Tree-grass competition for soil water in arid and semiarid savannas: The role of rainfall intermittency - École polytechnique Access content directly
Journal Articles Water Resources Research Year : 2015

Tree-grass competition for soil water in arid and semiarid savannas: The role of rainfall intermittency

Abstract

Arid and semiarid savannas are characterized by the coexistence of trees and grasses in water limited conditions. As in all dry lands, also in these savannas rainfall is highly intermittent. In this work, we develop and use a simple implicit-space model to conceptually explore how precipitation intermittency influences tree-grass competition and savanna occurrence. The model explicitly includes soil moisture dynamics, and life-stage structure of the trees. Assuming that water availability affects the ability of both plant functional types to colonize new space and that grasses outcompete tree seedlings, the model is able to predict the expected sequence of grassland, savanna, and forest along a range of mean annual rainfall. In addition, rainfall intermittency allows for tree-grass coexistence at lower mean annual rainfall values than for constant precipitation. Comparison with observations indicates that the model, albeit very simple, is able to capture some of the essential dynamical processes of natural savannas. The results suggest that precipitation intermittency affects savanna occurrence and structure, indicating a new point of view for reanalyzing observational data from the literature.

Domains

Climatology
Fichier principal
Vignette du fichier
2014WR015515.pdf (676.66 Ko) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

hal-01180324 , version 1 (23-10-2021)

Licence

Copyright

Identifiers

Cite

Donatella d'Onofrio, Mara Baudena, Fabio d'Andrea, Max Rietkerk, Antonello Provenzale. Tree-grass competition for soil water in arid and semiarid savannas: The role of rainfall intermittency. Water Resources Research, 2015, 51 (1), pp.169-181. ⟨10.1002/2014WR015515⟩. ⟨hal-01180324⟩
176 View
66 Download

Altmetric

Share

Gmail Facebook X LinkedIn More