Coming Up in Yellowstone Science: The Vital Signs Issue
by Andrew Ray, Adam Sepulveda, David Thoma, Mike Tercek, Robert Al-Chokhachy, & Robert Diehl
In medicine, vital signs, such as blood pressure and pulse rate, are simple routine measurements used to assess human health. When tracked over time, vital sign measurements contribute to diagnoses and support decisions concerning the response of patients to medical treatments. Slight abnormalities in vital sign measurements (e.g., elevated body temperature) are usually not critical but may warrant a more careful diagnosis, whereas extremely abnormal vital signs may indicate a life-threatening condition requiring an immediate medical response.
Vital sign monitoring has strong parallels in ecology for understanding the health and function of plant and animal populations, ecosystems, parks, and even the Earth itself. Ecological vital signs include both physical and biological indicators that are sensitive to environmental change. Monitoring of vital signs can also reveal when ecosystems reach critical thresholds or tipping point. The most valuable vital sign indicators can be used to support decisions that promote human and ecological health and characterize the success of past management actions. To highlight the importance of indicators, consider how miners historically used caged birds to detect dangerous levels of carbon monoxide. A sick or dead bird served as a warning sign, prompting evacuation and cementing the phrase “canary in the coal mine” into our everyday language. Today, ecological vital sign surveillance programs employ reliable and standardized measurements to assess whether a physical or biological indicator is functioning within a natural or historical range of variation and whether it is nearing an ecological tipping points (Tierney et al. 2009).
Physical indicators include streamflow volumes, snowpack depths, and air temperatures. Tracking these indicators reveals important information about the health of parks, but the combined monitoring of physical and biological vital signs offers more clear evidence of ecosystem change. For example, increases in Yellowstone’s air temperature changed more precipitation to rain than snow and, ultimately, contributed to snowpack declines (Tercek and Rodman 2016). Reductions in snowpack lead to reduced soil moisture and, in turn, can alter the distribution of plant and animal species and rearrange the mix of species present. Since Yellowstone’s ecology is tightly linked to snow, increases in air temperature and reductions in snowpack may have cascading effects on ecological health.
As with humans, we argue that ignoring vital signs has real consequences for the health of our parks and surrounding natural areas. Further, tracking just one or two vital signs is as insufficient to characterize human health as it is the health of a complex ecosystem or park. Lastly, extremely abnormal vital signs are just as serious for ecosystems as they are for humans and may require a response matching in intensity. For example, following declines in Yellowstone cutthroat trout, a systematic removal of non-native lake trout was initiated to aid in the restoration of cutthroat trout in Yellowstone Lake and head off larger problems and more costly interventions (Arnold et al. 2017, Bigelow et al. 2017).
Yellowstone, like many of our nation’s parks, encompasses some of the most pristine and intact ecosystems— vital sign monitoring is a critical part of managing these ecosystems “for the enjoyment of future generations.” Beginning in 2000, the National Park Service’s Vital Signs Monitoring Program formalized the use of ecological vital signs to track the health of national parks (Fancy et al. 2009, Rodhouse et al. 2016). The Greater Yellowstone Network and its partners formally began collecting data on several vital signs in Yellowstone National Park and across neighboring public lands (Jean et al. 2005). Whitebark pine, river water quality, and wetland and amphibian vital sign monitoring programs were launched and began generating regional information on vital signs that were believed to be experiencing stress at regional and global scales. The next issue of Yellowstone Science will discuss how monitoring ecological vital signs is being used to understand and assess the health of Yellowstone National Park and the surrounding area. Through a series of Feature and Short articles, we will summarize how vital sign trends are likely to shape the future of future of the Greater Yellowstone Ecosystem.
Arnold, J.L., P.D. Doepke, B.D. Ertel, and T.M. Koel. 2017. Fish population responses to the suppression of non-native lake trout. Yellowstone Science 25:60-64.
Bigelow, P.E., P.D. Doepke, B.D. Ertel, C.S. Guy, J.M Syslo, and T.M. Koel. 2017. Suppressing non-native Lake Trout to restore native cutthroat trout in Yellowstone Lake. Yellowstone Science 25:53-59.
Fancy, S.G., J.E. Gross, and S.L. Carter. 2009. Monitoring the condition of natural resources in U.S. National Parks. Environmental Monitoring and Assessment 151:161–174.
Jean, C., A.M. Schrag, R.E. Bennetts, R. Daley, E.A. Crowe, and S. O’Ney. 2005. Vital signs monitoring plan for the Greater Yellowstone Network. National Park Service, Greater Yellowstone Network, Bozeman, Montana, USA.
Rodhouse, T.J., C.J. Sergeant, and E.W. Schweiger. 2016. Ecological monitoring and evidence-based decision-making in America’s national parks: highlights of the special feature. Ecosphere 7: e0 1608.
Tercek, M., and A. Rodman. 2016. Forecasts of 21st century snowpack and implications for snowmobile and snowcoach use in Yellowstone National Park. PLoS ONE 11: e0159218.
Tierney, G.L., D. Faber-Langendoen, B.R. Mitchell, W.G. Shriver, and J. P. Gibbs. 2009. Monitoring and evaluating the ecological integrity of forest ecosystems. Frontiers in Ecology and the Environment 7:308-316.
Last updated: April 10, 2019