Local nutrient addition drives plant biodiversity losses but not biotic homogenization in global grasslands

Abstract

AbstractNutrient enrichment typically causes local plant biodiversity decline due to losses of rare species and species with traits ill-suited for high nutrient levels. These local-scale losses can cause biotic homogenization at larger scales if they outpace losses of widespread species. This is a common, but untested, expectation. Using a standardized experiment across 72 grasslands on six continents, we found similar magnitudes of losses of spatially restricted and widespread species, causing proportional species loss at local and larger scales and no biotic homogenization, even up to 14 years of treatment. Such patterns of diversity changes held consistent across plant origins and life form variations. Thus, nutrient enrichment poses threats to all functional groups including dominant widespread species that are often critical for ecosystem functions and services.One-Sentence SummaryNo evidence for biotic homogenization following fertilization in grasslands worldwide