LTREB: Mechanisms Maintaining Diversity of Trees in Tropical and Subtropical Rain Forests

9806310康奈尔一项关于澳大利亚热带和亚热带雨林树木种群的长期研究已经进行了34年。目的是阐明这些森林中许多物种的高度物种多样性和种群结构多样性的过程和机制。已经收集了关于这些森林中所有树种的幼苗补充率以及各种大小树木的生长和死亡率的长期数据。近年来，还测定了103个树种成年树的开花和结果强度，以及随后的新幼苗发芽率和存活率。这项研究是在热带和亚热带树木上进行的时间最长的研究之一，也是在幼苗和幼树阶段进行的时间最长的研究。这项研究将测试的假设，多样性保持在这些森林中，因为空间上常见的物种有较低的繁殖率，生长和生存比空间上罕见的物种。其他有待探讨的假设是：（1）许多物种因专门生活在不同的生境而共存，（2）多样性带来的优势增加了幼苗的生长和存活，（3）当地（昆虫）和区域（降雨）因素相互作用，影响这些森林的多样性。总的来说，这个项目将促进我们对导致热带和亚热带雨林高树种多样性的不同因素的理解。这些是一些已知的最复杂和最多样化的生态群落，包含了世界上很高比例的陆地生物物种。像这样的详细、长期的研究将有助于了解控制这些森林多样性的因素，从而有助于管理和保护其完整性。

9806310 Connell A long-term study of tree populations in tropical and subtropical rain forests in Australia has been carried on for 34 years. The objective has been to elucidate the processes and mechanisms that are responsible for the high species diversity and the varieties of population structures among the many species in these forests. Long-term data have been collected on rates of seedling recruitment, and on growth and mortality of all sizes of all species of trees in these forests. In recent years the intensity of flowering and fruiting of adult trees of 103 species, and the subsequent germination and survival rates of new seedlings, has also been measured. This study is among the longest done on tropical and subtropical trees, and is the longest for the seedling and sapling stages. This study will test the hypothesis that diversity is maintained in these forests because spatially common species have lower rates of reproduction, growth, and survival than spatially rare species. Other hypotheses to be addressed are: (1) that many species coexist by specializing to live in different habitats, (2) that diversity confers advantages which increase growth and survival of seedlings, and (3) that local (insects) and regional (rainfall) factors interact to affect diversity in these forests. Overall, this project will advance our understanding of the different factors that lead to high tree species diversity in tropical and subtropical rainforests. These are some of the most complex and diverse ecological communities known, and contain a high proportion of the worlds terrestrial species of organisms. Detailed, long-term studies such as this one will contribute to an understanding of factors that control diversity in these forests, and therefore help to manage and preserve their integrity.