Ecosystem service gradients vary along protected area borders and across value domains

Conventional spatial planning often treats protected areas as static, self-contained units, failing to address the dynamic ecological and social processes at their borders. This approach is insufficient to halt biodiversity loss, making the integration of protected areas with surrounding human-dominated landscapes a critical challenge. We address this gap with an analytical approach that moves beyond static boundaries by characterizing ecosystem service gradients, offering a more dynamic and responsive tool for conservation.
Analyzing 16 protected areas in the French Alps, we modeled 12 ecosystem services using a combination of established biophysical approaches (e.g., for carbon storage and flood regulation) and innovative connectivity-based models for mobile species (e.g., pollinators and seed dispersers). To reflect diverse social perspectives, these services were aggregated into three value domains (rural, cultural, and urban) representing distinct societal demands. To measure gradients, we developed area-based structural buffers: concentric zones of similar landscape permeability that account for how topography and land use facilitate or impede movement. Using automated polynomial regression, we classified the resulting gradient profiles for each border segment into distinct types.
Our classification revealed five recurring patterns. The most common were linear 'Decreasing Gradients' (49% of segments), typically marking an abrupt transition to intensive agriculture or urban expansion, and 'Increasing Gradients' (25%). Our analysis reveals these patterns are driven by specific landscape configurations, uncovering frequent trade-offs. For instance, landscapes with small-scale agricultural mosaics that support rural values (like pollination) often fragment the continuous habitats required for cultural and urban services, creating a sharp conflict along the same border. However, our framework also pinpoints critical opportunities for synergies, identifying specific locations where landscape structure supports a simultaneous increase in services across all three value domains. This spatially explicit typology provides a powerful diagnostic tool to design targeted, context-specific interventions, such as prioritizing habitat restoration where all services decline or managing agricultural landscapes to mitigate conflicts, supporting a more effective and equitable integration of protected areas into the wider landscape.