Modeling water availability for trees in tropical forests

Wagner Fabien, Hérault Bruno, Stahl Clément, Bonal Damien, Rossi Vivien. 2011. Modeling water availability for trees in tropical forests. Agricultural and Forest Meteorology, 151 (9) : 1202-1213.

https://doi.org/10.1016/j.agrformet.2011.04.012

Article de revue ; Article de revue à facteur d'impact

Version publiée - Anglais
Accès réservé aux personnels Cirad
Utilisation soumise à autorisation de l'auteur ou du Cirad.
document_560331.pdf
Télécharger (817kB)

Quartile : Q1, Sujet : FORESTRY / Quartile : Q1, Sujet : AGRONOMY / Quartile : Q1, Sujet : METEOROLOGY & ATMOSPHERIC SCIENCES

Résumé : Modeling soil water availability for tropical trees is a prerequisite to predicting the future impact of climate change on tropical forests. In this paper we develop a discrete-time deterministic water balance model adapted to tropical rainforest climates, and we validate it on a large dataset that includes micrometeorological and soil parameters along a topographic gradient in a lowland forest of French Guiana. The model computes daily water fluxes (rainfall interception, drainage, tree transpiration and soil plus understorey evapotranspiration) and soil water content using three input variables: daily precipitation, potential evapotranspiration and solar radiation. A novel statistical approach is employed that uses Time Domain Reflectometer (TDR) soil moisture data to estimate water content at permanent wilting point and at field capacity, and root distribution. Inaccuracy of the TDR probes and other sources of uncertainty are taken into account by model calibration through a Bayesian framework. Model daily output includes relative extractable water, REW, i.e. the daily available water standardized by potential available water. The model succeeds in capturing temporal variations in REW regardless of topographic context. The low Root Mean Square Error of Predictions suggests that the model captures the most important drivers of soil water dynamics, i.e. water refilling and root water extraction. Our model thus provides a useful tool to explore the response of tropical forests to climate scenarios of changing rainfall regime and intensity.

Mots-clés Agrovoc : changement climatique, eau du sol, forêt tropicale

Mots-clés géographiques Agrovoc : Guyane française, France

Classification Agris : P40 - Météorologie et climatologie
U10 - Informatique, mathématiques et statistiques
P33 - Chimie et physique du sol
K01 - Foresterie - Considérations générales

Champ stratégique Cirad : Axe 6 (2005-2013) - Agriculture, environnement, nature et sociétés

Auteurs et affiliations