Abstract
This dataset contains biomass and precipitation data from a subset of sites (n=35) in the Nutrient Network coordinated fertilization experiment (NutNet; nutnet.org; Borer et al. 2014). These data were used for the analyses published in: Slette et al. 2026 "Nutrient enrichment increases grassland biomass sensitivity to interannual precipitation variation" in Global Change Biology.
Following a standardized protocol, nutrients (N, P, and K) were added to fertilization treatment plots annually. Control plots were unfertilized. Aboveground plant biomass was harvested annually from all plots at the time of peak biomass. Aerial surveys of plant cover by species were also performed annually in all plots. All sites included in this dataset have at least 6 years of data from both Control and NPK plots. The earliest sites records are from 2008, and the most recent are from 2023. Growing season precipitation data for each site were retrieved from either a gridded precipitation dataset or from a precipitation gauge near the site. More details in "Methods" and in Slette et al. 2026.
We used these data to test if nutrient addition alters the response of plant biomass to year-to-year variation in growing season precipitation, and whether the effects of nutrient addition vary with factors such as plant community composition. Nutrient addition increased biomass, rain-use efficiency, and the sensitivity of biomass to interannual variation in precipitation, but did not change the strength of the interannual precipitation-biomass correlation. These results suggest that grassland ecosystem functioning may become more variable from year to year as nutrient enrichment increases biomass sensitivity to precipitation and precipitation becomes more variable.
Reference: Borer, E.T., Harpole, W.S., Adler, P.B., Lind, E.M., Orrock, J.L., Seabloom, E.W., & Smith, M.D. (2014). Finding generality in ecology: A model for globally distributed experiments. Methods in Ecology and Evolution, 5, 65–73. https://doi.org/10.1111/2041-210X.12125