1. Aridity and salinity have a key role in driving physiological and ecological processes in desert ecosystems. However, how community‐scale foliar nutrients respond to aridity and salinity, and how these responses might vary with community composition along aridity and salinity gradients is unclear. We hypothesize that the response will be a shift in community stoichiometric values resulting from nutrient variability of shared species and unique species (site‐specific species), but little research has addressed the relative contribution of either component.
2. We analyzed the community‐scale stoichiometric response of a desert community of perennial plants along an aridity and salinity transect by focusing on foliar nitrogen (N) and phosphorous (P) concentrations and N:P ratios. After evaluating the shared and unique species variability, we determined their relative contribution to the community stoichiometric response to aridity and salinity, reflected by changes in nonweighted and weighted community‐average values.
3. Community‐scale stoichiometry decreased significantly under aridity and salinity, with significantly consistent changes in nonweighted and weighted community‐average stoichiometry for most shared and unique species measurements. The relative contribution of unique species shifts to the changes in community stoichiometry was greater (15%–77%) than the relative contribution of shared species shifts (7%–45%), excluding the change in weighted P concentration under aridity. Thus, the shifts of unique species amplified the community stoichiometric response to environmental changes.
4. Synthesis . These results highlighted the need for a more in‐depth consideration of shared and unique species variability to understand and predict the effects of environmental change on the stoichiometry of plant communities. Although variation in community stoichiometry can be expected under extreme aridity and salinity conditions, changes of unique species could be a more important driver of the stoichiometric response of plant communities.

中文翻译：

---

在干旱和盐碱沙漠环境中，通过物种更新产生的N：P化学计量变化。

1. 干旱和盐碱化在驱动沙漠生态系统的生理和生态过程中起着关键作用。但是，尚不清楚社区规模的叶面养分如何响应干旱和盐碱化，以及这些响应如何随干旱和盐度梯度的社区组成而变化。我们假设响应是共享物种和独特物种（特定地点物种）的养分变异性导致的社区化学计量值的变化，但是很少有研究针对这两种成分的相对贡献。
2. 通过重点研究叶面氮（N）和磷（P）的浓度以及N：P的比例，我们分析了干旱和盐分横断面的多年生植物沙漠群落的群落尺度化学计量响应。在评估了共享的和唯一的物种变异性之后，我们确定了它们对干旱和盐分的化学计量响应的相对贡献，反映在非加权和加权社区平均值的变化上。
3. 在干旱和盐度下，社区尺度的化学计量显着下降，对于大多数共享和独特物种的测量，未加权和加权的社区平均化学计量的变化具有显着的一致性。独特物种转移对群落化学计量变化的相对贡献（15％–77％）大于共享物种转移的相对贡献（7％–45％），其中不包括干旱条件下加权P浓度的变化。因此，独特物种的转移放大了社区对环境变化的化学计量响应。
4. 综合。这些结果表明，需要更深入地考虑共享和独特物种的可变性，以了解和预测环境变化对植物群落化学计量的影响。尽管在极端干旱和盐碱条件下可以预期群落化学计量的变化，但是独特物种的变化可能是植物群落化学计量响应的更重要驱动因素。