Submitted to: Confluence
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 16, 2012
Publication Date: January 14, 2014
Repository URL: http://handle.nal.usda.gov/10113/58879
Citation: Derner, J.D., Augustine, D.J., Kachergis, E.J. 2014. Cattle as ecosystem engineers: New grazing management enhances rangeland biodiversity. Western Confluence. Winter 2014:10-13. Interpretive Summary: Management practices used on rangelands in the western United States often emphasize livestock production as the primary product. Emerging demands from society for these lands to provide additional ecosystem services (clean air, abundant and clean water, biodiversity, wildlife habitat) may require new approaches to using management practices involving livestock to engineer or create differences in vegetation composition (types and abundance of plants present) and structure (height). These new approaches can use modified current practices of livestock management through changing the season and intensity of grazing across years, varying the length of rest (non-grazing) periods to longer time spans (1 year) to provide opportunities for greater vegetation height, and altering the type of livestock (cattle, sheep and goats) or combinations of these livestock types in multiple species grazing. Livestock mangers can control when livestock graze certain areas, for how long, and how much vegetation is left ungrazed (to a certain height or residue level), so the ability to engineer rangelands is present and the application of this often focuses on creating difference in vegetation composition and structure across pastures and ranches. Currently, the prevailing economic model for ranchers only involves markets for livestock, but possible economic markets for ecosystem services may lead to more widespread engineering uses of livestock on rangelands.
Technical Abstract: A confluence of factors has shaped the composition and structure of vegetation on rangelands in the American West. These factors include climate, soils, topography, history of grazing and fire (both wildfire and prescribed fire) as well as legacy effects from prior land management practices. Despite the inherent differences in vegetation of rangelands resulting from these factors, sustainable management practices involving matching forage availability to forage demand have resulted in managing large acreages in a similar fashion for livestock production. Due to the focus on sustainable grazing practices and livestock production, there is often high similarity in vegetation composition and structure within local landscapes. In contrast to management that increases “sameness”, and in an attempt to increase desired habitats for grassland birds that need low or high vegetation structure, livestock can be used as a tool to “engineer” rangelands to produce differences in vegetation Attaining greater use of livestock as ecosystem engineers to obtain differences in vegetation composition and structure can be accomplished with current management practices. Livestock managers can alter timing and intensity of grazing, length of rest periods, and type of livestock as well as combining grazing with use of prescribed fire and/or existing colonies of prairie dogs. Livestock mangers can control when livestock graze certain areas, for how long, and how much vegetation is left ungrazed (to a certain height or residue level). Using livestock to engineer rangelands entails focusing grazing management activities to create desired levels of differences in composition and/or structure of vegetation with decision-making encompassing both provision of ecosystem services and livestock weight gains. Providing the economic markets for these ecosystem services is the nexus for facilitating more widespread engineering by livestock of rangeland ecosystems in the American West. What is needed is a confluence of conservation and production outcome goals into marketable commodities from these rangelands in the American West. Then, development of markets to place economic value on these commodities for the land manager, as well as for the general public, should provide the foundation on which to foster more engineering of rangeland vegetation by livestock.