE) (Elaeis guineensis Jacq x Elaeis oleifera (Kunth) Cortés) in eastern Amazonia during the ENSO period (2015 and 2016) and in normal years (2017 and 2018). The CO₂ and H₂O flux data were calculated using the eddy covariance (EC) method. Photosynthetic parameters were estimated by adjusting the light response curve (LCR) using a non-rectangular hyperbole model. The averages of the Net Ecosystem CO2 Exchange (NEE) and the maximum rate of CO₂ assimilation (A_max) were higher during the years with ENOS, especially in the wet season. In the normal year of 2017, the greatest assimilation occurred in the dry season. The energy fluxes were higher in the years 2015 and 2016, showing high values of sensitive heat flux (H) and latent heat flux (LE). Most of the net radiation (R_n) was used for evapotranspiration processes (52 to 74%). Biophysical controls such as aerodynamic conductance (C_a), surface conductance (C_s) and decoupling factor (Ω) were also calculated to better understand the behavior of the oil palm. C_s showed higher values in 2015 and 2016, indicating greater stomatal opening. Result that corroborated with the same period of the maximum found for NEE and LE. C_a was higher in the dry season, especially in 2015, favoring gas exchange. In 2015 (ENSO), Ω (in both seasonal periods) demonstrated that evapotranspiration was more influenced by vegetation. The physical variables showed weak to strong correlations with NEE, H, LE and C_s, depending on seasonality and year. The most significant were incident photosynthetically active radiation, vapor pressure deficit and soil moisture. Therefore, the interspecific hybrid was shown to be resilient to severe ENSO, with an increase in the assimilation of CO₂ and LE. As well, it was observed that HIE showed similar behaviors with the equatorial Amazonian forests and different to the plantations located in Southeast Asia in normal year.

Changes in land use and coverage are a major cause of climate change. Studies aim to find sustainable production systems, such as the SAFs that are being disseminated as a proposal to replace deforested areas. The study of the biomass estimate in SAF resulting from land use and land cover changes is relevant to reduce the uncertainties regarding the estimates of carbon emissions and removals and to understand how they act in the environmental processes. This work aims to estimate the carbon stock in above-ground biomass in SAFs resulting from land use and land cover changes, in the municipality of Tomé-Açú, Pará. The interpretation and classification of the images were carried out by class discrimination. The polygons were classified into 6 ranges of size of the areas. The mapping results were edited and thematic letters were prepared. Classes of land use and land cover were quantified and mapped based on visual interpretation, application of Random Forest, quantification of area for comparisons between the mappings of the years 1990, 2000, 2010 and 2018. Additionally, an inventory was made in SAFs, regression analyzes were carried out between the biomass data of the inventory and SR, followed by spatialization of biomass for the SAFs. For the period between 1985 and 2018, the expansion of deforestation resulted in a loss of forest of approximately 298 thousand ha, with 57% of the area of the municipality. In all years, high values of polygons were observed in the range <6.25 ha and low values in the range> 50 ha. Small fragments (<6,25 ha) accounted for 15% of all deforestation, while large fragments (> 50 ha) accounted for 45%. The SAF1 class was observed to have a slight growth with 7,049 ha (1,4%) in 1990, for the year 2018 it presented 9,148 ha (1,8%). The SAF2 class had its area progressively reduced from 16,803ha (3,3%) in 1990, to 10,508ha (2%) in 2018. For all periods, the SAF 1 and SAF 2 classes showed persistence of less than 8%. For both SAF 1 and SAF 2, a large part of the increase was due to the advance on the areas of VS, forest and pasture. The three equations resulting from the regression analysis of SR data with inventory showed the same trend. . The total value of the carbon stock in SAFs of Tomé-açu was 41,982.52 MgC for NDWI, 42,534.28 MgC for TSAVI x NDWI and 43,094.75 MgC for B5 x NDWI. It is concluded that the analyzed period presented differences both in the temporal analysis, as in the patterns of distribution of deforestation, indicating a strong future potential for forest loss. The classification of images through GEE proved to be valid for monitoring changes in classes of use and coverage, including SAFs. The SAFs' spectral responses follow different patterns from other types of vegetation and are altered according to the variation of biomass. The NDWI vegetation index showed greater efficiency in the prediction of above-ground biomass of SAFs.

Forest fragmentation in the Brazilian Amazon has increased alarmingly and is among the greatest threats to tropical biodiversity. Among the threatened species is Euxylophora paraensis Huber. Endemic species, whose natural occurrence is restricted only to the north of Brazil, and in regions with a continuous and intense history of logging and conversion of forest cover to other uses. The advancement of fragmentation and the threat of extinction of E. paraensis motivated this work, whose aim was to evaluate phenology and natural regeneration in order to identify the influence of the fragmented environment on the reproduction of this species. The study was carried out in a forest fragment adjacent to areas with bauxite mining activities, located in the municipality of Paragominas in the southeast of the state of Pará, Brazil. For evaluating the phenology, activity and intensity data were collected from 38 seed bearers in the period from 2013 to 2017. Reproductive phenophases were related to the individual's distance to the fragment edge, dendrometric measurements (DBH and height), climatic elements and photoperiod, using multiple linear regression analysis. Natural regeneration, in turn, was quantified and monitored using 10 circular plots with a radius of 20 meters each. The density of individuals of natural regeneration was evaluated at the edge and inside of the fragment and also in relation to the matrix tree. The Annual Periodic Increment of diameter (IPA_DAP) and height (IPA_HT) were also determined and the GLM (General Linear Model) was applied to verify if there was a difference between the environments and size of the individuals. The results indicated that the vegetative phenological pattern of the E. paraensis population is evergreen and the reproductive pattern is annual, regular, and long lasting. The reproductive phenodynamics (bud, flower and fruit) of the individuals observed was related only to climatic elements. The distance from the matrix in relation to the fragment's border and the size of the individuals (Height and DBH) were not statistically correlated. The most significant climatic elements for the reproduction of E. paraensis were rainfall, number of days without rain, average temperature, maximum of the maxima, minimum of the minima and photoperiod. Reproductive activity occurred during the dry season or with less rainfall, revealing strong seasonality in reproduction. As for natural regeneration, the density increased with the distance from the seed bearer and there was a negative correlation with the canopy area, that is, the smaller the canopy area, the greater the density of the regenerating individuals. There was a statistical difference in density, IPA_DAP and IPA_HT both in relation to the size of the individual and to the location in the fragment. There was a greater diametric increase in seedlings and trees in the edge area and a greater increase in height in the trees at the edge and inside the fragment. Thus, natural regeneration was influenced by forest fragmentation processes, favoring seed germination and establishment of seedlings at the edges. No small trees were found in this environment. In general, it was identified that the conservation of E. paraensis is jeopardized, in view of the increasing deforestation and fragmentation, as this species presents some fragility to drastic changes in climate. Such disturbances can impact flowering and fruiting and hamper the development of natural regeneration to adulthood.

The use of native forest species, either for wood production or for recovery of degraded areas, is further hampered by the lack of information on their nutritional requirements for the establishment and development of plants in the field. The absence of soil vegetation cover, besides implying less accumulation of organic matter, favors the increase in temperature due to direct exposure to light energy, reducing water retention capacity, which affects leaf water potential, nutritional status. and leaf gas exchange. Adequate nutrient supply, such as phosphorus (P) and potassium (K), may favor different plant growth mechanisms, such as photosynthetic performance, effectively contributing to the establishment of plants in the field, as it acts in the expression of phenotypic plasticity in relation to tolerance of plants to limited conditions of primary resources (water, light and nutrients), contributing to incorporate degraded areas into production processes. Tachigali vulgaris L. G. Silva & C. Lima is a pioneer species that often initiates secondary succession in open areas and is considered ideal for reforestation due to its high biomass production capacity, rapid growth in adverse conditions and high resistance to environmental disturbances. Its wood produced has similar characteristics to eucalyptus wood, in terms of calorific value and weight and volume yield in the carbonization process, bringing together promising characteristics for energy crops in the Brazilian Amazon and bordering regions. In this context, the present study aimed to evaluate the response to fertilization with different levels of phosphorus and potassium on growth, water and nutrient use efficiency and gas exchange in young Tachigali vulgaris planting in degraded soil. The experiment was installed in the municipality of Igararé-açu / PA and the treatments were established by applying three doses of P (0, 26.7 and 53.5 kg^-1 ha, as triple superphosphate) and three K rates (0, 50 and 100 kg^-1 ha, as potassium chloride), as well as their combinations, in a 3 x 3 factorial scheme and a randomized complete block design. The study was divided into two chapters, chapter 1 with the objective of evaluating the influence of fertilization with different levels of phosphorus and potassium on growth, water and nutrient use efficiency in young Tachigali vulgaris cultivated in degraded soil. The parameters of soil fertility, growth and efficiency of water and nutrient use will be evaluated. The results are expected to detail the behavior of Tachigali vulgaris species cultivated in degraded area in response to fertilization with different levels of P and K and to define the best dose of phosphate fertilizer to improve water and nutrient use efficiency in the second. year after planting. In chapter 2, the objective was to evaluate the effect of increasing doses of P and K on gas exchange in young Tachigali vulgaris cultivated in degraded area. Spot measurements of gas exchange were performed in April 2018, between 9:00 am and 11:00 am, in the middle third of the treetops, with an Infrared gas analizer (IRGA). The experiment with nine treatments was installed in randomized blocks with four replications, totaling 36 plots. To assess the effect of treatments, data were first evaluated for normality and homogeneity of variance by Shapiro-Wilk and Bartlett tests, respectively. Subsequently, the treatment means were subjected to analysis of variance and comparisons of means by means of the Tukey test at 5% and Pearson's linear correlation test. Multivariate statistics was also used through factor analysis (FA) and principal component analysis (PCA). Tachigali vulgaris stocking responded positively to potassium fertilization in relation to the photosynthesis rate (A), resulting in an increase of approximately 30% compared to the control treatment (without fertilization). An antagonistic effect on A was observed with the combined application of the highest doses of P and K. Increasing doses of potassium fertilizer, up to the dose of 78.2 g kg^-1 of K, provided the highest averages of water use efficiency. Intrinsic water use efficiency when combined with 16.6 g kg^-1 P application. AF and ACP are tools that enable the initial reduction of 8 gas exchange variables to 2 main components (CP1: interpreted as “assimilation”). and carbon fixation in biomass by plants ”and CP2: responsible for“ gas exchange with the atmosphere, transpiration and maintenance of leaf temperature ”) that encompass these 8 variables analyzed.

The objective of this study is to comprehend the transition process of convetional systems of agricultural production for the Agro Forestry Systems (SAFs), in the property of familiar farmers of the municipality of Tomé-Açu, Pará. The collection of the data occured in the local SAFs. The research was organized in three chapters. The first chapter approaches the process of transition of the convetional system of the land  to the use of the SAFs. For this research were utilized qualitatives and quantitatives types of approach, the method of the gathering of data was done with a structured interview guided via the tool ODK Collect. The results show that: The transition of the conventional system for the SAF in the properties of the local farmers occured in the areas of monoculture of the black pepper to diversify the products that generate income along the year and give environmental comfort to the farmer; It was identified various sequential processes of change from the conventional system to the SAF. 66,7% of the properties in the three categories (pasture, black pepper and farm) presented a transition before the application of the SAF and 3,3 % of the properties showed four types of use before the application of the SAF; The diversity of species living in the zone of the SAFs favor the food safety and the income of the families, then contributing in the sustainable development strategy in the municipality. The second chapter evaluates the space-time dynamic, in the years of 2010 and 2020 of the transition of the conventional system to the SAF. The methodology was based in the elaboration of maps of the Kernel density, thematic maps and the application of semi-structured questionaires. The results show that: the space-time analysis turned out that alterations of the landscape, originally composed of pasture, farm and black pepper were substituted gradually for SAFs areas, the Kernel density analyzed too the behavior of the SAFs density, the SAFs changed the scenario of the properties, increasing the areas of legal reserve. The applicability of the geotechnology tools turns out to be important to monitor the areas occupied with the SAF. The third chapter looks to evaluate the SAFs from processes of transition of different productive systems via the indicators of sustainability using the methodology proposed by Altieri & Nicholls (2002). The results shows that: The area that the conventional systems presented the lower medium value of indicators that suggest the necessity of proper handling to prevent environmental issues in those areas, the higher the medium values of the indicators were obtained in areas of capoeira and SAFs, standing out the role these areas have in recovering the productive potential of agrosystems.

Although wood wastes from sustainable forest management are a promising alternative for supplying charcoal production in the Brazilian Amazonia, this biomass and derived charcoal present a heterogeneous quality. The segregation of wood proved to be an important alternative to increase the productivity and yield of charcoal in the production unit, as it promotes the homogenization of the raw material inside the kiln. However, this study aims to study the effects of wood waste segregation on the quality, combustibility, and occurrence of spontaneous combustion in charcoal produced in brick kilns in the State of Pará. The study of charcoal quality was based on physical (bulk density and moisture), mechanical (friability), chemical (fixed carbon content, volatile materials, and ash), and energy (higher heating value and energy density) properties. The parameters analyzed in combustion were ignition temperature, burnout temperature, maximum temperature, maximum combustion rate, average combustion rate, and ignition time. The combustion characteristic index, ignition index, and flammability index were the studied indices. The study revealed that the segregation of residual wood culminated in an increase in the charcoal quality produced in brick kilns, especially regarding bulk density, friability, ash content, fixed carbon content, higher heating value, and energy density. Group 1, formed by charcoal from branches of the D. excelsa species, presented the best values for bulk density (0.737 g cm^-3), ash content (1.20%), heating value (28.9 MJ kg^-1), and energy density (21.3 MJ m^-3). On the other hand, conventional carbonization proved to be very variable, resulting in more friable and less resistant charcoal. Two groups of charcoal did not show spontaneous combustion (1 and 4), which demonstrates that segregation can reduce the occurrence of this phenomenon. On the other hand, traditional charcoals showed samples with spontaneous combustion. Groups 1, 2, and 4 had the best ignition temperatures (379.72°C, 365.98°C, and 367.67°C), burnout temperatures (547.23°C, 533.15°C, and 545.15°C), temperatures at which the greatest loss of mass occurs (515.43°C, 494.02°C, and 499.32°C) and ignition times (33.39 min, 31.86 min, and 32, 26 min). Group 5 produced charcoals with low ignition temperature (361.65°C) and low maximum combustion rate (9.54 % min⁻¹). Therefore, the segregation of wood waste promoted positive results in terms of quality, combustibility, and spontaneous combustion of charcoal produced in brick kilns.

