Human pressure drives biodiversity–multifunctionality relationships in neotropical wetlands
Abstract Many studies have shown that biodiversity regulates a multitude of ecological functions that are needed to maintain the productivity and efficiency of a variety of types of ecosystems. What is not known is how human activities may change the ‘multifunctionality’ of ecosystems as they have both direct impacts on ecosystems and indirect effects on the biodiversity that serves to control ecological functions. Using a database on hundreds of lakes spanning four large neotropical wetlands, we demonstrate that species richness and the functional diversity of fish, macrophytes, microcrustaceans, rotifers, protists, and phytoplankton are positively associated with ecosystem multifunctionality, including nutrient concentrations, standing biomass, and ecosystem metabolism. However, we also found that the relationship between biodiversity and multifunctionality is weakened by human pressures and that part of this impact occurs through changes in biodiversity. Our results suggest that human activities may break down the biological controls needed to maintain the suite of ecosystem functions that sustain wetlands.