Individual study: Cover components on long-term seasonal sheep grazing treatments in three-tip sagebrush steppe
Bork E.W., West N.E. & Walker J.W. (1998) Cover components on long-term seasonal sheep grazing treatments in three-tip sagebrush steppe. Journal of Range Management, 293-300
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Use fences to exclude livestock from shrublands
A replicated, controlled study in 1950–1996 in sagebrush steppe in Idaho, USA (Bork et al. 1998) found that fencing to reduce grazing had mixed effects on shrub, grass, forb, and herb cover. Cover of shrubs in ungrazed areas was lower (21%) than in areas that were grazed only in spring (27%) and not significantly different to shrub cover in areas that were grazed only in autumn (19%). Grass and forb cover were not significantly different in ungrazed areas (grass: 16%, forb: 10%) and areas that were grazed in spring or autumn only (grass: 15–17%, forb: 7–12%). Herb cover in ungrazed areas was lower (25%) than in areas grazed only in autumn (30%) and not significantly different from herb cover in areas grazed only in the spring (23%). In 1950 six areas were fenced, two of which were subsequently grazed by sheep in spring only, two of which were grazed in autumn only, and two of which were not grazed. Vegetation cover was recorded in June 1995 and 1996 in eight randomly placed 1.75 m2 quadrats in each of the fenced areas.
(Summarised by Phil Martin)