Climate‐induced glacier and snow loss imperils alpine stream insects

Abstract

Climate warming is causing rapid loss of glaciers and snowpack in mountainous regions worldwide. These changes are predicted to negatively impact the habitats of many range-restricted species, particularly endemic, mountaintop species dependent on the unique thermal and hydrologic conditions found only in glacier-fed and snow melt-driven alpine streams. Although progress has been made, existing understanding of the status, distribution, and ecology of alpine aquatic species, particularly in North America, is lacking, thereby hindering conservation and management programs. Two aquatic insects - the meltwater stonefly (Lednia tumana) and the glacier stonefly (Zapada glacier) - were recently proposed for listing under the U.S. Endangered Species Act due to climate-change-induced habitat loss. Using a large dataset (272 streams, 482 total sites) with high-resolution climate and habitat information, we describe the distribution, status, and key environmental features that limit L. tumana and Z. glacier across the northern Rocky Mountains. Lednia tumana was detected in 113 streams (175 sites) within Glacier National Park (GNP) and surrounding areas. The probability of L. tumana occurrence increased with cold stream temperatures and close proximity to glaciers and permanent snowfields. Similarly, densities of L. tumana declined with increasing distance from stream source. Zapada glacier was only detected in 10 streams (24 sites), six in GNP and four in mountain ranges up to ~600 km southwest. Our results show that both L. tumana and Z. glacier inhabit an extremely narrow distribution, restricted to short sections of cold, alpine streams often below glaciers predicted to disappear over the next two decades. Climate warming-induced glacier and snow loss clearly imperils the persistence of L. tumana and Z. glacier throughout their ranges, highlighting the role of mountaintop aquatic invertebrates as sentinels of climate change in mid-latitude regions.

Congruent population genetic structure but differing depths of divergence for three alpine stoneflies with similar ecology and geographic distributions

“…yond those previously described(Baumann & Call, 2012;Baumann & Kondratieff, 2010;Giersch et al, 2016;Jordan et al, 2016;Muhlfeld et al, 2011). Phylogenetic analyses strongly supported the existing, morphology-based Lednia taxonomy with PPs of 1.0 for all nodes and described species resolved as monophyletic (Figure 3b).…”

“…In contrast, very few Lednia adults have been collected earlier than mid-August (Baumann & Call, 2012;Baumann & Kondratieff, 2010;Giersch et al, 2015Giersch et al, , 2016, and L. tumana adults have been collected into October (Baumann & Kondratieff, 2010 Beerli and Palczewski (2010). In contrast, very few Lednia adults have been collected earlier than mid-August (Baumann & Call, 2012;Baumann & Kondratieff, 2010;Giersch et al, 2015Giersch et al, , 2016, and L. tumana adults have been collected into October (Baumann & Kondratieff, 2010 Beerli and Palczewski (2010).…”

Environmental DNA metabarcoding: Transforming how we survey animal and plant communities

“…Groundwater microorganism metabarcoding studies have shown high fungal (Sohlberg et al, 2015) and bacterial (Kao et al, 2016) (Valiere & Taberlet, 2000). Environmental DNA metabarcoding of water from glacial run-off will also likely be a valuable tool to survey animal and plant richness living in glacial and subglacial habitats, which are undergoing dramatic change because of climate warming (Giersch, Hotaling, Kovach, Jones, & Muhlfeld, 2017).…”

Demographic modelling reveals a history of divergence with gene flow for a glacially tied stonefly in a changing post‐Pleistocene landscape

“…Lednia tumana inhabits short sections (~500 m) of cold, meltwater streams directly below glaciers, permanent snowfields and groundwater‐fed springs (Giersch et al., ; Muhlfeld et al., ). As glaciers and permanent snowpack decline, L. tumana 's range is expected to contract by more than 80% (Giersch et al., ; Muhlfeld et al., ). Historical and contemporary patterns of genetic diversity and demographic history for L. tumana however, remain explored.…”