Determining Species-Specific Seed Shadows Using Molecular Genetic Methods

智力价值：测量和分析种子向环境中的传播被认为是种子传播和植物招募研究的主要限制。到目前为止，种子阴影一直基于从无线电跟踪的动物或种子陷阱收集的数据。在前一种方法中，种子阴影是概率的，因为传播是基于一段时间内的平均肠道通过时间和移动的距离，但数据不提供评估动物产生的种子阴影的物种特定差异的方法。在后一种情况下，种子雨提供了种子到达微环境的直接衡量标准，尽管不同动物传播者的贡献无法区分。为了了解种子传播者对植物种群的进化影响，有必要剖析动物传播者的个体生态角色。这项SGER建议研究了一种新的方法，利用分子标记和粪便样本直接测量鸟类特定物种的种子传播。含有种子的新鲜鸟类粪便很容易在森林环境中找到或在种子陷阱中收集。在这个探索性的研究项目中，我们将收集含有已知鸟类(即捕获的鸟类)种子的粪便样本，并对鸟类掉落的情况进行遗传分析，以获得“物种信号”。这项前期工作对于测试从禽类粪便中检测微卫星标记的能力是必要的。如果没有足够的证据表明这项新技术将发挥作用，任何依赖这种方法来检查鸟类种子传播功能的种间差异的提议都不太可能成功。如果成功，这项技术可能会彻底改变我们对热带低地森林种子传播效率的研究，因为它将提供一种直接研究种子传播到种子和幼苗建立条件不同的微环境中的手段。这项新技术的应用将使我们第一次能够建立种子传播者行为和植物种群之间的关键联系，从而提供关键的经验数据来确定动物对植物种群的影响。广泛影响：拟议的研究有效地结合了主要研究人员的生态、行为和分子遗传学专业知识，并为新的协作研究提供了途径，这将加强每个高级研究人员的研究计划。如果我们能够成功地开发出利用鸟类粪便样本中的分子遗传数据来获取物种信号的方法，这种方法很可能会被许多研究人员采用，并应用于广泛的生态学、种群和行为研究。该研究项目的实地和实验室部分也将为密歇根大学圣彼得堡分校的学生提供关键机会。路易和来自拉丁美洲的研究人员将获得研究经验。

Intellectual Merit: Measuring and analyzing seed dissemination into the environment is considered a major limitation in seed dispersal and plant recruitment studies. To date, seed shadows have been based on data collected from radio-tracked animals or from seed traps. In the former method, seed shadows are probalistic as dissemination is based on average gut passage times and distance moved during some time period, but data do not provide a means to evaluate species-specific differences in animal-generated seed shadows. In the latter case, seed rain provides a direct measure of seed arrival into microenvironments, although the contribution of different animal dispersers is not possible to discern. Dissecting out individual ecological roles of animal dispersers is necessary to understand the evolutionary impacts of seed dispersers on plant demography. This SGER proposal investigates a new method for directly measuring species-specific seed dissemination by birds using molecular markers and fecal samples. Fresh bird droppings that contain seeds are readily found in forest environments or collected in seed traps. In this exploratory research project we will collect fecal samples containing seeds from known species of birds (i.e., captured birds) and conduct genetic analyses on the bird dropping to get a "species signal". This preliminary work is necessary to test the ability of detecting microsatellite markers from bird droppings. Without sufficient evidence that this novel technique will function, any proposal relyingon this method to examine interspecific differences in seed dispersal function by birds is unlikely to be successful. If successful, this technique could revolutionize our studies on seed-dispersal efficiency in tropical lowland forests as it would provide a means to directly study seed dissemination into microenvironments that differ in seed and seedling establishment conditions. The application of this novel technique would allow us, for the first time, to develop the critical link between seed disperser behavior and plant demography, and thus, provide the key empirical data to determine the influence of animals on plant demography.Broader Impact: The proposed research effectively combines the ecological,behavioral, and molecular genetic expertise of the principal investigators and provides an avenue for new collaborative research that will enhance research programs of each senior investigator. If we can successfully develop the methods to obtain species signals using molecular genetic data from bird fecal samples, this method will likely become adopted by many researchers and applied to a wide range of ecological, population, and behavioral studies. Field and laboratory components of the research program will also provide key opportunities for a student from UM-St. Louis and from Latin America to gain research experience.