Can agro-ecosystems efficiently complement protected area networks?

- We found that most breeding birds in Israel are inadequately covered by existing protected areas.
- We compared three strategies for expanding the target species' habitat coverage.
- The strategies were establishing new reserves, improving agro-systems for conservation, and a combined strategy.
- The combined strategy, which focused on both natural and agricultural sites, was most beneficial.

Threats to biodiversity are often enhanced in human-dominated and densely-populated regions. The prospects for establishing new protected areas are generally more limited in such regions, due to competition with other land-uses. Improving the conservation value of agricultural lands has been proposed as a complementary strategy. Our goal was to compare alternatives for expanding an existing protected area system. We used the conservation planning software Marxan to select candidate sites for addition to an existing protected area system, based on the following three strategies: (1) focusing on remaining natural habitats; (2) prioritizing agricultural lands for wildlife-friendly farming and agri-environmental measures that can improve conservation value; and (3) a strategy combining the former two. We used area as a surrogate for cost with the aim of minimizing the total area needed to meet our conservation objectives. We evaluated the sites found via each strategy with respect to their landscape structure and the coverage they provided to the target species' habitats. We focused on breeding bird species in Israel's Mediterranean region, a challenging and relevant case study due to the area's high level of urbanization, population density, and its heterogeneous landscape. We found that the existing protected areas provided adequate coverage to only 23% of the target species, clearly demonstrating the need for action. Of the three strategies, expanding the existing protected area system based on the combined strategy was the most beneficial since it provided greater coverage to the target species' habitats, and resulted in a larger, more compact, and less patchy conservation area network. In addition to protected area planning, our approach can be used to target agricultural lands for agri-environmental schemes, particularly in human-dominated and densely-populated regions.