Synergistic effects of renewable energy infrastructure-driven Spartina alterniflora control and salt marsh wetland restoration: a case study of an integrated photovoltaic–hydrogen–energy storage project in Jiangsu, China

Objective The invasion of Spartina alterniflora has become a major threat to the ecological security of coastal wetlands worldwide, while conventional control approaches are often constrained by high costs and high recurrence rates. Against the background of China’s “dual carbon” goals and coastal renewable energy development, integrated photovoltaic–hydrogen–energy storage projects provide an innovative pathway for the coordinated advancement of invasive species control and ecological restoration.

Method This study focused on the Rudong integrated photovoltaic–hydrogen–energy storage project in Jiangsu Province, China, which covers a total area of 290.57 hm² and includes a 400 MWp photovoltaic system, a 33.5 MW/67 MWh energy storage system, and hydrogen production facilities. By comparing water quality, soil physicochemical properties, benthic faunal community structure, and food-web topological characteristics before and after project implementation, this study systematically evaluated the effectiveness of the “physical removal + photovoltaic shading” model in controlling S. alterniflora and promoting ecological restoration.

Result The project achieved rapid removal of S. alterniflora, with the recurrence rate approaching zero one year after treatment. Compared with the pre-treatment conditions, total nitrogen, total phosphorus, and chemical oxygen demand in water decreased by 25.0%, 25.0% and 20.0%, respectively. Soil total nitrogen and total phosphorus increased by 60.0% and 33.3%, respectively, indicating improved soil fertility. The number of benthic faunal species increased from 22 to 47, representing a 113.6% increase, and the diversity index increased from 0.5 to 1.5. The dominant community structure shifted from a mollusk-dominated assemblage, accounting for 54.5%, to a more complex structure characterized by the coexistence of arthropods, accounting for 31.9%, and mollusks, accounting for 51.1%. The stability of the benthic food web was significantly enhanced, with the number of predation links increasing to 125, representing a 443.5% increase, and trophic redundancy increasing by 50.1%, forming a multilayered, highly connected, and robust network.

Conclusion The integrated photovoltaic–hydrogen–energy storage project can simultaneously achieve efficient control of S. alterniflora and clean energy production, providing a green and sustainable model for invasive species control and ecological–energy coordinated development in coastal wetlands. This model has important practical significance for coastal ecological security and low-carbon transition. However, as the current observation period was limited to one year, the long-term ecological effects and impacts on higher trophic levels require further monitoring and verification.