Biodiversity is a significant predictor of ecosystem functions such as primary production across terrestrial, freshwater, and marine systems, with significant implications for the services that these habitats provide to humans. For instance, diverse species assemblages are approximately twice as productive as monocultures of the component species, and the positive effects of diversity typically increase through time. Benefits of biodiversity also result from genetic variation within species: in particular, plant genetic diversity can increase primary production, colonization success, and community abundance and diversity across a wide array of habitats. Biodiversity-ecosystem function relationships have clear relevance for habitat restoration efforts, where managers directly manipulate the identity and composition of species with the goal of achieving specific functions. However, the degree to which biodiversity has been incorporated into restoration design or implementation is unclear. To address this knowledge gap, we conducted a systematic review of the published literature on habitat restoration to examine the proportion of empirical restoration efforts that included a component of biodiversity, as well as whether the prevalence of biodiversity in restoration varied across ecosystems.
Results/Conclusions
The number of published restoration studies including the term biodiversity has increased exponentially from 1990 to 2015, consistent with the growth of restoration ecology and biodiversity-ecosystem function research over this same period. Of the empirical studies, a greater percentage was from terrestrial than freshwater or marine ecosystems. In addition, a higher percentage (67%) of published empirical restorations in terrestrial ecosystems had a biodiversity component compared to freshwater (51%) and marine (38%) ecosystems. However, among the studies with a biodiversity component, the majority considered it as a response to restoration (e.g., species diversity or richness of the community post restoration) rather than incorporating it in the restoration design itself. Thus, our review revealed a significant gap in applying the large body of science demonstrating positive biodiversity-ecosystem function relationships to restoration practice. This science-practice gap was particularly wide in marine and coastal ecosystems, indicating the importance of greater collaboration between scientists and practitioners, and simultaneously highlighting a potential technique for improving coastal restoration success. Considering the typically limited resources and high economic costs involved with ecosystem restoration projects, bridging this gap to promote strategies that maximize ecosystem function and enhance restoration outcomes is imperative.