Main Narrative » Fragile Alpine Ecosystems

Alpine Refugia

By Charles J. Zimmerman

Sep 27 2019

Mountaintops have served as unlikely shelter for populations of cold-adapted species throughout geological history. During the last Pleistocene ice-age, when global temperatures were substantially lower and glaciers covered up to 25% of the Earth surface, plants and animals took refuge on high-mountains which peaked above the ice. Geographically isolated from one another, many creatures that inhabited these mountain-top islands (called "Nunatuks") became evolutionarily distinct species.

The traces of this phenomenon can be observed by the prevalence of endemic plants (which occur nowhere else on earth) in today’s mountain ranges. Olympic Mountain Groundsel (Senecio neowebsteri) is one example of a species that diverged from wider-ranging ancestors and now exists exclusively within a narrow Alpine region on the Olympic Peninsula in Washington State. Unfortunately, forecasted climate changes indicate that Alpine habitats, which have harbored species and spawned new biodiversity for thousands of years, may no longer provide conditions of sanctuary for many endemic species.

A Closer Look

More about: Climate change


Wershow, S.T. & DeChaine, E.G. (2017). Retreat to refugia: Severe habitat contraction projected for endemic alpine plants of the Olympic Peninsula. American Journal of Botany 105(4): 760-778.