Stochastic soil moisture dynamics and vegetation response

This chapter describes work on a stochastic soil moisture model that has been used to investigate the relationship between the hydrologic and vegetation dynamics ecohydrology in water-controlled ecosystems. Such systems are complex evolving structures whose characteristics and dynamic properties depend on many links between climate, soil, and vegetation. After a discussion of the soil water balance and a brief account of rainfall modeling, infiltration, and runoff, evapotranspiration and drainage are sketched. The probabilistic modeling of the soil moisture process and of long-term water balance are discussed, followed by minimalist modeling of soil moisture dynamics. The chapter concludes with a brief account of plant water stress, with an application to the Kalahari precipitation gradient.