入侵植物互花米草克隆分株间氧气运输规律的研究

Relationship between plant clonality and invasion is a hot spot in invasive ecology. Clonal integration plays an important role in adapting stressful environment and expanding new habitats. Transportation and resource sharing of oxygen is quite meaningful for aquatic plants, however, little is known about the direction and intensity of oxygen transportation among clonal ramets under aquatic environments. Exotic invasive plant, Spartina alterniflora, affected seriously the coastal wetland ecosystem in China. This study aims to quantify the oxygen transportation among clonal ramets of Spartina alterniflora grown in different waterlogged conditions, by using stable isotope techniques. Meanwhile, the development of the oxygen transportation tissues and the oxygen physiological characters would be observed. These results of the study could reveal regularity of materials transportation among clonal ramets of halophytes in coastal environments. Moreover, the adaptive strategy of clonal plant and biological invasions mechanism would be improved, and the theoretical basis for the control of alien invasive plants would be provided.

植物克隆性与入侵性的关系，是入侵生态学关注的热点。克隆整合作用在水生克隆植物适应逆境，拓展新生境的方面起到了重要的作用。氧气的传输和共享对于湿地植物来说异常重要，但是我们目前仍然缺乏对克隆植物分株在湿地环境下氧气传输规律的了解。本项目拟以对我国海滨湿地生态系统影响最严重的外来入侵植物互花米草为研究对象，利用稳定同位素技术，定量分析在淹水生境下互花米草克隆分株间氧气传输的速率和方向，同时对淹水胁迫和生理整合共同作用下植株体内氧气传输组织的发育和氧生理特征展开研究。其结果不仅能揭示潮间带环境下克隆植物内部氧气运输的规律，同时有助于我们更深入地了解和把握克隆植物对生态环境的适应策略和生物入侵的机制，为科学控制外来入侵植物提供理论依据。

湿地生境如泥沙掩埋、水淹等导致植物的缺氧影响到植物的生长与繁殖。本项目以对我国海滨湿地生态系统影响最严重的外来入侵植物互花米草为研究对象，研究了互花米草对缺氧生境的响应机制及其适应策略。通过对不同盐度和硫化物水平下海滨植物碱蓬、互花米草和芦苇生境中溶解氧的变化及种子的萌发特征，探讨海滨植物生长早期适应策略；监测不同淹水条件下互花米草根际溶解氧的变化规律，分析了克隆整合作用对克隆分株光合生理特征及抗氧化系统的影响；比较了水体不同可溶性碳氮比条件下，有无互花米草植株土壤温室气体二氧化碳、甲烷和氧化亚氮排放的规律及其土壤剖面溶解氧的变化趋势。结果有助于我们更深入地了解和把握互花米草对生态环境的适应策略，为科学控制生物入侵及评价入侵后果提供参考。