Species loss in global grasslands: 2017-2019

These data support an examination of the effect of nutrient supply and herbivore density on species diversity. We analyzed the effects of experimental manipulations of nutrient supply (nitrogen, phosphorus, potassium and micronutrients) and herbivore presence on species richness across a range of spatial scales (0.01 – 75 m2). Data are included from 30 sites in 10 countries which are part of the Nutrient Network (NutNet, http://www.nutnet.org) distributed experiment. Data tables are arranged by treatment: from control plots at 30 sites and from two experiments at subsets of the sites: the Multiple-nutrient experiment (21 sites) and the Consumer-nutrient experiment (16 sites). Sampling over 3 years (2017-2019). From the paper abstract (Seabloom et al, "Species Loss Due to Nutrient Addition Increases with Spatial Scale in Global Grasslands"): Effects of human-induced changes to nutrient supplies and herbivore density on species diversity vary with spatial scale, because coexistence mechanisms are scale dependent. This scale dependence may alter the shape of the species-area relationship (SAR), which can be described by changes in species richness (S) as a power function of the sample area (A): S=cAz, where c and z are constants. We analyzed the effects of experimental manipulations of nutrient supply and herbivore density on species richness across a range of scales (0.01 – 75 m2) at 30 grasslands in 10 countries. We found that nutrient addition reduced the number of species that could coexist locally, indicated by the SAR intercepts (log c), but did not affect the SAR slopes (z). As a result, proportional species loss due to nutrient enrichment was largely unchanged across sampling scales, while total species loss increased over threefold across our range of sampling scales.