Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Etats Unis → 2003 → Impacts of grazing removal on vegetation, soils, and biological soil crusts in Wyoming sagebrush steppe

University of Wyoming (2003)

Impacts of grazing removal on vegetation, soils, and biological soil crusts in Wyoming sagebrush steppe

Muscha, Jennifer M

Titre : Impacts of grazing removal on vegetation, soils, and biological soil crusts in Wyoming sagebrush steppe

Auteur : Muscha, Jennifer M

Université de soutenance : University of Wyoming

Grade : Master of Science (MS) 2003

Résumé
In the 1950s and 1960s numerous rangeland exclosures were established on previously grazed areas in Wyoming sagebrush steppe. Fenced exclosures were used by range scientists to determine the effects of livestock grazing on vegetation and soils. In the summers of 2001 and 2002 we re-examined nine exclosures in Natrona, Fremont, Sweetwater, Bighorn, Hot Springs, and Washakie counties. Original sagebrush levels were low in most exclosures when they were constructed and grazing use outside the exclosures differed among the nine sites. We compared vegetative and biological soil crust cover and soil properties inside and outside the 32-44 year old exclosures. Bare soil was greater outside exclosures at three sites and litter cover was greater inside the exclosure at three of the nine sites. Shrub cover was greater inside than outside only at the Poison Spider exclosure site. Biological soil crust cover did not differ between inside and outside exclosures at any of the nine sites. Microbial biomass carbon, organic carbon and total nitrogen did not differ inside and outside. Potential carbon mineralization rates were greater collected inside the exclosure at Big Trails and Donlin, and greater outside at Poison Spider. Islands of fertility exist beneath shrub canopies and grass patches relative to bare interspaces both inside and outside exclosures. There were few differences between the vegetative characteristics, soil parameters studied, biological soil crust cover and species richness between inside and outside positions at most sites. Our results are mixed with respect to the impacts of livestock exclusion from Wyoming sagebrush steppe.

Mots clés : Range management, Biological sciences

Proquest Dissertations & Theses

Research Gate

Page publiée le 3 février 2015, mise à jour le 12 septembre 2018