Life at the Top: Four Rare Alpine Plants of Great Basin National Park Are Moving Uphill

Great Basin National Park, the University of Nevada, Reno, and botanist Jan Nachlinger set out to track how the ranges of four rare alpine plants have changed and may change in future:

• Nachlinger catchfly (Silene nachlingerae);
• Holmgren's buckwheat (Eriogonum holmgrenii);
• Nevada primrose (Primula cusickiana var. nevadensis);
• Pennell beardtongue (Penstemon leiophyllus var. francisci-pennellii).

All four are rare herbaceous plants of conservation concern, found at high elevations and endemic — limited to the park or a few other ranges of eastern Nevada. Living on the highest ground, they have nowhere higher to go as temperatures rise, and with so few locations they have no "backup" populations. That makes them especially vulnerable to human-caused climate change.

Two surveys, 15 years apart

Researchers Wade Plafcan and Thomas Albright mapped where the plants grew in the past, where they grow now and where they may grow in future. They compared a survey from 2004–2006 with a new one, and current climate with the climate projected for the mid-21st century, and looked for the environmental factors most tied to each plant's habitat and the places most important to conserve.

Armed with GPS units, sturdy boots and plenty of water, the team searched thousands of acres in the summers of 2021 and 2022 — sometimes three or four people on hands and knees for minutes to find a single plant. Thanks to the earlier survey, they could look for places where plants had died out and new populations had appeared. They found about half of the plants still where they had been.

The comparison revealed a potentially alarming pattern. For every species, plants low in its elevation range were more likely to have disappeared, while new and surviving populations were higher up — an upward shift. Many alpine species are moving uphill to track cooler conditions, but those already on the summits may run out of room. New populations of Holmgren's buckwheat, for example, averaged 11,150 feet, against 10,500 feet for the plants lost since the earlier survey.

Modelling the future

Beyond cutting greenhouse gas emissions worldwide, the best protection for such species is to find suitable habitat and focus conservation there. Species distribution models relate where a species grows to environmental conditions — here climate, terrain and soils — to map likely habitat now and in future, and show which conditions matter most for each species. The models were projected to 2050 and 2070 under several climate scenarios, combining different emissions, warming and wetter or drier conditions.

• Nachlinger catchfly is of greatest concern: it could lose almost all its favourable habitat by 2050.
• Pennell beardtongue may lose a moderate amount and shows the largest predicted rise in average elevation, which could fragment its habitat.
• Holmgren's buckwheat and Nevada primrose are predicted to be fairly stable and might even gain habitat under some scenarios — although the survey comparison suggests they may already be shifting upward. Time will tell which is right.

Projected habitat change for Nachlinger catchfly to 2050 and 2070 under four climate scenarios: red for habitat lost, yellow stable, green gained; the black line is the park boundary. NPS.

What comes next

Continued monitoring will track changes and test the predictions. Precipitation will be especially important to watch: under the driest scenario, all four species lose substantial habitat. Snow, precipitation and temperature matter greatly to these plants' biology and timing, and a SNOTEL (Snowpack Telemetry) station set up near Wheeler Peak in 2011 will provide valuable data. Finding that range shifts may already be under way is jarring but not surprising. The researchers hope that cutting emissions can avoid the worst of climate change, and that conservation can protect these species and their habitats in the right places.

The article says the project began in fall 2021, but also that the team surveyed in the summers of 2021 and 2022; this page gives no start date.

Words on this page from people and organisations outside the federal government are paraphrased; rewritten in hubnx's own words.

Sources

• Wade Plafcan and Thomas Albright, researchers, University of Nevada, Reno, "Life at the Top: Range Shifts of Four High Elevation Plants," The Midden (Great Basin National Park), vol. 22, no. 2, winter 2022, National Park Service. https://www.nps.gov/articles/000/life-at-the-top-range-shifts-of-four-high-elevation-plants.htm
• The article's photographs, by Wade Plafcan, are not reproduced here.