The effect of hierarchical environmental structure and catchment-scale land cover on fish assemblage composition in streams from the Brazilian south-eastern rain forest

Author(s)

Almeida, Rodrigo da Silva ; Averna Valente, Roberta de Oliveira ; Cetra, Mauricio

• Document type: Journal article
• Source: Hydrobiologia; v. 849, n. 20, p. 13-pg., 2022-02-23.

Abstract

The effect of land use and land cover (LULC) on the structure of stream fish assemblages involves factors on multiple scales. By adopting a hierarchical conceptual model, we assessed the importance of river basin physical characteristics and spatial factors on LULC across three spatial scales: catchment, riparian, and reach. Additionally, we verified the direct importance of the river basin physical characteristics, spatial factors, and local environment, and the indirect effect of LULC on fish assemblages. We sampled fish assemblages at 30 sites with different LULC from the Upper Paranapanema River basin. At the catchment scale, the average slope was positively correlated with forest cover and negatively correlated with agriculture and forestry. The river basin with forest cover had a more consolidated substrate and low quantity of silt. Altitude, shade, and spatial structure played an essential role in data variation at the sampling sites. Distance from the river mouth was negatively correlated with consolidated substrate and bank stability. Three groups of fish species were correlated with different sets of explanatory variables. Our work indicated that the hierarchical conceptual model identified environmental factors that affected the fish assemblages. This study highlights the importance of catchment-scale management on the conservation of stream fishes. (AU)

• FAPESP's process: 13/24737-2 - Local and regional effects on the fish communities structure in streams of the Upper Rio Paranapanema (SP)
• Grantee: Mauricio Cetra
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants