外来红树植物拉贡木的生态风险及主要生态效益研究

This project to introduced foreign fast-growing mangrove plant Laguncularia racemosa as the main object, use physiological ecology method, total accumulative biomass and other methods, to research the carbon storage capacity, and so as the main index to evaluation the main ecological resources value. Using the morphological structure and physiological and biochemical method to research its fast-growing mechanism. This project obtain the foreign introduction mangrove plant species carbon storage capacity and then compare with the known local mangrove plant carbon storage ability, to know more the carbon storage ability for estuary coastal mangrove carbon storage ability, to provide more comprehensive and scientific basis. This project is also based on ecological and physiological adaptability and mechanism of the Laguncularia racemosa introduced to China, the ability to adapt to the cold, salinity ecological amplitude and mechanism of ecological system, and other biological niche, the influence of the mangrove plants native to our country whether there are problems such as allelopathy research, from a biological basic characteristics and ecological behavior nature and biochemistry to evaluate the possible potential ecological risks, making corresponding evaluation, and puts forward the preventive measures, help in guarantee under the premise of ecological security, and give full play to the ecological restoration of the benefit, for the future of the introduction and development of the system to provide more scientific basis, not only have scientific significance, but also have the national economic and social development needs to solve the key problems of science and technology, having good application prospect.

本项目以引种的外来速生红树植物拉贡木为主要对象，应用生理生态学方法、生物量累计等方法，研究其碳储能力，以此作为主要指标评估其主要的生态效益资源价值；从形态结构和生理生化上探索拉贡木速生快长的机制。本项目获取的外来引种红树植物种类碳储能力与已知的乡土红树植物的碳储能力的比较分析，可为河口海岸红树林固碳能力的核定提供更全面的科学依据。本项目还通过对拉贡木在我国引进后的生理生态适应能力和机制、抗寒能力、盐度适应生态幅和机制、对生态系统其他生物生态位的影响、对我国本土红树植物是否存在化感作用等问题开展研究，从生物学基本特性以及生态行为本质和生物化学来评估分析其可能潜在的生态风险，作出相应的评价，并提出防范措施，有助于在保证生态安全的前提下，充分发挥其在生态恢复中的效益，为其今后的引进和发展提供更系统的科学依据，不仅有科学意义，而且是国民经济和社会发展中需要解决的关键科技问题之一，具有较好的应用前景

本项目以引种的外来速生红树植物拉关木为主要研究对象，分析拉关木凋落物及土壤呼吸季节动态、土壤总有机碳含量等方面研究其碳储能力；并从生理生化及结构研究拉关木速生快长机制；同时研究拉关木在我国引进后的生理生态适应能力和机制来分析其可能潜在的生态风险。其主要结论为：⑴ 4、6、8 年生拉关木林年凋落量分别为10930.1、12085.3、13723.4 kg /hm2。⑵ 4、6、8年生拉关木人工林土壤呼吸速率的季节动态均也表现出夏季＞冬季。不同龄林拉关木人工林各样地的土壤总有机碳含量表现为4年生(0.56 g/kg)＞6年生(0.50 g/kg)＞8年生(0.40 g/kg)。⑶拉关木叶肉细胞中叶绿体的内无淀粉颗粒，而乡土红树植物叶片叶绿体内则有淀粉颗粒。⑷拉关木1年生苗在白骨壤林内及林缘种植13个月后，其存活率仅为4.7%和5.3%；而其在秋茄林内及林缘种植9个月后，林内拉关木苗存活率为0，林缘仅为19.0%。⑸分布于中国东南沿海的19个拉关木群落的繁育系统属于雄性两性异株型，其植株的性别比例与其生境海水盐度的相关性显著（p=0.001）。⑹海南东寨港不同龄林拉关木人工林（6a，11a，19a）的群落丰富度指数dM随林龄的增加而增加；乡土树种秋茄、木榄、白骨壤等进入拉关木人工林群落下层。珠海淇澳岛引种园内的拉关木群落的结构组成简单、林下植被主要为老鼠簕，占群落总数的86.40%。福建莆田拉关木幼苗在其自身群落边缘光滩分布最多，为38.1株/100 m2，但这些扩散苗绝大多数为当年生幼苗；而邻近芦苇样地、及秋茄林内均未发现拉关木幼苗。本项目从生态系统的观点来全面衡量，在保证生态安全的前提下，充分发挥其在生态恢复中的效益，为其今后的引进和发展提供更系统的科学依据。