Developing Guidelines for Sustainable Livestock Grazing in South Dakota Ponderosa Pine Forests: Balancing Economically Important Ecosystem Goods with Ecological Integrity

View the project final report

Commodities

• Additional Plants: trees
• Animals: bovine

Practices

• Animal Production: free-range, grazing management, grazing - continuous, grazing - rotational, pasture fertility, range improvement, stocking rate
• Crop Production: agroforestry, forestry
• Education and Training: extension
• Natural Resources/Environment: biodiversity, habitat enhancement
• Pest Management: weed ecology
• Production Systems: holistic management
• Sustainable Communities: sustainability measures

Ponderosa pine forest management in the Black Hills, SD currently focuses on reducing tree stocking and fuels to minimize wildfire and mountain pine beetle risks.  While many of these lands are grazed by livestock, management practices which optimize both timber and cattle production simultaneously have not been identified.  Better understanding of relationships among livestock grazing, timber and forage production, wildlife, aesthetics, and plant community composition is critical to reduce uncertainty and optimize management.  Proposed research will investigate relationships among duration and intensity of livestock use, forage production, plant species diversity, and ponderosa pine regeneration.  Research was conducted in the Black Hills for the following reasons: 1) the Black Hills National Forest is the most intensively managed National Forest in the U.S. with well documented timber harvest methods and livestock grazing practices, and 2) the forest provides many economically important ecosystem goods and services such as cattle and timber production, big game hunting, tourism, and recreation.  Short-term outcomes include the collection of data and development of relationships among management practices and ecosystem goods and services.  Intermediate and long-term outcomes include increases in knowledge and understanding, and guidance in management practices for ranchers and public land stewards.  Progress in short-term outcomes will be monitored and reported at the end of the data collection season.  A presentation of research results will be given to the Rangeland Management Specialists at the Black Hills National Forest to increasing knowledge and understanding of relationships between management practices and resource condition.  Long-term outcomes of changing management practices may take several years to decades, and will not be measured as part of this project.  Relationships among management practices and ecosystem goods and services can be integrated into future management plans to sustainably produce livestock and timber while maintaining a diverse and productive native plant community.  Optimizing livestock and timber production and maintaining native plant communities has the potential to improve rancher profitability, and environmental quality.  Enhancements to the Black Hills forest resource base may also benefit wildlife, hunting, ascetics, tourism, and recreation.

Introduction:

Natural resource management of ponderosa pine forests in the Black Hills, SD has generally focused on reducing tree stocking and hazardous fuels to reduce risks associated with wildfire and mountain pine beetle.  While many of these lands are grazed by livestock, the relationship between management practices, tree growing stock levels, timber production, forage production, livestock grazing, wildlife, aesthetics, and ecological integrity is not well understood.  Science-based management guidelines are necessary to broaden the scope of current forest management and optimize various ecosystem goods and services.  The goal of this project is to develop management guidelines, which sustainably and efficiently provision multiple ecosystem goods and services for grazed forested lands, by integrating relationships among forest density, cattle and timber production, plant community structure, forage productivity, and previous management practices.  These guidelines can then be incorporated into future resource management plans, and have the potential to improve rancher profitability, environmental quality, and enhance quality of life for ranchers, communities, and society as a whole.

Multiple use and ecological sustainability are increasingly important management considerations in the Black Hills, SD, which provide many economically important ecosystem goods and services including cattle and timber production, big game hunting, tourism, and recreation.  Public and private forested lands of the Black Hills provide forage for cattle grazing.  Ponderosa pine from the Black Hills supply mills and forest products businesses in several Black Hills communities.    The Black Hills provide valuable wildlife habitat for many game animals including deer, elk, bighorn sheep, and mountain lion.  Mount Rushmore National Memorial, which draws two million visitors annually, is one of many area attractions which support a large tourism industry in many Black Hills communities. 

