低氧胁迫导致白骨壤退化死亡的机制

白骨壤最显著的特征是其具有发达的地上呼吸根，能够克服潮汐滩涂土壤的低氧环境，因而成为我国分布面积最大的红树林树种之一。但是海平面上升、海水酸化、近岸污染和海岸建设所形成的粘土溢流等均能降低表层土壤的含氧量，进而对白骨壤地下根系的正常呼吸作用造成不利影响，同时，藻类和淤泥粘附、团水虱蛀蚀、污损动物胶粘、人为挖捕也严重干扰地上呼吸根对氧气的吸收效果，进而诱发小蠹等树干钻蛀性害虫危害而快速死亡。本项目拟通过野外生态观测、室内生理试验和病虫害研究的方法，通过白骨壤根系呼吸串起金属离子毒害、昆虫病原菌侵染、人为挖捕、海平面上升等一系列问题的内在联系，提出了低氧胁迫下白骨壤树干呼吸的问题，探索小蠹对白骨壤的侵染过程，从而揭示白骨壤退化死亡机制。研究结果有望对红树林保护修复提供科学依据和技术支撑，对白骨壤的生理生化、生态环境和病虫害研究也是有益的探索。

The most significant feature of Avicennia marina is that it has developed above-ground respiratory roots, and can overcome the low-oxygen environment of tidal flat soil. Therefore, it becomes one of the mangrove species with the largest distribution area in China. However, sea level rise, seawater acidification, coastal pollution and clay overflow caused by coastal construction can all reduce the oxygen content in the surface soil, which will have a negative impact on the normal respiration of the under-ground roots of Avicennia marina. Moreover, the adhesion of algae and silt, sphaeroma harm, defaced animal glue as well as artificial digging and catching seriously interfere with the absorption of oxygen by the above-ground respiratory roots, and thereby inducing the damage of borer pests to tree trunk such as Scolytidae and rapid death. In this project, the internal relationships among a series of problems such as metal ion toxicity, infection of insect pathogenic bacteria, artificial digging and catching and sea level rise were linked through the root respiration of Avicennia marina using field ecological observation, indoor physiological experiment and research on diseases and insect pests. Moreover, the problem of trunk respiration of Avicennia marina under hypoxia stress was put forward, and the infection process of Scolytidae on Avicennia marina was explored, so as to reveal the mechanism in the degradation and death of Avicennia marina. The research results are expected to provide scientific basis and technical support for mangrove conservation and restoration, and also beneficial exploration for the research on the physiology and biochemistry, ecological environment and diseases and insect pests of Avicennia marina