An integrative approach to reveal community responses to multiple stressors

据估计，全球生物多样性的下降所造成的物种损失比人类压力出现之前大好几倍，在淡水生态系统中最为明显。在这里，生态学家经常惊讶于这些新的和极端的人为环境变化的累积影响，或“压力”，特别是当他们的综合影响不等于他们已知的个人影响的总和。虽然许多研究都集中在压力的性质及其相互作用，以解释这种非加性效应，但相对较少考虑受影响的物种本身及其相互作用如何介导群落反应和生态系统过程（例如，初级生产）。因此，没有一个发达的概念框架，在社区生态学的实证调查可以建立在检查多种压力的净效应。 在这里，我专注于经验升级经常引用的物种共耐受性概念（SCC），以推进它作为一种工具，揭示从主要淡水的角度来看，社区对多种压力源的反应的性质。SCC的主要原则是，物种对各种压力源的耐受性的相关性决定了它们对群落水平特性的综合影响（例如，物种丰富度，总产量）;然而，它仍然需要假设检验和进一步完善。我们最近的发现指出，SCC需要一个改进的基于物种的空模型，以及更好地整合物种相互作用及其特征，使其更具预测性和机械洞察力。在接下来的五年里，我的短期目标包括确定如何将这些因素整合到SCC中，影响其突破性预测的潜力，并了解社区对同时或连续暴露于压力源的反应。 对HQP的广泛培训是我的研究计划成功的核心。我亲自指导和协助HQP设计和启动现场和实验室研究，随后的定量分析，以及他们的发现的交流。我采取全面的方法来培训HQP的标准，以新颖和先进的藻类和无脊椎动物分类技术，开发越来越多的需求，但在环境部门供应短缺的技能。我还在我的实验室中促进积极的技能转移，以发展高级实验室成员的指导，同时也强烈鼓励高度协作和多样化的实验室环境。我特别兴奋的是，我们的研究结果将导致教科书改变社区生态学的进步，将其更多地放在全球变化的背景下，同时也解决了更好的环境风险评估多种压力源的累积生态影响的需要。

Global decline in biodiversity is estimated to involve a several-fold greater loss of species than before the onset of human pressures, being most pronounced in freshwater ecosystems. Here, ecologists are often surprised by the cumulative impacts of these novel and extreme anthropogenic environmental changes, or "stressors," especially when their combined effect does not equal the sum of their known individual effects. While much research has focused on the properties of the stressors and their interactions to explain such non-additive effects, relative little consideration has been given to how the affected species themselves and their interactions may mediate community responses and ecosystem processes (e.g., primary production). Consequently, there does not exist a well-developed conceptual framework in community ecology upon which empirical investigations can be built to examine the net effects of multiple stressors. Here, I focus on empirically upgrading the often cited Species Co-tolerance Concept (SCC) to advance it as a tool for revealing the nature of community responses to multiple stressors from a mainly freshwater perspective. The primary tenet of the SCC is that the correlation of species tolerances of various stressors determines their combined impact on community-level properties (e.g., species richness, total production); however, it has remained in need of hypothesis-testing and further refinement. Our recent discoveries point to the SCC requiring an improved species-based null model, and also better integration of species interactions and their traits to make it more predictive and mechanistically insightful. Over the next five years, my short term objectives involve determining how integration of these factors into the SCC affect its potential for groundbreaking predictions and understanding of community responses to simultaneous or sequential exposures to stressors. Extensive training of HQP is at the core to the success of my research program. I personally mentor and assist HQP in their design and start of field and lab studies, subsequent quantitative analyses, and communication of their findings. I take a comprehensive approach to training HQP in standard to novel and advanced algal and invertebrate taxonomic techniques, developing skill sets that are increasingly in demand yet short in supply in the environmental sector. I also foster active transfer of skills in my lab to develop mentorship in senior lab members, while also strongly encouraging a highly collaborative and diverse lab environment. I am particularly excited that our findings will lead to textbook-changing advances in community ecology by placing it more in a global change context while also addressing the need for better environmental risk assessment of the cumulative ecological impacts of multiple stressors.