Mid-February 2023, five Chinese government departments, including the National Forestry and Grassland Administration, together with relevant departments of the State Council, issued the Special Action Plan for the Prevention and Control of Spartina (2022-2025), which sets the goal of effectively controlling Spartina alterniflora throughout China by 2025, with a removal rate of over 90% in all provinces. The Action Plan is undoubtedly a shot in the arm for the coastal provinces to triumph over this invasive Spartina cordgrass and safeguard coastal ecosystems.
Spartina cordgrass is native to the east coast of North America and the Gulf of Mexico, and was introduced to China for scientific research and utilization in 1979. Due to its salt tolerance and flood resistance, strong fecundity and well-developed root system, it was considered to be the best plant for promoting sedimentation, protecting embankments, and facilitating siltation and land formation. In the following 20 years, Spartina was widely introduced in many estuaries and mudflats of coastal China. However, there have been unforeseen negative consequences. With artificial planting and natural spread, Spartina now grows on coastal mudflats from Liaoning in the north to Hainan in the south, severely altering the natural environment and ecosystem processes of China's coastal wetlands. This, in turn, has negatively impacted biodiversity and ecosystem service values, and caused significant losses to aquaculture and shipping industries, among others.
The history of Spartina control in China can be traced back to the late 1990s, when some scholars pointed out the danger of "widespread and uncurbed growth of Spartina" and recommended thorough research and development of site-specific eradication plans before implementing control projects. Later, as biological invasion became a new research topic of high interest to Chinese ecologists, the harmfulness of Spartina was further revealed, drawing the attention of the Chinese government. In order to tighten the prevention and control of Spartina, the Ministry of Ecology and Environment (formerly SEPA) included Spartina in the List of Invasive Alien Species (First Batch) in 2003, and the Ministry of Agriculture and Rural Affairs (formerly Ministry of Agriculture) included Spartina in the List of Invasive Alien Species for Key Nationwide Efforts of Control (First Batch) in 2013. Although Spartina was classed as an invasive species by China, some scholars suggested recognizing its positive ecological effects, such as wind and wave resistance, siltation and land formation, and carbon sequestration thus balancing the negative ecological effects. Since there was no strict legal basis to regulate exotic plants management at the time, and the two-sided nature of Spartina's ecological benefits had diminished the determination at the local level to eradicate this weed, control measures were not adopted fast enough to curb its rapid spread. Even in the late 2000s, Spartina was still being artificially planted in the mudflats of intertidal zones in some areas.
Fortunately, while Spartina was spreading rampantly along China's coastline, the legal and policy system for invasive species was constantly being revised and improved. The 13th Five-Year Plan for National Ecological Protection called for "actively preventing and controlling invasive alien species" and "exploring and driving the system for managing biosafety and invasive alien species". This process has accelerated in recent years.
The Biosafety Law of the People's Republic of China, which was implemented in 2021, proposes to "develop a list of invasive alien species and management methods" and "enhance the investigation, monitoring, early warning, control, assessment, removal and ecological restoration of invasive alien species". It also clearly stipulates that "no organization or individual may release or discard alien species without approval." The Wetland Protection Law of the People's Republic of China, which came into force in June 2022, also provides that "it is prohibited to introduce and release alien species into wetlands, and there should be science-based evaluation and approval in accordance with the law for those that do need to be introduced". To effectively strengthen the management of invasive alien species, the Ministry of Agriculture and Rural Affairs, the Ministry of Natural Resources, the Ministry of Ecology and Environment, and the General Administration of Customs promulgated the Measures for the Management of Invasive Alien Species in August 2022, which stipulates risk assessment, monitoring and early warning, and comprehensive control of invasive alien species. This document also proposes that invasive alien plants can be controlled with manual uprooting, mechanical eradication, spraying of green chemicals, release of natural enemies and other methods during the critical growth periods such as seedling, flowering or fruiting.
At the same time, in response to the serious challenges facing coastline protection and utilization, China has introduced a series of targeted policies and invested resources to support the protection of coastal zones and the restoration of coastal wetland ecosystems, including the restoration of intertidal mudflats encroached by Spartina. For example, in 2020, the Master Plan on the Major Projects for the Protection and Restoration of China’s Key Ecosystems (2021-2035) proposed to "pursue comprehensive coastline and mudflats restoration, habitat conservation and restoration, and prevention and control of invasive alien species and ecological disasters", and "improve ecosystem quality of near-shore sea areas, restore typical habitats that have degraded and step up the protection of habitats along bird migration routes". The Plan also places particular emphasis on reinforcing the prevention and control of overgrown invasive alien species such as Spartina. In August 2020, the Ministry of Natural Resources and the National Forestry and Grassland Administration jointly issued the Special Action Plan for Mangrove Protection and Restoration (2020-2025), which focuses on " intensifying the efforts to prevent and control harmful overgrowth of species such as Spartina".
The just-released Special Action Plan for the Control of Spartina (2022-2025) was proposed in the context of the general trend that the Spartina invasion has caused a continuous decline in coastal wetland biodiversity, as well as recognizing that its invasion has not been effectively curbed and control measures are therefore much needed. In addition to a whole-territory background survey and comprehensive control, monitoring and assessment, the Action Plan will promote the ecological restoration of treated mudflats, bolster later-stage management and protection, and "adapt the measures to local conditions" by referring to the original ecosystems. At the same time, it will strengthen the scientific and technological support for Spartina prevention and control, formulate the Technical Guideline for Comprehensive Prevention and Control of Spartina to guide the precise treatment in different places, and further improve the laws and regulations and institutional system for work in this area.
It is estimated that the current area of Spartina in China is about 68,000 hectares, more than twice the area of existing mangroves and equivalent to half the size of Chongming Island. If these mudflats can be restored to their original ecological functions after the removal of Spartina, they will provide new high-quality habitats for many migratory waterbirds along the East Asian-Australasian Flyway, protecting this shared natural heritage for future generations.
Spartina control pilot in Yancheng (left) and Luannan (right) © Paulson Institute
另一方面，针对海岸线保护与利用的严峻形势，中国出台了一系列针对性政策，并投入了大量经费支持海岸带保护治理和滨海湿地生态修复，修复的受损湿地中也包括被互花米草侵占的潮间带滩涂。如2020年《全国重要生态系统保护和修复重大工程总体规划（2021—2035年）》提出要“综合开展岸线岸滩修复、生境保护修复、外来入侵物种防治、生态灾害防治”、 “改善近岸海域生态质量，恢复退化的典型生境，加强候鸟迁徙路径栖息地保护”，还特别强调加强互花米草等外来入侵物种灾害防治。而2020年8月，自然资源部、国家林草局联合印发《红树林保护修复专项行动计划（2020-2025年）》，也提到 “重点加强对互花米草等有害生物灾害的预防和控制”。
林如求. 三都湾大米草和互花米草的危害及治理研究. 亚热带资源与环境学报, 1997(01):16-19. Lin Ruqiu. Research on the damage and management of Spartina Alterniflora in Sandu Bay. Journal of Subtropical Resources and Environment, 1997(01):16-19.
Nie, Ming, Liu, Wenwen, Pennings, Steven C., and Li, Bo. 2023. “ Lessons from the Invasion of Spartina Alterniflora in Coastal China.” Ecology 104( 1): e3874. https://doi.org/10.1002/ecy.3874.
Prepared by Dr. Xiaojing Gan
Conservation Manager, Paulson Institute https://www.paulsoninstitute.org/staff/xiaojing-gan/