两种入侵水生克隆植物对生境异质性的适应性对策

According to statistics, 24% of the world's malignant invasive plants are aquatic plants and most of them have strong clonal ability. Therefore, the invasive aquatic plants are an important global change problem in aquatic ecosystems. Growth traits are the key factors determining the successful invasion of alien plants, which have been extensively validated in the study of terrestrial invasive ecology, but not explored in the study of aquatic invasive ecology. In this study, the regional invasive aquatic plant Myriophyllum aquaticum and the world invasive aquatic plant Alternanthera philoxeroides were taken as the experimental materials. Based on the theory of functional ecology and invasive ecology, compared with native aquatic plants of the same living type, the clonal growth traits related to resource utilization and resistance to environmental interference were taken as the key points, and physiological ecology and comparative biology were comprehensively utilized. The research methods of ecology, field investigation and controlled experiment were used to compare the growth traits of invasive aquatic plants and native aquatic plants, in order to find out the characteristics advantages of invasive aquatic plants, and to study the changes of the characteristics of invasive aquatic plants in heterogeneous environments caused by resource heterogeneity and environmental interference, in order to find out the effects of resource heterogeneity and environmental interference on the characteristics of invasive aquatic plants. The effect of invasiveness of aquatic plants was discussed, in order to reveal the invasion mechanism of alien aquatic plants. This study is of great significance to enrich and develop the theory of invasive ecology, and can provide theoretical support for the prevention, control and management of alien invasive aquatic plants.

根据数据统计，世界上24%的恶性入侵植物为水生植物且大多具有较强的克隆拓殖的能力。因而，外来水生植物入侵是水生生态系统面临的重要全球变化问题。生长性状是决定外来植物成功入侵的关键因素，这在陆生植物入侵生态学研究中得到大量验证，而在水生植物入侵生态学研究中缺乏探索。本研究以区域性入侵水生植物粉绿狐尾藻和世界性入侵水生植物喜旱莲子草为研究对象，以功能生态学和入侵生态学理论为基础，与同生活型的水生植物本地种相比较，以与资源利用和抵抗环境干扰相关的克隆生长性状为主要切入点，综合利用生理生态学和比较生态学的研究方法，比较入侵种与乡土种的性状差异，以期发现入侵水生植物所具备的性状优势，并研究资源异质性和环境干扰对水生植物入侵性的影响，从而探讨性状在水生植物入侵中的作用，以期更深入地揭示外来入侵水生植物的入侵机制。本研究对丰富和发展入侵生态学理论具有重要意义，并可为外来入侵水生植物的防控管治提供理论支撑

克隆植物生长在具有时空异质性的环境中，它们可以有效地适应异质环境，并通过自身独特的生长特征进一步提高生长性能。为了探究土壤营养和水分的异质性对外来种和本地水生植物的生长性能和觅食行为的综合影响，以及异质性的污染胁迫生境中水生植物的风险分摊能力，本论文以相似生活型的入侵种喜旱莲子草、粉绿狐尾藻和本地种水龙为研究对象，开展了受控实验。研究结果表明：1）营养异质增强或维持了喜旱莲子草、粉绿狐尾藻以及水龙的生长表现，水分异质对喜旱莲子草与水龙的生长表现没有显著影响，且营养异质对水龙的作用明显受到水分异质作用的影响。在资源异质条件下，喜旱莲子草与水龙都展现出了将分株优先放置于资源丰富的斑块中的现象，并以此进一步提高生长；2）克隆整合增强了喜旱莲子草、粉绿狐尾藻以及水龙在异质性污染胁迫生境下的生长表现，且整合作用在资源顶向运输时更为明显。微塑料与三氯生的混合污染增强了喜旱莲子草的生长表现。喜旱莲子草、粉绿狐尾藻以及水龙都可以通过不同的抗氧化酶调节机制来缓解胁迫；3）在克隆整合作用下，混合污染显著增加了水龙的株高，单独添加铜污染降低了水龙的总生物量，水龙可以通过不同的抗氧化酶调节机制来缓解胁迫。综上，受益于克隆整合与觅养行为，三种克隆植物对异质性和污染胁迫环境具有较高适应能力，且这种适应能力有可能促进喜旱莲子草的入侵。