Macrophyte species diversity and community stoichiometric homeostasis are correlated with different dimensions of stability following disturbance

1. Understanding how biodiversity and community functional traits preserve lake ecosystem multidimensional stability under global environmental changes is crucial for sustaining the vital ecosystem services we depend on.
2. Based on sediment nutrient gradient experiments and three-year seasonal monitoring of macrophyte communities in Erhai Lake, southwest China, spanning pre- and post-algal bloom periods, we explored how species diversity and a key community functional trait (stoichiometric homeostasis) affect multiple dimensions (temporal stability, resistance, resilience and recovery) and facets (function, composition, diversity and functional trait) of stability of macrophyte communities following algal blooms.
3. Generally, we found that species diversity and stoichiometric homeostasis of phosphorus (HP) had positive relationships with functional and compositional temporal stability, resistance, and recovery, indicating that ecosystems with high species diversity and community HP are more resistant and stable in response to external algal bloom disturbances. However, species diversity and community HP had no positive or even negative relationships with resilience, suggesting that high biodiversity with high-HP species-dominated ecosystems is not beneficial for the rapid recovery from disturbances, probably due to the slow growth and reproduction rate of high-HP species. In addition, we found strong positive correlations between functional and compositional stability across the four dimensions of stability, while stability of species diversity and the key functional trait (HP) exhibited complex relationships, implying the difficulty of optimizing multiple dimensions and facets of stability simultaneously.
4. Synthesis. Our work demonstrated that macrophyte species diversity and community HP are critical in determining the multiple dimensions and facets of stability in response to disturbances, which provides new insights for predicting the responses of macrophyte-dominated lake ecosystems to the current increasing frequency of algal blooms.

1. 探明全球环境变化背景下，生物多样性与群落功能性状如何维持湖泊生态系统的多维度稳定性，对维系人类赖以生存的关键生态系统服务至关重要。
2. 本研究依托中国西南洱海的沉积物营养盐梯度实验，以及覆盖藻华前后阶段的为期三年的大型水生植物（macrophyte）群落季节监测数据，探讨了物种多样性与关键群落功能性状——化学计量内稳性（stoichiometric homeostasis）如何影响藻华后大型水生植物群落稳定性的多个维度（时间稳定性、抗性、复原力与恢复能力）与组分（功能、组成、多样性及功能性状）。
3. 总体而言，研究发现物种多样性与磷化学计量内稳性（stoichiometric homeostasis of phosphorus, HP）与功能及组成维度的时间稳定性、抗性和恢复能力呈显著正相关，表明物种多样性高、群落HP水平较高的生态系统在应对外源藻华干扰时抗性更强、稳定性更优。但物种多样性与群落HP与复原力无显著正相关，甚至呈现负相关关系，这意味着以高HP物种为主的高生物多样性生态系统并不利于快速摆脱干扰实现恢复，推测其原因可能是高HP物种的生长与繁殖速率较为缓慢。此外，本研究还观察到，在四个稳定性维度下，功能与组成稳定性之间存在极强的正相关；而物种多样性与关键功能性状（HP）的稳定性则呈现复杂关联，这意味着同时优化稳定性的多维度与多组分存在较大难度。
4. 综合分析。本研究证实，大型水生植物物种多样性与群落HP是决定生态系统响应干扰时稳定性多维度与多组分的核心因素，该发现为预测以大型水生植物为主的湖泊生态系统对当前日益频发的藻华事件的响应提供了全新视角。