Efeito do fogo na ecologia funcional e filogenética em uma vegetação de canga na Serra dos Carajás.

Abstract

Cangas are ecosystems of high biodiversity, high rates of plant endemism and widely endangered (eg mining activity, urbanization, disturbances and others). Thus, diversity measures that incorporate information on the distribution, composition, and structure of communities are especially important in adverse environments. Our objective was to describe the effects of an accidental buming in an area of canga vegetation in the Serra dos Carajás to help understand diversity on the premise of the mies of assembly. For this, we conducted sampling in the Serra Norte, specifically in the NI plateau, demarcating 10 2 x 2 m plots in environments that suffered bumings and 10 plots in an area with no evidence of burning. In these plots ali species of phanerogams were sampled. The species were classified according to the phenophases (seedling, presence and absence of leaf, flowering and fruiting), life cycle (annual or perennial) syndromes of pollination and dispersion. For each campaign and treatment were calculated measures of taxonomic diversity (Shannon and Simpson), phylogenetic (PD) and functional (RaoQ) of the communities. In addition, the phylogenetic and functional structure of the communities were analyzed through the indexes (MPD, MNTD, NRI and NTI) using the software Phylocom 4.2 and program R. The results indicate that the phylogenetic structure does not differ from that expected at random, confirming fire action as the structurer of the communities, while in relation to the functional structure there was a predominance of grouping, reinforcing the importance of the fire action as a possible environmental filter of the community. Finally, in addition to the structural analyzes, we show results associated with phenological events and the non-action of fire in them. Therefore, studies on mies of assembly in the canga contributed to the understanding of the maintenance, diversity and functioning of plant communities.