Coupled hydrologic and vegetation dynamics in wetland ecosystems

Abstract

The stochastic nature of long-term dynamics of soil moisture, water table, and vegetation in wetland ecosystems driven by precipitation are investigated through this modeling study. A simple model is presented here to couple the hydrologic and vegetation dynamics via transpiration and ecosystem carrying capacity. The simulation results portray possible competition outcomes between plant species having different survival strategies in response to the fluctuating soil moisture and water tables under different rainfall conditions. Long-range correlations in the dynamics were detected in several of the key variables of wetland ecosystems, as the result of their dependence on the long- memory structure of the water table. The statistical structure of the modeled water table fluctuations is found to be similar to that obtained from a real case study, validating the ability of the model in capturing water table dynamics and suggesting its potential toward the quantification of the long-term dynamics of wetland vegetation. Copyright 2008 by the American Geophysical Union.