植物入侵对我国滨海盐沼湿地植被及其相关碳过程影响的地理格局与预测

Coastal saltmarshes are the important insurance against the ecological safety of the coastal zone that is heavily populated. However, biological invasions caused by human activities are threatening the coastal saltmarshes and have altered and are still changing their structure and functions both regionally and globally. Using an exotic plant Spartina alterniflora native to North America as model organism that is widely invading Chinese saltmarshes on the east coast, the project, through using the principles and methods of ecology and geoscience, is aimed to investigate the impact of plant invasions on vegetation distribution and structure, productivity, belowground carbon stock and stability of saltmarsh ecosystem and the key ecosystem processes that are related to carbon cycle. Through comparative and synthetic approaches, we will attempt to generalize the geographical patterns of the effects of plant invasions on the saltmarsh’s structure and functions in different regions on Chinese coasts, and explore the underlying mechanisms that generate those patterns. On the basis of our observations, we will further employ modelling approach to characterize the key carbon processes in the coastal saltmarshes of China, and predict the long-term dynamics of carbon sinks and sources influenced by plant invasions under future climate change scenarios. Through the comparative study of the invasion effects across the coastal saltmarshes of China, this project can not only potentially reveal how plant invasions affect carbon sinks and sources of the saltmarsh ecosystems but generalize the features of carbon processes in the saltmarshes on the Chinese coasts, which can eventually make a significant step towards understanding spatial patterns of carbon processes of Chinese coastal wetlands and approaches that maintain their carbon sequestration potentials. Moreover, it is also hoped that the outcomes of this proposed project can make original contributions to the fields of global change and biological invasion ecology from which a reputable research team may emerge in the near future, and improve evidence-based scientific management of Chinese coastal saltmarshes.

滨海盐沼湿地是人口稠密的海岸带区域生态安全的重要保障，但其系统的结构和功能的演变被认为与入侵种的影响密切相关。本项目拟以广泛入侵我国东海岸滨海盐沼湿地的外来植物互花米草为对象，应用生态学与地学的原理和方法，研究其对我国土著盐沼湿地植被分布与结构、生产力、生态系统地下碳储量及其稳定性以及相关生态系统过程等的影响，揭示其影响的地理变异格局与成因。在此基础上，通过模拟途径探讨我国滨海盐沼湿地生态系统碳过程的格局，并基于未来气候变化情景预测植物入侵背景下盐沼湿地碳汇/源的变化趋势。本项目通过对该入侵种影响的全国性比较，不仅能认识植物入侵背景下盐沼湿地碳汇/源的动态，而且也有助于揭示我国盐沼湿地碳过程的基本特征，增进对我国盐沼碳的空间分异规律和维持机制的理解。此外，通过本项目的实施，有望在全球变化与生物入侵等领域取得重要的原创性成果，形成一支享有一定学术声誉的研究队伍，并推动我国盐沼湿地的科学管理。

滨海盐沼湿地是人口稠密的海岸带区域生态安全的重要保障，但其系统的结构和功能的演变被认为与入侵种的影响密切相关。本研究项目以广泛入侵我国东海岸盐沼湿地的北美入侵植物——互花米草为对象，应用生态学与地学的原理和方法，实验与模型研究相结合的途径，研究其对土著盐沼湿地植被和碳过程影响及其地理差异；进而通过模拟途径探讨我国东海岸盐沼湿地生态系统碳过程的格局，并基于未来气候情景下预测植物入侵对盐沼湿地碳循环影响的未来趋势。本项目于2017年1月启动，按照年度研究计划，各项工作进展顺利，计划目标和各项指标均已经或者超额完成。在Nature Climate Change、Nature Sustainability、Science Advances等国际重要期刊上发表SCI论文35篇（其中3篇为ESI高被引论文），相关研究成果总结于《植物入侵生态学：互花米草案例研究》专著中，并获得了2019年度上海市自然科学奖一等奖。本项目形成一支在国际地学与生态学交叉领域有一定竞争力的研究队伍，培养了博士后与研究生18名。通过5年项目的实施，从盐沼外来入侵互花米草对我国土著盐沼湿地生物地球化学循环影响的角度，深层次地揭示其影响的地理变异格局与成因，为理解生物入侵驱动下盐沼功能的维持机制以及未来趋势预测提供新思路。