IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Physiognomic changes in response to herbivory increase carbon allocation to roots in a temperate grassland of central Argentina
Autor/es:
CINGOLANI, ANA MARÍA; PESTONI, SOFÍA; SARQUIS, AGUSTÍN; PÉREZ-HARGUINDEGUY, NATALIA; CINGOLANI, ANA MARÍA; PESTONI, SOFÍA; SARQUIS, AGUSTÍN; PÉREZ-HARGUINDEGUY, NATALIA
Revista:
PLANT ECOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2019
ISSN:
1385-0237
Resumen:
In most temperate grasslands, cattle graz- ing can promote physiognomic changes on plant communities, as well as changes in species growth patterns. Through these changes in vegetation, cattle grazing can generate changes in allocation to total, fine and coarse root biomass, which can further affect ecosystem processes. The objective of this work was to evaluate differences in root biomass, in the propor- tions of fine and coarse root biomass and in root C:N ratio across physiognomies from 0 to 30 cm. We selected plots of grazing lawns (associated to rela- tively high stocking rates), and plots of thin and thick tussock grasslands (associated to relatively low stock- ing rates) within the Pampa de Achala system in central Argentina. We found that total, coarse, and fine root biomass were highest in grazing lawns, interme- diate in thin tussock grasslands, and lowest in thick tussock grasslands. Thick tussock grasslands showed the highest relative proportion of fine roots while root C:N ratio did not vary among physiognomies. Higher root biomass in lawns was probably caused by the dominance of species that allocate more biomass to roots than to shoots, as well as by the complementarity of soil resource extraction and by compensatory root growth in response to herbivory. In addition, and contrary to what was expected based on their above-ground attributes, thick tussock grasslands presented higher proportion of fine roots, which suggests a more acquisitive resource use strategy. However, root C:N from thick tussock grasslands did not differ from other physiognomies which might indicate there are not clear differences in below-ground resource use strate- gies. Our results show that grassland root biomass in this study system can increase in patches associated to higher cattle grazing due to changes in plant compo- sition and physiognomy, while changes in root quality seem to be uncoupled from the above-ground traits.p, li { white-space: pre-wrap; }