Multi-scale controls on and consequences of aeolian processes in landscape change in arid and semi-arid environments

Aeolian processes are tightly linked to soil and vegetation change in arid and semi-arid systems at multiple spatial and temporal scales. Wind influences patterns of vegetation and soil within the landscape, and these patterns control wind erosion at patch to landscape scales. Aggregated at larger scales, patterns in soil and vegetation distributions influence global distributions of dust and its biogeochemical impacts. Understanding the controls on aeolian processes is therefore important not only in understanding the biogeochemistry and land cover patterns in dryland environments, but also in understanding global land cover, climate, and biogeochemistry. Although the microscopic physics that control aeolian processes are well understood, the controls on these processes in real landscapes are poorly constrained, particularly for structurally complex plant communities such as shrub-invaded grasslands. This paper reviews the controls on aeolian processes and their consequences at plant-interspace, patch-landscape, and regional-global scales. Based on this review, we define the requirements for a cross-scale model of wind erosion in structurally complex arid and semi-arid ecosystems. (c) 2005 Elsevier Ltd. All rights reserved.