Nutrient availability controls the impact of mammalian herbivores on soil carbon and nitrogen pools in grasslands

• Autores: Sitters, Judith; Wubs, E. R. Jasper; Bakker, Elisabeth S.; Crowther, Thomas W.; Adler, Peter; Bagchi, Sumanta; Bakker, Jonathan; Biederman, Lori; Borer, Elizabeth; Cleland, Elsa E.; Eisenhauer, Nico; Firn, Jennifer; Gherardi, Laureano; Hagenah, Nicole; Hautier, Yann; Hobbie, Sarah E.; Knops, Johannes M. H.; MacDougall, Andrew S.; McCulley, Rebecca L.; Moore, Joslin L.; Mortensen, Brent; Peri, Pablo Luis; Prober, Suzanne M.; Riggs, Charlotte; Risch, Anita C.; Schütz, Martin; Seabloom, Eric; Siebert, Julia; Stevens, Carly J.; Veen, G. F.
• Año de publicación: 2020
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: CARBON SEQUESTRATION; EXCLOSURE; FERTILIZATION; GLOBAL CHANGE; GRAZING; HERBIVORY; NUTRIENT DYNAMICS; NUTRIENT ENRICHMENT; NUTRIENT NETWORK (NUTNET); SOIL MICROORGANISMS
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Grasslands are subject to considerable alteration due to human activities globally, including widespread changes in populations and composition of large mammalian herbivores and elevated supply of nutrients. Grassland soils remain important reservoirs of carbon (C) and nitrogen (N). Herbivores may affect both C and N pools and these changes likely interact with increases in soil nutrient availability. Given the scale of grassland soil fluxes, such changes can have striking consequences for atmospheric C concentrations and the climate. Here, we use the Nutrient Network experiment to examine the responses of soil C and N pools to mammalian herbivore exclusion across 22 grasslands, under ambient and elevated nutrient availabilities (fertilized with NPK + micronutrients). We show that the impact of herbivore exclusion on soil C and N pools depends on fertilization. Under ambient nutrient conditions, we observed no effect of herbivore exclusion, but under elevated nutrient supply, pools are smaller upon herbivore exclusion. The highest mean soil C and N pools were found in grazed and fertilized plots. The decrease in soil C and N upon herbivore exclusion in combination with fertilization correlated with a decrease in aboveground plant biomass and microbial activity, indicating a reduced storage of organic matter and microbial residues as soil C and N. The response of soil C and N pools to herbivore exclusion was contingent on temperature – herbivores likely cause losses of C and N in colder sites and increases in warmer sites. Additionally, grasslands that contain mammalian herbivores have the potential to sequester more N under increased temperature variability and nutrient enrichment than ungrazed grasslands. Our study highlights the importance of conserving mammalian herbivore populations in grasslands worldwide. We need to incorporate local-scale herbivory, and its interaction with nutrient enrichment and climate, within global-scale models to better predict land–atmosphere interactions under future climate change.
Fil: Sitters, Judith. Vrije Unviversiteit Brussel; Bélgica
Fil: Wubs, E. R. Jasper. Netherlands Institute of Ecology; Países Bajos
Fil: Bakker, Elisabeth S.. Netherlands Institute of Ecology; Países Bajos
Fil: Crowther, Thomas W.. Netherlands Institute of Ecology; Países Bajos
Fil: Adler, Peter. State University of Utah; Estados Unidos
Fil: Bagchi, Sumanta. Indian Institute of Science; India
Fil: Bakker, Jonathan. University of Washington; Estados Unidos
Fil: Biederman, Lori. University of Iowa; Estados Unidos
Fil: Borer, Elizabeth. University of Minnesota; Estados Unidos
Fil: Cleland, Elsa E.. University of California; Estados Unidos
Fil: Eisenhauer, Nico. Universitat Leipzig; Alemania
Fil: Firn, Jennifer. University of Queensland; Australia
Fil: Gherardi, Laureano. Arizona State University; Estados Unidos
Fil: Hagenah, Nicole. University of Pretoria; Sudáfrica
Fil: Hautier, Yann. University of Utrecht; Países Bajos
Fil: Hobbie, Sarah E.. University of Minnesota; Estados Unidos
Fil: Knops, Johannes M. H.. Xi’an Jiaotong Liverpool University; China
Fil: MacDougall, Andrew S.. University of Guelph; Canadá
Fil: McCulley, Rebecca L.. University of Kentucky; Estados Unidos
Fil: Moore, Joslin L.. Monash University; Australia
Fil: Mortensen, Brent. Benedictine College; Estados Unidos
Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Sur. Estación Experimental Agropecuaria Santa Cruz. Agencia de Extensión Rural Río Gallegos; Argentina
Fil: Prober, Suzanne M.. No especifíca;
Fil: Riggs, Charlotte. University of Minnesota; Estados Unidos
Fil: Risch, Anita C.. Swiss Federal Institute for Forest, Snow and Landscape Research; Suiza
Fil: Schütz, Martin. Swiss Federal Institute for Forest, Snow and Landscape Research; Suiza
Fil: Seabloom, Eric. University of Minnesota; Estados Unidos
Fil: Siebert, Julia. Universitat Leipzig; Alemania
Fil: Stevens, Carly J.. Lancaster University; Reino Unido
Fil: Veen, G. F.. Netherlands Institute of Ecology; Países Bajos