Range shift and climatic refugia for alpine lichens under climate changes

Mountain biodiversity is highly threatened by climate change, with many species facing habitat reduction and/or local extinction. Poikilohydric organisms like lichens are extremely sensitive to environmental conditions and changes. A comprehensive overview of the impact of climate change on the future distribution of lichens is still missing. Thus, we quantified the range shift, loss in suitable areas, and potential climatic refugia for more than 250 lichens, exploring these trends for each species and grouping them by their ecological needs and functional traits. We performed species distribution models to investigate the range shifts of 272 lichens under different climate change scenarios. Range shift was investigated by modelling gain and loss in suitability score along the elevational gradient, for each species separately, and grouping them based on growth forms and temperature affinities. Based on the \"high suitability score stability\" index, we developed maps of potential refuge a..., The lichen occurrences were derived from the following sources: Dolichens (https://italic.units.it/dolichens/), ITALIC 7.0 (https://italic.units.it/), GBIF (https://www.gbif.org/). We retained only occurrence data collected after 1975 and with a coordinate uncertainty of 500 m or less. To reduce spatial bias due to pseudo-replication of occurrences, we performed spatial thinning. Then, we retained only the species with at least 25 occurrence records, a limit that has been shown to provide reliable results in modeling studies. The resulting dataset includes 25 to 469 occurrence records of 272 infrageneric taxa, for a total of 23,521 occurrences. For each species, we generated 10 replicate sets of background points, in a 10:1 ratio with the number of presence points, with an exclusion buffer of 500 m from the presence point.
, , # Range shift and climatic refugia for alpine lichens under climate changes

Dataset DOI: [10.5061/dryad.ns1rn8q2s](10.5061/dryad.ns1rn8q2s)

## Description of the data and file structure

The repository contains the data required to repeat the species distribution models performed in Francesconi et al.

For each of the 272 lichen species, we present in sdm_data_table.csv file the 10 sets of generated background points and occurrences for the calibration area from 3 different sources (Dolichens database, ITALIC 7.0, GBIF). Due to copyright restrictions, occurrences from GBIF have been removed from the file, but can be obtained at the following link: https://doi.org/10.15468/dl.f7563s

For each point, we also provide the corresponding value of the 3 CHELSA bioclimatic variables chosen as predictors. We extracted the mean values of the bioclimatic variables within an area with a radius corresponding to the associated uncertainty value.

In addition, four scripts are available for downloa...,