Chacón-Labella Julia, de la Cruz Marcelino, Pescador David S, Escudero Adrián
Departamento de Biología y Geología, ESCET, Universidad Rey Juan Carlos, Móstoles, Spain.
Oecologia. 2016 Apr;180(4):975-87. doi: 10.1007/s00442-016-3547-z. Epub 2016 Jan 28.
Evaluating community assembly through the use of functional traits is a promising tool for testing predictions arising from Niche and Coexistence theories. Although interactions among neighboring species and their inter-specific differences are known drivers of coexistence with a strong spatial signal, assessing the role of individual species on the functional structure of the community at different spatial scales remains a challenge. Here, we ask whether individual species exert a measurable effect on the spatial organization of different functional traits in local assemblages. We first propose and compute two functions that describe different aspects of functional trait organization around individual species at multiple scales: individual weighted mean area relationship and individual functional diversity area relationship. Secondly, we develop a conceptual model on the relationship and simultaneous variation of these two metrics, providing five alternative scenarios in response to the ability of some target species to modify its neighbor environment and the possible assembly mechanisms involved. Our results show that some species influence the spatial structure of specific functional traits, but their effects were always restricted to the finest spatial scales. In the basis of our conceptual model, the observed patterns point to two main mechanisms driving the functional structure of the community at the fine scale, "biotic" filtering meditated by individual species and resource partitioning driven by indirect facilitation rather than by competitive mechanisms.
通过使用功能性状来评估群落组装是检验生态位和共存理论所产生预测的一种很有前景的工具。尽管相邻物种之间的相互作用及其种间差异是具有强烈空间信号的共存驱动因素，但评估单个物种在不同空间尺度上对群落功能结构的作用仍然是一项挑战。在这里，我们探讨单个物种是否对局部组合中不同功能性状的空间组织产生可测量的影响。我们首先提出并计算两个函数，它们描述了多个尺度上围绕单个物种的功能性状组织的不同方面：个体加权平均面积关系和个体功能多样性面积关系。其次，我们建立了一个关于这两个指标的关系和同时变化的概念模型，针对一些目标物种改变其邻域环境的能力以及所涉及的可能组装机制，提供了五种替代情景。我们的结果表明，一些物种会影响特定功能性状的空间结构，但其影响总是局限于最精细的空间尺度。基于我们的概念模型，观察到的模式指向在精细尺度上驱动群落功能结构的两个主要机制，即由单个物种介导的“生物”过滤和由间接促进而非竞争机制驱动的资源分配。
