Adaptive Grazing Management Using Surface Cover Change Detection on Shrub-Steppe
Location
USU Eccles Conference Center
Event Website
http://www.restoringthewest.org/
Abstract
The Wild Horse Coordinated Resource Management group developed a unified grazing plan designed to maintain or improve rangeland health on the Puget Sound Energy wind facility and adjacent public land. Committed to adaptive management, the group selected two trend monitoring methods for measuring results of grazing: Land EKG® and the line-point intercept as described by Herrick, et al 2005. These would serve as an early warning system for negative trend, as objective documentation of positive changes, and as a guide for adjusting management inputs, primarily grazing timing, intensity, and duration of use, to achieve the landscape goals set by the group during its formation in 2006. WSU Kittitas County Extension has been responsible for collecting and interpreting this long-term monitoring data with the objective of establishing a model approach to sustainable rangeland grazing and rangeland health monitoring for other large grazing areas in the Intermountain West. This poster provides a comparison of the ability of two different monitoring methods, Land EKG and the line-point intercept as described by Herrick, et al, to detect change in surface cover attributes (percent basal area, litter, and bare soil) on high-condition shrub-steppe sites in central Washington. Land EKG relies on an ocular estimate to assign surface cover percentages within two or four 4.8 ft2 hoops on
a transect line coupled with repeat photography. The line-point intercept uses point sampling at every meter on three 50-meter transect lines per site to collect canopy and surface cover data. Data were collected from 2007 to 2011 on six different sites within two large (~5000-acre) pastures managed with light stocking rates (<20% utilization). We have evaluated the two methods’ ability to detect change rather than comparing the absolute values derived from the two methods. The direction of change in basal area was consistent across methods. Although the degree of change was not consistent, this is a notable finding as basal area is notoriously difficult to estimate. Percent litter was relatively inconsistent across methods, we suspect due in part to the high spatial heterogeneity of this plant community, annual changes in litter distribution at the microsite level based on the timing and severity of precipitation events that move litter, and the significant difference between the methodologies for measuring litter. Bare soil values were consistent more often than not; new technology for image analysis could be used to make quantitative measurements from Land EKG photographs. This data will be collected approximately every three years and used to guide grazing plans.
Tipton D. Hudson, Rangeland & Livestock Management Faculty, Washington State University Extension, 507 Nanum Street, Suite 2, Ellensburg, WA, 98926, hudsont@wsu.edu
Adaptive Grazing Management Using Surface Cover Change Detection on Shrub-Steppe
USU Eccles Conference Center
The Wild Horse Coordinated Resource Management group developed a unified grazing plan designed to maintain or improve rangeland health on the Puget Sound Energy wind facility and adjacent public land. Committed to adaptive management, the group selected two trend monitoring methods for measuring results of grazing: Land EKG® and the line-point intercept as described by Herrick, et al 2005. These would serve as an early warning system for negative trend, as objective documentation of positive changes, and as a guide for adjusting management inputs, primarily grazing timing, intensity, and duration of use, to achieve the landscape goals set by the group during its formation in 2006. WSU Kittitas County Extension has been responsible for collecting and interpreting this long-term monitoring data with the objective of establishing a model approach to sustainable rangeland grazing and rangeland health monitoring for other large grazing areas in the Intermountain West. This poster provides a comparison of the ability of two different monitoring methods, Land EKG and the line-point intercept as described by Herrick, et al, to detect change in surface cover attributes (percent basal area, litter, and bare soil) on high-condition shrub-steppe sites in central Washington. Land EKG relies on an ocular estimate to assign surface cover percentages within two or four 4.8 ft2 hoops on
a transect line coupled with repeat photography. The line-point intercept uses point sampling at every meter on three 50-meter transect lines per site to collect canopy and surface cover data. Data were collected from 2007 to 2011 on six different sites within two large (~5000-acre) pastures managed with light stocking rates (<20% utilization). We have evaluated the two methods’ ability to detect change rather than comparing the absolute values derived from the two methods. The direction of change in basal area was consistent across methods. Although the degree of change was not consistent, this is a notable finding as basal area is notoriously difficult to estimate. Percent litter was relatively inconsistent across methods, we suspect due in part to the high spatial heterogeneity of this plant community, annual changes in litter distribution at the microsite level based on the timing and severity of precipitation events that move litter, and the significant difference between the methodologies for measuring litter. Bare soil values were consistent more often than not; new technology for image analysis could be used to make quantitative measurements from Land EKG photographs. This data will be collected approximately every three years and used to guide grazing plans.
Tipton D. Hudson, Rangeland & Livestock Management Faculty, Washington State University Extension, 507 Nanum Street, Suite 2, Ellensburg, WA, 98926, hudsont@wsu.edu
https://digitalcommons.usu.edu/rtw/2012/posters/5