Framework of multidimensional macrobenthos biodiversity to evaluate ecological restoration in wetlands

Sustaining biodiversity is a priority for ecological restoration in degraded wetlands, and biodiversity is an inherently multidimensional ecosystem property, as it includes genetic, taxonomic, functional, and other types of diversity. However, most restoration projects have only employed taxonomic diversity to assess restoration, and given the multidimensional nature of biodiversity, this may partially describe the true situation. In this paper, we constructed a multidimensional macrobenthos biodiversity framework (for genetic, taxonomic, and functional diversity), developed a holistic biodiversity index that accounted for these dimensions, and explored the consequences of freshwater restoration in a case study of this index. We found that freshwater restoration increased genetic and taxonomic diversity, but had no significant effect on functional diversity, and that the functional traits of the macrobenthos appeared to have converged on homogeneous functional traits. On the other hand, freshwater restoration had a significant positive effect on the holistic biodiversity. The relationship between ecosystem function (in macrobenthos biomass) and holistic biodiversity in the restoration areas was unimodal, with the highest biomass found at intermediate levels of holistic biodiversity. The multidimensional framework challenged the utility of using any one dimension of biodiversity as a surrogate for other dimensions. The holistic biodiversity index provided more comprehensive and holistic insights into the management of freshwater restoration projects.