Received: 29 July 2013 / Accepted: 11 December 2013 Springer Science+Business Media New York (outside the USA) 2014
Abstract (for more information see: http://rangelandwatersheds.ucdavis.edu/Main/projects.htm)
In a previous article, Beschta et al. (Environ Manag 51(2):474–491,2013 ) argue that grazing by large ungulates (both native and domestic) should be eliminated or greatly reduced on western public lands to reduce potential climate change impacts. The authors did not present a balanced synthesis of the scientific literature, and their publication is more of an opinion article. Their conclusions do not reflect the complexities associated with herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be achallenge. Legacy effects of uncontrolled grazing during the homestead era further complicate analysis of current grazing impacts. Interactions of climate change and grazing will depend on the specific situation. For example, increasing atmospheric CO2 and temperatures may increase accumulation of fine fuels (primarily grasses) and thus increase wildfire risk. Prescribed grazing by livestock is one of the few management tools available for reducing fine fuel accumulation. While there are certainly points on the landscape where herbivore impacts can be identified there are also vast grazed areas where impacts are minimal. Broad scale reduction of domestic and wild herbivores to help native plant communities cope with climate change will be unnecessary because over the past 20–50 years land managers have actively sought to bring populations of native and domestic herbivores in balance with the potential of vegetation and soils. To cope with a changing climate, land managers will need access to all available vegetation management tools, including grazing.
….Beschta et al. (2013) devote a significant portion of their climate change discussion to warmer spring temperatures, reduced snow packs, earlier peak flows, and reduced summer stream flows. It is unclear how removing grazing would overcome the effects of large-scale climatic changes (such as reduced snow packs) that are triggered by larger and more complex resource issues than grazing. Some of the discussion on carbon sequestration is particularly unclear. For example, Beschta et al. (2013) cite Lal (2001) as saying that heavy grazing has long-term negative impacts on soil organic carbon. That citation is a chapter in a book titled ”The Potential of US Grazing Lands to Sequester Carbon and Mitigate the Greenhouse Effect” (Follett et al. 2001). This book provides examples where grazing increases carbon sequestration compared to no grazing. Beschta et al. (201 ) suggest that the economic impacts of their proposal would be ”relatively minor to modestly positive”. That may be true for unique areas with high recreational potential such as Jackson Hole, Wyoming, but it is not true for most of the rural West and not necessarily for even some of the high value recreation areas. A few studies have examined the regional economic impact of removing public land grazing from representative ranches and all show significant negative impacts to local economies (Torell et al. 2002 ; Rimbey et al. 2003; Tanaka et al. 2007). Whether recreation service jobs will replace ranching jobs and income lost in a local economy is largely unknown. To summarize, grazing is a complex ecological process with impacts that vary across time and space. This complexity leads to challenges in synthesizing the scientific literature and allows authors to select the literature which supports particular points of view about grazing impacts. Legacy impacts of homestead era over-grazing and potential climate change further complicate assessment of current grazing impacts. Clearly, there are examples where reduced grazing can increase the potential negative impacts of climate change (in the case of wildfire risk). We suggest that land managers in the western US will need all available vegetation management tools to cope with climate change.
Original Paper by Beschta:
Beschta RL, Donahue DL, DellaSala DA, Rhodes JJ, Karr JR, O’Brien MH, Fleischner TL, Williams CD (2013) Adapting to climate change on western public lands: addressing the ecological effects of domestic, wild, and feral ungulates. Environmental Management. 51(2):474–491
Abstract. Climate change affects public land ecosystems and services throughout the American West and these effects are projected to intensify. Even if greenhouse gas emissions are reduced, adaptation strategies for public lands are needed to reduce anthropogenic stressors of terrestrial and aquatic ecosystems and to help native species and ecosystems survive in an altered environment. Historical and contemporary livestock production-the most widespread and long-running commercial use of public lands-can alter vegetation, soils, hydrology, and wildlife species composition and abundances in ways that exacerbate the effects of climate change on these resources. Excess abundance of native ungulates (e.g., deer or elk) and feral horses and burros add to these impacts. Although many of these consequences have been studied for decades, the ongoing and impending effects of ungulates in a changing climate require new management strategies for limiting their threats to the long-term supply of ecosystem services on public lands. Removing or reducing livestock across large areas of public land would alleviate a widely recognized and long-term stressor and make these lands less susceptible to the effects of climate change. Where livestock use continues, or where significant densities of wild or feral ungulates occur, management should carefully document the ecological, social, and economic consequences (both costs and benefits) to better ensure management that minimizes ungulate impacts to plant and animal communities, soils, and water resources. Reestablishing apex predators in large, contiguous areas of public land may help mitigate any adverse ecological effects of wild ungulates.