Cattle graze on both public and private lands in the coniferous forests of the Black Hills, SD.  There are 1.04 million acres of suitable grazing land in the Black Hills National Forest representing 83 percent of Forest Service land (USDA 2006).  This land is expected to produce 233 million pounds of forage on a sustainable annual basis with 127 million pounds or 128,000 animal unit months (AUM) allocated to livestock (USDA 2006). In 2009, 260 permittees leased the suitable grazing lands in the Black Hills National Forest (Hocking et al. 2010), and depend on public land grazing access to achieve the operational scale necessary to sustain their livelihood.  Grazing also occurs on many of the 308,000 acres of private coniferous forest land in the Black Hills.  Lawrence County, where conifer forests cover more than 90 percent of its area, generated nearly 12 million dollars in cattle receipts in 2007 (USDA 2009).  Cattle use of forested areas will likely increase with projected temperature increases from climate change (Allred et al. 2013).  There are questions relating to ecological integrity, and relationships among: cattle grazing, plant community composition, herbaceous production, and ponderosa pine regeneration.

Understanding relationships between grazing practices and plant community structure is important to economically and environmentally sustainable multiple-use of forested grazing lands.  Science-based ecologically sustainable management of forested grazing lands may improve economic profitability of livestock grazing on private lands, and help ensure economically viable livestock grazing access to public lands, while also improving environmental quality of both private and public lands.  Management guidelines for the Black Hills National Forest highlight sustainable use (USDA 2006), and maintaining a diverse array of native species (Mystic Ranger District 2010).   While short-term livestock exclosures increase native plant cover and stature in conifer forests (Kerns et al. 2011), relationships among livestock grazing, herbaceous production and plant community composition in forested landscapes have not been identified.  Identifying and incorporating these relationships into management plans has the potential to improve rancher profitability, environmental quality, and the natural resource base on which livestock production, wildlife, hunting, aesthetics, tourism, and recreation depend.

The first federal timber sale was in the Black Hills, and today virtually all of the federal forested lands in the Black Hills have had timber harvests.  Approximately 865,890 acres or 70 percent of Forest Service land in the Black Hills is suitable and available for timber harvest (USDA 2006).   In 2007, the allowable sale quantity from suitable lands in the Black Hills National Forest was 838 million board feet (USDA 2008).  For the decade ending in 2007, 163 thousand acres were harvested yielding 656 million board feet of sawtimber (USDA 2008).    Abundant ponderosa pine regeneration every two to five years in the Black Hills (Boldt and Van Deusen 1974) contributes to an ever increasing backlog of pre-commercial  and commercial thinning projects which are necessary to maintain desired tree densities and cost effectiveness of timber harvest  (Shepperd and Battaglia 2002).

Identifying relationships between livestock grazing and ponderosa pine regeneration has implications for rancher profitability and maintenance of the natural resource base.  The effect of cattle grazing on ponderosa pine regeneration remains an open question, and may improve the long term profitability of timber harvest.  Most research hypothesizes that cattle grazing increases tree density by reducing the understory vegetation which in turn leads to more resource availability for increased tree recruitment (Rummell 1951, Zimmerman and Neuenschwander 1984, Belsky and Blumenthal 1997, Shepperd and Battaglia 2002).  On the other hand, cessation of grazing is associated with increased canopy cover, tree density, and basal area and decreased diameter at breast height (Bakker and Moore 2007); these changes to forest structure tend to decrease profitability of timber harvest and increase wildfire hazard.  Grazing practices may reduce pine regeneration and intermediate thinning treatments required to produce merchantable timber, thereby increasing the profitability of timber harvest and improving rancher profitability.  Because catastrophic wildfires cross public and private land boundaries, a reduction in wildfire risk irrespective of land ownership, helps ensure rancher profitability by protecting the natural resource base.

Objectives for this project include: 1)field data collection and analysis, 2) a presentation for the Rangeland Management Specialists at the Black Hills National Forest, 3) extension publications and online resources, 4) one chapter of my Ph.D. dissertation, and refereed papers.  Project funds were used for data collection and analysis.  We collected data in 44 pastures during the summer of 2015.  All data has been entered, and data analysis is well under way.  Data from this project will be presented on February 1, 2016 at the 2016 Society for Range Management meeting in Corpus Cristi, TX., and discussions with some of the local public land stewards are planned for January.  Data from this project is forming the basis for one of my dissertation chapters.  Presentations, extension publications and online resources, my dissertation, and refereed papers will all contribute to increasing knowledge and understanding of how livestock grazing practices in forested landscapes influence the natural resource condition and its ability to sustainably provide goods and services, and may lead to improved management practices which increase profitability, environmental quality, and quality of life.