A Global Review of Wetland Biodiversity and Carbon Connections

As human actions have degraded global ecosystems over time, communities have often combated ecosystem function loss through restoration with a singular focus, falling on one side of the habitat and biodiversity protection or carbon sequestration dichotomy. Wetlands are no exception to this trend, and the large global push to protect and restore wetlands has widely ignored multiple-benefit practices. This scoping review aimed to determine whether this historic restoration dichotomy was also represented in studies of wetlands and to what extent the potential biodiversity and carbon synergy differs between taxonomic groups. Of the 106 studies included in this review, a majority did not investigate this synergy despite many studies reporting metrics of both biodiversity and carbon cycling. In studies that included synergy comparisons, floral diversity increased carbon sequestration overall while microbial diversity could increase or decrease carbon sequestration depending on which functional groups were present. We discuss limitations in metric selection, wetland types, restoration stage, and time scales that prevent current work from improving the ability for restored wetlands to support multiple benefits and take advantage of the synergy seen in other wetlands.