Historical and recent land use affects ecosystem functions in subtropical grasslands in Brazil

Land-use changes such as conversion of semi-natural grasslands to agriculture, silviculture, or high-intensity pastures affect biodiversity and ecosystem functions and services. However, which ecosystem functions are affected when highly diverse grasslands are converted remains largely unknown. As a model system, we studied 80 grasslands in Rio Grande do Sul, southern Brazil, comprising exceptionally diverse permanent grasslands that are traditionally managed with burning of accumulated biomass and moderate grazing, and four additional grassland types with different present or historical management: permanent grasslands with reduced or increased current management intensity and secondary grasslands after past agricultural or silvicultural use. We measured ten ecosystem functions covering all major below-and aboveground ecosystem components and the processes that link them, using the novel rapid ecosystem function assessment approach. Ecosystem functions included primary and secondary production, and species interactions, that is, herbivory, pollination, predation, seed dispersal, and decomposition. Ecosystem functions differed significantly among grassland types, most distinctly between permanent and secondary grasslands. Historical land-use changes to agriculture and silviculture led to altered ecosystem functions even after reconversion to grassland, including lower primary and secondary production, lower decomposition, lower seed dispersal capabilities, and higher invertebrate herbivory. Current management practices explained additional variation in some ecosystem functions, including strong positive effects of intensified management on secondary production. Other ecosystem functions such as pollination and predation were not affected. The findings suggest that conversion of grasslands to more intensive land-use types has long-lasting consequences for some ecosystem functions, with effects persisting even many years after reconversion, resulting in changes in the ecosystem services provided by these grasslands.