The Dynamics of a Neotropical Forest: The Year 2000 Recensus

巴罗科罗拉多岛（BCI）森林动态项目是世界上对热带森林进行的时间最长的大规模研究，旨在测试种群和整个群落水平上的竞争理论，以维持热带潮湿森林的高树种多样性。BCI研究是自1980年以来在整个新大陆和旧大陆热带地区建立的全球类似地块网络的旗舰项目和模型。目前的活动是在2000年对BCI的50公顷地块进行第五次全面普查，将研究延长到20年。第五次普查的目标是（1）更新所有木本植物1cm胸径的补充、生长和存活数据（240，000茎），（2）将普查范围扩大到较小的树苗大小类;（3）分析所有树木的命运（生长，生存）作为当地生物邻居的功能，以及（4）使用该邻域分析和其他信息来开发BCI森林的第一代动态模型。了解这些当地的邻里效应是必不可少的树冠树木替代，这反过来又是至关重要的了解如何保持在BCI森林树种多样性的预测理论。对上一次人口普查中23万株植物13年生存情况的初步社区分析已经完成。有显着的，往往是强大的，邻居的焦点植物生存的影响。四个邻居因素的影响进行了分析：邻居的数量相同的物种的焦点植物，从第一次到最后一次普查的邻居生存的数量，无论物种，大小的焦点植物相对于它的邻居，和物种的数量之间的焦点植物的邻居。如果下一次普查的额外数据证实了这一结果，则对了解导致热带森林社区树种多样性高的因素具有重要意义。

9909947HubbellThe Barro Colorado Island (BCI) Forest Dynamics Project is the longest running large-scale study in the world of a tropical forest, established to test competing theories at the population and whole community level for the maintenance of high tree species diversity in tropical moist forests. The BCI study is the flagship project and model for a global network of similar plots established since 1980 throughout the New and Old World tropics. Current activities are to conduct the fifth complete census of the 50 ha plot on BCI in the year 2000, extending the study to two decades. The goals of the fifth census are (1) to update the data on recruitment, growth, and survival of all woody plants 1 cm dbh (240,000 stems) in the plot since the last census 5 years ago, (2) to extend the census to smaller sapling size classes; (3) to analyze the fate of all trees (growth, survival) as a function of their local biotic neighborhood, and (4) to use this neighborhood analysis and other information to develop a first-generation dynamical model of the BCI forest. Understanding these local neighborhood effects is essential for developing a predictive theory of canopy tree replacement, which in turn is critical for understanding how tree species diversity is maintained in the BCI forest. A preliminary neighborhood analyses on the 13-year survival of 230,000 individual plants through the last census has been completed. There were significant, often strong, neighborhood effects on focal plant survival. The effects of four neighborhood factors were analyzed: the number of neighbors of the same species as the focal plant, the number of neighbors surviving from the first to the last census irrespective of species, the size of the focal plant relative to its neighbors, and the number of species among the focal plant's neighbors. The results, if borne out by additional data from the next census have important implications for understanding the factors that lead to high tree species diversity in tropical forest communities.