Secondary forests provide important ecosystem services, especially in helping to mitigate climate change. The expressive growth rate causes the intensive removal of atmospheric CO2 and the storage of carbon in the biomass of tree species. This service depends on the conditions of regeneration and development of secondary forests, which are influenced by previous use, the magnitude of the disturbances and the duration of the disturbances. Therefore, it is necessary to understand the formation process of secondary forests in order to identify the potential for mitigating global warming due to the regional contexts of land use and change in land use in the Amazon. In order to analyze the influential factors and the estimates of biomass and carbon in secondary forests, we highlight the methods that combine data from forest inventory and remote sensing, such as images from satellite sensors and point clouds obtained by LiDAR (Light Detection and Ranging ), with mathematical and spatial modeling. In this context, the present research aimed to know the spatial distribution and estimate the accumulation of biomass in secondary forests in the state of Pará. The spatial patterns of secondary forests in Pará were evaluated by kernel density algorithms and by hotspot analysis using data provided by the project. TerraClass. In order to map the regeneration of secondary forests, data on land use class were used to attribute the previous use in the years 2000, 2004, 2008, 2010, 2012 and 2014. Through cartographic modeling, the permanence and the emergence of secondary forests in the analyzed chronosequence, making it possible to identify age groups in each year of study and by class of previous use. Biomass estimate data resulting from LiDAR statistical modeling were combined with forest inventories for secondary forests in the municipalities of Paragominas and Santarém provided by Longo et al. (2016), Almeida et al. (2019) and Baccini et al. (2012), as well as biomass data estimated in primary forest from the RainFor project. The results showed that the spatial distribution of secondary forests does not occur randomly in space, suggesting local geopolitical influences. Considering the dynamics of secondary forests in the state's landscape, the positive balance of 16.0 thousand km² between 2012 and 2014 decreased by 2.4% in relation to the period from 2010 to 2012. The decrease in secondary forest areas was influenced by the high rate deforestation (11,500 km² year-1), almost three times the rate of increase (4,300 km² year-1) between 2012 and 2014. It was found that there was an accumulation of average biomass in secondary forests above of 14 years is 73.57 MgC.ha-1, corresponding on average to 27.48% of the biomass of a mature forest in the same region a for both municipalities, being significant (p <0.001) over time at the ages of secondary forests. There was a significant difference (p <0.001) between biomasses comparing the municipalities of Paragominas and Tapajós when related to the accumulation of biomass in the studied period for the three databases. Secondary forests from mature forests or pasture recover more biomass over time and are age dependent.

The objective is to evaluate logging in public and private forests through the volume actually logged and number of trees logged from timber management plans and managed forest species. We analyzed 68 licensed timber management plans through official electronic forest product control systems located in public (forest concessions) and private native forests in the state of Pará, eastern Amazonia, Brazil. The PMFS were categorized into federal, state, and private public forests from a single UPA and with more than one UPA. The PMFS were randomly selected, with minimum authorized forest area and volume of 500ha and 20 thousand m3, respectively. Data were obtained from the official forest control systems, federal (Document of Forest Origin - DOF / IBAMA / MMA) and state (System of Commercialization of Forest Products - SISFLORA / SEMAS / PA) used in the licensing and management of management plans. We obtained the actual harvested volume and the number of harvested trees from timber management plans and managed forest species calculated through a simple relationship between authorized volume and harvested volume, as well as the number of trees cleared and harvested. T-test will be applied to check for differences between treatments (logging yield index and number of trees logged) between management plans and between forest species using IBM SPSS Statistics, version 20.

Habitat degradation and fragmentation are considered serious threats to biodiversity in the Amazon. These losses alter the structural integrity and functioning of ecosystems. Due to intensive exploitation, many natural populations of Brazilian mahogany (Swietenia macrophylla King.) have been suppressed or had their stock drastically reduced, especially in the Brazilian Amazon. Considering the importance of species conservation, techniques of potential species distribution can serve as a basis for decision making regarding definition of conservation areas. Thus, this work aimed to predict areas of ecological niche for S. macrophylla, in the geographical space of the Brazilian Amazon. The real occurrence points of the species were obtained in the databases of the Global Biodiversity Information Facility - GBIF and the RadamBrasil Project with occurrence data for South and Central America. The statistical program R was used to exclude points of occurrence with no consistent information. A total of 138 predictors with climatic, topographic and soil property characterization values were used, to which, Principal Component Analysis (PCA) was applied. The distribution modeling was performed in the statistical program R-3.6.2, based on a function for creating ecological niche models “ENMTML”, using four algorithms. The Consensus Map (Ensemble) was synthesized from the set of predictions based on the first 14 axes of the main components of the generated models. The processed output image was cropped to the limits of the geographic area of the Brazilian Amazon. The delineations of the area of actual occurrence of mahogany, inferred by Lamb (1966) and Barros et al. (1992), for the Brazilian Amazon, were compared to the area defined by the consensus model as an ecological niche of the species, in order to verify the percentage of modeled area existing in the area classified by the authors. The binary map was superimposed by the shapefile of accumulated deforestation area in the Brazilian Amazon from the National Institute for Space Research (INPE), in the years 2008 to 2019, for subtracting deforested areas. The area described was calculated from the modeling as a niche of the species, occurring in Conservation Units (UC), from the database of the Chico Mendes Institute for Biodiversity Conservation (ICMBio) and the I3Geo portal of the Ministry of the Environment (MMA), at the State and Federal levels in the Amazon biome. As a result, we had a total of approximately 2,395,593.72 km² of ecological niche area for the species. The overlapping of the ecological niche area for S. macrophylla, corresponded to 65.25% of the area demarcated by Lamb and about 81.56% of Barros et al delimitation for the  area classified as high volume occurrence of mahogany in the Brazilian Amazon.  Deforestation occurring in the area modeled as an ecological mahogany niche, was approximately 2.07% of the total predicted by the model. The deforestation incident in areas of State and Federal Conservation Units, revealed loss of ecological niche areas with possible occurrence of Brazilian mahogany. Therefore, the present study was developed in an attempt to update the geographical limits of possible occurrence of mahogany and to help improve public policies aimed at environmental conservation of the Amazonian flora, giving the main focus to Brazilian mahogany.

In order to implement and conduct hydroelectric plants, highways or mining activities, it is necessary to suppress native vegetation. In these situations, wood biodegradation products generated in the log storage yards and wood residues interact with water from precipitations or volatilize and may impact the environment and hamper future efforts to recover degraded areas. The objective of this work was to verify if the biodegradation of tropical wood stored in different conditions affects the soil properties and the initial growth of seedlings of the pioneer species Schizolobium parahyba var. amazonicum (Huber exDucke) Barneby. The woods of four tropical species were selected: timborana (Pseudopiptadenia suaveolens (Miq.) J.WGRIMES); yellowwood (Euxylophora paraensis Huber); clover (Aegiphila integrifolia (Jacq.) Moldenke); and para-pará (Jacaranda copaia (Aubl.) D.Don) collected in the storage yard of a bauxite mining company. The chemical, anatomical and physical characterization of the wood was carried out before and after storage in the soil for 75 days, in three conditions: buried wood, positioned horizontally and positioned vertically (partially buried), in relation to the substrate contained in the pot. For the soil, pH, cation exchange capacity, organic matter content, base saturation, aluminum saturation and macronutrients were determined. In the germinated seedlings, biometric properties and biomass production were analyzed. The seedling development test was conducted in a greenhouse. Mass losses were 2.7%, for Euxylophora paraensis and 13.1%, for Pseudopiptadenia suaveolens, both high density woods, and 8.7% for Aegiphila integrifolia and 18.4%, for Jacaranda copaia, woods low density. The woods with the highest biodegradation rate also showed higher levels of water-soluble extracts (8.4% and 5.4%). Longer fiber length (1172.96 μm), vessel length (768.67 μm) and wall thickness (5.92 μm) were observed for the species with the lowest biodegradation rate and largest lumen diameter (21.64 μm) and vessel diameter (255.67 μm) for species with the highest rate of biodegradation. The biodegradation of all species has negatively modified soil properties causing reductions in pH, organic matter content, macronutrients and increased H + Al content. In addition, there was a reduction in growth in Schizolobium parahyba plants of 28%, 18%, 46%, 34% and 57% for height, stem diameter and dry weight of root, stem and leaves, respectively, when grown in soil in the presence of biodegradation of tropical woods. It is concluded that the intensity of biodegradation depends on the species and varies depending on its anatomical and chemical properties, but it does not depend on the storage position in the soil. Biodegradation negatively affected soil properties and, consequently, the development of Schizolobium parahyba var. amazonicum. This work indicates that the maintenance of wood in the storage yard of mining areas can impair the recovery of degraded areas. 

The seed bank is an important indicator for assessing restored areas as it is a response to the dynamic process of succession, representing part of the potential stock of individuals within the ecosystem. Thus, the objective of the present study was to evaluate forest structure and composition of the seed bank in a successional area 32 years after multiple cycles, with plots subjected to different treatments. The 120 samples, distributed in three treatments, were obtained with the aid of a hollow sampler in a square format with an area of 0.0625m², in the evaluation period of eight months. A total of 1810 seeds were identified, distributed in 32 species and 26 families, with a total density of 692 ind./m². The speeds and the average time of emergencies of the treatments, varied from 2.5 to 6.13 seeds emerged per day and on average from 60 to 54 days. As for the density and number of emerged seeds, the highest occurred in the Control treatment, followed by the Irrigation treatment, and the lowest value for the Removal treatment, with significant differences (p <0.01) for the density variable. The estimated degree of equability (J ') closest to one was that of the Controls plots (0.78), which differed significantly from the other plots (p <0.05) and Shannon the values indicated better homogeneity of the seed bank in the plots of Removal that presented lower value (p <0.05), which means that few species from the collection site are responsible for the highest proportion of seeds in the soil. The species present in the seed bank were classified according to the dispersion syndrome, life form and ecological group, with an emphasis on the zoochoric dispersion, shrub form and pioneer individuals, respectively. This study provides important information that characterizes the seed bank in forest ecosystems regeneration process, indicating that pioneer tree and shrub individuals are responsible for the post-disturbance process.

Cadmium (Cd) is one of the most toxic heavy metals for plants and animals and has the highest soil accumulation rates. There has been a growing environmental awareness over the years, followed by an increased interest in research on tree species aiming at the recovery of degraded areas. Phytoremediation aims at the recovery of soils contaminated by heavy metals using plants. African mahogany (Khaya ivorensis A. Chev), which belongs to the Meliaceae botanical family and has noble wood of great economic potential for commercialization. Silicon (Si) is used as a beneficial nutrient, acting as a stress attenuator, this mineral seems to involve the regulation of detoxification processes. The objective of this research is to evaluate the effects of cadmium and silicon on carbon and nitrogen metabolism of the shoot and root system and Si responses on the metabolism of African mahogany, aiming at the phytoremediation capacity of this species to Cd. Federal Rural da Amazônia and the experimental design was a randomized block design in a 4x4 factorial scheme with five replications, and the factors constituted by increasing levels of heavy metal (Cd 0, 25, 50 and 75 mg L-1) and silicon doses. (Si 0, 100, 150 and 300 mg L-1), the obtained data were submitted to statistical analysis through the application “Statical Analysis System” (SAS INSTITUTE, 2000). Treatment with Cd 75 mg L-1 generated the largest accumulations of the leaf metal reaching maximum values of 57 mg g-1 MS through the analysis of cadmium bioaccumulation factor (FB). The maximum translocation factor (TF) found was 4.2 mg g-1MS in the Cd 75 mg L-1 treatment being 38% higher when compared to the control treatment and the Cd tolerance index (IT) was minimal. Silicon concentration in dry matter (DM) was not affected by doses 25 mg L-1 and 50 mg L-1, only Cd 75 mg L-1 negatively affected Si concentrations in plants. Cd generates changes in biochemical metabolism due to its toxicity.

ABSTRACT

The Brazilian territory is now increasingly under the eyes of the world, either by its large carbon reserve, which comprises much of the total biomass of terrestrial plants, or negatively by the high levels of burning and deforestation. Regarding the ways employed for monitoring, control and detection of forests affected by logging intensities, the use of remote sensing and geoprocessing are evidenced, which certainly subsidize possible techniques for the detection of modifications under the forest canopy, resulting from logging. Mappings carried out in areas where forestry activities are carried out generally use Landsat series satellites. From satellite images, one can extract the textural information from the image. Texture is one of the most important attributes for recognizing and categorizing objects and scenes and can be characterized by transitions in pixel values that repeat regularly or randomly throughout the image or object. In this context, the present study seeks to identify areas before and after logging and to monitor the development of forest structure through biometric information of the area and processing / analysis of satellite images. The study will be carried out in the municipality of Paragominas, Pará, in the forest management area of the Rio Capim farm, specifically in the Annual Production Unit-UPA 7, Work Unit-UT 14, where the forest inventory information is monitored in the 2004 to 2014. This information will be correlated with the textural information of the satellite image, which will undergo a preprocessing process (radiometric and atmospheric corrections) and subsequent generation of texture images. These procedures will be performed using ENVI 5.3 and QGIS 3.6 software. The statistical analysis will consider the relation of the gray level average of the textural attributes and the sum of the basal area (m² / ha) in each sample unit, to calculate the determination coefficient (R²) and the ANOVA significance test. From the results will be shown the relationship of biometric data (forest inventory data) with textural variables (correlation, SMA, entropy, among others.), observing if this relationship is statistically significant for the study periods, and if the coefficients of determination indicate that the values of the variance proportion of the dependent variable (remaining basal area) around its mean can be satisfactorily explained by the explanatory variables (Haralick texture), with a probability of confidence (α = 95 %).

Studies for the anatomical characterization of native wood waste are still scarce and necessary for the advancement of technologies for the utilization of this material. The objective of this work was to anatomically characterize the secondary xylem structure of Forest Management residues and correlate it with the occurrence and pattern of cracks formed during the carbonization process, aiming at the formation of groups in order to optimize the production process of charcoal. For this, the waste was collected at the Fazenda Rio Capim Forest Management Unit in Paragominas - PA. We randomly sampled three trees of eleven species occurring in the Brazilian Amazon. In each tree three discs were collected for wood analysis and carbonization conducted on a laboratory scale. Through the anatomical characterization of the wood and the analysis of the charcoal produced, it is expected to find a relationship between the greater cell wall thickness of the fibers, as well as the lower frequency of vessels, with the lower occurrence of cracks, highlighting the importance of waste separation, considering these characteristics to reduce the heterogeneity of the carbonization material and to produce charcoal with better physical and mechanical properties.

