Taxocenose de Collembola (Arthropoda, Hexapoda) e seu papel ecológico no processo de decomposição, em áreas preservadas e degradadas de Mata Atlântica

Abstract

The Atlantic Forest bears high biodiversity and is being degraded by human activities for use and occupation of soil. The edaphic fauna is potentially vulnerable, and Collembola respond very quickly to environmental perturbations, considered efficient bioindicators of soil quality. Therefore, this study evaluated the Collembola community in an Atlantic Forest comparing different vegetation types in preserved areas and sugar cane fields, and analyzing how the group influences the decomposition process in these sites. Soil samples were collected and decomposition experiments conducted in the dry and rainy season in three regions of distinct phytophisionomic features, of three fragments of Atlantic Forest called SEMA I, II and III, and surroundings, at Biological Reserve Guaribas. In each region of the three fragments was established one sample point with five sub-samples, distributed linearly and equidistant, amounting 45 sub-samples of soil and decomposition bags by season. It was observed high diversity and homogeneity in the distribution of species of springtails in forest regions. Suga cane fields and savanna tree were more heterogeneous. The β-diversity was highest among the preserved regions of the SEMA I, and lowest in the SEMA III, showing up among the most conserved area. The springtails abundance of Reserve Guaribas was low, possibly due to the organic composition of soil or long periods of drought. The species composition of Collembola and also environmental factors were distinct for each vegetation type, the group may be used as a tool of segregation of environments within forest ecosystems. Collembola was not correlated with decomposition rates in the surface layer of litter in both seasons, being linked to later stages where there is action of microbes specialized. The maximum understanding of the functioning of this group and intrinsic processes that maintain a forest ecosystem, provide more tools for management strategies and conservation for the Atlantic Forest.