An Ecosystem Approach to Defining Conservation Boundaries: Concepts and a Case Study

Much of conservation biology has focused on developing approaches for selecting high value sites for protecting biodiversity; what has been lacking are objective criteria for delineating conservation boundaries. Defining protected area boundaries based on occupied species' habitat offers no guarantee that those reserves will continue to provide suitable habitat over time. Focusing on ecosystem protection rather than just species' populations offers a mechanism to protect those species, and does so in a dynamic context. It is the multiple temporal and spatial scales of ecosystem processes that drive habitat dynamics, foster biodiversity, and facilitate adaptations to changing conditions. Embracing the dynamics of ecosystems and their boundaries as criteria for reserve designs also forces a conceptual shift in how to assess populations within conservation areas. Monitoring programs must focus on understanding drivers of change rather than how much change has occurred relative to an arbitrary baseline. The conceptual shift to an ecosystem focus broadens the levels of biodiversity encompassed in a conservation design, and gives greater resilience to the stressors of fragmentation, invasive species, and climate change. California's Coachella Valley Multiple Species Habitat Conservation Plan is highlighted as a conservation design that has adopted an ecosystem focus.