Solo, topografia, mortalidade e recrutamento de árvores na floresta tropical decidual

Abstract

reSumo -Muitos são os fatores que podem aumentar ou diminuir a intensidade da dinâmica nas florestas tropicais. Com certeza o clima pode ser considerado fator determinante para as taxas de mortalidade e recrutamento de árvores nestas florestas. Entretanto, a topografia e o tipo de solo também são fatores que sinergicamente influenciam a distribuição e composição das espécies arbóreas, consequentemente alterando as taxas de dinâmica, pois algumas espécies são mais sensíveis às mudanças no ambiente. O objetivo deste trabalho foi avaliar a dinâmica de uma floresta tropical decidual situada sobre um gradiente edáfico e topográfico, juntamente com a interpretação das variações pluviométricas registradas no intervalo do estudo. Os resultados revelam que a floresta apresenta uma dinâmica menos intensa, com taxas de mortalidade e recrutamento abaixo do esperado paras as floresta tropicais deciduais sob forte sazonalidade, assemelhandose as taxas das florestas pluviais tropicais. A relação do grupo de espécies arbóreas com o tipo de solo e topografia e uma possível estabilidade pluviométrica podem interferir e direcionar os fatores que determinam os resultados das taxas de mortalidade e recrutamento em estudos de dinâmica nas florestas tropicais. palavraS-chave: Rotatividade; FloResta estacional; Unidade de conseRvação. Soil, topography, mortality and recruitment in SeaSonal deciduouS tropical foreStSabStract -There are many factors that can increase or decrease the dynamics intensity in tropical forests. Certainly, the climate can be considered a determining factor for tree mortality and recruitment rates in these forests. However, topography and soil are factors that synergistically influence the distribution and the composition of tree species, consequently altering the dynamic rates, since some tree species are more sensitive to changes in the environment. The objective of this study was to evaluate the dynamics in deciduous tropical forest located on an edaphic and topographic gradient, as well as to interpret the rainfall variations observed during the research. The results show that the forest has a less intense dynamics, with mortality rates and recruitment below the rates one would expect in a seasonal deciduous tropical forests, resembling the rates of a tropical rainforest. The relationship between a group of tree species and soil and topography type and a possible rainfall stability can interfere and direct the factors that determine the results of the mortality and recruitment rates in dynamic studies of tropical forests.

Damming water influences the structure, composition and functions of adjacent savannahs

“…However, species from moist soils were also observed, such as Alibertia edulis and Protium heptaphyllum. Even small changes in the water regime can induce changes in vegetation structure (Gusson, Vale, Araújo and Schiavini, 2012;Vale et al, 2013a) and the dam clearly favors water-associated species, such as those observed in other dams (Vale et al, 2013a). Some recent studies have shown that richness can increase over time, due to the establishment of moisture-associated associated species in sectors near the lakeshore created by the Groups 1(white), and 2 (small squares) consist of cerrado species, G3 (light gray), G4 (dark gray), and G5 (black) consist of forest species.…”