春季降雨量变化对滨海盐沼湿地植物光合碳分配的影响机制

滨海盐沼湿地具有较高的土壤固碳速率，是重要的“蓝色碳汇”。植物光合碳固定是盐沼湿地碳循环的起点，解析植物-土壤系统中光合碳的分配过程及机制是估算盐沼湿地土壤固碳功能的先决条件。春季受水盐胁迫影响，滨海盐沼湿地植物萌发和生长对淡水补给具有高度依赖性和敏感性，然而春季降雨量变化对滨海盐沼湿地植物光合碳固定及其分配的影响过程及机制尚不清楚。本项目以黄河三角洲滨海盐沼湿地为研究对象，依托野外春季降雨变化控制试验平台，开展滨海盐沼湿地植物光合碳分配对春季降雨变化的响应机制研究，揭示春季降雨量变化对滨海盐沼湿地植物群落特征和物种多样性、光合碳固定及其在植物-土壤系统中分配模式的影响机制，将有助于深入认识季节降雨变化下滨海盐沼湿地土壤碳库稳定性变化的影响机制，为准确评估滨海盐沼湿地土壤碳汇潜力及其对未来气候变化的响应提供科学依据。

Coastal salt marshes are considered as important contributors to global "blue carbon" resources, with strong soil carbon sequestration capacity. Plant photosynthetic carbon fixation is the starting point of the carbon cycle of salt marsh, and plant photosynthetic carbon fixation and distribution in the plant-soil system are the prerequisite to estimate the soil carbon sequestration function. Under the influence of water and salt stress in spring, the germination and growth of plants in coastal salt marsh are highly dependent and sensitive to fresh water supply. However, the influence mechanism of spring precipitation change on plant photosynthetic carbon fixation and distributions in coastal salt marshes has not yet been well understood. Here, we conducted a manipulative experiment of spring precipitation change in a coastal salt marsh of the Yellow River Delta. Conduct research on the response mechanism of photosynthetic carbon allocation of plants to seasonal precipitation changes, and to reveal the influence mechanism of seasonal precipitation changes on plant community characteristic and species diversity, photosynthetic carbon fixation and distribution pattern in plant-soil system in coastal salt marsh. The result will enhance scientific understanding of the dynamic of carbon pool stability under variation of seasonal precipitation change, and provide scientific basis for the assessment of soil carbon sink potential and their responses to future climate change in salt marshes.