Assessing Large Herbivore Management Strategies in the Northern Great Plains Using Rangeland Health Metrics

Abstract

Maximizing rangeland health has become a popular theme in North American grassland management. Quantifying rangeland health is particularly important when attempting to compare different management strategies ongoing in priority conservation areas, such as those within the Northern Great Plains (NGP). We investigated the response of five vegetative components of rangeland health to three large grazer management strategies on individual sites within public and private rangelands in northeastern Montana: Bureau of Land Management allotments that continuously maintained rotational cattle (Bos taurus) grazing, US Fish and Wildlife Service designated wilderness areas where cattle were removed, and lands managed by the American Prairie Reserve where cattle were removed and bison (Bison bison) were reintroduced. We then compared sites relative to historical climax plant community (HCPC) conditions—our management target. Our bison-restored site had exotic plant abundances most similar to the HCPC, and significantly lower than our other sites. Our cattle-removal site maintained litter cover most similar to the HCPC, while other sites were lower than target conditions. Overall, differences among our bison-restored and cattle-retention sites were slight relative to the HCPC. Although our treatments were represented by a single site, no single management strategy achieved all five vegetative measures of rangeland health based on HCPC targets. We observed several differences between sites that could inform future grazer management in this region. We provide a novel process to quantifiably compare rangeland health across areas with different grazer management approaches. Without quantitative assessments and long-term monitoring, assessing rangeland health can be overly subjective, and may not inform ongoing concerns surrounding grazing management in the NGP.