Habitat restoration in spatially explicit metacommunity models.

In a time of rapid habitat destruction threatening the existence of many species, restoration of degraded habitats plays a crucial role in hampering biodiversity decline and recovering ecosystem services. The goal of this study is to advance the understanding of the consequences of habitat restoration on metacommunities, which is of upmost importance for designing successful restoration projects. We approach habitat restoration from a theoretical perspective by analysing spatially explicit metacommunity models which have previously been essential to understanding the effects of habitat loss and fragmentation. We investigate the efficiency of various restoration strategies on metacommunities involving interactions ranging from pairwise competition, predation and mutualism to more complex three-trophic modules. Our novel approach for measuring the restoration efficiency enables direct comparison of the responses of species in different metacommunities. We show that species recovery is affected by the amount of habitat destroyed, and the restoration strategy. When habitat is restored by randomly selecting destroyed sites, species recovery becomes less efficient and more uncertain with increasing amount of previously destroyed habitat. However, when the destroyed sites are restored in clusters, minimising the effects of fragmentation, species recovery and the certainty of success are substantially improved. Furthermore, we demonstrate that the community structure and the types of interactions involved determine the most efficient restoration approach. Our findings highlight the importance of carefully planning the restoration process, especially in landscapes where a large proportion of habitat has been destroyed, and with species at the brink of extinction. Our results may be used as guidelines for designing habitat restoration projects.