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Wind erodibility of soils at Fort Irwin, California (Mojave Desert), USA, before and after trampling disturbance: Implications for land management

Earth Surface Processes and Landforms

By:
, , ,
DOI: 10.1002/esp.1372

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Abstract

Recently disturbed and 'control' (i.e. less recently disturbed) soils in the Mojave Desert were compared for their vulnerability to wind erosion, using a wind tunnel, before and after being experimentally trampled. Before trampling, control sites had greater cyanobacterial biomass, soil surface stability, threshold friction velocities (TFV, i.e. the wind speed required to move soil particles), and sediment yield than sites that had been more recently disturbed by military manoeuvres. After trampling, all sites showed a large drop in TFVs and a concomitant increase in sediment yield. Simple correlation analyses showed that the decline in TFVs and the rise in sediment yield were significantly related to cyanobacterial biomass (as indicated by soil chlorophyll a). However, chlorophyll a amounts were very low compared to chlorophyll a amounts found at cooler desert sites, where chlorophyll a is often the most important factor in determining TFV and sediment yield. Multiple regression analyses showed that other factors at Fort Irwin were more important than cyanobacterial biomass in determining the overall site susceptibility to wind erosion. These factors included soil texture (especially the fine, medium and coarse sand fractions), rock cover, and the inherent stability of the soil (as indicated by subsurface soil stability tests). Thus, our results indicate that there is a threshold of biomass below which cyanobacterial crusts are not the dominant factor in soil vulnerability to wind erosion. Most undisturbed soil surfaces in the Mojave Desert region produce very little sediment, but even moderate disturbance increases soil loss from these sites. Because current weathering rates and dust inputs are very low, soil formation rates are low as well. Therefore, soil loss in this region is likely to have long-term effects.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Wind erodibility of soils at Fort Irwin, California (Mojave Desert), USA, before and after trampling disturbance: Implications for land management
Series title:
Earth Surface Processes and Landforms
DOI:
10.1002/esp.1372
Volume
32
Issue:
1
Year Published:
2007
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Earth Surface Processes and Landforms
First page:
75
Last page:
84
Number of Pages:
10