Governing spatial-temporal dynamics of biodiversity conservation networks using a tradable permit market scheme

Networks of protected areas are widely accepted as an appropriate strategy for biodiversity conservation, particularly in intensively used landscapes. In such regions, (semi)natural habitat mainly occurs in small, spatially scattered areas, embedded in land used for food and fiber production, housing, infrastructure and working facilities. Conserving biodiversity successfully in such fragmented landscapes requires sufficient levels of spatial cohesion, allowing species to utilize the individual areas as a large network. Current conservation networks are conceptualized as static structures, with the individual sites (areas) protected by law. Recent arguments in literature suggest that a certain degree of spatial dynamics might be beneficial for several reasons. With spatial dynamics we mean that parts of the network are being used for other land use functions, while elsewhere the network is strengthened via habitat restoration. Such a flexible approach allows improving the ecological effectiveness of networks in a wider landscape context, as well as improving robustness to climate change. Furthermore, it enables the incorporation of conservation networks and habitat provisioning into sustainable spatial development. However, it is largely unknown at with rate the spatial change of the networks is compatible with retaining biodiversity goals. Another unanswered question is how this change can be governed in a way that is more compatible with sustainable development than the current strict regulations. For a case study in the west of the Netherlands (Green Heart) we simulated loss and gain of wet grassland habitat sites using the policy instrument of tradable permits. We explored how such instruments should be governed to generate robust and resilient ecosystem networks.We compared various combinations of market incentives and spatial planning rules with respect to their ability to realize cost-effective patterns of ecosystem sites in the case study area. The patterns of habitat turnover produced by different governance settings were assessed for ecological effectiveness using population-dynamic models for a few species with different ecological strategies. The results suggest that with a strong bonus for maintenance and enhancement of spatial network cohesion, market based policy instruments could improve the ecological effectiveness and the adaptive capacity of ecosystem networks.