Preferential states of seasonal soil moisture: The impact of climate fluctuations

The impact of climate fluctuations on the dynamics of soil moisture is studied through a stochastic model of soil water balance. The analysis focuses on the changes of soil water content induced by the interannual variability of rainfall observed at the decade‐to‐century timescale. Extensive data analyses have been performed to characterize the statistical properties of such a variability. Particular attention is paid to the year‐to‐year variability of the average value of soil moisture during the growing season because of its relevance to the mechanisms affecting the physiology of plants and the dynamics of ecosystems. It is found that the probability distribution of the average seasonal soil moisture may be either unimodal or bimodal depending on the different combinations of climate, soil, and vegetation parameters. The possible occurrence of a double mode has both hydrologic and ecologic implications that are analyzed here.

[1]  G. Hornberger,et al.  Empirical equations for some soil hydraulic properties , 1978 .

[2]  Dara Entekhabi,et al.  Nonlinear Dynamics of Soil Moisture at Climate Scales: 2. Chaotic Analysis , 1991 .

[3]  E. Eltahir.  Role of vegetation in sustaining large‐scale atmospheric circulations in the tropics , 1996 .

[4]  R. Sosebee,et al.  Water relations and transpiration of honey mesquite on 2 sites in west Texas. , 1991 .

[5]  R. Pielke,et al.  Evaluation of vegetation effects on the generation and modification of mesoscale circulations , 1988 .

[6]  E. Nilsen,et al.  Physiology of Plants Under Stress , 1987 .

[7]  T. Swetnam,et al.  Mesoscale Disturbance and Ecological Response to Decadal Climatic Variability in the American Southwest , 1998 .

[8]  Luca Ridolfi,et al.  Tree‐grass coexistence in Savannas: The role of spatial dynamics and climate fluctuations , 1999 .

[9]  Dara Entekhabi,et al.  Analysis of Feedback Mechanisms in Land-Atmosphere Interaction , 1996 .

[10]  T. Black,et al.  A growing season water balance model applied to two Douglas fir stands , 1981 .

[11]  K. Tinley.  The Influence of Soil Moisture Balance on Ecosystem Patterns in Southern Africa , 1982 .

[12]  V. Isham,et al.  Probabilistic modelling of water balance at a point: the role of climate, soil and vegetation , 1999, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[13]  W. R. Gardner,et al.  The influence of soil water on transpiration by plants , 1963 .

[14]  I. Rodríguez‐Iturbe,et al.  A Spatial Model for Soil-Atmosphere Interaction: Model Construction and Linear Stability Analysis , 2000 .

[15]  Richard A. Anthes,et al.  Enhancement of Convective Precipitation by Mesoscale Variations in Vegetative Covering in Semiarid Regions , 1984 .

[16]  Luca Ridolfi,et al.  On the spatial and temporal links between vegetation, climate, and soil moisture , 1999 .

[17]  M. Ludlow.  Ecophysiology of C4 Grasses , 1976 .

[18]  W. Larcher.  Physiological Plant Ecology , 1977 .

[19]  Robert C. Maggio,et al.  Autogenic succession in a subtropical savanna: conversion of grassland to thorn woodland , 1988 .

[20]  R. H. Haas,et al.  Water‐Stress Patterns in Honey Mesquite , 1972 .

[21]  W. Schlesinger.  Biogeochemistry: An Analysis of Global Change , 1991 .

[22]  E. O'Loughlin,et al.  A Lysimeter Characterization of Evaporation by Eucalypt Forest and its Representativeness for the Local Environment , 1985 .