Twin pressures of intensification and abandonment negatively impact grassland biodiversity in the burren

A major component of Earth's dry surface is human-managed grassland, making the relationships among management actions, grassland biodiversity and ecosystem services of great ecological interest. Common management practices-fertiliser addition and large herbivore grazing-influence grassland diversity and productivity. The Nutrient Network, a distributed research effort, investigates these relationships across grasslands at a global scale. The Burren contains internationally important grasslands with high biodiversity maintained by traditional farming practices. Using six years of data from the Slieve Carran Nutrient Network site, we examine the effects of fertilisation and large mammal herbivory on plant diversity and biomass in a unique Irish context. We find 1) fertiliser addition and herbivore exclusion both decrease diversity and increase biomass, and 2) independent of our experimental treatments, biomass increased throughout the study. Our findings on treatment effects align with results from the wider Nutrient Network experiment. Additionally, the increase in biomass during the study is consistent with an abandonment effect. This research shows twin pressures of agricultural intensification and abandonment of traditional management practises detrimentally impact Burren grassland biodiversity.This is relevant to future management decisions, as biodiversity provides key ecosystem services in the Burren, including supporting tourism that contributes to local economies.