Disturbance effects on infiltration and erosion susceptibility for biologically crusted soils in the Mojave Desert

Title	Disturbance effects on infiltration and erosion susceptibility for biologically crusted soils in the Mojave Desert
Publication Type	Conference Paper
Year of Publication	2001
Authors	Herrick JE, Belnap J, Van Zee J, Johansen J.
Conference Name	86th Annual Meeting, Ecological Society of America
Date Published	August 5-10, 200
Conference Location	Madison, WI
ARIS Log Number	129783
Abstract	The effects of soil surface disturbance on water infiltration into arid and semi-arid soils have been widely debated in both the popular and scientific literature. Previous studies suggest biological crusting reduces infiltration on soils with >80% sand content. We tested the hypothesis that trampling would significantly increase infiltration and sediment production at sandy Mojave Desert sites dominated by biological crusts. W used a rainfall simulator to apply an intense 30-minute storm to four trampled and nontrampled plots at each of three sites with physical crusts and three sites with biological crusts, as indicated by soil chlorophyll analyses. Differences in crust cover were attributed to historic disturbance regime. Trampling reduced the infiltration rate 36% at both the physically and biologically crusted sites. Trampling increased sediment production by a factor of 2.4 at the sites dominated by physical crusts and by a factor of 4.1 at the biologically crusted sites. Chlorophyll content was negatively correlated with sediment production and positively correlated with soil aggregate stability. We concluded maintenance of biological crusts should reduce soil erosion. The hypothesis that biological crusts reduce infiltration capacity on sandy soils was not supported by the data.