Large‐ and small‐seeded species have contrasting functional neighborhoods in a subtropical forest
Large‐ and small‐seeded species have contrasting functional neighborhoods in a subtropical forest
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DOI：
10.1002/ecs2.3016
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发表时间：
2020-01
期刊：
影响因子：
2.7
通讯作者：
M. Umaña;G. Arellano;Jimena Forero‐Montaña;C. Nytch;N. Swenson;Jill Thompson;M. Uriarte;J. Zimmerman
中科院分区：
文献类型：
--
作者：
M. Umaña;G. Arellano;Jimena Forero‐Montaña;C. Nytch;N. Swenson;Jill Thompson;M. Uriarte;J. Zimmerman
。森林群落组成是多种力量共同作用的结果，既包括增加分类和功能分化的力量，也包括促进特征趋同的力量。这些力量背后的机制可能不会在群落内同质运作；不同物种的个体永远不会完美混合，因此，物种往往被包围并与不同的物种亚群相互作用。事实上，不同局部物种的社区的分类和功能组成可能有很大的差异。在这里，我们考察了推动物种水平邻里关系的机制是否与局部物种的内在特征有关，如生活史和资源吸收策略的差异，并反过来与物种生存有关。我们关注两个关键特征：(1)种子质量，这是与逆境耐受有关的生活史策略的主导轴线；(2)林下光照偏好，将物种从需要光照的先锋物种分类到耐荫物种。(2)种子质量(Seedfi)是与逆境相关的生活史策略的主导轴。我们监测了波多黎各超过10年的苗木群落，并使用7个功能性状计算了物种水平邻域中的邻域特征分散度。我们使用线性模型检验了种级特征、种子质量和偏爱光照条件在fl中是否影响苗木社区的功能扩散格局。然后，我们研究了物种水平的功能邻里如何影响幼苗的存活。我们发现，小种子和大种子物种在它们所关联的功能社区类型上存在差异。大种子树种与相邻树种在叶经济性状上比预期更相似，但在种子质量和叶面积性状上比预期差异更大，而小种子树种则相反。物种功能邻域的这种变异是决定幼苗存活的重要因素。总而言之，我们的结果表明，发散和汇聚的力量并不是在整个社区中均匀地运作。它们的相对作用在空间上以及在逐个物种的基础上发生变化，可能与种子质量等特征有关的确定性基础。
. Forest community composition is the outcome of multiple forces, including those that increase taxonomic and functional divergence and those that promote convergence in traits. The mechanisms underlying these forces may not operate homogenously within communities; individuals of different species are never perfectly mixed, and thus, species tend to be surrounded and interact with different subsets of species. In fact, taxonomic and functional composition of neighborhoods of different focal species can be highly variable. Here, we examine whether mechanisms driving species-level neighborhoods relate to intrinsic characteristics of focal species such as differences in life-history and resource-uptake strategies and in turn relate to species survival. We focus on two key characteristics: (1) seed mass, which de fi nes a dominant axis of life-history strategies related to stress tolerance, and (2) understory light preferences that sort species from light-demanding pioneers to shade-tolerant. We monitored seedling communities over 10 yr in Puerto Rico and calculated neighborhood trait dispersion in species-level neighborhoods using seven functional traits. We examined whether species-level characteristics, seed mass and preferred light conditions, in fl uence patterns of functional dispersion in seedling neighborhoods using linear models. Then, we examined how species-level functional neighborhoods impact seedling survival. We found that small- and large-seeded species diverge in the type of functional neighborhoods they associate with. Large-seeded species associate with neighbors that are more similar than expected in leaf economic traits, but more different than expected in seed mass and leaf area traits, while the opposite was found for small-seeded species. This variation in species functional neighborhood was important in determining seedling survival. In sum, our results suggest that divergent and convergent forces do not operate homogenously over entire communities. Their relative role changes in space, and on a species-by-species basis, probably with a deterministic foundation linked to traits such as seed mass.