Artículo
Plant quality and primary productivity modulate plant biomass responses to the joint effects of grazing and fertilization in a mesic grassland
Fecha de publicación:
05/2021
Editorial:
Wiley Blackwell Publishing, Inc
Revista:
Applied Vegetation Science
ISSN:
1402-2001
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Questions: Human activities are increasing the density of domestic grazers and global nutrient loads, modifying the main determinants of vegetation community dynamics. Grazing (top-down control) and nutrient availability (bottom-up control) may interactively modify plant biomass, which is particularly important in grasslands devoted to livestock production. Here, we aim to understand the interactive effects of grazing and fertilization on grassland plant biomass. We hypothesized that the joint effects of nutrient addition and domestic grazing on above-ground plant biomass are not additive, but they modify each other through changes in ground-level light, leaf nutritional quality, above-ground net primary productivity (ANPP), and below-ground plant allocation. Location: Flooding Pampa (Buenos Aires, Argentina). Methods: We carried out a factorial experiment of grazing exclusion and fertilization with nitrogen, phosphorus, and potassium + micronutrients during several years in a mesic grassland devoted to livestock production. Results: After four years, grazing reduced live above-ground plant biomass by 52%, and when combined with fertilization this reduction was 70%. Nutrient addition in the grazed grassland increased ANPP and leaf nutrient concentration. These changes in turn intensified grazing pressure and cattle’s plant consumption. By contrast, fertilization did not produce any significant effect on plant biomass or ANPP inside the exclosures, where ground-level light was low. A structural equation model revealed that the increase in ANPP fostered above-ground and reduced below-ground plant biomass. Conclusions: This is the first study conducted in the Pampas grasslands that evaluated the effect of cattle grazing and fertilization on plant communities under field conditions over several years. Grazing and nutrient addition synergistically controlled grassland plant biomass, as the reduction in above-ground biomass by cattle consumption was greater in fertilized plots. Our results provided empirical evidence that leaf nitrogen and ANPP modulated plant biomass dynamics in grasslands devoted to livestock production in the context of increased nutrient loads in terrestrial ecosystems.
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(IFEVA)
Articulos de INST.D/INV.FISIOLOGICAS Y ECO.VINCULADAS A L/AGRIC
Articulos de INST.D/INV.FISIOLOGICAS Y ECO.VINCULADAS A L/AGRIC
Citación
Campana, María Sofía; Yahdjian, María Laura; Plant quality and primary productivity modulate plant biomass responses to the joint effects of grazing and fertilization in a mesic grassland; Wiley Blackwell Publishing, Inc; Applied Vegetation Science; 24; 2; 5-2021; 1-10
Compartir
Altmétricas