The goal of this study was evaluate changes in richness, diversity and the contribution of successional groups to tree species composition of a Valley Forest in the Chapada dos Guimarães National Park, Mato Grosso State, Brazil, over 14 years (1996 - 2010) from five surveys intervals (1996-1999, 1999-2003, 2003-2006, 2006-2010, 1996-2010). All tree species (dbh > 5 cm) were sampled systematically in a total of 18 plots (600 m²) established into three transects in valley. Whereas the changes in species richness were positive, but barely noticeable when analyzed in shorter intervals, the range considering the whole interval (1996-2010) was significant (comparisons of Poisson counts) with a net increase of 20 species. Despite the observed species turnover, maintaining evenness seems to have given the absence of significant changes in diversity over the period studied (Hutcheson t test). The contribution of successional groups to the tree species composition of tree community also did not show significant changes during 14 years of monitoring. These results suggest that tree community dynamics of a Valley forest is accelerated in tree species composition, although maintaining temporal diversity and distribution of species among successional groups.
communities; dynamic; Semideciduous forest; Gallery Forest; Chapada dos Guimarães National Park