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Plant mineral nutrition at adequate levels is critical to maintain vigorous growth and high yields. In this sense, new monitoring patterns have been established, such as the method of assessing nutritional status through leaf diagnosis of Kenworthy, DRIS and CND. In addition, it is believed that machine learning technology such as artificial neural nets (RNAs) can also provide robust analyzes that can assist in decision making regarding the level of fertilization that provides sustainability to managed planting. The Amazon region, more specifically in the southeast Paraense mesoregion, is considered a silvicultural frontier and, therefore, research that guides the theme under discussion is considered rare. Thus, the objective of the research was to evaluate the nutritional status and fertilization levels of a clonal planting of Eucalyptus brassiana S.T. Blake X Eucalyptus grandis W. Hill ex Maiden in the southeastern Pará mesoregion. For the nutritional status analysis, the Kenworthy, DRIS and CND methods were used. For this, 62 plots were selected, of which 33 were separated for the composition of the standards used as a nutritional reference. To define the biological maximum, 9 trees were cubed and divided into 3 diameter classes: 17 to 28.5 cm (Class I), 28.6 to 40.2 cm (Class II) and 40.3 to 52 cm (Class III). In the analysis with artificial neural networks were separated 60% of the database for training and 40% for validation. In which, 20 nets with three multilayer perceptron RNA configurations were trained. To test the biological maximum levels in the field, 6 plots of 10 x 12.5 meters each were systematically distributed. The treatments were allocated in a randomized block design with six treatments and four replications: T1 - 0% fertilization, T2 - 50% fertilization, T3 - 75% fertilization, T4 - 100% fertilization, T5 - 125 % fertilization and T6 - 150% fertilization respectively. Fertilizers were applied in two stages, one at 10 and one at 90 days after seedling planting, in which survival, growth diameter, crown diameter and total height were measured. It was found that the techniques used to assess nutritional status were similar. In the nutrient compartmentation it was observed that only the leaf contents are not sufficient to provide differences in the IMA biomass production, thus, these contents are not to be used as nutritional standards of the studied hybrid. However, by analyzing the nutritional status with RNAs, tree volume can be reliably estimated by nutrient contents allocated to tree compartments and leaf contents. The methodologies for the Eucalyptus nutritional status evaluation provided concordant results and can be reliably used under the study conditions. The level of fertilization that used the maximum biological was the one that generated the highest productivity, so it can be taken with a fertilizer program guide in the southeast paraense mesoregion.

In order to study the nutrient cycling, as well as the spatial distribution of the cutting ant Atta laevigata and to know the contribution of this species in the soil fertility associated to the Brazilian mahogany, it is intended to answer the following questions: What is the contribution of the Brazilian mahogany litter in ecosystems forestry How is the spatial distribution of the Ata laevigata in different forest ecosystems with Brazilian mahogany? What are the contributions of leaf-cutting ants to soil fertility? The hypotheses were elaborated for the questions: The litter produced in the cultivated ecosystems of Brazilian mahogany contributes to the enrichment of the soil because they produce organic matter and chemical elements. The spatial distribution of the herbal Atta laevigata is aggregated. Cutting ants of the species Atta laevigata contribute to the increase of macronutrients and organic matter in Brazilian mahogany ecosystems. This research was divided into three chapters, where the first one sought to verify the importance of Atta laevigata for nutrient cycling and soil fertility; the second was to analyze the availability and concentration of nutrients such as C, N, P, K, Ca, Mg and litter organic matter in different mahogany forest ecosystems and the third was to characterize the spatial distribution of Atta laevigata in mahogany plantations using geostatistical analysis. This research took place during two years in forest plantations belonging to the Tramontina Company, located in the municipality of Aurora do Pará-PA, eastern Amazonia. Ecosystem 1 was characterized by a consortium of Brazilian mahogany with other meliaceae, such as Australian cedar (Toona ciliata), African mahogany ( Khaya ivorensis) and neem (Azadiractha indica). Ecosystem 2 characterized by mahogany monoculture and Ecosystem 3 characterized by mahogany enriched forest. Pitfall traps were used to collect the cutting ants, which were installed 80 traps / forest ecosystem, spacing 10 m equidistant between pitfalls. To collect the litter, four plots of 50 mx 50 m were installed in each treatment, where each plot contained two collectors with 1 m opening, systematically distributed every 15 m (between plants) and suspended at 0,15 m soil level, totaling eight collectors per treatment and also to collect litter accumulated on the ground was used a metal jig with collection area of 0.625 m², with eight collections per treatment.

In the Tapajós National Forest, a Conservation Unit located in the western part of the State of Pará, northern Brazil, there is a common practice among riparians that consists of the extraction of latex from native and planted rubber trees present in the backyards. However, there are two large planted rubber plantations called Terra Rica and Ponte where the population has aroused interest in producing natural rubber, but they are abandoned. Thus, the need arose to investigate the feasibility of the revitalization of the rubber trees in order to restructure the activity, making the extraction of the latex a working alternative to the traditional population. In this context, the objective of this work was to evaluate the silvicultural situation, the growth, the production and to carry out an economic analysis of the production of latex and natural rubber. In order to evaluate the silvicultural situation and the growth, two forest inventories were used in 100% of the rubber groves, carried out in 2013 and 2018, and a sampling to investigate the relationship of dendrometric, morphometric and competition indices with growth in diameter, where Pearson correlation analysis (r) was used to verify the existence of correlation. 2.965 rubber trees were inventoried in 2013 and 2,927 in 2018, with a density of 97.9 individuals.ha^-1 and 96.6 individuals.ha^-1, respectively. The t test detected a significant difference in total height and height of the bole of rubber trees between the inventories of 2013 and 2018, but in diameter, the rubber trees remained the same and, in general, in general, there were no problems of plant health in the plantations. The correlation between the dendrometric, morphometric and competition indices showed that growth in diameter has moderate and weak correlations with all variables, but it presents a significant correlation with the degree of slenderness and salience index. It was concluded that the dendrometric, silvicultural characteristics and growth in diameter of Hevea guianensis have been influenced by the absence of intervention in planting. To evaluate the production of latex and natural rubber, the production of rubber trees was analyzed by means of a sample of 105 young and adult trees, in all diametric classes, during the harvest season in the region. The average productivity per diameter class and the monthly production were evaluated. It was also investigated the existence of possible influences in the production: diameter at 1.30 m from the soil (DBH), bark thickness, crown form and sociological position. Through (r) the correlation of these variables with the production was calculated and the modeling of the latex and natural rubber production (Y) was calculated as a function of the variable of higher correlation (X). It was concluded that the trees with DBH ≥ 80 cm are the most productive and the production presented seasonal variation, being higher in the period of greatest rainfall in the year. As for the influences on the production of latex and natural rubber, these correlated positively and significantly with the DAP and the Rational and Sinusoidal models were the ones that best estimated the production, respectively. Finally, to evaluate the resumption of production, a survey of production costs and an economic evaluation was carried out. The results showed that it is feasible to resume production at the Terra Rica and Ponte with latex production being the most profitable, since it generates a higher profit in the commercialization. The resumption of latex production in the rubber plantations, in addition to profit, contributes to the generation of jobs and strengthens the non-timber forest products sector in the Tapajós National Forest.

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Abstract

The objective of this work was to determine the volumetric yield coefficient of four forest species studied in the city of Itaituba - PA, according to different logs obtained from the trunk and the type and year of the machinery used. It will also seek to compare the coefficients obtained with the established in the specific legislation and to suggest an ideal amount of sample effort to meet the precision required by the legislation. The study will be carried out in four sawmills located in the district of Moraes Almeida, municipality of Itaituba - PA. The volumes of the sample logs will be determined by the Smalian formula, discounting the volume of the hollow. The lumber volume will be determined by multiplying the thickness, width and length of each piece produced. The yield calculation is defined as the ratio between the lumber volume and the log volume, given as a percentage. The logs will be classified, according to the position in the trunk, in A, B and C to verify if there is difference of the yield between these classes. The sawmills will be separated into two groups, Group 1 with the most modern industrial park and Group 2 with the most obsolete industrial park. The ideal quantity of samples will be calculated using the formula used to determine the sample adequacy of the simple random sampling process. The Analysis of Variance and the Tukey test at 95% of probability will be used to verify if there will be difference between the means, having as a response variable the CRV. Sections of the trunk and the sawmills will be the treatments to be compared. The yields found in all cases are expected to exceed 35% and that logs closest to the base of the trunk show a better yield compared to top logs and that the group of companies which own the most modern machinery higher yields compared to older machines. It is expected to recommend the ideal number of logs to estimate the yield of the species studied.

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The aim of this work was to evaluate the nutritional parameters and the antioxidant system of young plants of the species (Schizolobium amazonicum Huber ex Ducke) when submitted to different concentrations of cadmium. The experiment was carried out at the home of the Amazon Region (UFRA), located in Belém, Pará, from December 2017 to June 2018. Initially, seedlings were produced from paricá seeds originating from the Association of the State's Timber Exporting Industries of Pará in Benevides-Pará. The seeds were sown in Leonard pots with a capacity of 4.6 L adapted with pet bottles containing washed and sterilized sand (120 ºC for 40 min). After 15 days after sowing, they received a nutrient solution from Sarruge. After 60 days after sowing, the application of cadmium concentrations in the form of hydrated cadmium chloride (CdCl2.H2O). The experimental design was completely randomized, with 5 treatments being composed of control plants (without cadmium) and with doses of cadmium (CdCl2 178µM, CdCl2 356 µM, CdCl2 534µM, CdCl2 712 µM). The data were submitted to analysis of variance by the F test (p <0.05) using the Statistica software, and the differences between the treatments analyzed by the Tukey test (p <0.05) were adjusted by equations of polynomial regression P <0.01 or 0.05 using the Sisvar program. The main nutritional variables were destabilized in their functions with the increase of cadmium doses, influencing the physiological process of the plant. For the antioxidant system, the enzymes (G-POD, APX, SOD and CAT) provided a decrease as the doses were increased. The changes in nutritional parameters and antioxidant enzymes, consequently led to structural changes of these plants, evidencing low activity for the reversion of stress in the leaves and greater activity in the roots. Therefore, cadmium accumulated mainly in the roots, but there was translocation to aerial part. Therefore, it can be characterized as a phytoextractor.

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Virola surinamensis (Ucuúba), is a Neotropical tree occurring naturally in the floodplain of the lowland forests, igapó and estuaries. Cadmium (Cd) is one of the most toxic and persistent heavy metals in the environment, and can be incorporated and bioaccumulated into the components of the food chain. The objective of the study was to evaluate the physiological and biochemical responses, vegetative growth, nutrient distribution, phytoextraction capacity and tolerance of young plants of V. surinamensis submitted to five concentrations of Cd (0, 15, 30, 45 and 60 mg L^-1) for 60 days. The predawn water potential (Ψ_am), stomatal conductance (gs), transpiration (E), the liquid assimilation rate of CO₂ (A), the concentration of intercellular CO₂ (Ci), the relation of liquid photosynthesis and intercelular CO₂ concentration (A/Ci), the instantaneous efficiency of water use (EWU), the chlorophyll total content (Chl), the maximum photochemical efficiency of PSII (Fv/Fm), the photochemical extinction coefficient (qP), the non-photochemical extinction coefficient (NPQ), electrons transport rate (ETR), bioconcentration factor (BCF), translocation factor (TF), the tolerance index (TI), the nitrate concentration, nitrate reductase (NR), free ammonium, total soluble aminoacids (TSA), total soluble proteins (TSP), starch, proline, sucrose and total soluble carbohydrates (TSC), reducing sugars, plant height, stem diameter, number of leaves, dry matter of aerial part (DMAP), dry matter of root (DMR), total dry mass (TDM), root aerial part reason (R/AP) were evaluated. The Ψam, gs, E, A, A/Ci and EWU were lower than the control, but Chl increased at the dose of 15 and 30 mg L^-1 and Ci was higher than the control. Fv/Fm, qP, ETR reduced in plants with Cd, but NPQ increased. Cd concentrations increased in different plant tissues (root> stem> leaf). The highest BCF value was 30 and 45 mg L^-1 Cd and FT at 45 mg L^-1 Cd, whereas IT was higher at 15 mg L^-1 Cd dose. Cd did not affect the nitrate concentration in the root, but had a positive effect on the leaves. The NR, ammonia, AST and PST decreased in plants with Cd. CST, proline, sucrose and reducing sugars increased in plants with Cd. Cd affected height, stem diameter, number of leaves and biomass production. The Cd negatively influenced Fe, Mg, Ca, N, P and K, especially in the root. Zn increased in the roots and leaves, while the Mn reduced in the root and increased in the leaves of the plants with Cd. All the plants survived until the end of the experiment. The results demonstrate tolerance and low plant capacity in the phytoextraction of Cd, indicating that V. surinamensis may be promising for Cd phytostabilization.

Among the heavy metals (MPs), cadmium (Cd) represents one of the biggest threats to the environment on a global scale, due to its high ecotoxicological potential and increasing soil indices, which contributes to the loss of carbon dioxide. productivity and biodiversity of ecosystems. Fast-growing woody plants represent effective tools for Cd extraction in contaminated soils. In this sense, African mahogany (Khaya ivorensis A. Chev), a tree species belonging to the Meliaceae family, presents satisfactory characteristics for remediation due to accelerated growth, axial root system and high biomass production. However, the phytoremediation strategies and mechanisms of Cd tolerance implemented by this species, associated with the improvement of nutritional status, are not clear. From the above, this research aims to identify the modulations of silicon (Si), a beneficial micronutrient, in physiology , biochemistry, antioxidant system and anatomy of African mahogany seedlings submitted to toxic levels of Cd and correlate these processes with the increase of phytoremediation potential to MP. The experimental design was a randomized block design in a 4x4 factorial scheme with five repetitions, and the factors constituted by increasing levels of MP (Cd 0, 25, 50 and 75 mg L^-1) and doses of silicon (Si 0, 100, 150 and 300 mg L^-1). Polynomial regression, response surface. The concentrations of Cd 50 and 75 mg L^-1 were toxic and caused changes in biochemical processes with negative physiological and anatomical repercussions in Khaya ivorensis. There were photoinhibitory damages to the PSII, where the variables of chlorophyll a, (ΦPSII), (qP) and (ETR) fluorescence, photosynthesis (A), gas exchange (gs), (Ci/Ca) and photosynthetic pigments, especially chlorophyll b, were the most affected by the highest metal level and presented respective minimum points by the regression adjustment of 0.05; 0.07; 0.15 µmol CO₂ molar^-1; 3.2 mmol CO₂ m^-2 s^-1; 0.1 mol H₂O m^-2 s^-1; 0.06 µmol CO₂ molar^-1  and 0.18 mg g^-1 and were 78%, 82%, 75%, 83%, 96%, 93% and 95% lower than the control. Disruption in cytosolic metabolism caused lipid peroxidation. Malonoaldehyde (MDA) content was increased by 63% and 69% in leaves and roots, which was accompanied by reductions in activity of antioxidant enzymes. Above all, APX expression decreased by 69% in the root system. Anatomical changes in tissues occurred with marked decreases in epidermal thickness. The palisade parenchyma and root cortex were 84% and 72% less thick under that toxic level of Cd. However, Si attenuated the stress promoted by the ion and modulated an overpressure in those variables, which ensured the growth and development of Kaya ivorensis under conditions of MP contamination. Normal plant metabolism was resumed only in those treated with Cd 50 mg L^-1 and nourished with Si 150 mg L^-1. Canonical analysis showed that the combination of Cd 45 mg L^-1 and Si 160 mg L^-1, resulted in the maximum expression points of those parameters, where the values came close to the control. Si modulation in antioxidant metabolism was confirmed by the 31% increase in SOD activity. These response patterns were related to the reduction of Cd translocation to the aerial parts and its Si-induced entrapment in the root system. Thus, the micronutrient increased the tolerance and phytoremediation potential of Khaya ivorensis to Cd by phytostabilization of the MP, was due to mechanisms of cocomplexation of Si to Cd, as well as to the ion restrictions imposed by the caspary striae, mediated by Si. We also attributed to the improvement in water relations.

