**6. Conclusions**

*Glaciers and the Polar Environment*

now available on their effects on ground beetle fauna.

more successfully enhance and protect glacial biodiversity.

naturalistic value of glacialized mountain regions.

well as the glacial biodiversity they host.

**services**

Among organic contaminants detected in glacier-fed streams, attention was paid to the insecticide chlorpyrifos, since high toxicity to insects and peak release by glacier melting occur concurrently with the period in which the streams are more densely populated by macroinvertebrates [76]. Chlorpyrifos and other organophosphate insecticides are known to exhibit increased toxicity in invertebrates at elevated temperatures [77]. Specifically, warming influences chlorpyrifos uptake in aquatic insects magnifying its negative effect on fauna. Other contaminants are heavy metals released by remains of the Great War, such as bombs, bullets, cannon parts and barbed wire buried in the ice 100 years ago, that are emerging due to glaciers retreating. These new sources of contamination have been recently documented for ice melt waters in the Italian Alps (mainly by nickel, arsenic and lead, unpublished data). Contamination of soils of the 1914–1918 Western Front zone, in Belgium and France by copper, lead and zinc was previously detected by [78]. Pesticides, fragrances and heavy metals affect swimming behavior and metabolism of *Diamesa* species from glacier-fed streams [79] at trace concentration (in order of ng/L), with still unknown effects on aquatic food web and on terrestrial fauna (*via* food web). To our knowledge, the understanding of final environmental fate of such pollutants is still scarce and fragmentary. Recently, evidences of microplastic bioaccumulation are given for freshwater amphipods from Svalbard glacier-fed streams [80] and for *Diamesa zernyi* larvae from the Amola Glacier-fed stream (Italy). No information is

**5. Role of glacial biodiversity in the glacial-ecosystem functioning and** 

Given the global change scenarios, it is opportune to analyze the role of glaciated areas in the context of persistent change from the physiographic point of view as

Standardized long-term monitoring, additional high-quality empirical studies on key organisms and landforms, and further development of analytical methods are of extreme importance in helping to quantify the extinction debt better and to

Glacier shrinkage will alter hydrological regimes, sediment transport, and biogeochemical and contaminant fluxes from rivers to oceans, which will profoundly influence the natural environment and the ecosystem services that glacier-fed rivers provide to humans, particularly provision of water for agriculture, hydropower and consumption [4]. Biodiversity influences ecosystem functioning through changes in the amount of resource use or water self-depuration processes (regulating services)

Glacial biodiversity has an intrinsic value; most of the species are highly specialized to live in harsh environments, thus highly vulnerable to changes also of low intensity, have low dispersal ability and in most of the glacialized area of the world are endemic. Therefore, glaciated areas become territories with a collection of communities and species that mostly differ from those dominant in middle and low altitudes as well as differ between geographic areas. In addition, insects and other arthropods (e.g., spiders) living on the moraines, on the glaciers or flying on the glaciers (e.g., chironomids and stoneflies) act as additional source of food for some high-altitude mammals and bird species living at the edge of ice-related landforms [81, 82]. Therefore, glacial biodiversity is able to furnish an additional important

Aquatic and terrestrial insects living in glacialized areas are trophically connected [83, 84], but not all insect groups react in the same way to the ongoing

but is also a source of scientific and tourist attraction (cultural service).

**156**

A recent large-scale study aimed to investigate trends in insect abundances over space and time has brought evidences about an average decline of terrestrial insect abundance (ca. 9%) per decade and an increase of freshwater insect abundance (ca. 11%) per decade. Both patterns were particularly strong in North America and some European regions [85], and the hypothesized drivers are land-use change and climate change.

Ground beetles and non-biting midges are among the animals best adapted to live at high altitudes, specifically to colonize the glaciers and surrounding terrestrial and aquatic habitats. They are present with few species adapted to low temperatures and food scarcity, factors that make these habitats extreme for life.

Spatio-temporal shift in insect communities in relation to the ongoing climate change is one of the most common patterns in mountain regions, but it is important to highlight that it will not affect all species equally [85, 86]. Aquatic and terrestrial insect communities seem to be differently affected by climate change. Firstly, because temperature variability is stronger on the ground with respect to water, aquatic insects are required to make smaller behavioral or physiological adjustments than terrestrial insects and aquatic habitats will be more buffered from climate warming [86]. In addition, terrestrial insects may have wider opportunities to survive in appropriate microclimate colonizing or surviving in ice-related microhabitat, thanks to the higher microhabitat heterogeneity on the ground with respect to the aquatic habitat.

The chapter provides a synthesis about the fascinating adaptations in morphology, behavior and physiology in terrestrial and aquatic species, on the species distribution in relation to the ice-related landform heterogeneity and on which species are threatened with extinction due to climate change and pollution. The future challenge will be to try to improve the knowledge of the glacial biodiversity in high-altitude and high-latitude areas notwithstanding the difficulty of accessing most of these areas.

Three research goals should be addressed in the near future: (i) increase the studies aimed at describing the glacial biodiversity; (ii) plan long-term monitoring projects in key areas and (iii) improve the scientific communication about the threats on high-altitude habitats. Thus, with this chapter, we are confident to inspire young researches to investigate the life in glacial ecosystems of the world before its possible disappearance.
