Dois hotspots tropicais, caminhos diferentes para a energia em riachos

Abstract

Local factors, such as characteristics of riparian vegetation and stream typology, may affect in the structure and composition of benthic macroinvertebrate assemblages. To better understand the effects of biomes on lotic ecosystems, we evaluated whether Atlantic Forest (AF) and Neotropical Savanna (NS) biomes showed distinct patterns on the structuring of (i) benthic macroinvertebrate assemblages and (ii) shredder functional feeding group. We predicted that (i) richness, biomass, instant secondary production, eco-exergy and specific eco-exergy are higher for benthic macroinvertebrate assemblages in streams in the AF than in the NS and (ii) length, biomass, instant secondary production, eco exergy and specific eco-exergy are higher for shredders in the AF. We used number of taxa richness, density, biomass, instant secondary production, eco-exergy and specific eco-exergy as community structuring metrics. We found that benthic macroinvertebrate assemblage composition and taxa richness were significantly different between the two biomes, with the AF biome being the richest, but there were no differences in terms of density, biomass, instant secondary production, eco-exergy and specific eco-exergy. For AF shredders, the size, density, biomass, secondary production and eco-exergy were higher than for NS. These differences were attributed to the quality of leaf litter, which was generally higher in AF than in NS streams. This indicates that the intrinsic characteristics of the AF and NS biomes can act as structuring factors for benthic macroinvertebrate assemblages, influencing the structure and functioning of tropical lotic ecosystems