Pervasive density-dependent recruitment enhances seedling diversity in a tropical forest
Pervasive density-dependent recruitment enhances seedling diversity in a tropical forest
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DOI：
10.1038/35006630
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发表时间：
2000-03-30
期刊：
影响因子：
64.8
通讯作者：
Herre, EA
中科院分区：
文献类型：
--
作者：
Harms, KE;Wright, SJ;Herre, EA
负密度依赖的幼苗补充（即，如果某一物种的密度较高，则该物种的种子不太可能成为已建立的幼苗）被认为是促进热带树木群落异常多样性的重要机制(1-3)，因为它可以潜在地防止任何特定物种侵占所有可用空间，无论是在靠近种子源的地方还是在相对较大的空间尺度上(1-18)。然而，密度依赖的招募并不一定会增强群落多样性(14)。此外，尽管在某些物种的某些生命阶段发现了密度依赖性效应(3-13)，但没有研究表明密度依赖性补充会影响群落多样性(14,15)。在此，我们报告了在巴拿马共和国一片低地潮湿森林中的观察结果，其中将到达 200 个种子捕捉器的 386,027 颗种子的物种身份与在 4 年期间招募到邻近地块的 13,068 颗幼苗的物种身份进行了比较。在 200 个站点中，新苗多样性显着高于种子多样性。这种差异的部分原因是平均招募成功率的种间差异。然而，即使在考虑了这些差异之后，负密度依赖性补充也显着促进了从种子到幼苗补充的多样性的增加。
Negative density-dependent recruitment of seedlings, that is, seeds of a given species are less likely to become established seedlings if the density of that species is high, has been proposed to be an important mechanism contributing to the extraordinary diversity of tropical tree communities(1-3) because it can potentially prevent any particular species from usurping all available space, either in close proximity to seed sources or at relatively larger spatial scales(1-18). However, density-dependent recruitment does not necessarily enhance community diversity(14). Furthermore, although density-dependent effects have been found at some life stages in some species(3-13), no study has shown that density-dependent recruitment affects community diversity(14,15). Here we report the results of observations in a lowland, moist forest in the Republic of Panama in which the species identities of 386,027 seeds that arrived at 200 seed traps were compared with the species identities of 13,068 seedlings that recruited into adjacent plots over a 4-year period. Across the 200 sites, recruit seedling diversity was significantly higher than seed diversity. Part of this difference was explained by interspecies differences in average recruitment success. Even after accounting for these differences, however, negative density-dependent recruitment contributes significantly to the increase in diversity from Seeds to seedling recruits.