Long-term effectiveness of Natura 2000 network to protect biodiversity: A hint of optimism for common birds

The Natura 2000 protected area network (N2000), implemented under the Birds and Habitats Directives (respectively, Special Protection Areas, SPA, and Special Areas of Conservation, SAC), constitutes a key tool for the conservation of European biodiversity. To date, few studies have looked at its long-term effect on biodiversity and even fewer on common species. Here, using citizen science data, we investigated this effect on the temporal trends of widespread and common bird species in France, over the period 2002-2016. We found results consistent with previous findings demonstrating a significant decline of common bird populations in France. However, we show that this decline is less steep within N2000 areas than outside, especially for farmland specialists. While SPAs and SACs contribute to the overall effect on bird populations, SACs contribute most to the less steep decline of farmland species within N2000 network. Despite generally more diverse bird communities within N2000 areas, their designation has not prevented their ongoing functional biotic homogenization. We conclude that, common bird species - not directly targeted by the Directives - may have benefited from the N2000 protection or management measures. However, the positive but limited effect of the N2000 network suggests that it is not able to reverse negative population trends either because the land management or spatially extent are insufficient. As such, we suggest that improving management plans, expanding existing PA, establishing new ones, are the priority actions that may help improve N2000 effectiveness.

Automated summary

The Natura 2000 protected area network is a key tool for the conservation of European biodiversity. A study in France showed that common bird populations are declining, but the decline is less steep within N2000 areas, especially for farmland specialists. Despite more diverse bird communities within N2000 areas, their ongoing functional biotic homogenization suggests a limited effectiveness of the network in reversing negative population trends. Improving management plans and expanding protected areas are suggested as priority actions to enhance the effectiveness of N2000.