|| 要旨トップ | 目次 |||日本生態学会第62回全国大会 (2015年3月、鹿児島) 講演要旨
一般講演（口頭発表） I1-08 (Oral presentation)
Much of the tree diversity in tropical forests consists of a few common species and many rare species, but why rare species are rare is still largely unanswered. Rare tend to be more susceptible to negative density dependence, and this may leave a different signature in the spatial distribution of tree common and rare species. However, whether these differences are intrinsic to the species or simply reflections of current abundance is unknown. Using long-term data on Barro Colorado Island, Panama, we studied how differences and changes in species abundance are associated with spatial dispersion in species that were consistently common or rare, and species that either increased or decreased over time. Although it is not a logical necessity, distance to the nearest conspecific adult was consistently greater in rare than common species. In species that increased and decreased, conspecific neighbor distances approached that for common and rare species over time, respectively. Except in rare species, sapling to adult distances were greater than adult to adult distances, suggesting that the negative density dependence weakens with growth. Our results suggest that species abundance and changes leave traces in spatial distributions and emphasize the importance of long-term data.