PREMISE Determining which traits characterize strategies of coexisting species is important to developing trait-based models of plant communities. First, global dimensions may not exist locally. Second, the degree to which traits and trait spectra constitute independent dimensions of functional variation at various scales continues to be refined. Finally, traits may be associated with existing categorical groupings. METHODS We assessed trait integration and differentiation across 57 forest understory plant species in Douglas-fir forests of western Oregon, United States. We combined measurements for a range of traits with literature-based estimates of seed mass and species groupings. We used network analysis and nonmetric multidimensional scaling ordination (NMS) to determine the degree of integration. RESULTS We observed a strong leaf economics spectrum (LES) integrated with stem but not root traits. However, stem traits and intrinsic water-use efficiency integrated LES and root traits. Network analyses indicated a modest grouping of a priori trait dimensions. NMS indicated that multivariate differences among species were related primarily to (1) rooting depth and plant height vs. specific root length, (2) the LES, and (3) leaf size vs. seed mass. These differences were related to species groupings associated with growth and life form, leaf lifespan and seed dispersal mechanisms. CONCLUSIONS The strategies of coexisting understory plant species could not be reduced to a single dimension. Yet, species can be characterized efficiently and effectively for trait-based studies of plant communities by measuring four common traits: plant height, specific leaf area, leaf size, and seed mass.

中文翻译：

---

共存植物物种之间的性状整合和功能分化


前提 确定哪些性状表征了共存物种的策略对于开发基于性状的植物群落模型非常重要。首先，全局维度可能不存在于局部。其次，性状和性状谱在不同尺度上构成功能变异的独立维度的程度不断完善。最后，特征可能与现有的分类分组相关联。方法 我们评估了美国俄勒冈州西部花旗松森林中 57 种林下植物物种的性状整合和分化。我们将对一系列性状的测量与基于文献的种子质量和物种分组的估计结合起来。我们使用网络分析和非度量多维尺度排序（NMS）来确定集成程度。结果我们观察到与茎但不与根性状相结合的强大的叶子经济谱（LES）。然而，茎性状和内在水分利用效率整合了 LES 和根性状。网络分析表明先验特征维度的适度分组。 NMS 表明，物种间的多变量差异主要与 (1) 根深和株高与比根长度、(2) LES 以及 (3) 叶片大小与种子质量有关。这些差异与与生长和生命形式、叶子寿命和种子传播机制相关的物种分组有关。结论 林下植物共存策略不能简化为单一维度。然而，通过测量四种常见性状，可以有效地表征物种，以进行基于性状的植物群落研究：株高、比叶面积、叶子大小和种子质量。