Rock glaciers and related cold rocky landforms: overlooked climate refugia for mountain biodiversity

Abstract

Mountains are global biodiversity hotspots where cold environments and their associated ecological communities are expected to shift upward and disappear as climates warm. Considerable research attention has been focused on the ecological effects of alpine glacier and snowfield recession and warming temperatures in aquatic and terrestrial habitats. However, little attention has been devoted to identifying climate refugia in mountain ecosystems where present-day environmental conditions will be maintained, at least in the near-term, as other habitats change. Around the world, montane communities of microbes, animals, and plants live on, adjacent to, and downstream of rock glaciers and related cold rocky landforms (CRL). These geomorphological features have been overlooked in the ecological literature despite being extremely common in mountain ranges worldwide with a propensity to support cold, stable terrestrial and aquatic habitats. Due to the insulating nature of debris cover and their internal ventilation patterns, CRLs are less responsive to atmospheric warming than alpine glaciers and snowfields. Here, we argue that CRLs represent global climate refugia for mountain biodiversity, offer guidelines for incorporating CRLs into management practice, and identify key areas where future research is needed.

New distributional data for the northern forestfly,Lednia borealisBaumann and Kondratieff, 2010 (Plecoptera: Nemouridae), Washington, USA

“…increasing evidence shows that these features are highly important to mountain stream biodiversity (Brighenti et al 2020. Regardless, the most abundant habitat for L. borealis in Washington is likely in the North Cascades ecoregion.…”

Contrasting physical and chemical conditions of two rock glacier springs

“…Rock glaciers are efficient thermal buffers, and for this reason they represent potential climate refugia for cold‐adapted terrestrial and aquatic organisms under global warming (Brighenti et al, 2021). Springs fed by intact rock glaciers are typically very cold (<2°C), which testifies to the occurrence of permafrost (Carturan et al, 2016).…”

Consensus-Based Rock Glacier Inventorying in the Torngat Mountains, Northern Labrador

“…Recent studies show that rock glaciers exhibit complicated kinematic responses to climate change (Eriksen et al 2018;Scotti et al 2017;Sorg et al 2015) but can be associated with geocryological hazards (Marcer et al 2020) and can distribute large quantities of freshwater into local ecosystems (Jones et al 2019b). Further, rock glaciers are of significant ecological importance as they provide long-term cold habitat for local biodiversity (Brighenti et al 2020). Numerous studies have used rock glaciers to inform interpretations of past or present permafrost distributions in areas where in situ observations of permafrost conditions are limited (Fernandes et al 2017;Lilleøren et al 2013;Marcer et al 2017;Sattler et al 2016;Schmid et al 2015).…”