Physical and ecological processes of the earth surface are intrinsically coupled. This work seeks to test the following hypothesis: River basins organize through local non-linear interactions (between vegetation, soils and topography) in such a way that identifiable global patterns emerge on the 3-D structure of the river network and on the organization of vegetation.
The above hypothesis suggests a vegetation-modulated erosion in response to stochastic climatic forcing that involves a co-organization of the structure of the river network and the vegetation of the basin. Modeling will be used within the context of data from two different grass dominated sites. The co-evolution of landscape morphology and its vegetation patterns will be studied under stochastic climate forcing, and constant and varying tectonic uplift (or base level drop). The major questions to be addressed are: 1) Are there any large-scale signatures of vegetation organization in river basins? 2) Is there any global strategy in the organization of landscape morphology and its vegetation cover? 3) What is the impact of climate or uplift fluctuations on vegetation self-organization and erosion rates on a complex adaptive topography? 4) What is the effect of disturbances such as fire and grazing on the co-organization
The results will add to an expanding body of work in grasslands and water limited regions of US and the world. It will provide added scientific and operational value to the ongoing ecosystem monitoring efforts in grasslands in United States. The potential payoff of this type of research includes broad social and economic benefits related to water supply and quality as well as ecosystem health and diversity.
This is a highly interdisciplinary effort that will combine research results from different branches of earth sciences (i.e., ecology, geomorphology, hydrology) under the umbrella of a physically-based numerical framework.
