Herbivory and eutrophication mediate grassland plant nutrient responses across a global climatic gradient.

Journal Article (Journal Article)

Plant stoichiometry, the relative concentration of elements, is a key regulator of ecosystem functioning and is also being altered by human activities. In this paper we sought to understand the global drivers of plant stoichiometry and compare the relative contribution of climatic vs. anthropogenic effects. We addressed this goal by measuring plant elemental (C, N, P and K) responses to eutrophication and vertebrate herbivore exclusion at eighteen sites on six continents. Across sites, climate and atmospheric N deposition emerged as strong predictors of plot-level tissue nutrients, mediated by biomass and plant chemistry. Within sites, fertilization increased total plant nutrient pools, but results were contingent on soil fertility and the proportion of grass biomass relative to other functional types. Total plant nutrient pools diverged strongly in response to herbivore exclusion when fertilized; responses were largest in ungrazed plots at low rainfall, whereas herbivore grazing dampened the plant community nutrient responses to fertilization. Our study highlights (1) the importance of climate in determining plant nutrient concentrations mediated through effects on plant biomass, (2) that eutrophication affects grassland nutrient pools via both soil and atmospheric pathways and (3) that interactions among soils, herbivores and eutrophication drive plant nutrient responses at small scales, especially at water-limited sites.

Full Text

Duke Authors

Cited Authors

  • Anderson, TM; Griffith, DM; Grace, JB; Lind, EM; Adler, PB; Biederman, LA; Blumenthal, DM; Daleo, P; Firn, J; Hagenah, N; Harpole, WS; MacDougall, AS; McCulley, RL; Prober, SM; Risch, AC; Sankaran, M; Schütz, M; Seabloom, EW; Stevens, CJ; Sullivan, LL; Wragg, PD; Borer, ET

Published Date

  • April 2018

Published In

Volume / Issue

  • 99 / 4

Start / End Page

  • 822 - 831

PubMed ID

  • 29603733

Pubmed Central ID

  • 29603733

International Standard Serial Number (ISSN)

  • 0012-9658

Digital Object Identifier (DOI)

  • 10.1002/ecy.2175


  • eng

Conference Location

  • United States