SGER: Using a Stable Isotope to Track the Fate of Seeds and Seedlings

种子传播对植物群落多样性的形成和维持具有重要意义。然而，众所周知，种子传播模式很难研究，因为目前将分散的种子和/或幼苗与其母亲联系起来的技术成本高昂，而且只适用于少数植物物种。这限制了生态和进化研究的范围和准确性，这些研究需要在田间将母植物与其后代联系起来。这里提出了一种使用氮稳定同位素标记物(15N)的新技术，以帮助打破这一方法学空白。该方法包括在植物的叶片上喷洒15N标记的尿素。初步工作表明，15N信号可以可靠地从母株传递到种子，并保留在幼苗中，提供可靠的母子标记。将进行田间试验，以测试和验证这种标记技术的使用。测试包括使用不同的15N剂量对同一地点的单个植物或群体进行不同的标记，以及使用标记植物的批量加工种子以降低成本的能力。稳定同位素的使用促进了食物网、生理生态和生态系统功能研究的重大进展。然而，同位素技术还没有被用来研究种子的传播和招募。这种方法将具有广泛的吸引力，因为它允许在田间对植物进行标记，具有分子方法的严密性，并可以对许多样本进行廉价的分析。这项技术将特别适用于对种子的长期和远程监测。

Seed dispersal is important for the assembly and maintenance of diversity in plant communities. Yet, patterns of seed dispersal are notoriously difficult to study because current techniques to link dispersed seeds and/or seedlings to their mother are costly and available only for few plant species. This limits the scope and accuracy of ecological and evolutionary studies that require linking mother plants to their offspring in the field. A new technique that uses Nitrogen stable isotope markers (15N) is proposed here to help breach such a methodological gap. The method consists of spraying the leaves of plants with 15N -labeled urea. Preliminary work shows that 15N signals are reliably passed from mother plant to seeds and retained in seedlings, providing reliable mother-offspring markers. Field experiments will be conducted to test and validate the use of this labeling technique. Tests include the use of different 15N doses to differentially label individual plants or groups at a location, and the ability to use bulk-processed seeds from labeled plants to reduce costs.The use of stable isotopes has promoted major advances in the study of food webs, physiological ecology, and ecosystem function. Yet isotopic techniques have not been used to study seed dispersal and recruitment. This method will have broad appeal because it allows labeling of plants in the field, has the rigor of molecular approaches, and could permit the cheap analysis of many samples. This technique will be particularly relevant for the long-term and long-distance monitoring of seeds.