Banca de DEFESA: JOYCE ANANDA PAIXÃO DUARTE

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JOYCE ANANDA PAIXÃO DUARTE
DATE: 26/05/2021
TIME: 14:30
LOCAL: Sala de reuniões do google
TITLE:

ECOLOGICAL BEHAVIOR OF Euxylophora paraensis Huber IN A FOREST FRAGMENT IN THE MUNICIPALITY OF PARAGOMINAS -PARÁ STATE

KEY WORDS:

Forest fragmention; climatic changes;natural regeneration; phenology; Amazônia

PAGES: 77
BIG AREA: Ciências Agrárias
AREA: Recursos Florestais e Engenharia Florestal
SUMMARY:

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.

BANKING MEMBERS:
Presidente - 142.060.489-91 - JOSE NATALINO MACEDO SILVA - Oxford
Interna - 2410727 - LINA BUFALINO
Interno - 741.673.590-49 - GUSTAVO SCHWARTZ - EMBRAPA
Interno - 3160854 - DIVINO VICENTE SILVERIO
Interno - 4143218 - JOAO OLEGARIO PEREIRA DE CARVALHO
Externa à Instituição - IMA CÉLIA GUIMARÃES VIEIRA - MPEG
Externo à Instituição - GIL VIEIRA - INPA