A contaminação do solo por cádmio representa um potencial perigo agrícola, para produção de alimentos, e ambiental em todo o mundo. Diante dos problemas causados por este e outros metais é necessário que se remova ou estabilize os mesmos do solo, para que não haja contaminação dos ecossistemas. Uma das opções para se recuperar a atividade e a diversidade desses ambientes é a fitorremediação. Com isso o objetivo deste trabalho foi avaliar as respostas de crescimento, características fisiológicas e bioquímicas de plantas de Khaya ivorensis A. Chev. submetidas a diferentes doses de CdCl₂. O experimento foi conduzido em Belém/Pa, nos meses de dezembro de 2015 a abril de 2016. Utilizou-se o delineamento experimental inteiramente casualizado, com 5 tratamentos (Controle, Cd 10 mg/L, Cd 20 mg/L, Cd 30 mg/L, Cd 40 mg/L) e 7 repetições. As crescentes doses resultaram em declínio nos parâmetros biométricos, fisiológicos e bioquímicos. Os tratamentos de Cd 10 mg/L e Cd 20 mg/L, obtiveram maior valor no fator de translocação, enquanto que Cd 30 mg/L e Cd 40 mg/L, foram os maiores na bioacumulação, nenhum dos tratamentos apresentou nível critico de toxidez. A espécie Khaya ivorensis A. Chev mostrou ser uma excelente alternativa para o método de fitorremediação em áreas contaminadas com cádmio.

Este estudo teve como objetivo comparar as ferramentas utilizadas para mensurar o volume de madeira em pé em florestas naturais, por meio da análise de regressão e treinamento de Redes Neurais Artificiais-RNA em uma floresta ombrófila densa no município de Breu Branco-PA. Foram cubadas 531 árvores pela metodologia de Smalian e utilizadas as informações de 431 árvores, para estimativa dos coeficientes das equações volumétricas e 100 árvores para validação dos dados. Foram ajustados quatro modelos de simples entrada e cinco de dupla entrada. Os critérios utilizados para seleção dos melhores modelos foram os valores de F,  R²aj e CV%, e distribuição dos resíduos. Foram treinadas 120 RNA para cada análise de estimativa de volume da árvore, utilizando variáveis quantitativas (DAP e Altura do fuste) e qualitativa (espécie). Para a melhor estimativa da RNA foram utilizados os parâmetros RQME, R²aj, CV% e Bias. A equação de regressão selecionada foi a de shumacher e Hall logaritimizada, LogV= -3,7082+1,8519 Log D +0,7940 Log H, que melhor atendeu aos critérios de seleção. (CV=11,05%; R²aj 93,84% e melhor distribuição dos resíduos) com o volume das nove RNA, que melhor atendeu os critérios de seleção. 

Este trabalho teve por objetivo avaliar a capacidade produtiva de plantios clonais de Tectona grandis Lin F. em Capitão Poço, estado do Pará, Brasil, pertencente à empresa Tietê Agrícola LTDA. O monitoramento foi realizado por meio de inventário florestal contínuo, pelo método de área fixa, utilizando parcelas circulares distribuídas sistematicamente em uma grade de 320 m x 320 m. As variáveis dendrométricas coletadas foram: Altura total (Ht) em metros, diâmetro à altura do peito (DAP) em centímetros, idade em anos e coordenadas geográficas no centro de cada parcela. Para a determinação da Altura Dominante (Hdom), foi aplicada a definição de Assmann. Fez-se uma análise exploratória dos dados compreendendo estatística descritiva e teste de normalidade. A construção das curvas de índice de sítio foi feita pelo método da curva guia por regressão, com curvas anamórficas. Foram consideradas três classes de capacidade produtiva, classes de baixa (I), média (II) e de alta (III) produtividade. Foi realizada uma análise da variabilidade espacial do Índice de Sítio por meio de geostatística, que consistiu de uma análise variográfica e de interpolação por krigagem. Para estimativa da variável Índice de Sítio (IS), foram ajustados três modelos de semivariogramas: esférico, gaussiano e exponencial. Os resultados da classificação de sítio revelaram a existência de três classes distintas de produtividade, gerando curvas com IS de 15,5 (Classe I), 17,5 (Classe II) e 19,5 metros (Classe III) para o plantio de 2010 e curvas com IS de 12,3 (Classe I), 14,8 (Classe II) e 17,3 metros (Classe III) para os plantios 2012 e 2013. O modelo de semivariograma exponencial foi o que apresentou melhores estimativas da variável IS, sendo gerada a partir do mesmo uma malha de pontos interpolados que permitiu visualizar o comportamento do índice de sitio, a partir da krigagem ordinária. Obteve-se, com isso, um mapa dos Índices de Sítio com 32,03% da área mapeada classificada nas classes de produtividade média à alta (classes II e III); 53,37% na classe de média produtividade (classe II), e apenas 14,6% com capacidade produtiva alta (classe III). No planejamento da produção de plantios novos é comum a utilização de um índice de sítio. Nesse contexto a krigagem mostrou-se muito eficiente porque definiu para cada local não amostrado, um índice de sítio, ou seja, dentro de um mesmo talhão ha áreas com diferentes índices de sítio onde poderão ser aplicados diferentes alternativas de manejo visando otimizar a produção.

Árvores ocas ocorrem devido a ação de cupins subterrâneos. O oco pode ocorrer desde a base da árvore, prolongando-se por toda sua extensão. Devido a isso há perda de volume na colheita florestal. O objetivo deste trabalho foi determinar a proporção de árvores com oco por espécie e classes de diâmetro em duas Unidades de Produção Anual (UPA 5/2106 – UMF II e UPA 2/2016 – UMF 1A) e determinar perda de rendimento volumétrico devido à ocorrência de ocos por espécie. A área de estudo localiza-se na Floresta Nacional de Saracá-Taquera, Estado do Pará. Na UPA 5/2016, verificou-se que do total de árvores selecionadas para a colheita florestal, 1.175 encontravam-se ocas, e não puderam ser exploradas. A espécie Manilkara huberi (Maçaranduba) com 784 indivíduos selecionados para o corte (6.449,448 m³), concentrou o maior número de indivíduos ocos nas classes diamétricas 75|-85, 85|-95 e 95|-105, com 157, 193 e 305 árvores, respectivamente. Já nas classes superiores, a quantidade de árvores ocas foi menor. Entre todas as espécies selecionadas para o corte, esta espécie representou o maior número de árvores com ocos com 308 indivíduos (251,533 m³). Do total de árvores de todas as espécies selecionadas para a colheita na UPA 5 (3.191), 53,54% estavam ocas. Isso gerou uma perda de rendimento volumétrico de 21,24%. Na UPA 2/2016, o maior número de árvores com ocos ocorreu com Mezilaurus itauba (Itaúba), com 156 indivíduos. Do total de árvores a explorar (4.823) de todas as espécies, 31,79 % estavam ocas, indicando, portanto, a perda de rendimento volumétrico de 58,69%.

Dentre as tipologias florestais amazônicas atingidas pelo desflorestamento estão as matas ciliares. A conversão dessas florestas em áreas de cultivos agrícolas e pastagens tem gerado a degradação desses ecossistemas, portanto, além da necessidade legal de recomposição é necessário criar condições para que o ecossistema restaure a sua integridade ecológica, sua biodiversidade e atinja a estabilidade a longo prazo. Desta forma, essa dissertação teve por objetivo analisar os benefícios de métodos de restauração florestal, com diferentes níveis de intervenção, no processo inicial de restauração de mata ciliar convertida em pastagem e dominada por gramínea exótica. O experimento foi implantado em uma pastagem estabelecida na década de 1990, no município de Terra Alta, Nordeste do estado do Pará. Foram testados quatro tratamentos (métodos): controle (sem intervenção); estímulo ao banco de sementes do solo (controle inicial de gramínea e revolvimento do solo); introdução de espécies arbóreas por sementes (semeadura em covas) e introdução de espécies arbóreas por mudas (plantio em linhas). O período estudado foi de 22 meses após o isolamento da pastagem e implantação dos tratamentos. O estímulo ao banco de sementes do solo diminuiu a dominância de cobertura do solo com gramíneas do gênero Brachiaria e acelerou o processo de regeneração natural das espécies nativas, inicialmente com elevada densidade de indivíduos e espécies herbáceas, mas com aumento gradativo do estabelecimento de espécies arbustivo-arbóreas. Aos 22 meses, a densidade de indivíduos e riqueza foram baixas e semelhantes entre os quatro tratamentos, demonstrando que as gramíneas exóticas atuam como filtro ecológico dificultando o estabelecimento das espécies. Acacia mangium, Cecropia palmata e Vismia guianensis são espécies pioneiras regenerantes capazes de competir com as gramíneas e estruturam a mata ciliar, sendo necessário o manejo da espécie exótica A. mangium. A espécies introduzidas por sementes apresentaram germinação acima de 85% em cinco de oito espécies. A sobrevivência foi elevada para Hymenea courbaril (100%) e Carapa guianensis (87,5%). Schizolobium parahyba var. amazonicum apresentou maior crescimento em altura (175,5 cm) e quatro espécies têm altura inferior a 100 cm. A maioria das espécies introduzidas por mudas apresentaram elevada sobrevivência (acima de 85%). A altura média foi maior nas espécies Inga edulis (153, 9 cm) e Virola surinamensis (107,7cm), as demais apresentaram altura inferior a 100 cm. Na introdução de mudas por sementes e mudas não houve diferença entre os valores de diâmetro das espécies dentro dos tratamentos. A predominância de espécies de ervas e lianas e os parâmetros avaliados para a vegetação lenhosa (arbustos e árvores) indicam que a mata ciliar sob diferentes níveis de intervenção, está no estágio inicial da sucessão secundária, caracterizado por diferentes hábitos de vida heliófilos, baixa riqueza de espécies lenhosas e recuperação da estrutura florestal pouco expressiva. O ingresso e recrutamento de espécies arbóreas regenerantes de maneira igual nos métodos de restauração, evidencia a resiliência da mata ciliar dominada por gramínea exótica.

A crescente demanda por energia, em decorrência da melhoria das condições produtivas e aumento da qualidade de vida da população, impulsiona novas áreas de pesquisa na busca por fontes economicamente viáveis e sustentáveis do ponto de vista ambiental. Dentre as fontes naturais disponíveis, os resíduos lignocelulósicos provenientes de atividades agrícolas e florestais ganham destaque quanto a sua quantidade e disponibilidade. Com isso, o trabalho teve como objetivo avaliar o potencial energético de resíduos gerados do beneficiamento de cinco cultivos agrícolas produzidos no estado do Pará, a fim de verificar sua viabilidade para uso como matéria prima energética.  Para isso, a pesquisa foi dividida em duas etapas, na primeira etapa foram realizados o levantamento produtivo e a caracterização das propriedades físicas, químicas e energéticas e na segunda parte foi realizado o estudo do comportamento térmico dos resíduos. O delineamento adotado foi o inteiramente casualizado, composto por cinco tratamentos (casca do coco, cacau, cacho de dendê, sabugo do milho, caroço do açaí) e três repetições. As análises mostraram que houve diferença entre as propriedades e composição dos resíduos. A umidade inicial dos resíduos, a baixa densidade e o alto teor de cinzas foram considerados como os principais fatores limitantes. Dentre os resíduos estudados, o caroço de açaí, o sabugo de milho e o cacho de dendê, foram os que apresentaram maior potencial para utilização energética tendo em conta a sua disponibilidade e valor calórico. Estimou-se que a potencial energético estadual seja em torno de 42 mil GJ/ano. As microrregiões de Cametá, Tome-açú e Paragominas apresentaram maior aptidão para aproveitamento energético dos resíduos. Com os resultados referente a análise termogravimétrica, foi observado que a combustão dos resíduos ocorreu em três estágios. A perda de massa dos resíduos, se deu em temperatura e intensidades diferentes. O caroço de açaí foi a biomassa que apresentou maior resistência térmica e regularidade na liberação da energia.

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O Tachigali vulgaris (Tachi-branco) é uma espécie leguminosa arbórea, nativa da região amazônica que devido as suas características tecnológicas, ecológicas e silviculturais, possui significativo potencial para expansão em plantios energéticos na Amazônia. No entanto, é necessário conhecer o crescimento dessa espécie em diferentes espaçamentos de plantio e as implicações desse fator nas propriedades da madeira visando o uso energético. Este estudo teve como objetivo avaliar a produtividade das árvores e o comportamento tecnológico da madeira da espécie Tachigali vulgaris L. G. Silva & H.C. Lima relevantes para bioenergia. Foram coletadas árvores aos 7 anos de idade, em diferentes espaçamentos 4,5 m² (3x1,5m), 6 m² (3x2 m), 7,5 m² (3x2,5 m), 9 m² (3x3 m), 10,5 m² (3x 3,5 m) e 12 m² (3x4 m), provenientes de um plantio experimental, localizado no Distrito de Monte Dourado, estado do Pará, Brasil. O delineamento experimental foi em blocos ao acaso, onde foram coletadas 3 árvores em cada um dos 3 blocos analisados, em cada 6 espaçamentos, totalizando 54 árvores-amostra. Em cada parâmetro foram realizadas análises de variância (ANOVA) e quando houve efeito significativo do espaçamento, foram ajustados modelos de regressão linear simples. Houve efeito significativo do espaçamento para as características de crescimento (volume com e sem casca) e produtividade (massa seca de madeira, massa de carbono e massa combustível), em que os maiores espaçamentos (9 m² e 12 m²) alcançaram melhores desempenho e os menores espaçamentos (6 m² e 7,5 m²) foram inferiores. Porém não exerceu influência significativa na qualidade da madeira para uso energético (composição química, poder calorífico da madeira, morfologia das fibras e no perfil de decomposição da madeira). Apesar disso, o aumento do espaçamento conduziu a uma tendência positiva na densidade básica da madeira, produtividade e densidade energética, e negativa para a relação cerne/alburno. O espaçamento indicado foi o 3 x 3m (9 m²), pois apresentou desempenho satisfatório no crescimento e na produtividade individual (árvore) e por área (hectare). Os resultados encontrados mostram que o uso da espécie Tachigali vulgaris como fonte de bioenergia na produção direta de calor, pode ser altamente viável, dadas as suas características físicas, químicas e energéticas.

