Long-Term Studies of Small-Sapling Community Dynamics in Relation to Light Gaps in a Neotropical Forest

哈贝尔这项研究的目的是对巴拿马热带雨林的苗木和树苗进行年度普查，监测它们的年生长、存活和5年来的补充情况。我们还将记录在森林中开放的所有树木瀑布光隙的位置和动态，因为这些是森林更新的主要地点，在那里，苗木和小树苗的动态被加速。位于巴拿马运河巴罗科罗拉多岛(BCI)的这片森林的动态在过去20年里一直被研究，但到目前为止还没有包括树苗和小树苗。这些新数据将使我们能够测试替代假设，即300多种树木是如何在BCI森林中维持和共存的。新的证据表明，杀死种子和幼苗的寄主专一性真菌病原体可能是调节BCI森林树木多样性的重要因素。我们将验证这一假说，并在苗木和小树苗群落中测试密度依赖调控的强度。我们还将测试这一假设，即树冠空隙与有限的种子传播相互作用，限制了BCI森林中大多数树种的招募成功。这项工作可能对理解热带森林总体上如何维持高等乔木物种多样性具有更广泛的意义。

HUBBELL The objective of this research is to conduct an annual census ofseedlings and saplings in a tropical rain forest in Panama, to monitor theirannual growth, survival, and recruitment for 5 years. We will also recordthe location and dynamics of all treefall light gaps that open in theforest, because these are the main sites for forest regeneration, whereseedling and small sapling dynamics are accelerated. The dynamics of thisforest, located on Barro Colorado Island (BCI) in the Panama Canal, has beenstudied for the past two decades, but thus far seedlings and small saplingshave not been included. These new data will enable us to test alternativehypotheses for how the more than 300 species of trees are maintained andcoexist in the BCI forest. New evidence suggests that host-specific fungalpathogens that kill seeds and seedlings may be important agents regulatingtree diversity in the BCI forest. We will test this hypothesis and testthe strength of density-dependent regulation in the seedling and smallsapling community. We will also test the hypothesis that treefall gaps,interacting with limited seed dispersal, limit the recruitment success ofmost tree species in the BCI forest. The work is likely to have broadersignificance for understanding how tropical forests in general maintain hightree species diversity.