Agritrop
Home

Does water shortage generate water stress? An ecohydrological approach across Mediterranean plant communities

Barkaoui Karim, Navas Marie-Laure, Roumet Catherine, Cruz Pablo, Volaire Florence. 2017. Does water shortage generate water stress? An ecohydrological approach across Mediterranean plant communities. Functional Ecology, 31 (6) : pp. 1325-1335.

Journal article ; Article de revue à facteur d'impact
[img] Version Online first - Anglais
Access restricted to CIRAD agents
Use under authorization by the author or CIRAD.
Barkaoui_et_al-2017-Functional_Ecology.pdf

Télécharger (614kB) | Request a copy
[img] Published version - Anglais
Access restricted to CIRAD agents
Use under authorization by the author or CIRAD.
Barkaoui_et_al-2017-Functional_Ecology-edite.pdf

Télécharger (622kB) | Request a copy

Quartile : Q1, Sujet : ECOLOGY

Abstract : The interactions between hydrological and ecological processes are key issues to improve our predictions of ecosystem responses to increasing droughts. However, predicting the dynamics and the impacts of vegetation water stress remains challenging because of complex ecohydrological feedbacks. The ecohydrological optimality approach proposes that functional adjustments within plant communities may buffer the increase in vegetation water stress despite local water shortage. This study aimed to test whether vegetation water stress may be invariant across contrasting plant communities, reflecting possible optimality processes. We addressed the following question: does a lower soil water storage capacity under the same climate generate greater vegetation water stress over time? We hypothesized that vegetation water stress would be buffered around a low and constant level through the adjustment of vegetation biomass productivity net primary productivity (NPP), evapotranspiration (ET) and/or water-use efficiency (WUE) in relation with local soil water storage capacity. We monitored 12 native plant communities distributed along a gradient of soil water storage capacity (ranging from 20 mm to 120 mm) during five successive years. Net primary productivity, ET, WUE as well as soil water dynamics were assessed and modelled for each plant community throughout the 5 years of study. Vegetation water stress was determined for each plant community as the deviation of between actual ET and their maximum ETm rate achieved under non-limiting conditions. We found that NPP and ET were together proportionally related to local soil water storage capacity across the 5 years of study while WUE did not differ between plant communities. Vegetation water stress was found quite similar for all plant communities whatever the soil water storage capacity. These results suggested that vegetation water stress was strongly buffered by the community-level plant growth rates and total water use along the soil gradient, but not by WUE. Our results suggest that stressful environments rarely exist for plant communities. A dynamic scaling relationship between NPP and ET may underpin the control of vegetation water stress over seasonal and pluriannual time-scales. Such results could contribute to better understanding processes associated with ecohydrological optimality and improve the predictions of vegetation dynamics under increasing droughts. (Résumé d'auteur)

Mots-clés Agrovoc : Hydrologie, Sécheresse, Stress dû à la sécheresse, Besoin en eau, Évapotranspiration, Dynamique des populations, Écosystème, Changement climatique, Communauté végétale, Productivité, Biomasse, Zone méditerranéenne

Classification Agris : F40 - Plant ecology
H50 - Miscellaneous plant disorders
F60 - Plant physiology and biochemistry
P01 - Nature conservation and land resources

Champ stratégique Cirad : Axe 6 (2014-2018) - Sociétés, natures et territoires

Auteurs et affiliations

  • Barkaoui Karim, CIRAD-PERSYST-UMR SYSTEM (MAR) ORCID: 0000-0002-5787-3748
  • Navas Marie-Laure, Montpellier SupAgro (FRA)
  • Roumet Catherine, CEFE (FRA)
  • Cruz Pablo, INRA (FRA)
  • Volaire Florence, INRA (FRA)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/583964/)

View Item (staff only) View Item (staff only)

[ Page générée et mise en cache le 2021-02-27 ]