Cover and species richness of vascular and cryptogamic components of the plant community were inventoried in experimental grazing paddocks at the USDA/FS Desert Range Experimental Station, Millard County, Utah. The grazing treatments considered have been applied continuously for over 50 years. The effects of heavy (ca 17 sheep days/acre) grazing treatment applied in two different seasons (early winter versus a split between early and late winter) differed significantly between seasons. Cryptogamic cover and cryptogamic species richness both showed larger decreases under early-late as opposed to early winter only grazing. Vascular plant cover (relative to controls) was also reduced by early-late winter grazing, but not to a significant degree. Late season grazing, likewise, had no significant effect on number of vascular species per transect.
Marble, James R. and Harper, Kimball T.
"Effect of timing of grazing on soil-surface crytogamic communities in a Great Basin low-shrub desert: a preliminary report,"
Great Basin Naturalist: Vol. 49
, Article 12.
Available at: http://scholarsarchive.byu.edu/gbn/vol49/iss1/12