Climate Change and Seagrass Meadows: A Study Analyzes the Effects of Habitat Fragmentation

Climate change is altering Mediterranean seagrass meadows, and the impact on the communities of species that inhabit them depends on how much—and in what way—these habitats lose spatial continuity and become fragmented.

A new study published in the Journal of Biogeography assessed the effects of changes in the geographic distribution of two seagrass species typical of the Mediterranean Sea, Posidonia oceanica and Cymodocea nodosa, on the communities they support.

By using distribution data for these two species in the Mediterranean, together with physical and biogeochemical models, researchers were able to simulate how the areas occupied by these plants might change in the near future and how these distributional changes could affect the biodiversity of the communities of organisms living there.

The main results show that the habitats of P. oceanica and C. nodosa will generally undergo strong contraction and fragmentation, leading to a decrease in biodiversity among species within the same community (alpha biodiversity) and an increase in diversity among species from different communities (beta biodiversity). However, responses are modulated at the local scale, meaning they may differ across the various basins of the Mediterranean Sea. At the local scale, diversity within a single community is strongly correlated with habitat availability, while diversity among communities is largely influenced by changes in the spatial configuration of the habitat.

The method used in this research may be useful in the future for planning conservation and restoration measures at both local and regional scales.

This research is the result of work carried out within the Horizon Europe Project NECCTON - New Copernicus Capability for Trophic Ocean Networks, and the PNRR Project NBFC – National Biodiversity Future Centre.

Image: Edu Aguilera/Visualhunt