Ecological Science

Essentially, the “jury is in” on the fact that domestic livestock grazing on western rangelands that did not evolve with large herds of grazing ungulates (basically bison, Mack & Thompson 1982) can have profound impacts on western ecosystems and their native flora and fauna.  While it is not necessary to provide here an exhaustive list of individual published ecological studies that demonstrate these impacts, a few well-known literature reviews and meta analysis on the topic will likely prove helpful, such as:

• Fleischner et al. 1994: the most cited, and classic literature review on livestock grazing impacts on western N. American ecosystems.
• Trimble Mendel 1995: a comprehensive literature review focused on the impacts of livestock grazing on soils and hydrology of arid and semi-arid ecosystems.
• Belsky et al. 1999: the most cited, and classic literature review on livestock grazing impacts on streams and riparian ecosystems in the American West. 
• Jones 2000: a quantitative review, or “meta analysis” of the effects of cattle grazing in arid N. American systems on 16 response variables ranging from soil bulk density to total vegetative cover to rodent species diversity. 
• Beschta et al. 2013: a critical piece examining how livestock grazing can alter vegetation, soils, hydrology, and  wildlife species composition and abundances in ways that exacerbate the effects of climate  change on these resources, and why these impacts require new  management strategies for limiting their threats to the long-term supply of ecosystem services on public lands.

We refer readers to the resource page of the Healthy Public Lands Project website to gain access to much more information on the many various impacts livestock grazing has been shown to have on waters, upland,s and their native flora and fauna , with links to individual studies if desired.