Revealing the pathways by which agricultural land‐use affects stream fish communities in South Brazilian grasslands

• DOI: 10.1111/fwb.12825
• Publication Date: 2016-09-01T06:53:14Z
• Authors: Renato B. Dala‐Corte; Xingli Giam; Julian D. Olden; Fernando G. Becker; Taís de F. Guimarães; Adriano S. Melo
• Keywords: Siltation

Summary Understanding mechanisms by which agricultural practices affect freshwater ecosystems helps to inform land‐use policies and management strategies aimed at mitigating effects of agriculture on biodiversity. Land‐use activities in the catchment, riparian local scales likely influence stream fish communities via multiple pathways, for instance, modifying instream habitat. We investigated driving taxonomic richness functional diversity South Brazilian grasslands testing a theoretical path model we specified priori relationships predicting how land use affects habitat communities. Agricultural adjacent streams (i.e. impact streambank) catchment‐scale cropland area were positively related macrophyte cover negatively associated with coarse particulate organic matter ( CPOM , i.e. woody debris leaf litter). Local also increased substrate siltation homogenisation. Riparian vegetation upstream buffer ameliorated condition dampening proliferation providing . Fish species both revealing pathways influence. However, decreased only siltation, response sample sites. showed replacement benthic lithophilic larger number morphologically similar macrophyte‐associated nektonic fish. Our study indicates that zones is critical maintaining taxonomically functionally diverse due their strong Protection recovery from change can mitigate grasslands.