Alpine Lichens and Climate Change on Wheeler Peak

This article was originally published in The Midden – Great Basin National Park: Vol. 15, No. 1, Summer 2015.

By Nastassja Noell and Jason Hollinger, Researchers

In 1955 a lichenologist named Henry Imshaug climbed to the top of Wheeler Peak to inventory the alpine lichens. His study was part of a larger research project involving 92 alpine areas across western North America. This past autumn, we began revisiting Imshaug’s sites to evaluate whether alpine lichens have responded to climate change during the past 60 years, and if so, investigate methods for using lichens as biomonitors of climate change in alpine areas.

Lichens are widely regarded as “canaries in the coal mine”; the disappearance or appearance of certain sensitive species signals significant environmental changes, forewarning ecological shifts. The US Forest Service, Bureau of Land Management, and other agencies throughout the world use lichens to monitor the quality of forests and rangelands. Most land management studies involve lichen indices to evaluate air quality, forest health, or rangeland health. Emerging research suggests that lichens may also be useful bioindicators of regional climate change.

Our study investigates lichens as bioindicators of climate change by focusing on habitats that are relatively unaffected by anthropogenic factors: alpine habitats. Over the next few years, we will revisit Imshaug’s 92 baseline alpine lichen inventories, comb through tombs of his unidentified crustose lichens, and complete much of his unpublished work. Our results from Wheeler Peak suggest the endeavor is more than worthwhile.

On the summit of Wheeler Peak, the GLORIA vascular plant inventory found 15 species of plants; our preliminary survey found over 56 species of lichens. The ratio of nearly 1:4 (plants:lichens) is striking. Although this remarkable figure is reduced to 1:3 in the humid alpine habitats of the Northern Cascades, existing research suggests that lichens dominate the biodiversity of most alpine habitats in Western North America. Despite these numbers, most alpine researchers shy away from documenting lichens because of the difficulty of lichen taxonomy, a lack of local alpine lichen inventories, and a need for simple monitoring methodology. Our study aims to help close this gap.