This study had the objective to evaluate mortality and growth of different eucalyptus clones
under inoculation of mycorrhizal fungi as well as and mortality and growth of paricá under
inoculation of mycorrhizal fungi and rhizobacteria in the southeast of Pará state, Brazil. The
experiment with the eucalyptus clones was installed following a randomized block design
with three replicates (three blocks) with 12 treatments and six clones. The seedling spacing
was 3.0 x 3.0 meters with each plot having 56 seedlings. Half of the seedlings were inoculated
with the arbuscular mycorrhizals fungi (endomycorrhizal) Glomus etunicatum, Glomus
clarum, and the ectomycorrhizal Pisolithus microcarpus and the other half of the seedlings
had no inoculation and served as a control. Each eucalyptus clone had 168 seedlings, totaling
1008 seedlings. Up to the last experiment measurement, the inoculation with the mycorrhizal
fungi did not promote higher growth in diameter and height of the eucalyptus clones tested,
when compared to the treatment without inoculation. The clones VM01 Eucalyptus urocan,
373 E. platyphylla, and 1250 E. urograndis had the lowest mortality rates. Therefore, the
most recommended clones for Southeastern Pará were VM01 E. urocan, A 2017 E.
urograndis, 373 E. platyphylla and 1250 E. urograndis because they presented better growth
in diameter, height and lower mortality rate. The experiment with paricá was installed
following the randomized block design with three replicates (three blocks) for each treatment
being one replicate with 49 individuals, totaling 147 trees per treatment. The seedling spacing
was 3.0 x 3.0 meters. In total, 588 paricá seedlings were used in the experiment. The
development of paricá was evaluated under the influence of four treatments: (T0) control,
(T1) conventional chemical fertilization (thermophosphate and, in the cover, NPK), (T2)
inoculation with arbuscular mycorrhizal fungi, and (T3) inoculation with arbuscular
mycorrhizal fungi and use of the plant growth promoting rhizobacteria. Inoculation with the
plant growth promoter rhizobacteria (Enterobacter sp., Enterobacter aerogenes, Bacillus sp.
and Pantoea sp.) and arbuscular mycorrhizal fungi in the species Glomus ethunicatum and
Glomus clarum during the period evaluated did not influence development in diameter,
height, and mortality of paricá plants. The paricá trees with conventional chemical
fertilization had the best growth in height and diameter and lower mortality rate. However
chemical fertilization is recommended in paricá plantations up four years in age in southeast
Pará.

As boas práticas de manejo florestal requerem que as estimativas do volume disponível na floresta sejam obtidas com eficiência e precisão para ajudar na tomada de decisões sobre o uso da floresta. A metodologia convencional aplicada consiste no uso do fator de forma para corrigir o volume cilíndrico e o ajuste de equações de regressão pelo método dos mínimos quadrados. Recentemente uma nova alternativa vem sendo usada que usa técnicas computacionais de inteligência artificial ou as chamadas redes neurais artificiais (RNA) que, também buscam estimativas precisas dos volumes das árvores inventariadas em pé. Diante disso esse estudo objetiva aplicar esta nova tecnologia para estimar o volume de arvores em pé na Floresta Estadual do Amapá. Foram cubadas 1028 árvores caídas em bom estado de conservação com DAP ≥10cm pelo método de Smalian combinado com o de Hohenald em 30 unidades amostrais distribuídas em três fitofisionomias: Floresta de Terra Firme de Baixo Platô (FTFBP), Floresta de Terra Firme Submontana (FTFSM) e Transição Cerrado Floresta (TCF). Foram treinadas 50 redes neurais artificiais do tipo MultilayerPerceptron (MPL) para cada fitofisionomia usando DAP (diâmetro à altura do peito) e HC (altura do comercial) na camada de entrada e Volume (m³) na camada de saída. O tipo de treinamento aplicado foi o ResilientPropagation com função Sigmoidal e critérios de parada baseados em erro médio e numero de ciclos. Os critérios usados para a avaliação da melhor RNA foram: análise gráfica dos resíduos, coeficiente de correlação (r_ŷy), bias (viés) e raiz quadrada do erro quadrático médio (RQME). Também foram ajustados cinco modelos volumétricos matemáticos via análise de regressão tendo como varáveis independentes o DAP (diâmetro à altura do peito) e HC (altura do comercial). De acordo com os resultados obtidos, as RNAs e os modelos matemáticos apresentaram resultados semelhantes. As RNAs com arquitetura 2-6-1 com variáveis de entrada DAP e HC,algoritmo de treinamento (MLP), com 30.000 ciclos e função de ativação sigmoidal, produziram os melhores resultados nas redes treinadas. O modelo de regressão proposto de Schumacher e Hall foi o que melhor se ajustou aos dados, podendo ser utilizado para estimar o volume de árvores em pé na Floresta Estadual do Amapá em suas três fitofisionomias FTFDBP, FTFDSM E TCF.

Os ecossistemas florestais, suas composições vegetais e diferentes formas de manejo apresentam na entomofauna edáfica os elementos fundamentais para seu funcionamento, de forma que o conhecimento destas comunidades é importante para perspectivas de manejo sustentável dos ecossistemas florestais com mogno brasileiro (Swietenia macrophylla King). Estes insetos são importantes para o funcionamento dos plantios florestais, apresentando-se como grandes aliados na manutenção da biodiversidade florestal na Amazônia. O plantio de monoculturas florestais, apesar de importante economicamente, resulta em efeitos negativos devido à baixa diversidade de produtos vegetais. A população de insetos apresenta uma tendência em acompanhar a riqueza vegetal, pois muitos insetos dependem direta ou indiretamente desta para sua sobrevivência. A presença de áreas monodominantes pode, desta forma, influenciar a diversidade de espécies de insetos associada a essas áreas, já que a baixa diversidade vegetal acarreta diferenças na disponibilidade de recursos em tais ambientes. Estudos sobre a dinâmica de produção e decomposição da serapilheira em plantios de espécies nativas, tendo como exemplo o mogno na Amazônia, são necessários e, muitas vezes, pouco compreendidos. Desta forma se fez importante o estudo da produção e decomposição da serapilheira nos diferentes ecossistemas florestais desta pesquisa com mogno brasileiro na Amazônia Oriental. Esta pesquisa foi dividida em três artigos científicos, onde no primeiro buscou conhecer a entomofauna edáfica, o segundo a diversidade de Coleopteros e o terceiro a produção e a decomposição de serapilheira em três ecossistemas florestais com mogno brasileiro, assim como a influência dos fatores climáticos na população dos insetos edáficos e na produção da serapilheira. Esta pesquisa ocorreu durante dois anos em plantios florestais pertencentes a Empresa Tramontina, localizada no município de Aurora do Pará-PA, Amazônia Oriental. 

O papel funcional das espécies mais abundantes em comunidades vegetais tem sido um dos pontos principais em ecologia. Na Amazônia, a importância das espécies mais abundantes entrou em evidência a partir da identificação de um grupo de espécies arbóreas dominantes na Amazônia ocidental, que intitulou de oligarquia de espécies. Mais recentemente, foi encontrado padrão similar para toda a Amazônia, chamando de espécies hiperdominantes as que detêm 50% de todos os indivíduos arbóreos (HA). Também foram definidas quais espécies detêm 50% da biomassa arbórea da Amazônia, as hiperdominantes em biomassa (HB). Buscando compreender o comportamento das espécies hiperdominantes em áreas sob influência antrópica, essa tese teve como objetivos: (1) Compreender como os padrões de HA e HB descritos para florestas primárias diferem dos encontrados em diferentes tipos de vegetação em paisagens antropizadas, (2) avaliar o efeito das métricas de uma paisagem antropizada em diferentes escalas sobre a estrutura e composição florística em diferentes estratos da vegetação e (3) descrever os padrões de hiperdominância de espécies vegetais em diferentes paisagens agrícolas na Amazônia oriental, verificando como o grau de conservação das áreas pode afetar as relações de dominância e hiperdominância das comunidades vegetais. Foram analisadas 07 áreas distribuídas na Amazônia oriental, em cada área, foi conduzido inventário do estrato inferior (indivíduos com altura ≤ 2m), médio (indivíduos com altura < 2 m até 10 de DAP) e superior (indivíduos com DAP ≥ 10 cm), em 9 propriedades agrícolas. Nelas, foram analisadas de 03 a 05 tipos de cobertura: pasto, roça, floresta secundária (inicial e avançada) e floresta remanescente. O longo histórico de antropização na região do Guamá tem causado mudanças drásticas nas comunidades vegetais, reduzindo os estoques de biomassa aérea e afetando os padrões de HA e HB. Quão mais intensa é a perturbação antrópica, mais forte é o “efeito de hiperdominância”, i.e. menos espécies detêm 50% dos indivíduos. No Guamá, quase totalidade das espécies HA e HB foram classificadas como pioneiras, não foi encontrado efeito da densidade da madeira sobre os padrões de abundância ou biomassa aérea e o tamanho máximo dos indivíduos das espécies tiveram efeito sobre a biomassa aérea. No Oiapoque, as métricas proporção de área não-florestada e densidade de fragmentos influenciaram os três estratos da vegetação em todas as escalas, refletindo o forte efeito da perda de hábitat e fragmentação sobre a vegetação. A proporção de espécies dominantes pioneiras apresentou maiores valores associados aos pastos e às florestas secundárias. Métricas ligadas ao processo de dispersão têm influência sobre o estrato inferior até 800 m e as árvores adultas (estrato superior) só parecem ser influenciadas pela configuração da paisagem a partir dos 2000m. Foram encontradas 141 espécies hiperabundantes para as áreas antropizadas da Amazônia oriental, sendo 38% consideradas pioneiras. Poucas espécies hiperdominantes foram exclusivas de uma única área. O efeito da conservação das áreas, expresso pelo percentual de cobertura florestal, não afetou os padrões de hiperdominância, nem a proporção de espécies florestais/pioneiras hiperdominantes em cada área.

The objective of this work was to evaluate the physiological, growth and biochemical parameters of young plants of paricá Schizolobium amazonicum Huber ex Ducke when submitted to different concentrations of cadmium. The experiment was carried out in a greenhouse of the Institute of Agricultural Sciences (ICA), belonging to the Federal Rural University of Amazonia (UFRA), located in Belém-Pará. Initially seedlings were produced from paricá seeds from the Association of Timber Exporting Industries of the State of Pará. Seeds were placed to germinate in a Leoanard pot with capacity of 4.6 L adapted with pet bottles containing autoclaved washed sand. After 15 days after sowing, they received nutritive solution of Sarruge (1/4 and 1/2 strength). After 60 days after sowing, increasing concentrations of cadmium in the form of cadmium chloride (CdCl2.H2O) were started. The experimental design was completely randomized (DIC), with 5 treatments consisting of control plants (without cadmium doses) and with doses of Cadmium (CdCl2 178μM, CdCl2 356 μM, CdCl2 534μM, CdCl2 712 μM) with 7 replicates each plant / vessel) totaling 35 experimental units. The data were submitted to analysis of variance by the F test (p <0.05) and the means were compared by the least significant difference of the Tukey test (p <0.05) and were adjusted by polynomial regression equations P <0, 01 or 0.05 using the Sisvar program. The main physiological variables were destabilized in their functions with the increase of cadmium doses, influencing the energy process of the same ones. For the biophysical variables, the cadmium provided a decrease of growth as the doses were increased, interfering in smaller production of biomass. The negative changes of the physiological parameters, consequently led to changes in the carbon and nitrogen metabolism of these plants, evidencing low concentrations of the variables that contain nitrogen in their structures. Cadmium accumulated mainly in the roots of paricá, characterizing a low translocation for aerial part. Moreover, due to the circumstances applied in this study and the high concentrations of cadmium used in paricá seedlings, complementary research is necessary to understand more comprehensively the harmful effect of this element in paricá plants.

Mesmo sofrendo grandes alterações, a floresta é um valioso recurso natural renovável, que pode ser utilizado pelas gerações presentes e futuras, por meio da conservação de sua regeneração natural. Avaliou-se a dinâmica da abundância de indivíduos de regeneração natural de quatro espécies comerciais, no período de 30 anos após exploração florestal de impacto reduzido. Dados de inventário florestal contínuo em parcelas permanentes foram utilizados na avaliação da regeneração natural das espécies estudadas em cinco ocasiões (1981, 1983,1989, 1995 e 2012). O delineamento experimental foi inteiramente ao acaso, com 4 tratamentos, com 12 repetições cada. Para monitorar a regeneração natural, pequenas parcelas (5m x 5m) foram alocadas no centro de cinco sub-parcelas de 10 m x10 m, onde os indivíduos de 2,5 - 5,0 cm DAP (varas) foram medidos. Indivíduos ≥ 30 cm de altura e < 2,5 cm DAP (mudas) foram contados em parcelas triangulares de 6,25 m², estabelecidas aleatoriamente dentro de cada parcela (5m x 5m). Os resultados obtidos mostraram que as espécies tiveram acréscimo no número de indivíduos em relação à área testemunha, que não sofreu qualquer alteração, com um número maior de indivíduos voltado a espécie Carapa guianensis, que se destacou tanto na junção das classes de mudas e varas, quanto nas avaliações feita por tratamento. A exploração florestal possibilitou o estabelecimento de regeneração das espécies comerciais, indicando que essas espécies necessitam de condução tal como a abertura do dossel, para garantir o estoque para futuros cortes.

Os plantios comerciais de espécies do gênero Eucalyptus tem se expandido e conquistado destaque na economia nacional. Dada as oscilações de mercado e da economia nacional, a busca por condução de rebrotas tem se tornado uma alternativa de menor custo quando comparada à reforma de plantios, contudo é necessário que se conheça os fatores que influenciam as características da rebrota a fim de se obter os melhores resultados de sobrevivência e vigor nos tocos no período pós colheita. O método de colheita, tipo de clone e época do ano são comumente citados como fatore que influenciam o percentual e vigor das rebrotas o que leva às questões: O método de colheita, devido ao grau de dano aos tocos influencia no percentual e no vigor da rebrota? Existem diferenças significativas de percentual e vigor de rebrota entre dois clones do mesmo híbrido? A época do ano em que é feita a colheita (período seco e chuvoso) determina diferença de percentuais e vigor de rebrota? O objetivo desse trabalho foi avaliar se o método de colheita (Manual x Mecanizada), o Clone (A217 x 321) e a época do ano (seca x chuva) influenciam no percentual de rebrota e no vigor das rebrotas (número de gemas por toco e altura do maior broto) de clones híbridos de Eucalyptus grandis W. Hill ex Maiden x Eucalyptus urophylla L.C. Blake. Foram instalados três ensaios na região do bioma cerrado, no município de Grajaú, no estado do Maranhão, cada ensaio possuía dois tratamentos que contaram com 4 parcelas e cada parcela continha 30 tocos, Os dados foram analisado por análise de variância e indicaram que o tipo de colheita não afeta o percentual de rebrota nem o número de gemas nos tocos, enquanto que a colheita manual proporcionou brotações mais altas, indicando crescimento mais acelerado nesse método de colheita.  Os clones A217 e 321 não apresentaram diferença significativa no percentual de rebrota, contudo o clone A217 foi superior no número de gemas e na altura do maior broto. A resposta do percentual de rebrota, número de gemas e altura do maior broto se mostrou favorecida pelo período seco, contudo a análise dos índices pluviométricos nos períodos mostrou que não houve diferença de pluviosidade nos dois períodos, descaracterizando o tratamento, levando a crer que o melhor desempenho da rebrota no suposto período seco se deu por outras variáveis não controladas e mensuradas. 

