Priority conservation areas for protected saproxylic beetles in Romania under current and future climate scenarios

Climate change threatens biodiversity, putting habitats critical for saproxylic beetles under significant stress. These beetles, essential for indicating the health of forest ecosystems, have become a conservation priority in the EU. We developed ensemble species distribution models for five saproxylic beetles, considering present conditions and three future time frames, under two emission scenarios and two GCMs. We applied a systematic conservation planning method to evaluate the Romanian Natura 2000 network's effectiveness and climate resilience for saproxylic beetles, identifying areas for future expansion to achieve EU conservation goals. Our study revealed that under all scenarios and time horizons, the saproxylic beetles will lose over 80% of their suitable habitat and restrict their distribution to higher elevations. According to the prioritization analysis, we found that when considering 30% of the landscape as protected, an average of 85% of species distribution is retained with priority areas overlapping the Carpathian Mountains, while for the current conditions (18% of Romania’s terrestrial surface), the existing Natura 2000 network does not perform well, with almost ~30% of the saproxylic species distributions falling inside. Our results support the idea that the distribution of saproxylic beetles could change as a result of climate change, and the effectiveness of the current Natura 2000 network is put into question as it may be insufficient in protecting these species. To achieve the goals of the EU Biodiversity Strategy 2030 of protecting at least 30% of the EU’s land, we urge the expansion of the Natura 2000 sites.