Benefits of grassland livestock production to aquatic ecosystems.

Abstract

Grass-based livestock systems are both criticised and valued for their influences on biodiversity, climate change and water quality. This paper compares impacts of grassland livestock and arable systems on stream ecology in the Eye Brook catchment, Leicestershire, based on two Defra-funded research projects. Suspended sediment and phosphorus concentrations in water were significantly lower in a pasture sub-catchment than in an arable sub-catchment. Aquatic macro-invertebrate and diatom diversity was higher, and diatom biomass was lower in the grassland sub-catchment than in the arable one. Pasture 'buffered' the stream from diffuse pollution during rainfall. Grassland ditches flowed more continuously and supported higher macro-invertebrate diversity than did ditches associated with drained arable fields. These results suggest that, relative to arable systems, pasture managed for sheep and beef production is associated with higher chemical and ecological status of watercourses and that it provides ecosystem services associated with flood control and nutrient cycling.