气候变化领域集成服务门户

Landscape and site-scale data analyses aid the interpretation of biological data and thereby help us develop more cost-effective natural resource management strategies. Our study focused on environmental influences on stream assemblages and we evaluated how three classes of environmental variables (geophysical landscape, land use and cover, and site habitat), influence fish and macroinvertebrate assemblage richness in the Brazilian Cerrado biome. We analyzed our data through use of multiple linear regression (MLR) models using the three classes of predictor variables alone and in combination. The four MLR models explained dissimilar amounts of benthic macroinvertebrate taxa richness (geophysical landscape R (2) a parts per thousand 35 %, land use and cover R (2) a parts per thousand 28 %, site habitat R (2) a parts per thousand 36 %, and combined R (2) a parts per thousand 51 %). For fish assemblages, geophysical landscape, land use and cover, site habitat, and combined models explained R (2) a parts per thousand 28 %, R (2) a parts per thousand 10 %, R (2) a parts per thousand 31 %, and R (2) a parts per thousand 47 % of the variability in fish species richness, respectively. We conclude that (1) environmental variables differed in the degree to which they explain assemblage richness, (2) the amounts of variance in assemblage richness explained by geophysical landscape and site habitat were similar, (3) the variables explained more variability in macroinvertebrate taxa richness than in fish species richness, and (4) all three classes of environmental variables studied were useful for explaining assemblage richness in Cerrado headwater streams. These results help us to understand the drivers of assemblage patterns at regional scales in tropical areas.