Soil-water and vegetation dynamics through 20 years after big sagebrush control
AuthorSturges, D. L.
soil water content
soil water regimes
MetadataShow full item record
CitationSturges, D. L. (1993). Soil-water and vegetation dynamics through 20 years after big sagebrush control. Journal of Range Management, 46(2), 161-169.
PublisherSociety for Range Management
JournalJournal of Range Management
AbstractSoil water withdrawal and vegetation characteristics of mountain big sagebrush (Artemisia tridentala ssp. vaseyana Rydb. Beetie) areas sprayed with 2,4-D (2,4-Dichlorophenoxyacetic acid) were measured for 20 years after treatment. Herbaceous productivity more than doubled in the first 3 years after spraying and was still twice as great as untreated vegetation 10 to 17 years after treatment. Sagebrush removal reduced seasonal water depletion 9% to a 1.8-m soil depth, equal to 2.4 cm of water. The entire difference was realized from soil 0.9-1.8 m deep. Depletion from the surface 0.9 m of soil under grass-dominated vegetation slightly exceeded depletion under sagebrush-dominated vegetation. Mathematical relationships were developed that predict the percent reduction in seasonal water depletion in relation to time since sagebrush control for soil depths of 0.0-1.8 m, 0.0-0.9 m, and 0.9-1.8 m. Mountain big sagebrush was a minor vegetation constituent on treated areas 20 years after spraying. Sagebrush density increased from 2,100 to 4,400 plant/ha between 10 and 20 years after spraying while herbaceous production ranged between 28 and 52 kg/ha. Both density and canopy cover of sagebrush on untreated areas declined significantly over the study because of the actions of a snowmold fungus.