Metacommunity ecology currently lacks a consistent functional trait perspective across trophic levels. To foster new cross-taxa experiments and field studies, we present hypotheses on how three trait dimensions change along gradients of density of individuals, resource supply and habitat isolation. The movement dimension refers to the ability to move and navigate in space, the tolerance dimension addresses the ability to tolerate prevailing environmental conditions and the interaction dimension aggregates the abilities to acquire resources in competition with other species, to defend against consumers or to profit from other species by mutualism and facilitation. In multi-trophic studies, functionally analogous traits associated to these dimensions need to be defined across taxa and measured. The dimensions represent subnetworks of strongly correlated traits within the overall phenotypic trait network. These subnetworks can be aggregated to trait modules using dimension reduction techniques. We demonstrate how to derive dimensions from species distributions and trait correlation networks, using salt marshes as an example. We hypothesize that at the single-community scale, investments by organisms in the tolerance dimension increase with decreasing resource supply. Investments to the interaction dimension increase with increasing density. Communities with densely packed individuals are characterized by convergence under equal competition and by increasing divergence under stabilizing and equalizing competition. At the metacommunity scale, trade-offs between the movement dimension and the interaction dimension shape the community functional composition. Biomass removal by consumers act as an equalizing factor and increase divergence in the interaction and movement dimension, particularly in well-connected habitats. As future research directions to advance functional metacommunity ecology, we propose investigating 1) the feasibility of using dimensions as broad generalizations of multiple functions in different meta-ecosystems, 2) functional trait analogues across taxa, 3) dimension responses and effects on gradients of meta-ecosystems and 4) matching of functionally analogous traits between trophic levels.

中文翻译：

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营养元群落的功能特征维度

元群落生态学目前缺乏跨营养级一致的功能特征观点。为了促进新的跨类群实验和实地研究，我们提出了关于三个特征维度如何随着个体密度、资源供应和栖息地隔离的梯度变化的假设。运动维度是指在空间中移动和导航的能力，宽容维度涉及容忍普遍环境条件的能力，而交互维度则是在与其他物种竞争中获取资源、防御消费者或从其他物种中获利的能力。通过互利共生和促进物种。在多营养研究中，需要跨分类群定义和测量与这些维度相关的功能相似性状。维度代表整个表型特征网络中强相关特征的子网络。可以使用降维技术将这些子网络聚合为特征模块。我们以盐沼为例，演示了如何从物种分布和性状相关网络中推导出维度。我们假设在单一社区尺度上，生物体在耐受维度上的投资随着资源供应的减少而增加。对交互维度的投资随着密度的增加而增加。人口密集的社区的特点是在平等竞争下趋同，在稳定和均等竞争下增加分歧。在元社区尺度上，运动维度和交互维度之间的权衡塑造了社区功能组成。消费者清除的生物质作为平衡因素，增加了相互作用和运动维度的差异，特别是在连接良好的栖息地。作为推进功能性元社区生态学的未来研究方向，我们建议调查 1) 使用维度作为不同元生态系统中多种功能的广泛概括的可行性，2) 跨分类群的功能性状类似物，3) 维度响应和对元梯度的影响-生态系统和 4) 营养级之间功能相似性状的匹配。特别是在连接良好的栖息地。作为推进功能性元社区生态学的未来研究方向，我们建议调查 1) 使用维度作为不同元生态系统中多种功能的广泛概括的可行性，2) 跨分类群的功能性状类似物，3) 维度响应和对元梯度的影响-生态系统和 4) 营养级之间功能相似性状的匹配。特别是在连接良好的栖息地。作为推进功能性元社区生态学的未来研究方向，我们建议调查 1) 使用维度作为不同元生态系统中多种功能的广泛概括的可行性，2) 跨分类群的功能性状类似物，3) 维度响应和对元梯度的影响-生态系统和 4) 营养级之间功能相似性状的匹配。