Submitted to: Wildland Shrub Symposium Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2004
Publication Date: 8/1/2004
Citation: Vermeire, L.T., Wester, D.B., Mitchell, R., Fuhlendorf, S.D. 2004. Shrub dynamics: fire and water. Wildland Shrub Symposium Abstracts.
Technical Abstract: Fire and grazing have independently been shown to affect soils. Selective grazing of burned patches within greater non-burned areas can be expected if animal distribution is not controlled. Our objectives were to quantify the effects of patch burning and grazing on soil temperature, water content and wind erosion in sand sagebrush mixed-grass prairie. We selected 24, 4-ha plots on sand sagebrush-dominated sites near Woodward, OK. Four plots were burned during fall, 4 during spring and 4 served as non-burned controls for each of 2 years. Pastures were moderately stocked with cattle (Apr.-Sep.) given unrestricted access to burned patches (<2% of pastures). Wind erosion, soil temperature and water content were measured monthly. Wind erosion was 27 times greater on fall-burned plots than non-burned plots during the 2000 dormant period, but similar between treatments in 2001. Growing season erosion on fall-burned plots was double that of spring- and non-burned plots in 2000, but similar in 2001. Soils of burned plots were generally warmer than those of non-burned plots, based on diurnal measurements. Soil water content was unaffected by patch burn treatments. Burning at the beginning of the growing season prevented increased erosion, even though the burned patches were heavily grazed. Diurnal soil temperatures were higher on burned patches, but were likely cooler at night because of reduced insulation at the surface. Our results conflicted with those that have shown burned sites to be drier than non-burned sites. We believe the differences were caused by the lower water holding capacity of sandy soils.