Can trees buffer the impact of climate change on pasture production and digestibility of Mediterranean dehesas?
2022
Hidalgo-Galvez, Maria Dolores | Barkaoui, Karim | Volaire, Florence | Matías, Luis | Cambrollé, Jesús | Fernández-Rebollo, Pilar | Carbonero, Maria Dolores | Pérez-Ramos, Ignacio Manuel | Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS) ; Consejo Superior de Investigaciones Cientificas [España] = Spanish National Research Council [Spain] (CSIC) | Universidad de Sevilla = University of Seville | Agrosystèmes Biodiversifiés (UMR ABSys) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre International de Hautes Etudes Agronomiques Méditerranéennes - Institut Agronomique Méditerranéen de Montpellier (CIHEAM-IAMM) ; Centre International de Hautes Études Agronomiques Méditerranéennes (CIHEAM)-Centre International de Hautes Études Agronomiques Méditerranéennes (CIHEAM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro) | Département Performances des systèmes de production et de transformation tropicaux (Cirad-PERSYST) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | Centre d’Ecologie Fonctionnelle et Evolutive (CEFE) ; Université Paul-Valéry - Montpellier 3 (UPVM)-École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [Occitanie])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Montpellier (UM) | Département agronomie et sciences de l'environnement pour les agroécosystèmes (AgroEcoSystem) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Universidad de Córdoba = University of Córdoba [Córdoba] | IFAPA Centro Alameda del Obispo ; Instituto Andaluz de Investigación y Formación Agraria y Pesquera (IFAPA) | This work was supported by the MICINN project DECAFUN (CGL2015-70123-R) and the Association of Hispanic-French Friendship (AVENIR-DIALOGO). M. D. Hidalgo-Galvez was funded by a 'Formacion de Personal Investigador (FPI)' contract (BES-2016-078248) . | Experimental Station of Zaidin (INAN-EEZ-CSIC, Granada)Analysis - Service of the Institute of Natural Resources and Agrobiology of Seville (IRNAS-CSIC, Seville)
International audience
显示更多 [+] 显示较少 [-]英语. Highlights:• Habitat type had a significant influence on biomass productivity and digestibility.• Experimental warming increased by 33% biomass productivity, but reduced its quality.• Reduced rainfall decreased by 13% biomass productivity.• Changes in plant functional composition affected productivity and digestibility.• Tree canopy played a buffering role in mitigating the impact of climate change.Abstract:Sustainability and functioning of silvopastoral ecosystems are being threatened by the forecasted warmer and drier environments in the Mediterranean region. Scattered trees of these ecosystems could potentially mitigate the impact of climate change on herbaceous plant community but this issue has not yet tested experimentally. We carried out a field manipulative experiment of increased temperature (+2-3 ?) using Open Top Chambers and rainfall reduction (30%) through rain-exclusion shelters to evaluate how net primary productivity and digestibility respond to climate change over three consecutive years, and to test whether scattered trees could buffer the effects of higher aridity in Mediterranean dehesas. First, we observed that herbaceous communities located beneath tree canopy were less productive (351 g/m(2)) than in open grassland (493 g/m2) but had a higher digestibility (44% and 41%, respectively), likely promoted by tree shade and the higher soil fertility of this habitat. Second, both habitats responded similarly to climate change in terms of net primary productivity, with a 33% increase under warming and a 13% decrease under reduced rainfall. In contrast, biomass digestibility decreased under increased temperatures (-7.5%), since warming enhanced the fiber and lignin content and decreased the crude protein content of aerial biomass. This warming-induced effect on biomass digestibility only occurred in open grasslands, suggesting a buffering role of trees in mitigating the impact of climate change. Third, warming did not only affect these ecosystem processes in a direct way but also indirectly via changes in plant functional composition. Our findings suggest that climate change will alter both the quantity and quality of pasture production, with expected warmer conditions increasing net primary productivity but at the expense of reducing digestibility. This negative effect of warming on digestibility might be mitigated by scattered trees, highlighting the importance of implementing strategies and suitable management to control tree density in these ecosystems.
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