Vegetation patterns and soil-atmosphere water fluxes in drylands

While periodic and irregular vegetation patterns in drylands have been extensively studied and modeled in recent years, the effect of patterning on atmospheric-soil water fluxes at a local and at the mesoscale has yet to be determined in detail. This represents a crucial issue for assessing the possible need of adequate parametrizations or models of vegetation patterning also in local-area and large-scale climate models. In this study we discuss a new explicit-space model for vegetation dynamics in water-limited ecosystems, capable of reproducing vegetation patterns and characterized by a more detailed representation of soil humidity, compared with earlier models. We apply the model to study the variation of soil-atmospheric evapotranspirative fluxes as a function of precipitation climatology and of associated vegetation pattern states, and we discuss the implications for climate modeling.