Bryophyte dispersal rates too slow to keep up with changing climates

Despite their high dispersal capacities, bryophytes may be centuries behind future climate change

Data resources used via GBIF : 174,335 species occurrences
Cyrtomnium hymenophyllum
Cyrtomnium hymenophyllum Holmen, 1957 observed in Vågå, Norway by Anders Breili (CC BY-NC-SA 4.0)

In response to warming climates, organisms may adapt by shifting their range, but the extent to which species can mitigate the effects of climate change remains somewhat unexplored. Highly efficient wind-dispersers, bryophytes are potentially excellent candidates for keeping up with shifts in areas of suitable climate.

This study used GBIF-mediated occurrence data of 40 European bryophyte species combined with climatic variables to produce suitability models calibrated under present and projected under future climatic conditions.

The authors used species-specific traits and environmental variables (e.g. spore size, canopy height and wind speed) to build mechanistic dispersal models simulating potential migrations in the future.

The suitability models for 2050 predicted the highest rates of range loss for Arctic-alpine species, while Mediterranean species had the highest range gain. The dispersal simulations showed that less than 30 per cent of species would be able to colonize newly suitable areas fully by 2050.

Simulations beyond 2050 predicted that most species would need up to 500 years to successfully colonize newly suitable areas fully, signifying that even highly dispersive species may not be able to compete with the rates of climate-induced range loss.

Zanatta F, Engler R, Collart F, Broennimann O, Mateo RG, Papp B, Muñoz J, Baurain D, Guisan A and Vanderpoorten A (2020) Bryophytes are predicted to lag behind future climate change despite their high dispersal capacities. Nature Communications. Springer Science and Business Media LLC 11(1). Available at: https://doi.org/10.1038/s41467-020-19410-8