Estudos têm mostrado que o Al⁺³ prejudica o crescimento e o desenvolvimento de plantas sensíveis, como também mostrado a existência de plantas resistentes e/ou tolerantes. O excesso de alumínio, além de inibir a formação normal da raiz, interfere nas reações enzimáticas, na absorção, transporte e uso dos nutrientes pelas plantas. Diante do exposto, o presente trabalho objetivou avaliar os efeitos da aplicação de doses de alumínio no crescimento e no metabolismo de mudas de dendê Elaeis guineensis Jacq. O experimento foi conduzido em casa de vegetação do Instituto de Ciências Agrárias da Universidade Federal Rural da Amazônia, em Belém, Pará, no período de agosto de 2015 a janeiro de 2016, sendo as análises bioquímicas e fisiológicas realizadas no Laboratório de Estudos da Biodiversidade em Plantas Superiores (EBPS), estabelecido no mesmo local. As mudas de dendê na variedade Deli x Lamé com cinco meses de idade, foram cedidas pela empresa ADM (Archer Daniels Midland), localizada no município de Concórdia/PA, originadas da Embrapa Amazônia Ocidental-AM. O delineamento experimental foi em DIC-Delineamento Inteiramente Casualisado, com 5 repetições, sendo uma planta uma unidade experimental, onde foram aplicadas as dosagens de alumínio de 0 mg L^-1, 10 mg L^-1, 20 mg L^-1, 30 mg L^-1 e 40 mg L^-1 de Al⁺³, sendo este cátion, adicionado na forma de cloreto de alumínio hexahidratado 95% (AlCl₃.6H₂O). Perfazendo um total de 25 plantas analisadas. As características morfológicas e as respostas bioquímicas foram analisadas ao término do experimento. A maioria das características de crescimento das mudas de dendê Elaeis guineensis Jacq. foram influenciadas negativamente com o aumento das dosagens de AlCl_3. Observou-se um decréscimo na maioria das características biométricas analisadas, com a dosagem máxima aplicada. Observando as menores médias de Altura, Número de folhas, Número de folhas diferenciadas, MSPA-Matéria Seca da Parte Aérea, MST-Matéria Seca Total, MSPA/MSR-Matéria Seca da Parte Aérea/Matéria Seca da Raiz, nas plantas que receberam a dosagem de 40 mg L^-1 de Al⁺³. Em relação aos parâmetros bioquímicos analisados, verificou-se que o aumento das dosagens de AlCl_3, promoveram um maior VE-Vazamento de Eletrólitos. É admitido que o Al³⁺ afete a fluidez da membrana por alterar o ambiente químico dos lipídios da membrana, provavelmente, por formar ligações entre as regiões polares dos fosfolipídios. O aumento nas concentrações de NO₃^- e de NH₄⁺ nas raízes, podem estar relacionados a interferência do Al⁺³ no metabolismo de algumas enzimas, entre elas a RN-Redutase do Nitrato. Que apresentou uma redução em sua atividade no tratamento que recebeu a maior dosagem de 40 mg L^-1de Al⁺³. O aumento nas concentrações de aminoácidos, proteínas e carboidratos nas folhas e raízes, podem estar relacionados com a grande competição do Al⁺³ por componentes ligantes da membrana plasmática. A diminuição do conteúdo de clorofila provoca uma perturbação na homeostase celular redox, visto que esta molécula desempenha a função de aceptor de elétrons, aumentando assim a produção de EROs. Vários trabalhos têm mostrado que íons de Al⁺³ aumentam a produção de espécies reativas de oxigênio (EROs) e aumentam a peroxidação de lipídios de membrana. 

O presente estudo teve como objetivo avaliar o efeito da restauração florestal sobre os atributos do solo e da vegetação em áreas mineradas após a lavra de bauxita em áreas sobre dois métodos de restauração: Indução da Regeneração Natural e Plantio de mudas, em áreas com dois e sete anos sob ambos os métodos. Para tanto, avaliou-se: (I) quantificação das matrizes que circundam as áreas estudadas, numa escala de paisagem, na área sobre Regeneração Natural;(II) riqueza e diversidade da vegetação em três estratos: superior, médio e inferior e (III) atributos físicos e químicos do solo nas áreas de estudo sob os métodos de plantio e regeneração natural. O estudo foi realizado em uma área de atividade mineraria pertencente a Mineração Paragominas S.A., localizada no município de Paragominas, Sudeste do estado do Pará. Nas áreas de regeneração natural, mesmo numa paisagem de entorno predominantemente florestal, a baixa diversidade e a alta dominância de indivíduos regenerantes levam ao desaparecimento repentino e abrupto dos componentes arbóreos durante a fase de transição sucessional, ocasionando a exposição do solo à colonização por espécies pioneiras ou herbáceas, como gramíneas. O sistema de regeneração natural aos sete anos foi altamente eficiente na recuperação de importantes atributos relacionados à qualidade do solo em superfície. No estrato superior,o plantio de mudas com sete anos foi eficiente na formação de uma comunidade florestal próxima a uma floresta de referência no que se refere a diversidade e equabilidade. Porém a falta de um critério na distribuição das mudas em campo e a operação de capina para controle de indivíduos regenerantes nos cinco primeiros anos afetou não somente a formação de uma fisionomia florestal, como também permitiu a ocorrência de grandes áreas com solo exposto, resultando em substrato com sérias limitações físicas e estruturais no sistema de plantio com sete anos.

Pilocarpus microphyllus Stapf. ex Wanderw (Rutaceae) encontra-se ameaçada de extinção pela perda de área de ocupação e qualidade do hábitat, em consequência do desmatamento para atividades agropecuárias, assentamentos e pelos níveis de uso e importância econômica, estimando-se que a redução populacional ocorrida nos últimos 10 anos tenha sido maior que 50%. A Modelagem da Distribuição Potencial (MDP) é uma ferramenta importante para predizer a distribuição de espécies ameaçadas de extinção. O objetivo deste trabalho foi predizer a ocorrência de P. microphyllus por meio de técnicas de modelagem preditiva utilizando variáveis ambientais, em escala de abrangência regional, para mapeamento da distribuição geográfica da espécie. O estudo foi conduzido nos estados do Pará, Maranhão e Piauí, onde foram utilizados um total de 32 pontos georreferenciados, sendo coletados 12 em campo e 20 pontos obtidos da literatura. Dos 32 pontos, 22 foram utilizados para modelagem e 10 foram utilizados para validação dos modelos. As variáveis ambientais utilizadas para modelagem ambiental foram a temperatura média do mês mais frio (°C ) (BIO 06), a faixa de temperatura anual (mm) (BIO 07), a precipitação anual (mm) (BIO 12), precipitação da estação seca (mm) (BIO 17), precipitação da estação fria (mm) (BIO 18), precipitação da estação quente (mm) (BIO 19), altitude (m) (ALT) e o leptossolo lítico (SOLO). A modelagem da distribuição potencial de P. microphyllus foi conduzida no pacote estatístico R Core Team (2016), por meio da interface Model-R. A maior correlação ocorreu entre a variável BIO 06 e ALT, de valor negativo (0,96) para o coeficiente de Pearson. O processo de modelagem ocorreu utilizando os algoritmos BioClim, GLM e Maxent, ao qual foram configurados para gerar os modelos do tipo Kfold. Os modelos GLM e Maxent obtiveram os melhores valores de validação estatística para AUC (0,84 e 0,88) e TSS (0,76 e 0,79), e foram selecionados para geração do modelo consenso. O consenso foi validado com 80% de acerto com os dados de campo e utilizado para associação com Unidades de Conservação e áreas desmatadas para seleção de áreas para conservação. Foram selecionadas 12 áreas, com um total de 236.283,23 hectares de vegetação. A hipótese testada nesta pesquisa não foi rejeitada, pois com a modelagem potencial pôde-se identificar áreas não conhecidas com boa adequabilidade à presença de P. microphyllus, que podem servir para ações conservacionistas e a gestão sustentável deste recurso ameaçado de extinção, minimizando e redistribuindo as atividades extrativistas sobre as populações atualmente conhecidas.

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Na Amazônia, manejadores de florestas de produção não aplicam tratamento silvicultural por julgar que se trata de uma atividade onerosa, a ponto de inviabilizar o Manejo, e que os ganhos em crescimento da floresta não compensam os custos. Este estudo avaliou os benefícios oriundos da adoção do tratamento pós-colheita, Desbaste de Liberação de Copas associados ao anelamento com arboricida glifosato numa floresta de produção no leste da Amazônia. Foram instaladas na Fazenda Rio Capim em Paragominas-Pará, duas parcelas, cada uma com 25,5 hectares e, durante 5 anos, coletadas informações acerca do crescimento de árvores remanescentes selecionadas, mortalidade de árvores aneladas e produtividade e custos das atividades realizadas. O Incremento Periódico Anual em diâmetro na parcela testemunha e parcela com tratamento foi de 0,56 cm.ano^-1 e 0,47 cm.ano^-1, respectivamente, e não revelaram diferença significativa a 95 % de probabilidade. A variável área basal resultou em crescimento 0,43 m² ano^-1 (testemunha) e 0,48 m² ano^-1 (área tratada) com incrementos de 0,017 m² ha^-1 ano^-1 e 0,019 m² ha^-1 ano^-1, respectivamente. A mortalidade das árvores competidoras foi altamente significativa com aplicação de glifosato na concentração 33%, com mortalidade de 78,95 % em três anos e 91,23 % aos cinco anos. O estudo revelou que as menores produtividades estão associadas à preparação da área (2,16 ha/h) e ao anelamento das árvores competidoras (2,32 ha/h). As famílias Caesalpiniaceae, Burseraceae e Lecythidaceae requerem maior tempo de resposta para serem desvitalizadas. O anelamento associado à aplicação de glifosato 33% tem alta efetividade de mortalidade das árvores competidoras. Implantar um hectare do tratamento requer investimentos de R$ 53,23 reais a cada 10 anos. Financeiramente, resultou em VPL maior que 0 e RB/C maior que 1, com valores de referência do VPL em R$ 364,10 e RB/C 1,38, respectivamente. Avaliando-se uma UPA durante o ciclo de corte do manejo mais adição do Desbaste de Liberação de Copas, apresenta viabilidade financeira, e, portanto, não é um impedimento para a adoção dessa prática.

Resumo ainda sendo elaborado

O manejo das espécies ameaçadas deve ser utilizado como uma estratégia de conservação, sendo fundamental conhecer o comportamento dessas espécies em relação à exploração florestal e à taxa de recuperação do seu estoque dentro do ciclo de corte estabelecido para a floresta. Assim, avaliou-se a dinâmica das populações de Hymenaea parvifolia Huber; Hymenolobium excelsum Ducke e Vouacapoua americana Aubl. classificadas como ameaçadas de extinção pela União Internacional de Conservação da Natureza (IUCN). A pesquisa foi dividida em três artigos que contemplam seus objetivos específicos. No primeiro artigo avaliou-se a dinâmica das populações de H. parvifolia, H. excelsum e V. americana considerando a estrutura horizontal, as taxas de ingresso e mortalidade e a distribuição espacial de indivíduos. No segundo artigo avaliou-se a área basal, o volume e a distribuição diamétrica das espécies H. parvifolia e H. excelsum e no terceiro artigo avaliou-se a dinâmica da regeneração natural das populações de H. parvifolia, H. excelsum e V. americana, considerando a abundância de suas populações. A pesquisa foi realizada em três áreas experimentais sob a responsabilidade da Embrapa Amazônia Oriental, sendo duas localizadas na Floresta Nacional do Tapajós (Km 114 e Km 67 da BR 163) e uma no Campo Experimental da Embrapa no município de Moju. As alterações causadas pela exploração florestal de impacto reduzido sobre a estrutura, ingresso, mortalidade dos indivíduos das populações das espécies H. parvifolia; H. excelsum e V. americana avaliadas no período de 31 anos não foram significativos. O período de 30 anos após a exploração florestal não foi suficiente para H. parvifolia recuperar o número de árvores, a área basal e o volume existente antes da exploração. Atualmente a espécie tem volume disponível para colheita, na área do Km 67, porém não possui estoque em crescimento que possa assegurar novas colheitas em futuro próximo, necessitando de atenção especial no manejo de sua população. Na área do Km 114, a espécie possui um estoque que poderá garantir futuras colheitas. A alta intensidade de colheita não permitiu que H. excelsum recuperasse o número de árvores existente antes da exploração, no período de 30 anos, porém a espécie possui estoque em crescimento que poderá garantir a sua conservação e futura exploração. H. parvifolia e H. excelsum possuem poucos indivíduos na regeneração natural podendo prejudicar a permanência dessas espécies na floresta e levá-las a extinção no local de estudo. V. americana tem regeneração abundante e estará garantida em futuras colheitas. Recomenda-se a aplicação de tratamentos silviculturais direcionados para estimular a regeneração natural nas áreas do Km 67 e Km 114. O plantio e a condução da regeneração natural são recomendados para garantir a permanência da população das espécies na área de manejo. As espécies, embora estejam na lista vermelha da União Internacional de Conservação da Natureza e na lista de espécies ameaçadas publicada pelo Ministério Brasileiro do Meio Ambiente, não correrão o risco de extinção na Floresta Nacional do Tapajós e Moju, desde que suas populações sejam manejadas com técnicas e práticas adequadas, obedecendo à Legislação Florestal Brasileira.

Os sistemas agroflorestais (SAF) cumprem, em grande medida, o desafio de atender a crescente demanda de produção de alimentos alinhada com a conservação ambiental. O objetivo deste estudo é avaliar os sistemas agroflorestais através do manejo do componente arbóreo e da percepção dos agricultores na agricultura familiar e empresarial no município de Tomé Açu, estado do Pará, Brasil. A coleta de dados ocorreu em SAF da agricultura familiar (SAF-AF), SAF da agricultura empresarial (SAF-AE) e com artesãos que confeccionam artefatos em madeira. Os dados foram analisados pela estatística descritiva e estatística multivariada. A pesquisa foi organizada em três capítulos. O primeiro capítulo analisa a fitossociologia e o uso das espécies cultivadas nos SAF. Os resultados apontaram que: os SAF-AF apresentam maior riqueza florística, maior diversidade de espécies e maior equilíbrio na abundância das espécies em relação aos SAF-AE; As espécies frutíferas apresentam maior nível de importância e o maior número de finalidades nos SAF-AF e SAF-AE quando comparados às espécies arbóreas; Devido sua composição, estrutura, produção e uso diversificados, os SAF de Tomé-Açu constituem-se numa alternativa sustentável de produção agrícola. O segundo capítulo aborda o manejo dos SAF através da sustentabilidade e do potencial de utilização dos resíduos da poda. Os resultados apontaram que: O uso da poda como estratégia de manejo contribui para a sustentabilidade ambiental, econômica e sociocultural nos sistemas agroflorestais de Tomé-Açu e nas atividades de confecção de artefatos em madeira; A sensibilização dos agricultores para a prática da poda no manejo do componente arbóreo depende do conhecimento sobre os benefícios relacionados à sustentabilidade dos sistemas; A madeira obtida do resíduo da poda do componente arbóreo se estabelece como mais um produto dos sistemas agroflorestais familiares de Tomé-Açu. O terceiro capítulo contempla a percepção agroflorestal dos agricultores. Os resultados apontaram que: Os agricultores familiares e empresariais possuem percepções distintas sobre os SAF; O caráter ambiental é fortemente considerado pelos agricultores familiares enquanto que os agricultores empresariais baseiam-se em observações econômicas na construção da percepção agroflorestal; A sensibilização de agricultores para a adoção dos SAF depende da ampliação do aceso à informação, da valorização dos produtos, e de investimentos em insumos e mudas.  

