Recent research combining remote sensing with field observations in Yellowstone National Park has shown that bison can "engineer the green wave" (1). That is, their grazing changes the timing and speed of the spring greening across prairies. Bison grazing causes grasslands to green up faster, more intensely, and for longer duration. Cattle graze differently from bison (2), and therefore they are likely to have different effects on the dynamics of the green wave, as well as soil attributes and biodiversity. On evolutionary grounds, it is reasonable to hypothesize that native plant communities will exhibit greater resilience and total sequestration of carbon under grazing by bison, with which they coevolved, than under grazing by cattle, which are non-native. However, important questions about the ecological benefits of bison versus cattle in various grassland ecosystems remain unresolved (3-5).
The Shoshone and Arapaho tribal buffalo program has recently reintroduced bison in and around the Wind River Reservation, in Wyoming, and further expansions of the program are planned for the near future. This program is one example of several in which grasslands that were previously unoccupied or grazed by cattle have been repopulated at a known point in time with a population of bison of known size. This recent history of reintroduction offers a time-series of data from which we may be able to infer a great deal about the effects of bison on the ecological attributes of grasslands. Our plan in this lab is to investigate these areas using remote sensing together with existing data from ground-based observations to better understand the effects of bison reintroduction on prairie attributes such as the timing and intensity of "the green wave," carbon sequestration, soil characteristics, and possibly biodiversity.The steps in our proposed research are as follows:
1. Through communication with tribes around North America, compile a dataset documenting when and where a transition to bison has been or will be made. Simultaneously, through literature review, compile a meta-dataset of studies in which on-the-ground observations have been gathered in connection with bison reintroduction (such as (3, 5, 6)). It is possible that, in the course of this lab's work, grant funding will enable more field sampling.
2. Leveraging remote sensing datasets (7, 8), designate control plots that are matched for important ecological variables with our 'experimental plots,' but where bison were never reintroduced.
3. Build a machine learning model to predict remotely sensed properties, such as timing, intensity, and duration of spring green-up. With the help of this model, measure the effect of the presence or absence of bison on ecological variables. If connections between field measurements of ecological variables and remotely sensed data can be ascertained from the dataset compiled in step 1, investigate how inferred values of ecological variables are affected by bison reintroduction.
It is very clear that in certain cases the reintroduction of bison herds has played a pivotal role in regeneration not only of prairies but also of peoples (9). Further investigation of the relationship between bison and rates of carbon sequestration, resilience of prairie to climate change, and recovery of biodiversity could catalyze widespread transition to an ecologically and culturally beneficial choice to reintroduce bison to an increasing portion of their former range.
Gisel Booman is an experienced researcher who has been leading the Science Team at RND Inc. since 2018. In 2013, Gisel became an adjunct university professor, teaching GIS to agronomists at the UNMdP. Between 2015 and 2017, she was awarded a fellowship by CONICET, to contribute to the UE project iMetLand. She has authored important scientific publications and is the author of the CarbonPlus Grasslands Methodology, published on Regen Registry, with credits sold to the Microsoft Moonshot.
Jason Baldes sits on the board of directors for the Inter-Tribal Buffalo Council, board of trustees for the Conservation Lands Foundation, and the environmental commission of the Congress of Nations & States. He is the executive director of the Wind River Tribal Buffalo Initiative, and adjunct professor at Central Wyoming College and Wind River Tribal College. Jason is a member of the Eastern Shoshone Tribe and manages the Tribes’ herd of 65 buffalo.
1. C. Geremia et al., Migrating bison engineer the green wave. Proceedings of the National Academy of Sciences of the United States of America 116, 25707-25713 (2019).
2. M. T. Kohl, P. R. Krausman, K. Kunkel, D. M. Williams, Bison Versus Cattle: Are They Ecologically Synonymous? Rangeland Ecology & Management 66, 721-731 (2013).
3. N. A. McMillan, K. E. Kunkel, D. L. Hagan, D. S. Jachowski, Plant community responses to bison reintroduction on the Northern Great Plains, United States: a test of the keystone species concept. Restoration Ecology 27, 379-388 (2019).
4. R. C. Blackburn, N. A. Barber, H. P. Jones, Reintroduced bison diet changes throughout the season in restored prairie. Restoration Ecology 29, (2021).
5. L. E. Painter, W. J. Ripple, Effects of bison on willow and cottonwood in northern Yellowstone National Park. Forest Ecology and Management 264, 150-158 (2012).
6. M. Hillenbrand, R. Thompson, F. Wang, S. Apfelbaum, R. Teague, Impacts of holistic planned grazing with bison compared to continuous grazing with cattle in South Dakota shortgrass prairie. Agriculture Ecosystems & Environment 279, 156-168 (2019).
7. M. Drusch et al., Sentinel-2: ESA's Optical High-Resolution Mission for GMES Operational Services. Remote Sensing of Environment 120, 25-36 (2012).
8. D. P. Roy et al., Landsat-8: Science and product vision for terrestrial global change research. Remote Sensing of Environment 145, 154-172 (2014).
9. J. H. Haggerty, E. L. Rink, R. McAnally, E. Bird, Restoration and the Affective Ecologies of Healing: Buffalo and the Fort Peck Tribes. Conservation & Society 16, 21-29 (2018).