Climate change a threat to Great Plains bison sustainability

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BROOKINGS – Accelerating climate change throughout the Great Plains may present the next major challenge to bison sustainability.

That is the main point the director of research for the Center of Excellence for Bison Studies at South Dakota State University, Dr. Jeff Martin, made in his article recently published in the People and Nature journal, titled “Vulnerability assessment of the multi-sector North American bison (Bison bison) management system to climate change.”

The article was a collaboration with researchers from Texas A&M University and Colorado State University. It can be found at: https://besjournals.onlinelibrary.wiley.com/doi/full/10.1002/pan3.10209.

“Climate change directly affects bison by increasing thermal stress and decreasing forage and water availability, issues that also challenge range beef cattle,” Martin says. “Indirect consequences of climate change include increasing distribution and intensity of parasites and several diseases that are known to reduce reproductive success. These stresses have been estimated to collectively reduce bison body size by 50% if global temperature warms by 4°C near the end of the 21st century.”

Furthermore, warming and drought may also result in declining productivity of the remaining grasslands of the Great Plains, which are the preferred habitat for both bison and cattle.

“Currently, 90% of grasslands and 85% of bison are privately owned, which justifies the need for robust private land conservation strategies to maintain this iconic species and its grassland habitats,” Martin says.

The current bison population of North America is approximately 400,000 animals and is maintained by a self-assembled bison management system (BMS). Martin and his team coined the term ‘bison management system’ as a way to describe the whole system of bison managers that represent a multi-sector interest in the conservation and production of bison across private, public, tribal and non-governmental organization (NGO) sectors. It is a unique animal management system in the world.

Martin conducted a vulnerability assessment of the bison management system to increasing climate variability and change to further clarify the challenges that bison conservation and production may face in future climates. He surveyed 132 bison managers within the private, public and NGO sectors located in North America, who mostly reside in the northern and central mixed-grass prairies and manage bison herds averaging 51-100 animals. He collected data on the exposure, sensitivity and adaptive capacity of the managers to climate change. 

“Results from the survey revealed that the bison management system is vulnerable to climate change and is susceptible to losing sustainability without preparing adaptation strategies for impending climate change issues such as warming, increasing drought and a resulting decline in productivity of grasslands,” Martin says. 

The study showed that access to grazing leases, varied external income, use of management plans and information exchange are variables that present stumbling blocks for bison managers across the private, public and NGO sectors to advance their adaptation to climate change and sustainability.

“The experiences and shared environmental values and attitudes of bison managers across the bison management system are foundational to enhanced collaboration across sectors,” Martin says. “We believe it would be beneficial for the bison management system to form a bison coalition to instigate enhanced coordination of knowledge sharing.”  

The Center of Excellence for Bison Studies is a partnership between South Dakota State University, the National Bison Association and the National Buffalo Foundation. Headquartered at SDSU’s West River Research and Extension Facility in Rapid City, South Dakota, the center focuses on research activities to improve bison herd health and the economic viability of both private and tribal bison producers.