A Parkia pendula (Willd.) Benth. ex Walp. é uma espécie florestal que quando submetida a condições edafoclimáticas adversas, desenvolve mecanismos fisiológicos e bioquímicos de tolerância ao estresse hídrico. Desta forma, o objetivo desse trabalho foi ampliar os conhecimentos sobre os mecanismos de respostas do Visgueiro, mediante o estudo de aspectos ecofisiológicos e bioquímicos visando uma melhor compreensão das estratégias desenvolvidas por esta espécie em processo de deficiência hídrica. O experimento foi conduzido em casa de vegetação da Universidade Federal Rural da Amazônia (UFRA), sendo as análises fisiológicas e Bioquímicas realizadas no Laboratório de Estudos da Biodiversidade em Plantas Superiores (EBPS), ambos pertencentes ao Instituto de Ciências Agrárias (ICA), campus Belém, Pará. As mudas utilizadas foram compradas na AIMEX, com aproximadamente sete meses de idade, medindo 10-15 cm de altura, sendo acondicionadas em vasos plásticos com capacidade para 7,5L. O substrato usado foi terra preta argilosa. O delineamento experimental utilizado foi inteiramente casualizado em parcelas subdivididas 2 x 3 (duas condições hídricas: controle e deficiência hídrica, e três tempos de avaliação), com 5 repetições, totalizando 30 unidades experimentais, sendo que cada unidade experimental foi composta de uma planta/vaso. Os resultados experimentais foram submetidos à análise de variância (ANOVA), e quando verificado diferenças significativas as médias foram comparadas pelo teste de Tukey ao nível de 5% de significância. O conteúdo relativo de água nas plantas submetidas à deficiência hídrica reduziu significativamente ao longo do tempo, quando comparados às plantas submetidas ao fornecimento de água. A suspensão da irrigação por 10 dias foi suficiente para alterar o metabolismo das plantas de Visgueiro, aumentando as concentrações de carboidratos solúveis totais e as concentrações de sacarose nas folhas e nas raízes, concentrações de amônio livre, glicina e prolina, como nas concentrações dos aminoácidos solúveis totais e as enzimas antioxidantes nas partes avaliadas reduzindo suas medidas de crescimento, as concentrações de proteínas solúveis totais, nitrato e a atividade da redutase do nitrato nos tecidos foliares e nas raízes. Contudo, pode-se observar que a espécie em estudo mesmo apresentando a redução no seu conteúdo relativo de água manteve ativo seu metabolismo do carbono. Os indicadores do Metabolismo do Nitrogênio e o sistema oxidativo analisados foram eficientes para avaliar o estado metabólico das plantas de Visgueiro submetidas à deficiência hídrica. 

É muito provável que as ondas de calor irão ocorrer com mais frequência e durar mais tempo, eventos de precipitação se tornem mais intensos e frequentes e que em certas regiões da Amazônia ocorreram diminuição na disponibilidade hídrica, que por sua vez afetarão diretamente a duração e intensidade do alagamento e da estação de seca. O experimento foi conduzido em casa de vegetação do laboratório de Estudos da Biodiversidade de Plantas Superiores EBPS/UFRA, o delineamento experimental utilizado foi inteiramente casualizado em esquema de parcela subdividida (três tempos: zero, cinco e dez dias de suspensão hídrica, e duas condições hídricas: controle e deficiência hídrica), com 4 repetições, totalizando 24 unidades experimentais (uma planta/vaso). Sendo aplicada a ANOVA nos resultados e quando ocorreu diferença significativa, as médias foram comparadas pelo teste t adotando-se o nível de 5 % de probabilidade através do pacote estatístico (Assistat 7.7 beta, 2015). O CRA, as trocas gasosas e as variáveis de crescimento foram fortemente afetados pelos fatores relacionados à disponibilidade hídrica do solo principalmente quando as condições de deficiência avançaram. Refletindo no metabolismo do carbono e do nitrogênio, com redução nas concentrações de nitrato, amido e redutase do nitrato; aumento nas concentrações de amônio, prolina, sacarose, aminoácidos e carboidratos. Bem como também comprometeu a atividade antioxidante das plantas, visto que estas foram capazes de acionar rapidamente o sistema de defesa, tanto enzimático (SOD, APX e CAT), quanto não enzimático (carotenoides), sendo que este último não apresentou incremento na sua atividade. No entanto, não conseguindo reduzir os danos oxidativos acarretando na morte das mesmas.

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O estudo da dinâmica florestal é um instrumento de observação do reestabelecimento de um ecossistema ao longo do tempo e envolve, dentro da comunidade, diversos processos entre seus componentes vegetacionais, tais como a sucessão, mortalidade, recrutamento, crescimento, regeneração e relações entre diferentes populações influenciadas pelo meio ambiente. Este estudo buscou gerar informações sobre a dinâmica da regeneração natural de um grupo de espécies da família Lauraceae, que são de grande importância econômica e ecológica e com isso determinar a melhor maneira para aproveitar os recursos das florestas, buscando reduzir os danos ao meio ambiente e garantir maior rentabilidade. Para a coleta de dados foi realizado um monitoramento em 200 ha na área experimental da Embrapa no município de Moju, após uma exploração florestal. Foram selecionadas nove clareiras causadas pela exploração e instaladas faixas de 10 m x 50 m, começando na bordadura da clareira para dentro da floresta, nas direções Norte, Sul, Leste e Oeste. Cada faixa foi dividida em parcelas quadradas de 10 m x 10 m numeradas de 1 a 5, onde foram medidos os indivíduos com DAP ≥ 10 cm, dentro das parcelas 1, 3 e 5 foram instaladas subparcelas de 2 m x 2 m, abordando os indivíduos com altura total (Ht) ≥ 10 cm e Diâmetro a Altura do Peito (DAP) < 5 cm, considerados como regeneração natural. No centro da clareira foi instalada também uma subparcela de 2 m de lado para efeito de comparação. As medições ocorreram de março de 1998 terminando a primeira etapa em 2001; em 2007 foram realizadas mais duas medições, e uma última medição no ano de 2010, totalizando dezesseis medições em um período de 12 anos de observação, para avaliar a taxa de regeneração natural (%), ingresso (%) e mortalidade (%) das espécies. Os resultados para a TR (%), I (%) e M (%), mostraram que houve diminuição da densidade na população das espécies, nas quatro direções cardeais, as taxas de regeneração foram positivas no início do estudo e negativas no fim, exceto no centro das clareiras em que as taxas foram nulas a partir do segundo período, indicando em determinado momento equilíbrio entre ingresso e mortalidade. Em relação aos tamanhos de clareiras as taxas de regeneração se mostraram positivas em clareiras pequenas e médias e negativas ou nulas nas clareiras grandes, comportamento esse de espécies tipicamente intolerantes à sombra, pois dificilmente sobrevivem a falta de luz solar. Dentre as espécies estudadas, Nectandra amazonicum Ness e Ocotea guianensis Aubl. apresentaram melhor desenvolvimento em clareiras nos períodos iniciais do estudo, porém com maior mortalidade ao final do período de 12 anos, o que comprova a intolerância à sombra das espécies, pois as mesmas necessitam totalmente de luz para sobreviver.

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Este estudo teve como objetivo verificar o efeito da manipulação de nutrientes com a remoção da serapilheira sobre as concentrações de fósforo e potássio no aporte de serapilheira, em uma floresta secundária. O experimento foi realizado na Estação de Piscicultura de Água Doce- UFRA, no município de Castanhal-Pa, nordeste paraense, em um ecossistema de floresta sucessional de 23 anos. As coletas de serapilheira foram realizadas a cada quinze dias no período de janeiro a dezembro de 2008, utilizando coletores medindo 1m² em dois sistemas de manejo, a saber: 1) Controle (testemunha); 2) Remoção de serapilheira; esta se deu com a retirada da camada de serapilheira com o auxílio de um ancinho. Foi utilizado o delineamento em blocos casualizados no esquema fatorial 2 x 12. Os dados foram submetidos a teste de normalidade e em seguida analisados segundo ANOVA no programa estatístico Statistic. O efeito da sazonalidade da precipitação influenciou a deposição de serapilheira, com maior deposição durante o período menos chuvoso (julho), apresentando valores total de deposição na faixa de 6,65 Mg.ha^-1ano^-1 (controle) e 6,24 Mg.ha^-1ano^-1 (remoção). As concentrações de K foram menores no período chuvoso, com concentração média de 1,07 g/kg e 0,93 g/kg para os tratamentos controle e remoção, respectivamente. Para P os valores médios foram para o tratamento controle de 0,49 g/kg e para a remoção de 0,39 g/kg. A manipulação de nutrientes pela remoção da serapilheira, não influenciou a concentração de P e K pelo aporte de serapilheira.

Esse artigo tem por objetivo apresentar a principal forma de uso do solo pelos agricultores
familiares da Amazônia, bem como as alternativas de produção baseadas nos princípios
agroecológicos através de levantamento bibliográfico. A agricultura familiar na Amazônia é
apontada com a principal causadora do desmatamento na região por praticar o corte e a
queima da vegetação como principal forma de preparo de áreas para o cultivo. Essa prática
consiste em derrubar e queimar a vegetação para a implantação de cultivos agrícolas por dois
ou três anos, posteriormente a área é deixada em pousio para que ocorra o estabelecimento da
vegetação secundária e o solo retome sua capacidade produtiva. No entanto, com o
crescimento populacional e a necessidade de geração de alimentos essa prática tornou-se
insustentável por apresentar períodos de pousio cada vez mais curtos. Com isso, o
desenvolvimento de novas formas de cultivo sustentável tornou-se necessário.

Na Amazônia, a prática de derruba e queima da vegetação secundária para o preparo da área e aumentar a disponibilidade dos nutrientes ofertadas às culturas agrícolas, causa prejuízos a qualidade do solo, aumenta a emissão de gases poluentes e eleva a quantidade de áreas desmatadas. Em virtude da necessidade de reduzir os efeitos negativos oriundos dessa pratica foi sugerida a utilização da técnica de corte-e-trituração da capoeira (sem queima) e a implantação de Sistemas Agroflorestais, pois, são alternativas sustentáveis e reduzem o aumento da degradação ambiental. Este estudo foi realizado com o objetivo de demonstrar a importância da substituição de técnicas degradadoras por alternativas que ofereçam benefícios ao ambiente e aos agricultores familiares, mostrar a necessidade de diversificação das áreas de cultivo para manter o sistema sustentável e de denotar a essencialidade do levantamento das informações de fertilidade do solo através da análise de seus atributos químicos. No primeiro capítulo realizou-se uma pesquisa bibliográfica sobre a agricultura familiar, sistemas agroflorestais e atributos químicos do solo na Amazônia, para que assim seja possível analisar a importância dos agricultores familiares e sua relação com a implantação das técnicas alternativas de substituição a degradação. O segundo capítulo foi realizado no município de Marapanim, no estado do Pará, onde se avaliou os atributos químicos de fertilidade do solo em áreas cujo preparo foi com a técnica de corte-e-trituração e corte-e-queima da vegetação secundaria, as quais se contrastaram com uma área de capoeira com 30 anos de idade. A análise desses atributos foi feita através da coleta de amostras de solo, as quais foram analisadas de acordo com a metodologia utilizada pelo laboratório da Embrapa. A determinação dos atributos químicos do solo mostrou que a queima da vegetação propiciou aumento do pH, fósforo, cálcio e magnésio além de outros atributos, concluindo-se que a queimada proporcionou benefícios a fertilidade do solo de forma imediata. O capítulo 3 comparou os atributos químicos de fertilidade do solo em um sistema agroflorestal de 14 anos, um sistema agroflorestal de 1 ano e uma área de capoeira de 20 anos de idade, em área do município de Tomé-açu. A análise desses atributos foi feita através da coleta de amostras de solo, as quais foram analisadas de acordo com a metodologia utilizada pelo laboratório da Embrapa. A disponibilidade de nutrientes foi semelhante para as três áreas podendo-se concluir que os Sistemas Agroflorestais oferecem benefícios a fertilidade do solo tal qual uma floresta natural é capaz de oferecer.

O Brasil possui a segunda maior cobertura florestal do mundo, tendo o estado do Pará como um dos principais desse meio ambiental do país, em função dos serviços ambientais prestados a comunidade florestal. O presente trabalho buscou espacializar e analisar a nível mesorregional as áreas reflorestadas no estado do Pará, através de Licenças de Atividade Rural (LAR’s) obtidas por meio do site da Secretaria de Estado de Meio Ambiente e Sustentabilidade (SEMAS) compreendidas no período de 2008 a 2015. De acordo com os dados obtidos observou-se que as mesorregiões sudeste e nordeste apresentaram maior área de plantio para reflorestamento, sudeste também apresentou um alto número de processos protocolados em comparação às demais mesorregiões, tal crescimento pode ser mais perceptível nos anos de 2009 e 2010. 

