Cryospheric ecosystems: a synthesis of snowpack and glacial research

Abstract

The fourteen letters that contributed to this focus issue on cryospheric ecosytems provide an excellent basis for considering the state of the science following a marked increase in research attention since the new millennium. Research letters from the focus issue provide significant insights into the biogeochemical and biological processes associated with snow, glacier ice and glacial sediments. This has been achieved via a significant, empirical effort that has given particular emphasis to glacier surface habitats. However, far less is known about aerobiology, glacial snow covers, supraglacial lakes and sub-ice sedimentary habitats, whose access for sampling and in-situ monitoring remains a great challenge to scientists. Furthermore, the use of models to explore key fluxes, processes and impacts of a changing glacial cryosphere are conspicuous by their absence. As a result, a range of process investigations and modelling studies are required to address the increasing urgency and uncertainty that is associated with understanding the response of cryospheric ecosystems to global change.

Water bears dominated cryoconite hole ecosystems: densities, habitat preferences and physiological adaptations of Tardigrada on an alpine glacier

“…Despite the fact that the understanding of cryoconite holes and glacial ecosystems is increasing (Cook et al 2015;Pittino et al 2018;Perini et al 2019;Takeuchi et al 2018), the knowledge on tardigrades inhabiting them is still far from satisfactory and may limit our understanding of the functions, dynamics and trophic relations in supraglacial ecosystems. Therefore, all knowledge on organism's dynamics, dispersal and interactions with ice must be acquired in order to understand biological aspects of the glacial biome (Hodson et al 2015;Cook et al 2015Cook et al , 2016. As a model, we used tardigrades in alpine cryoconite holes that contain these common, relatively large, black animal, which facilitates their observations.…”

Rapid development of anoxic niches in supraglacial ecosystems

“…Cryoconite holes are a distinct microbial niche within the polar biome (Anesio and Laybourn-Parry 2012b;Hodson et al 2015b). They are formed when dark-colored dust particles deposited on ice surfaces melt into the surrounding ice, creating a cylindrical or quasi-cylindrical hole that is filled with water and has a sediment layer at the bottom (Bagshaw et al 2007;Porazinska et al 2004b).…”

From dwindling ice to headwater lakes: could dams replace glaciers in the European Alps?

“…In support of such a possible utilization, the supposed 'neutrality' in terms of ecological value of the surfaces becoming ice-free is sometimes mentioned: Since the exposed forefields are bare, non-vegetated and relatively simple in their ecosystem structure (e.g. Nemergut et al 2007, Hodson et al 2015, a potential exploitation could result in comparatively limited ecological impacts. Similarly, it could be argued that an intervention in the uppermost part of a given river stretch would have only minimal consequences on river continuity.…”