Biodiversity and ecology of plants and arthropods on the last preserved glacier of the Apennines mountain chain (Italy)

Abstract

In the current global warming phase, relict glacial areas are one of the most threatened ecosystems in the world. They are “cold-spots” of biodiversity and of great interest both from the ecological and conservation point of view. We investigated the biological communities (plants and arthropods) hosted by one of the southernmost European glaciers: Calderone Glacier, the last preserved glacier of the Apennines mountain chain (Italy). We analyzed supraglacial debris and the nearby moraine and we found a rather diverse and peculiar biodiversity, which includes also new species. Some arthropods, such as the springtail Desoria calderonis, are particularly sensitive to the presence of ice at microtopographic level. Among plants, only Arabis alpina caucasica is able to grow on the supraglacial debris, perhaps because of factors related to the seed germination and seedling survival on this habitat type. Calderone glacier, with its particular biogeographic location, is probably currently acting as one of the last refugia for rare and endemic cryophilic species within the Mediterranean Region during the ongoing warm period.

Glacial biodiversity of the southernmost glaciers of the European Alps (Clapier and Peirabroc, Italy)

“…The Maritime Alps represent a peripheral chain with a unique combination of specific climatic features and taxonomic richness, with particular reference to endemic species. Due to their great variability and to the importance of glacial habitats as refugium for cold-adapted and endemic threatened species (Valle et al 2021(Valle et al , 2022, it is important to expand the number of case studies in order to have a more complete vision of the phenomenon.…”

“…An additional effect of climate change observed is the increase of supraglacial stony debris due to the reduction of the pressure of the ice volume on the headwalls and the amplification of frost and heat weathering that increase their erosion (Paul et al 2007). The supraglacial debris can hosts cold-adapted species currently threatened by global warming (Caccianiga et al, 2011;Gobbi et al 2011Gobbi et al , 2017Valle et al 2020;Valle et al 2022) and reduces the ablation rate (Nakawo and Rana 1999), thus potentially acting as refugium for these species during the current warm climatic stage.…”

Spatial distribution and stable isotopic composition of invertebrates uncover differences between habitats on the glacier surface in the Alps

“…Apart from cryoconite holes, some parts of glacier surface are covered by a layer of gravel and stones called supraglacial debris (e.g., Azzoni et al 2016). Due to glacier melting, supraglacial debris is a dynamic semi-aquatic environment which, depending on region and glacier, is inhabited by organisms, such as nematodes, springtails, and other minute and macro-arthropods (Buda et al 2020;Valle et al 2022;Zawierucha et al 2021). The surface of the ablation zone mostly consists of weathering crust (highly porous surface ice formed by solar heating of the glacier surface) which, due to microscopic water veins, can be compared to a shallow-perched aquifer with enhanced microbial activity on the glacier surface (Christner et al 2018;Cook et al 2016;Patterson 1994).…”