O objetivo da pesquisa foi avaliar os efeitos da deficiência hídrica e do alagamento nos comportamentos fisiológicos e metabólicos do carbono e nitrogênio em plantas jovens de pau- de-balsa (Ochroma pyramidale), para isso foi conduzido um experimento em casa-de-vegetação da Universidade Federal Rural da Amazônia, Campus de Capitão/Poço, em julho de 2013. Utilizado o delineamento experimental inteiramente casualizado em esquema fatorial (3x4) em três condições hídricas: controle (irrigado), deficiência hídrica e alagamento, em quatro períodos (0, 4, 8 e 12 dias), com 5 repetições, totalizando 60 unidades experimentais. As variáveis fisiológicas avaliadas foram: Potencial Hídrico de Antemanhã, (Ψ_am); Condutância Estomática, (gs); e Transpiração, (E), as variáveis bioquímicas (Ácido Abscísico, Teores de Amido, Carboidratos Solúveis Totais, Sacarose,  Nitrato, Atividade da Redutase do Nitrato, Teores de Amônio Livre, Atividade da Glutamina Sintetase, Aminoácidos Solúveis Totais, Proteínas Solúveis Totais, Teores de Prolina e Glicina Betaína). O potencial hídrico antemanhã e as trocas gasosas decresceram significativamente ao longo do tempo nas plantas sob estresse hídrico, enquanto que as concentrações de Ácido Abscísico aumentaram nas plantas sob deficiência hídrica e alagamento. Já os teores de amido decresceram tanto nas plantas sob deficiência hídrica quanto nas em alagamento representando uma queda de 2,06 e 8 vezes respectivamente, quando comparado as plantas controle. O conteúdo de carboidratos solúveis totais e sacarose aumentaram nas plantas sob deficiência hídrica ao longo do tempo representando 1,65 e 1,54 vezes, quando comparado as plantas controle. O mesmo não ocorrendo com as plantas sob alagamento para as mesmas variáveis onde decresceram em torno de 2  e  6,93 vezes respectivamente. Os teores de nitrato, atividade da redutase do nitrato e glutamina sintetase reduziu significativamente nas plantas sob estresse hídrico ao longo do tempo, fato não observado nas concentrações de amônio livre que aumentou significativamente. As concentrações de aminoácidos, glicina betaína e prolina aumentaram nas plantas sob deficiência hídrica, entretanto na condição de alagamento essas variáveis decresceram consideravelmente a partir do 4º dia. Os teores de proteínas decresceram nas plantas sob deficiência hídrica e alagamento. Contudo, a pesquisa concluiu que as condições sob deficiência hídrica e alagamento por um período de doze dias foi o suficiente para alterar os processos fisiológicos e metabólicos das plantas de pau-de-balsa.  Entretanto, os resultados apresentados mostram uma maior sensibilidade das plantas sob alagamento quando comparado as plantas sob deficiência hídrica.

ainda em finalização

Classificadas como pioneiras no processo de sucessão florestal, as espécies do gênero Cecropia, pertencente à família Urticaceae, popularmente conhecidas como embaúba, têm como características ocupar rapidamente clareiras abertas naturalmente ou pela exploração florestal e formações secundárias. Parâmetros como o rápido crescimento, a ampla distribuição espacial e elevada abundância, associados às propriedades tecnológicas da madeira favoráveis para utilização na indústria, colocam o gênero em destaque diante da necessidade de introduzir novas espécies no mercado, visando compor colheitas futuras, considerando a autoecologia das espécies. Assim, o objetivo deste trabalho foi determinar o potencial silvicultural do gênero através da fitossociologia das espécies, dinâmica populacional e potencial madeireiro com base na distribuição diamétrica e volume pós-colheita. O experimento está localizado no município de Belterra, Pará, onde em 1979 foi realizada a exploração florestal. Em 1981 foram instaladas ao acaso 36 parcelas permanentes, sendo inventariados todos os indivíduos com DAP ≥ 5 cm. As medições foram realizadas em nove cronossequêcias em 33 anos pós-colheita. Parcelas testemunhas também foram instaladas e avaliadas. Os resultados mostram que foram identificadas na área, duas espécies do gênero, Cecropia distachya e Cecropia sciadophylla. Foi observado um aumento considerável na densidade, atingindo um pico máximo quatro anos após a exploração (82,3 árvores/ha) e posterior decréscimo até atingir, após 28 anos, valores similares à área não explorada. Em termos de dominância e volume, o acréscimo foi significativo aos 13 anos pós-colheita (1,7 m²/ha; 14,3 m³/ha), com uma produtividade máxima levemente superior em volume aos 18 anos (15,6 m³/ha), tendo a partir deste momento um rápido declínio.  A distribuição diamétrica mostrou que, durante o peridodo de máxima produção em volume, grande parte dos indivíduos estão nas classes intermediárias e que nenhum indivíduo atingiu 50 cm de DAP, considerado o diametro mínimo de corte na atual legislação. Foram registradas altas taxas de ingresso logo após a colheita chegando a 83,1% ano^-1 para Cecropia distachya. O ingresso foi maior que a mortalidade até o terceiro periodo avaliado, tendo a partir desse momento um balanço negativo para as espécies até o final do monitoramento. O maior crescimento foi observado para C. sciadophylla com 3,77 cm ano^-1 no primeiro período do monitoramento. Conclui-se que as espécies do gênero Cecropia apresentam potencial para produção de madeira após exploração florestal em menor tempo do que o ciclo de corte estabelecido na legislação, que é de 35 anos, o que sugere um manejo diferenciado por apresentarem dinâmica de curta duração.

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O conhecimento das necessidades nutricionais para produção de mudas é um recurso fundamental para o sucesso de qualquer programa de plantio de espécies florestais. O nitrogênio é o nutriente encontrado em maiores concentrações nos vegetais superiores e vem se mostrando limitante ao crescimento e produção florestal, porém, existem poucos estudos sobre a demanda deste nutriente. Deste modo, o presente trabalho objetivou avaliar os efeitos da aplicação de fontes e doses de nitrogênio no crescimento, trocas gasosas e resposta bioquímica em mudas de Tachigali vulgaris L. G. Silva & H. C. Lima. O experimento foi conduzido em casa de vegetação do Instituto de Ciências Agrárias da Universidade Federal Rural da Amazônia, em Belém, Pará, no período de abril a julho de 2015. As mudas foram cultivadas em vasos contendo 3 dm³ de solo. As fontes de nitrogênio testadas foram ureia [(NH₂)₂CO], sulfato de amônio [(NH₄)₂SO₄], nitrato de amônio (NH₄NO₃) e nitrato de cálcio [Ca(NO₃)₂], em cinco doses de 0, 75, 150, 225 e 300 mg dm^-³, aplicadas na forma de solução em quatro porções, aos 25, 50, 75 e 100 dias após o transplantio. A unidade experimental foi constituída por um vaso e o delineamento experimental em blocos casualizados (DBC), em esquema fatorial (4 x 5), correspondendo a 4 fontes e 5 doses, com quatro repetições, totalizando 80 vasos. As características morfológicas e suas relações, as trocas gasosas e as respostas bioquímicas foram analisadas ao término do experimento. A maioria das características de crescimento e trocas gasosas das mudas de T. vulgaris foram influenciadas positivamente pela adubação nitrogenada. Quanto às fontes de N utilizadas, as maiores médias de altura, diâmetro do coleto e massa de matéria seca de raiz foram obtidos com o nitrato de amônio e nitrato de cálcio. A dose máxima empregada causou efeito negativo sobre os parâmetros morfológicos, prejudicando a qualidade das mudas, para todas as fontes. O menor crescimento das plantas cultivadas exclusivamente N-NH₄⁺ pode estar associado à menor atividade fotossintética dessas plantas, em virtude da ação negativa desse íon sobre a condutância estomática, o que refletiu no menor crescimento e produção de biomassa. A redução na concentração de proteínas com o nitrato de amônio e nitrato de cálcio, pode estar relacionada a formação de espécies reativas de oxigênio (EROs), pelo excesso de NO₃^-, provocando danos aos fotossistemas pela inibição da síntese de proteínas. O acúmulo de aminoácidos na folha e raiz foi influenciado positivamente pela aplicação de N, ocorrendo a máxima acumulação com a fonte nitrato de amônio, em doses próximas de 225 mg dm^-3. O crescimento de mudas de T. vulgaris é afetado pela presença de ambas as formas de nitrogênio mineral (N-NO₃^- e N-NH₄⁺) na adubação, sendo que a combinação das duas formas de N apresentou a maior média da atividade da enzima nitrato redutase e maior incremento do teor de clorofila total, em doses próximas de 225 mg dm^-3.

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A exploração de minérios é de grande importância para economia mundial e do Brasil. Nesse âmbito o minério de bauxita se destaca por estar presente em grandes reservas brasileiras, e contribuir para que o País ocupe importante posição nesse cenário. Todavia a exploração mineral implica em sérios danos ao meio ambiente, principalmente relacionados a alterações na paisagem e no solo, que são praticamente irreversíveis. Nesse contexto, o presente estudo avaliou o potencial da serapilheira na emergência e crescimento de plântulas na área de exploração de bauxita. Para o levantamento florístico foram instaladas 12 unidades amostrais de 20 x 50 m (1000 m²), e no delineamento experimental foram instaladas 24 amostras de 5x2 m (240 m²), localizadas no Platô Miltônia 3 da empresa Mineração Paragominas S.A, Paragominas, PA. No levantamento florístico do fragmento de floresta foram levantados os indivíduos arbóreos DAP≤10, e obtidos dados de nome vulgar, DAP e altura total, após foi feita a determinação científica das espécies. Foi averiguada também a suficiência amostral através da curva espécie área.  No delineamento experimental foi aplicado blocos ao acaso com cinco tratamentos: O primeiro tratamento T1(constituído de topsoil), o segundo T2 (Topsoil com a serapilheira), T3 (Topsoil mais a serapilheira adubada com NPK), e T4 (Topsoil com serapilheira coberta por sombrite). Após a coleta para caracterizar as análises florística e estrutural do fragmento florestal e no delineamento, as espécies foram classificadas em grupos ecológicos e formas de vida. No levantamento florístico foram registrados 320 indivíduos classificados em 29 famílias, 44 gêneros e 46 espécies definidas e 4 morfoespécies, o equivalente a 41 espécies/ha, sendo 90% das espécies árvores, 8% arbustos, e 2% palmeiras, 30 % secundárias tardias, 30% pioneiras e 28 %secundárias iniciais, sendo a família Fabaceae a mais rica e Ingá Alba a espécie que apresentou o maior número de indivíduos na área. No delineamento experimental, aos três meses de avaliação foram registrados em todos os tratamentos, 656 indivíduos, distribuídos em 20 famílias, 22 gêneros e 27 espécies.  Aos seis meses de avaliação foram registrados 228 indivíduos, distribuídos em 18 famílias, 18 gêneros e 20 espécies. O grupo das pioneiras aos três e seis meses de avaliação, apresentou respectivamente 71% e 73 % das espécies registradas. Nos primeiros três meses 41% das espécies eram arbustos, 32% árvores, 23% ervas e 4% lianas. Nas avaliações feitas aos seis meses 41% eram árvores, 33% arbustos, 11% ervas, 13% e 15%. Aos três meses de avaliação registou-se 2,73 ind.m², enquanto que aos seis meses registrou-se 0,95 ind.m². O T4 foi o tratamento que registrou o maior número de indivíduos regenerantes (3,95 ind.m²) 

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A avaliação da qualidade das águas superficiais e subterrâneas da microbacia do rio Capitão Pocinho, localizada no município de Capitão Poço/PA, foi realizado considerando as seguintes variáveis: pH, condutividade elétrica, alcalinidade, fluoreto, cloreto, brometo, nitrito, nitrato, fosfato-p, fosfato-total, sulfato, bicarbonato, sódio, potássio, cálcio, magnésio e amônio. Este rio situa-se entre as fazendas CITROPAR I e II, o qual sofre elevada possibilidade de erosão e fluxos de agroquímicos no deflúvio. Os dados empregados neste estudo foram coletados bimestralmente de janeiro a novembro de 2009, em dez estações de coleta de água superficial e dezesseis estações de coleta de água subterrânea (poços de monitoramento). A técnica da análise fatorial com extração de fatores por análise da componente principal (AF/ACP) foi aplicada com o objetivo de selecionar as variáveis mais significativas para a variabilidade total dos dados. Para uma melhor abordagem do efeito da precipitação nas concentrações dos parâmetros estudados, os dados referentes às águas superficiais e subterrâneas foram subdivididos em dois períodos, sendo: período chuvoso correspondente aos meses de janeiro, março e maio de 2009, e período seco, correspondente aos meses de julho, setembro e novembro de 2009. Para as águas superficiais, no período chuvoso, a técnica AF/ACP proporcionou a redução de 16 parâmetros em 5, sendo Cl-, Alc, CE, Na+e Mg2+, os quais explicaram 86,29% da variância total dos dados, sendo caracterizada como componente mineral, relacionada ao intemperismo geológico da região. Para as águas superficiais, no período seco, a técnica proporcionou a redução de 16 parâmetros em 4, Cl-, CE, Alc e NO2-, os quais explicaram 66,30% da variância total dos dados, sendo caracterizada como componente orgânica, relacionada a contaminação por despejo de esgoto doméstico. Para as águas subterrâneas, no período chuvoso, a técnica proporcionou a redução de 16 parâmetros em 5, sendo NO2-, NO3-, PO4-3, Ca2+ e Alc, os quais explicaram 89,86% da variância total dos dados primários. A primeira componente (Alc e NO3-), contendo 45,31% da variância total, foi caracterizada como componente temporal, sendo relacionada com o tempo de permanência na água. A segunda componente (NO2-, Ca2+ e PO4-3), contendo 44,58% da variância total, foi caracterizada como componente mineral, relacionada à utilização de defensivos e fertilizantes agrícolas. Para as águas subterrâneas, no período seco, a técnica proporcionou a redução de 16 parâmetros em 5, sendo Alc, CE, Ca2+, K+e HCO3-, os quais explicaram 71,76% da variância total dos dados, sendo caracterizada como componente geológica, relacionada ao intemperismo geológico da região. A segunda etapa do estudo consistiu na elaboração do índice de qualidade de água (IQA) a partir dos parâmetros selecionados na análise fatorial. O IQA apresentou uma boa adequação para avaliação da qualidade das águas superficiais e subterrâneas da microbacia do rio Capitão Pocinho. De um modo geral, as águas superficiais e subterrâneas apresentaram qualidade em nível ruim no ano de 2009 para consumo da comunidade residente na Vila Capitão Pocinho, bem como, pelas fazendas da empresa CITROPAR.

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Avaliou-se o efeito da exploração de madeiras na estrutura e dinâmica de algumas espécies de Sapotaceae em uma Floresta Ombrófila Densa, no município de Moju, estado do Pará (02º 08’ 14’’ e 02º 12’ 26” S; e 48º 47’ 34” e 48º 48’ 14” W). De uma área de floresta de 1.050 ha, foram selecionados 200 ha para exploração seletiva de madeiras (intensidade de 23 m³ ha^-1) em 1997. Foram alocadas 22 parcelas permanentes de 0,5 ha, totalizando 11 ha amostrais, onde foram medidas todas as árvores com DAP ≥ 10 cm, nos anos de 1995, 1998 e 2010. Os parâmetros avaliados foram: Densidade (Da), Dominância (Do), Índice de Valor de Cobertura (IVC), distribuição diamétrica, mortalidade (M), ingresso (I) e incremento periódico anual (IPA). No período de 1995 a 2010 Sapotaceae apresentou uma redução significativa de 7,7% na densidade (p= 0,0147) e aumento na dominância em 1,4%, sendo considerado igual à antes da exploração (p= 0,7851). Neste mesmo período observou-se redução da densidade e dominância para Pouteria laurifolia (Gomes) Radlk. (66,7% e 50,6%), Pouteria macrocarpa (Mart.) D. Dietr. (25% e 29,4%), Micropholis acutangula (Ducke) Eyma (20% e 11%), Manilkara huberi (Ducke) A. Chev. (16,4% e 17,7%) e Manilkara paraensis (Huber) Standl. (12,5% e 31,4%). Cinco espécies apresentaram balanço negativo comparando as taxas de ingresso e mortalidade: P. laurifolia (I= 0,0% ano ^-1 e M= 7,2% ano ^-1), P. macrocarpa (I= 1,2% ano^-1 e M= 3,1% ano ^-1), M. paraensis (I= 2,3% ano ^-1 e M= 3,1% ano ^-1), M. acutangula (I= 0,9% ano ^-1 e M= 2,4% ano ^-1) e M. huberi (I= 0,5% ano ^-1 e M= 0,9% ano ^-1). Treze anos após a exploração Sapotaceae apresentou redução na densidade. A espécie com maior valor comercial, M. huberi, não mostrou recuperação nesse parâmetro, porém houve ingresso de três novas espécies  na população de Sapotaceae estudada. 

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