Ecoregion and community structure influences on the foliar elemental niche of balsam fir (Abies balsamea (L.) Mill.) and white birch (Betula papyrifera Marshall)

Context: Changes in foliar elemental niche properties, defined by axes of carbon (C), nitrogen (N), and phosphorus (P) concentrations, reflect how species allocate resources under different environmental conditions. For instance, elemental niches may differ in response to large-scale latitudinal temperature and precipitation regimes that occur between ecoregions and small-scale differences in nutrient dynamics based on species co-occurrences at a community level.
Methods: at a species level, we compared foliar elemental niche hypervolumes for balsam fir (Abies balsamea (L.) Mill.) and white birch (Betula papyrifera Marshall) between a northern and southern ecoregion. At a community level, we grouped our focal species using plot data into conspecific (i.e., only one focal species is present) and heterospecific groups (i.e., both focal species are present) and compared their foliar elemental concentrations under these community conditions across, within, and between these ecoregions. Betw...

研究背景：以碳（C）、氮（N）、磷（P）浓度为维度定义的叶片元素生态位（foliar elemental niche）属性变化，反映了物种在不同环境条件下的资源分配策略。举例而言，元素生态位的差异可响应于生态区间的大规模纬度温度与降水格局，以及基于群落水平物种共现关系的养分动态小规模差异。
研究方法：在物种水平上，我们对比了北部与南部生态区内香脂冷杉（Abies balsamea (L.) Mill.）和白桦（Betula papyrifera Marshall）的叶片元素生态位超体积（hypervolume）。在群落水平上，我们基于样地数据将目标物种划分为同种组（conspecific group，即样地中仅存在一种目标物种）和异种组（heterospecific group，即样地中同时存在两种目标物种），并在两类生态区的内部、跨生态区以及生态区间的群落条件下，比较了两组的叶片元素浓度。Betw...