Project Overview
Annual Reports
Commodities
- Animals: bovine
- Animal Products: meat
Practices
- Animal Production: grazing management
- Education and Training: participatory research, workshop
Abstract:
Short term outcomes include: 1) knowledge of the rate of vegetation change following removal of prairie dogs, the impacts of grazing strategies on those changes, and the economic costs and benefits, 2) 200 ranchers and the scientific community will be informed of post-prairie dog vegetation recovery rates, and 3) 12 producers will measure forage change after prairie dog control. Intermediate outcomes include: 1) improved forage production for 12 cooperating ranches and 2) adoption of appropriate post-prairie dog control grazing management strategies by 25 regional ranchers. Thousands of acres of prairie dogs are undergoing control measures in the western region of the North Central Region, however there is scarce information on the rate of improvement of vegetation to be expected, appropriate grazing management strategies, and overall economic consequences. The focus of this project was on vegetation change on prairie dog towns where control measures occurred in fall/winter 2007-08 on 6 cooperator pastures, where 3 were grazed in summer and 3 grazed in fall/winter 2008-2011. Exclosures were established on the former prairie dog town in each pasture to examine the non-grazing option. Vegetation change over 4 years for each grazing strategy were evaluated. An additional 7 pastures were added to the study in 2011. Three of the pastures had active prairie dog towns, and the remaining 4 had been without prairie dogs for approximately 9 years (2 pastures) and 25 years (2 pastures). Differences in 2011 vegetation composition were evaluated between active prairie dog towns, short-term prairie dog-free (4 years grazed summer, winter, or not grazed) towns, moderate-term prairie dog-free (9 years) towns, and long-term prairie dog-free (25 years) towns. Results of the study have been presented at field days held on cooperator sites, at research station field days, and at scientific meetings. The results of this study have also been presented, by request, at a variety of meetings with ranchers, agency personnel, and scientists. Journal publications, Extension publications, and SDSU Beef Reports are being prepared for publication.
Introduction:
The black-tailed prairie dog (Cynomys ludovicianus Ord) is a native rodent found throughout the short- and mixed-grass prairies of North America. It is clearly valuable as a component of these grassland ecosystems, providing habitat to a number of plant and animal species. It is also viewed as a destructive pest when its populations are large. Prairie dogs clip vegetation short within their towns to enhance their ability to see predators (King 1955). This results in a shift of the plant community to a low seral stage, which, in the mixed-grass prairie, is represented by species of shorter stature, an increase in annual forbs and grasses, and an increase in species with greater grazing tolerance and/or lower palatability. As a result, less forage is available to large ungulates, such as bison and cattle (Koford 1958, Coppock et al. 1983, Bonham and Lerwick 1976, Archer et al 1987, Stoltenberg et al. 2005b). Prairie dogs were determined to be a candidate for threatened species (under the Endangered Species Act) by the U.S. Fish and Wildlife Service in 2000 (USDI USFWS 2000) but were removed from that status in August 2004. A state management plan that ensures maintenance of an acceptable minimum of prairie dog acres in South Dakota was approved by the South Dakota legislature, thereby allowing excess acres in the state to be available for prairie dog control. The South Dakota Game, Fish and Parks Department initiated prairie dog control measures for the state and for federal agencies in fall 2004 with the goal of providing ranchers with relief from losses of livestock forage due to prairie dogs that had migrated from federal onto private lands during a federal moratorium on their control. Additional control measures were implemented by the state in fall 2005. Where control measures have occurred, the expectation is that rangelands which are now characterized by extensive bare ground, annual forbs and grasses, and few desirable perennial grasses due to prairie dog occupation (Stoltenberg 2004, Stoltenberg et al. 2005a) will return to a more stable perennial, grass-dominated composition with improved ground cover for protection from erosion and greater production of livestock forage. The potential benefits for ranchers are great. Stoltenberg (2004) and Stoltenberg et al. (2005b) demonstrated that cattle were able to obtain only half as much forage/ha on ecological sites with prairie dogs compared to the same kinds of sites without prairie dogs, and Beutler et al. (2005) estimated the loss to producers at $10.40/ac of prairie dogs. Very little is known, however, about the rate at which desirable species will return following prairie dog control and the consequences of management strategies on that rate. Although ranchers have a number of management options that they may employ following prairie dog control, including seeding, rest, fire, and grazing, the biological effectiveness and economic consequences of those options are unknown. We know of only one study that has attempted to address the question of the impact of cattle grazing on plant community recovery following prairie dog control in mixed-grass prairie (Uresk 1985). That study concluded that prairie dog control did not increase production of individual plant species over a 4-year time period, regardless of whether or not the site was grazed by cattle. The design of that study, however, especially the lack of information regarding the similarity of soils across treatments within a site, limits the strength of that conclusion. Clearly, additional work is needed to evaluate the response of rangelands following prairie dog control regarding ground cover, species changes, and forage production, and to determine the impacts of post-control treatments on vegetation change. It will also be important to evaluate the economic consequences of prairie dog control so that ranchers can make informed choices regarding the management of rangelands with prairie dogs.
While South Dakota maintains the largest acreage of prairie dogs in the United States, they are also abundant in the western portions of other North Central Region states (North Dakota, Nebraska, and Kansas). Recent drought in the region and a moratorium on control measures resulted in rapid expansion of prairie dogs onto private rangelands, significant economic costs to ranchers, and a reduction in ranchers’ ability to maintain sustainable enterprises. NCR-SARE recently funded research that provided critical information on the impacts of prairie dogs on ranches in the region (NCR-SARE project #GNC 03-021, resulting in Stoltenberg 2004 and Stoltenberg et al. 2005a, 2005b). Beutler et al. (2005) used those results to determine the cost of prairie dogs to ranching operations. We have a unique opportunity, due to ongoing prairie dog control efforts by the state of South Dakota and other entities, to provide ranchers with additional critical information on the response of rangelands to prairie dog control. Many projects involving range management and cattle have been funded by NCR SARE, but only the Stoltenberg project (NCR-SARE project #GNC 03-021) has dealt specifically with interactions between prairie dogs and cattle. The importance of prairie dogs to the sustainability of agriculture in the western states of the North Central Region (ND, SD, NE, KS) makes this project very important to NCR SARE.
Project objectives:
The goal of this project was to evaluate plant community and forage production changes on prairie dog towns following prairie dog control, and to determine the effect of grazing on those changes. Specific objectives of this project were:
1. Evaluate the impact of grazing (none, growing season, non-growing season) on changes in plant community on former prairie dog towns, including
a. Total biomass production
b. Changes in biomass and species richness for perennial and annual species
2. Evaluate differences in plant communities on active towns and towns from which prairie dogs were removed for 4 years and greater.