Functional bat diversity and the role of the protected areas against climate change projections across Europe

Assessing the effect of climate change projections on functional bat diversity across Europe is crucial to evaluate if the European protected areas will be capable to safeguard that diversity under global warming. Specially, because bats provide a top-down regulation ecosystem service related with pest suppression which affect the agriculture, human and animal health. We used Bayesian Additive Regression Trees (BART) to estimate the current and future distribution of each species under CMIP6 climate scenarios on 5-arc-min grids spatial resolution. In each grid, current and future functional bat diversity were calculated based on three metrics: functional richness (FRic), specialization (FSpe) and divergence (FDiv). Null models were used to determine whether protected areas would protect high, medium and low functionality values compared to a random distribution based on 10,000 simulations. We also determined European functional bat groups through hierarchical cluster analysis. Our results showed that FRic would be mainly affected by the climate change, with a 56.3 % loss in protected areas in a high concentration scenario of greenhouse gases and would have a shift towards northern and eastern areas. Protected areas would over-protect high functional diversity values, permanently in time, only in the optimal climate change scenario. Most functional groups showed a clear imbalance between the habitat loss and gain they would have, with losses being significantly greater. The change on functional bat diversity would suppose alterations in the trophic networks of the Mediterranean area, with the loss of ecosystem services like crop pest suppression and human disease vectors (mosquitoes). Our results show that we need to develop conservation and management plans in an outside of the protected areas to prevent the effects of climate change on ecosystem service in those areas where the functional diversity would disappear.