Edaphic invertebrate diversity around the reservoir of a small hydroelectric power station in southern Brazil

Abstract

To meet the growing demand for electricity, considerable effort has been invested in the construction of hydroelectric stations in Brazil. The environmental impacts caused by these projects have been significant, especially on fauna. To evaluate the biodiversity of edaphic invertebrates, a study was performed in an area surrounding a small hydroelectric station of Flor do Sertão, in the Santa Catarina state, Brazil, covering three distances (5, 15 and 30 meters) from the flooded region of the reservoir. From December 2010 to June 2011, surveys of edaphic invertebrates were performed by pitfall traps. The invertebrates collected at each distance were compared and their diversity was calculated through Hill numbers. The dynamics were analyzed through the Shannon index exponential and the inverse Simpson index, and correlated climatic variables to invertebrate diversity. A total of 14,074 specimens were collected from 24 taxonomic groups (Order). The analyses according to size and sample coverage showed few differences in invertebrate diversity between the distances. Values of richness and diversity of common groups are similar for all distances. There is a trend decrease in diversity dynamics for common individuals, with a strong decline in June. The diversity of edaphic invertebrates exhibited high correlation with temperature and no correlation with pluviosity.