|Okin, G - UNIVERSITY OF VIRGINIA|
|Gillette, Dale - NOAA|
Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 29, 2005
Publication Date: April 1, 2006
Citation: Okin, G.S., Gillette, D.A., Herrick, J.E. 2006. Multi-scale controls on and consequences of aeolian processes in landscape change in arid and semi-arid environments. Journal of Arid Environments. 65:253-275. Interpretive Summary: Wind erosion plays an important role in shaping arid and semiarid regions worldwide. This paper reviews wind erosion processes in arid environments at multiple scales: plant interspace, patch-landscape and regional-global. It also discusses the role of feedbacks, thresholds, transport, landscape context, and historical legacies in determining the extent of wind erosion and deposition at all hierarchical scales. Feedbacks exist between individual plants and wind. Saltation physically impacts downwind plants and plant cover affects transport/erosion of soil. Threshold gap sizes exist below which erosion may not occur. Patch structure is also important given that horizontal flux increases with fetch. Mosaics of vegetation structure created by concentrated activities (e.g., grazing, ORVs) may result in areas that are more susceptible to erosion than would be predicted based on the average cover for a pasture.
Technical Abstract: Aeolian processes are tightly linked to soil and vegetation change in deserts at multiple spatial and temporal scales. Wind influences patterns of vegetation and soil within the landscape, while 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. These relationships are poorly understood, particularly for structurally complex plant communities such as shrub-invaded grasslands. The objective of this paper is to review 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.