Data from: Leaf nutrients, not specific leaf area, are consistent indicators of elevated nutrient inputs

Leaf traits are frequently measured in ecology to provide a 'common currency' for predicting how anthropogenic pressures impact ecosystem function. Here, we test whether leaf traits consistently respond to experimental treatments across 27 globally distributed grassland sites across 4 continents. We find that specific leaf area (leaf area per unit mass)—a commonly measured morphological trait inferring shifts between plant growth strategies—did not respond to up to four years of soil nutrient additions. Leaf nitrogen, phosphorus and potassium concentrations increased in response to the addition of each respective soil nutrient. We found few significant changes in leaf traits when vertebrate herbivores were excluded in the short-term. Leaf nitrogen and potassium concentrations were positively correlated with species turnover, suggesting that interspecific trait variation was a significant predictor of leaf nitrogen and potassium, but not of leaf phosphorus concentration. Climatic conditions and pretreatment soil nutrient levels also accounted for significant amounts of variation in the leaf traits measured. Overall, we find that leaf morphological traits, such as specific leaf area, are not appropriate indicators of plant response to anthropogenic perturbations in grasslands.NutNet_foliar_dataThis data includes leaf traits that were collected from the three to five most dominant species in each plot including specific leaf area, and leaf N, P and K concentrations. This file also include site level climatic and edaphic conditions: mean annual temperature, temperature seasonality, mean annual precipitation, precipitation seasonality, pre-treatment soil nitrogen by mass %, pre-treatment soil phosphorus by mass (ppm) and pre-treatment soil potassium by mass (ppm). A sheet is included in the data file explains each column and is called metadata