Aridity and Overgrazing Have Convergent Effects on Ecosystem Structure and Functioning in Patagonian Rangelands

Authors
Gaitán, Juan José; Bran, Donaldo Eduardo; Oliva, Gabriel Esteban; Aguiar, Martin Roberto; Buono, Gustavo Gabriel; Ferrante, Daniela; Nakamatsu, Viviana; Ciari, Georgina; Salomone, Jorge M.; Massara, Virginia; García Martínez, Guillermo Carlos; Maestre, Fernando T.
Publication Year
2018
Language
English
Format
article
Status
Published version
Description
Over 65% of drylands are used for grazing of managed livestock. Understanding what drives grazing effects on the structure and functioning of rangelands is critical for achieving their sustainability. We studied a network of 239 sites across Patagonian rangelands (Argentina), which constitute one of the world's largest rangeland area. We aimed to (i) evaluate how aridity and grazing affect ecosystem structure and functioning and (ii) test the usefulness of the landscape function analysis (LFA) indices (stability, infiltration and nutrient cycling) as surrogates of soil functioning. Aridity decreased species richness and the cover of palatable grasses but increased the cover of palatable shrubs. Grazing pressure negatively impacted the cover of palatable grasses and species richness but did not affect the cover of shrubs. Aridity had direct and indirect negative relationships with the LFA indices. Grazing pressure had no direct effects on the LFA indices but had an indirect negative effect on them by affecting vegetation structure. The LFA indices were positively and negatively correlated with soil organic carbon and sand contents, respectively, suggesting that these indices are useful proxies of soil functional processes in Patagonian rangelands. Our findings indicate that aridity and overgrazing have convergent effects on the structure and functioning of ecosystems, as both promoted reductions in species richness, the cover of palatable grasses and soil functioning. Rangeland management activities should aim to enhance species richness and the cover of palatable grasses, as these actions could contribute to offset adverse effects of ongoing increases in aridity on drylands. Copyright © 2017 John Wiley & Sons, Ltd.
Fil: Gaitán, Juan José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Suelos; Argentina
Fil: Bran, Donaldo Eduardo. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Oliva, Gabriel Esteban. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Aguiar, Martin Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. ; Argentina
Fil: Buono, Gustavo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Ferrante, Daniela. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Nakamatsu, Viviana. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Ciari, Georgina. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Salomone, Jorge M.. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Massara, Virginia. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: García Martínez, Guillermo Carlos. Instituto Nacional de Tecnología Agropecuaria; Argentina
Fil: Maestre, Fernando T.. Universidad Rey Juan Carlos; España
Subject
DESERTIFICATION
DRYLANDS
GRASS-SHRUB BALANCE
LANDSCAPE FUNCTION ANALYSIS
SPECIES RICHNESS
Otras Ciencias Biológicas
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/51495