Banca de DEFESA: WILSON FILGUEIRA BATISTA JÚNIOR

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : WILSON FILGUEIRA BATISTA JÚNIOR
DATE: 26/03/2021
TIME: 09:00
LOCAL: Videoconferência Google Meet
TITLE:

: INTRA-SPECIFIC COMPETITION AFFECTS the ONTOGENETIC STRUCTURE of Attalea speciosa Mart. ex Spreng. IN EAST AMAZON PASTURES

KEY WORDS:

Babassu, Height, Number of Leaves, Petiole, Population Structure, Spatial Distribution, Soils

PAGES: 68
BIG AREA: Ciências Biológicas
AREA: Botânica
SUMMARY:

Attalea speciosa Mart. ex Spreng. (babassu) has been considered invasive (superdominant) after the environmental changes caused by the change in land use, but it is also an important palm in Brazilian extractives activities. These contradictory importance appear as an unusual set of challenges for science, management, politics and society, especially since it is a native species. In this context, this study aims to analyze the ontogenetic structure of the species in pastures, in order to test the following null hypotheses: (1) the density, the spatial distribution and the intraspecific competition suffered are similar between the ontogenetic stages; (2) the edaphic characteristics do not influence the density and spatial distribution of any of the ontogenetic stages; (3) the morphometric variables are not influenced by the ontogenetic stages, density, spatial distribution, edaphic variables and intraspecific competition. For that, 27 plots were randomly installed in the pastures of the Benfica Settlement Project, municipality of Itupiranga (Pará); in these plots, babassu individuals were mapped from geographic coordinates (x, y) and categorized into six ontogenetic stages, in which the total height, number of leaves and petiole length were measured. Analyzes of 16 edaphic variables were performed in a soil sample composed of four replicates, collected in each plot. The ontogenetic structure was analyzed from the density distribution, type of spatial distribution and morphometric characteristics. The spatial distribution and the bilateral competition index were calculated with the K-Ripley function and Hegyi index, respectively. Linear models were used to test the effect of competition (fixed effect), stages and spatial distribution (random effect) on the morphometric variables. 2,174 individuals were found; the population structure presents a classic negative exponential curve, but with the absence of individuals in stage 4. From the smallest to the largest stage, there was a decrease in both density and in the competition suffered and in the degree of aggregation of individuals. The leave number, petiole length and total height respond to the competition, however the answer depends on the stage and the spatial distribution. The highest leave number, petiole length and total height were found in the aggregated individuals, which may be a mechanism used to compensate a reduction in the absorption of solar radiation. The edaphic characteristics of the plots showed no significant relationship with these behaviors. Although babassu is favored in pastures, competition still exists, especially in the early aggregated stages. Thus, even in pastures the population has density-dependent control mechanisms, which suggests that the increase in the density of the initial stages in the pastures may be linked to nondensity-dependent factors, such as pasture management and fragmentation of the natural habitat.

BANKING MEMBERS:
Externo à Instituição - FLAVIO MÃES SANTOS - UNICAMP
Externo à Instituição - AFONSO FIGUEIREDO FILHO
Presidente - 1312312 - IZILDINHA DE SOUZA MIRANDA
Externo à Instituição - LEANDRO VALLE FERREIRA - MPEG
Externo à Instituição - MARCELO TABARELLI - UFPE