Population Biology of Tropical Rain Forest Trees

森林砍伐对植物灭绝率的影响 热带雨林中的物种是有据可查的。 少即是 森林砍伐对基因丧失的影响， 因为没有足够的 关于空间分布的数量和模式的信息 自然种群中的遗传变异。 遗传变异 被认为是重要的长期生存， 人口。 因此，有关的数量和模式的信息 种群内和种群间的遗传变异是 设计适当措施保育热带树木 人口。 同样重要的是要了解基因 交配系统和基因交换水平等因素 在人口中，这极大地影响了人口的分布， 遗传变异 热带雨林中的许多树种种群数量很少 密度的 小种群可能会失去遗传变异， 也会受到近亲繁殖的抑制（ 由于近亲交配而产生的生殖输出）。 因此，在本发明中， 因此，研究遗传调节因子具有重要意义。 物种的变异通常发生在低密度。 的 本研究的目的是1. 分析金额， 遗传变异模式，2。 估计有效人口 尺寸，3. 测量异交（或近亲繁殖）的比率，4. 确定种群间的基因交换水平; 5. 研究密度对近亲繁殖水平的影响， 热带低地自然种群的生殖输出 雨林树木 现场工作将在洛杉矶进行 热带雨林组织热带雨林生物野外站 在哥斯达黎加学习，并在大学进行实验室工作 在波士顿的马萨诸塞州。

The effects of deforestation on the extinction rates of plant species in tropical rain forests are well documented. Less is known about the impact of deforestation on the loss of genetic variation within tree species because there is not enough information about the amount and patterns of spatial distribution of genetic variation in natural populations. Genetic variation is considered to be important in the long term survival of populations. Thus, information about the amount and patterns of genetic variation within and among populations is central to the design of appropriate measures to conserve tropical tree populations. Equally important is to understand the genetic factors, such as mating systems and the level of gene exchange among populations, which greatly influence the distribution of genetic variation. Many tree species in tropical rain forests have low population density. Small populations may lose genetic variation, and may also be subject to inbreeding depression (deleterious effects in reproductive output due to mating among close relatives). Thus, it is paricularly important to study factors regulating genetic variation in species that typically occur in low densities. The objectives of this research are to 1. analyze the amount and patterns of genetic variation, 2. estimate effective population size, 3. measure the rate of outcrossing (or inbreeding), 4. determine the level of gene exchange among populations, and 5. examine the effects of density on the level of inbreeding and reproductive output in natural populations of tropical lowland rain forest trees. The field work will be conducted at the La Selva Biological Field Station of the Organization for Tropical Studies in Costa Rica, and the laboratory work at the University of Massachusetts at Boston.