Over a third of the land surface of the earth is composed of drylands and much of this (about 65-70 %) is seriously degraded or desertified. The two major desertification drivers—climate change and human activities— have ecological and social impacts on various temporal and spatial scales. These impacts include potential alterations of carbon, water, and trace gas budgets, loss of vegetation cover, and increased wind-borne dust, all of which may affect global biogeochemistry, radiation balance, and climate. The societal consequences of land degradation are also serious, since the fate of rural people in drylands is dependent on the effective use of natural resources, e.g., water, soils, plants, livestock and wildlife. Here we discuss how ecosystem-level predictions may be used to address issues relevant to sustainable development of these semi-arid regions. We argue that the next step in assessing sustainability is to incorporate ecological impacts into higher level models that consider direct and other human impacts on these systems. This will require further testing and evaluation of ecosystem-level models in the context of different management and land-use alternatives. We propose the incorporation of both "natural" and human factors into a spatially explicit model of landscape elements and human land-use patterns in order to develop predictive tools capable of dynamic, integrated assessments of impacts of global climate change on human-dominated ecosystems.
Was this article helpful?