克隆劳动分工对外来水生植物入侵性的贡献及其适应性机制

Plant invasion has posed a great threat to the biodiversity, environment and economy both globally and locally. Many of these successful invaders are clonal plants, however, little is known about the roles and adaptive mechanism of clonal traits on their invasiveness. Based on the transdisciplinary theories and methodologies of individual, population and community ecology, with species pairs of several aquatic invasive plants and their relative (or co-occurring) native and exotic non-invasive species in China as research objects, we investigate the different effects of clonal division of labour (a key clonal trait of clonal plants) among the invasive aquatic plants and their relative native (or co-occurring) and exotic non-invasive species, and between the original and invasive populations of invasive aquatic plants, under homogeneous and heterogeneous resource availability, and under local disturbances and competitive environment by native aquatic plant communities, via the techniques and methods of comparative, field, experimental and physiological ecology. The purpose of this proposal is to explore eco-physiological and adaptive mechanisms of clonal division of labour in aquatic clonal plants, the implications and mechanisms of clonal traits on the invasiveness of alien aquatic plants, and therefore to reveal some invasive mechanisms of alien aquatic plants more deeply. This research will provide important implications for the development of theories in clonal plant, invasive and evolutional ecology. Furthermore, this research will provide powerful theoretical basis for the prevention and control of alien invasive aquatic plants.

外来植物入侵对全球和区域生物多样性、环境和经济都构成了巨大威胁，这些成功入侵的水生植物中多数为克隆植物，而克隆性状对外来水生植物入侵性的贡献及其适应性机制尚不清楚。本研究以国内三种主要的恶性入侵水生植物及其近缘（或共存）的乡土植物和外来非入侵植物种对为研究对象，以个体、种群和群落生态学理论为基础，以研究入侵水生植物及其近缘（或共存）的乡土植物和外来非入侵植物之间、入侵种原产地种群和入侵地种群之间的克隆劳动分工能力及其作用差异为切入点，综合运用比较生态学、野外生态学、实验生态学和生理生态学等研究技术和手段，研究同质和异质性资源分布条件下、局部干扰和植被竞争环境下克隆劳动分工对外来水生植物入侵的生理、生态意义及其适应性机理，以期更深入地揭示外来水生植物入侵的生理生态机制。本研究对丰富和发展克隆植物生态学、入侵生态学和进化生态学理论具有重要意义，并可为水生植物入侵种的防治提供有力的理论依据。

为探讨克隆劳动分工在外来水生植物成功入侵中的贡献及其适应性机理，我们选取克隆模式植物喜旱莲子草及其本地近缘和共存种为研究对象，分别研究了在同质和异质性资源环境、局部干扰和植被竞争胁迫下克隆劳动分工对外来水生植物入侵的生理、生态意义及其适应性机理。研究主要发现同质性土壤营养条件下喜旱莲子草克隆劳动分工现象的存在：即基部分株倾向于投入更多资源到地下以获取地下资源，端部分株分株倾向于投入更多资源到地上部分以获取更多光照和更强克隆扩散能力；发现在资源交互的斑块生境中，相比其同属和共存本地种，喜旱莲子草能更得益于劳动分工：表现为更强的端部分株专化吸收光照等地上资源和克隆扩散（地上部分生物量显著增加），从而使喜旱莲子草端部分株和整个克隆片段的收益显著更大。发现不同施氮频率下、不同斑块资源对比度下和局部去叶干扰环境下，入侵水生植物喜旱莲子草相对于其近缘和同生态型的乡土种能更得益于克隆劳动分工，表明劳动分工这一克隆属性可能是以喜旱莲子草为代表的外来水生植物成功入侵的关键性状之一。因此在水生植物入侵种的防控过程中，需重视其克隆劳动分工特征而有针对性地制定防控措施；在引入水生植物之前，需将其克隆属性作为评价其潜在入侵性的重要指标之一。本项目丰富和发展了克隆植物生态学和入侵植物生态学理论具有重要意义，同时有助于我们理解环境变化引起的恶性水生克隆植物的扩散、入侵及其对水生植被群落的影响，并可为主要水生植物入侵种的防治提供理论支撑。