Land and degradation as a complex stability problem

Resumo

This paper reviews recent work in the fields of ecology and economic ecology that contribute to a better understanding of the grazing and erosion debate. The approach is through dynamical systems models represented by differential equations and expressed by the phasespace diagrams for systems. The trophic web concept constrained by competitive and societal objective functions is found to be suitable to free-range grazing in environments that are spatially variable in their productivity. New models are needed for the case of grazing managed by shepherds.