ExoticSpartina alternifloraEnhances the Soil Functions of a Coastal Ecosystem

Abstract

Core IdeasExotic species do not always have negative impacts on soils.Changes in soil functions were identified after the introduction ofSpartina alterniflora.The basic functionality of soils could be enhanced by new species in areas that do not have native plants.The study highlights the potential benefits of non‐native plants for coastal soils.Coastal soils are recognized as a valuable global resource because of their important roles in maintaining ecosystem services, especially C storage. Exotic species often have negative impacts on biodiversity but less is known about their potential benefits for soil function. We investigated impacts ofSpartina alternifloraLoisel. on soil functions (based on basic chemical and physical properties) related to soil depth on a coastline of the East China Sea. Subsequently, we assessed the trend of soil functions by integrating multiple soil functions into a single index. The results showed that significant relationships were observed between the age ofS. alternifloraand the factors soil organic C (SOC) storage soil pH in the topsoil (30 cm), and soil salinity within the upper 1 m depth. These results implied that some soil functions were enhanced over time following the introduction of the species (i.e., C sequestration and desalinization).Spartina alterniflorahad a positive effect on the basic functionality of soils in areas that do not have native salt marsh species. Over the course of exotic plant introduction, soil pH made the highest contribution at the beginning, whereas salinity gradually became the most important factor controlling the physicochemical functionality of soils. We suggest that it is essential to explicitly test the impacts of species introduction on soil functions to address key issues of the sustainable management of coastal soils.