Abstract
The widespread shrinking and retreat of glaciers and ice sheets drive changes in the biodiversity associated with glacial and glacier-adjacent environments. In a recent meta-analysis of global biodiversity responses to deglaciation, Cauvy-Fraunie and Dangles carefully compiled hundreds of primary studies and presented a compelling analysis of global biodiversity responses to deglaciation.
They found increases in the abundance and richness of 'generalist' taxa in glacieradjacent habitats, as well as a decline in 'specialists', following glacier retreat, and concluded that biodiversity increases locally as glaciers recede. Glaciers themselves were largely considered as abiotic agents, affecting downstream moisture, temperature and salinity, and their intrinsic biodiversity ignored, while only glacier-adjacent habitats (tidewater glacier fjords, glacier-fed freshwaters and glacier forefields) were reported for their changes in biodiversity.
However, it is now widely accepted that glaciers and ice sheets comprise unique habitats that host distinctive organisms and metabolically active populations that form communities, and facilitate key connections to neighbouring ecosystems, all of which may be severely altered, reduced or lost following deglaciation. The lack of data on glacial ecosystems in a global synthesis of biodiversity responses to glacier retreat is a warning sign that the biodiversity of glacial habitats is still largely unquantified, overlooked by the broader ecology community and probably underestimated.
This is especially worrisome given the magnitude of glacial habitat loss anticipated this century