目的:无性系生长在草本植物中普遍存在,并通过连接克隆器官,通过资源整合帮助他们应对环境异质性。这种集成被认为是通过将资源从富补丁转移到差补丁来平衡异构性。然而,这样的“均衡”策略只是几种可能的策略之一。在一定条件下,可能会首选强调针叶运动和探索新领域的策略,或者在较旧的分株中积累资源的策略。最佳策略可以由环境条件决定,例如资源可用性和轻度竞争水平。我们旨在在概念分析中总结可能的易位策略,并研究来自不同栖息地的两个物种的易位。
方法:比较了来自不同生境的两个密切相关的物种之间的资源易位,并具有相反的生产力。该研究使用稳定同位素标记研究了在两个发育阶段在光异质性(一个ramet阴影)下生长的成对母子分株中碳和氮的双向易位。
结果:在早期发育阶段,这两个物种都将资源转移到了女儿,并且通过阴影改变了转移。稍后,低生产力栖息地的物种,Fragariaviridis,将碳转移到阴影分株(母亲和女儿),根据“均衡”策略。相比之下,高生产力栖息地的物种,委陵菜,不支持阴影母亲ramets。在这两个物种中,氮转运仍主要是顺生。
结论:两个研究物种表现出不同的易位策略,这可能与每个物种经历的栖息地条件有关。结果表明,我们需要考虑不同的可能策略。我们强调双向追踪在易位研究中的重要性,以及需要进一步研究以使用比较方法从对比栖息地调查物种的易位模式。
OBJECTIVE: Clonal growth is widespread among herbaceous plants, and helps them to cope with environmental heterogeneity through resource integration via connecting clonal organs. Such integration is considered to balance heterogeneity by
translocation of resources from rich to poor patches. However, such an \'equalisation\' strategy is only one of several possible strategies. Under certain conditions, a strategy emphasising acropetal movement and exploration of new areas or a strategy of accumulating resources in older ramets may be preferred. The optimal strategy may be determined by environmental conditions, such as resource availability and level of light competition. We aimed to summarise possible
translocation strategies in a conceptual analysis and to examine
translocation in two species from different habitats.
METHODS: Resource translocation was compared between two closely related species from different habitats with contrasting productivity. The study examined the bidirectional
translocation of carbon and nitrogen in pairs of mother and daughter ramets grown under light heterogeneity (one ramet shaded) at two developmental stages using stable-isotope labelling.
RESULTS: At the early developmental stage, both species translocated resources toward daughters and the translocation was modified by shading. Later, the species of low-productivity habitats, Fragaria viridis, translocated carbon to shaded ramets (both mother and daughter), according to the \'equalisation\' strategy. In contrast, the species of high-productivity habitats, Potentilla reptans, did not support shaded mother ramets. Nitrogen
translocation remained mainly acropetal in both species.
CONCLUSIONS: The two studied species exhibited different translocation strategies, which may be linked to the habitat conditions experienced by each species. The results indicate that we need to consider different possible strategies. We emphasise the importance of bidirectional tracing in
translocation studies and the need for further studies to investigate the translocation patterns in species from contrasting habitats using a comparative approach.