Poster
Threatening the giant: the response of Vesubia jugorum (Araneae, Lycosidae) to climate change Isaia, Marco Milano, Filippo; Mammola, Stefano;
1Department of Life Sciences and System Biology, University of Turin, Torino, Italy
Human-driven climate deterioration is expected to cause altitudinal shifts in biomes. There is a concern for high alpine species that suitable habitats will be reduced, and populations of cold-tolerant species living on mountain summits will be increasingly fragmented. Vesubia jugorum, the giant Alpine wolf spiders, represents a typical example of such cold-adapted species, as it occurs exclusively on rocky lands above 2,300 m asl. The species is paleoendemic, reported exclusively from the Maritime Alps (NW- Italy), with a very reduced number of populations reported in literature. On the base of literature and new original data, we generated a dataset comprising 37 occurrence of the species that we employed to model potential present distribution of the species via Ecological Niche Modeling (ENM). On the base of the model results, we estimated the bioclimatic suitability of V. jugorum in the past (Last Glacial Maximum, Pleistocene) and in the future, by projecting the present-day model into different global warming scenarios predicted by the International Panel on Climate Change (IPCC). As expected, given the colder climatic condition in the Pleistocene, the potential past distribution of V. jugorum was found to be wider than today. Future forecasts based on different temperature scenarios showed a general declining trend of suitable areas all over the investigated area. We interpreted our results in light of the expansion–contraction model, which describes the response of species to the fluctuations in temperature during glacial-interglacial cycles. According to our results the gian Alpine spider expanded its distribution during cooler periods and contracted it during interglacials. Therefore, we hypothesize that the species is currently in a refugial phase, and we suggest that future warmer conditions might determine a further contraction of the range.
