Assessment of riparian landscape structure and stream network connectivity influence in stream fishes diversity in catchments of Corumbataí river basin, SP.

Abstract

Fishes present high species diversity and most freshwater species are found in the Neotropical region. However, the diversity has been threatened due to lotic ecosystems degradation, mainly by the habitat modification, including the removal of riparian forests. The riparian forests act as a connection element between terrestrial and aquatic environments and they play important role in the functioning of lotic ecosystems and aquatic communities’ structure. For a long time the riparian forests had been widely altered and converted into agricultural use, contributing to the process of riparian zone fragmentation. That landscape change causes modifications of lotic ecosystem and aquatic communities’ structure, including freshwater fishes. They have complex lifecycles that depend of structural complexity of lotic ecosystems, mainly the connectivity between headwaters reaches and downstream reaches. In this study, we will try to analyze the stream fish’s diversity in function of riparian zone structure and stream network connectivity. It will be calculated fish communities diversity index and landscape metrics of riparian zones. ANOVA tests will be used to analyze differences in the fish communities’ diversity index in function of riparian forest cover composition and configuration and stream network connectivity. Next, a multiple regression analysis will be used to identity most important landscape variables that influence fish’s communities. This project is considerate important to increase the knowledgement about human impacts in streams and fishes in the Neotropical region and also to support recuperation, management and conservation projects related to these environments and the aquatic biodiversity.