In past times of warming, alpine mammals adapted with mixed success

If history is any guide, the ability for alpine fauna to adapt in the face of climate change may depend on the particular ecological nuances of different alpine environments, as study published in Biology Bulletin has found¹.

Based on an analysis of mammalian biodiversity during major warming and cooling period in our planet’s climatic past, researchers at the Russian Academy of Science’s Institute of Geography in Moscow have shown that the species richness and turnover in response to rapid temperature swings in alpine regions often differs from one mountain range to the next.

“The evolution of regional fauna shows features that most likely result from the geographic location of a particular mountainous region,” says study co-author and paleobiologist Andrey Yur’evich Puzachenko.

Climate change poses a grave threat to the health of all ecosystems—and high alpine zones, with their spectacular landscapes and rich biological diversity, are no exception. Mountain-dwelling animals are already seeing their habitats shift and shrink amid rising temperatures and extreme weather patterns, with many now pushed to the brink of extinction.

For a window into those animals’ future, Puzachenko looked to the past. With colleague Anastasia Markova, he developed statistical tools known as multivariate descriptive models to calculate changes in biological diversity among mammals living in six different alpine terrains of Eurasia over the past 130,000 years.

The researchers chose to focus on mountain ranges in particular because alpine ecosystems generally host a high degree of biodiversity, while also being particularly sensitive to temperature shifts and other environmental stresses that can push resident animals to the brink. The six locations studied were also spread widely across the entire Eurasian landmass, spanning 8,000 kilometres from the Pyrenees in southwest Europe to the Urals in western Russia and the Altai-Sayan region of central Asia.

Focusing on the last two periods of glacial retreat—one about 125,000 years ago, the other some 12,000 years ago—the researchers found differences in how the various mammal communities in each mountain chain evolved in response to the two warming events.

Fluctuations in species richness were also much more susceptible to rising temperatures in some regions over others. For example, the population crashes of cave bears, cave lion, cave hyena, and other cold-adapted megafauna populations was much more pronounced in European mountain regions compared to those in Asia.

“This transition did not take place simultaneously in different regions,” notes Puzachenko. “It was expressed in different ways.”

A similarly complex range of responses could be in store for today’s mountain mammals as they strive to adapt, yet again, to a warming world.