Interspecific variation in seedling responses to seed limitation and habitat conditions for 14 Neotropical woody species
Interspecific variation in seedling responses to seed limitation and habitat conditions for 14 Neotropical woody species
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DOI：
10.1111/j.1365-2745.2008.01444.x
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发表时间：
2009-01
影响因子：
5.5
通讯作者：
Natalia Norden;J. Chave;P. Belbenoit;Adeline Caubère;P. Châtelet;P. Forget;B. Riera;J. Viers;C. Thébaud
中科院分区：
文献类型：
--
作者：
Natalia Norden;J. Chave;P. Belbenoit;Adeline Caubère;P. Châtelet;P. Forget;B. Riera;J. Viers;C. Thébaud
[1]我们评估了法属圭亚那古老热带森林中14种木本植物（12种树木和2种藤本植物）在幼苗阶段结构植物种群的扩散和生态位过程的相对重要性。2我们结合了来自160个站点网络的长期数据，每个站点包括一个种子陷阱和两到三个相邻的幼苗地块，并对环境变量进行了精细量化。3对于每个物种，我们将种子限制量化为种子未到达的种子陷阱的比例，并将建立限制量化为种子到达但未出现幼苗的站点的比例。所有物种都表现出强烈的种子限制，而只有一个物种表现出显着的建立限制。4确定了由种子密度或环境因子解释的当地幼苗密度方差的比例，并评估了环境对幼苗存活的影响。5虽然所有物种的种子都表现出相当大的空间聚集，但只有五个物种的种子密度解释了幼苗密度变异的一个重要部分。栖息地偏好解释了一个显着的部分幼苗密度的方差为6个物种。其余的物种，四个没有表现出显着的关系，无论是种子到达或栖息地条件。6环境对本地幼苗多度的影响与对幼苗存活的影响相关性较弱。当幼苗密度与给定的环境因子显著相关时，存活率通常与该因子不相关。随着环境过滤的作用，栖息地的关联模式可能会随着时间的推移而改变。7合成。我们的研究结果表明，种子到达和栖息地的偏好有助于解释丰富的热带木本物种在幼苗阶段，但它们的相对重要性表现出重要的种间差异。虽然我们的研究仅限于木本物种的一个子集，他们占27%的个人组成的幼苗层。因此，我们的研究结果可能会有重要的后果，在幼苗群落的结构。
1 We assessed the relative importance of dispersal and niche processes in structuring plant populations at the seedling stage for 14 woody plant species (12 trees and 2 lianas) in an old‐growth tropical forest of French Guiana. 2 We combined long‐term data from a network of 160 stations, each comprising a seed trap and two to three neighbouring seedling plots, with fine‐scale quantification of environmental variables. 3 For each species, we quantified seed limitation as the proportion of seed traps that were not reached by seeds, and establishment limitation as the proportion of stations where seeds arrived but where seedlings did not occur. All species showed strong seed limitation, whereas only one species showed significant establishment limitation. 4 We determined the proportion of variance in local seedling density explained by either seed density or environmental factors, and we assessed the effect of environment on seedling survival. 5 Although seeds showed considerable spatial clumping in all species, seed density explained a significant fraction of the variance in seedling density for only five species. Habitat preferences explained a significant fraction of the variance in seedling density for six species. Of the remaining species, four showed no significant relationship with either seed arrival or habitat conditions. 6 Environmental effects on local seedling abundance were weakly related to those on seedling survival. When seedling density was significantly correlated with a given environmental factor, survival was usually not correlated with that factor. Habitat association patterns might change over time, as environmental filtering operates. 7 Synthesis. Our results show that both seed arrival and habitat preferences contribute to explaining the abundance of tropical woody species at the seedling stage, but their relative importance showed important interspecific differences. Although our study was limited to a subset of woody species, they accounted for 27% of the individuals composing the seedling layer. Thus, our findings are likely to have important consequences in the structuring of the seedling community.