Invasion of Spartina alternilora in the coastal zone of mainland China: Control achievements from 2015 to 2020 towards the Sustainable Development Goals

The Sustainable Development Goals (SDGs) and the Convention on Biological Diversity's 15th Conference of the Parties (CBD COP15) both emphasized the urgency of protecting biological diversity. Spartina alternilora (S. alternilora), as an invasive species in China, has posed severe biodiversity challenges, demanding nationwide control and management. This study aims to assess the effectiveness of S. alternilora management during China's SDGs implementation from 2015 to 2020. Landsat images acquired in 2015 (the beginning year of SDGs), 2018, and 2020 (the end year of SDGs' targets 6.6, 14.2, 14.5, and 15.8 related to alien invasion) were applied to quantify the spatiotemporal dynamics of S. alternilora extent. The results revealed a consistent shrinkage of S. alternilora, with a net areal reduction of 2610 ha from 2015 to 2020, implying the effectiveness of control measures on S. alternilora invasion. Provinces including Zhejiang, Jiangsu, and Shanghai have succeeded in controlling S. alternilora, evidenced by the sharp reduction in S. alternilora area by 4908 ha, 2176 ha, and 1034 ha, respectively, from 2015 to 2020. However, better management of S. alternilora is needed in regions with more severe S. alternilora invasion, e.g., Shandong, Fujian, and Guangdong provinces. Our results suggest that relevant policies, regulations, and ecological restoration projects implemented by national or local governments in China received satisfactory results in S. alternilora control. Nevertheless, S. alternilora potential utilities and its governance effectiveness should be objectively evaluated and weighed to obtain the greatest ecological benefits and promote sustainable coastal ecosystems. The results of this study are expected to provide important baseline information benefitting the formulation of coastal protection and restoration strategies in China.

Automated summary

This study assesses the effectiveness of Spartina alternilora management during China's implementation of the Sustainable Development Goals (SDGs) from 2015 to 2020. The results show a consistent reduction in the extent of S. alternilora, indicating the efficacy of control measures. Provinces such as Zhejiang, Jiangsu, and Shanghai have successfully managed S. alternilora, while regions with more severe invasion require better management. The study emphasizes the need for objective evaluation and weighing of S. alternilora's potential utilities and governance effectiveness to achieve maximum ecological benefits and promote sustainable coastal ecosystems.