Exploring ecological surprises by multiple stressors of aquatic food webs

探索水生食物网多重压力源带来的生态惊喜

• 批准号: 227347-2009
• 负责人: Vinebrooke, Rolf
• 金额: $ 2.7万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=523956
• 关键词: Exploring; ecological; surprises; multiple; stressors

The main goal of my research program is to discover ecological drivers of aquatic food-web responses to global change. Multiple human-related stressors that define global change often exert complex non-additive effects on food webs, which cannot therefore be easily predicted based on the sum of known effects by single stressors. Consequently, extreme climate change together with other stressors often generate alarming "ecological surprises." I have developed a conceptual model of the ecological mechanisms affecting multi-trophic responses to multiple stressors. The model is based on three operating hypotheses: 1) stressors exert more pronounced synergistic impacts on top predators than on plants because animals are less tolerant of rapid environmental change, 2) tolerant plant species more than top predators are able to readily colonize stressed ecosystems and functionally compensate for extinct species, and thus, 3) differences in tolerances among top predators, herbivores, and plants result in their interactions (e.g., predation and herbivory) being profoundly altered in stressed ecosystems. My research group tests these hypotheses by conducting experiments in naturally fishless alpine lakes of the Canadian Rockies, which are being increasingly impacted by extreme climate events, introduced invasive species, and air pollution. Therefore, these highly sensitive species-poor ecosystems are excellent venues for investigating the effects of multiple stressors on trophic complexity. We examine the responses of whole food webs, single trophic groups and their interactions by exposing them sequentially to summer heating events and other stressors using submersible greenhouse mesocosms. We also examine the importance of dispersal and colonization by tolerant species as a means of buffering alpine food webs against the impacts of rapid environmental change. I refine and upgrade my proposed model through comparison of experimental and naturally occurring food webs in alpine lakes that are exposed to the same combination of stressors. Our findings will help better explain why we should expect the unexpected from future global change.

我的研究计划的主要目的是发现水生食物 - 网络对全球变化的反应的生态驱动力。定义全球变化的多个与人相关的压力源通常会对食物网发挥复杂的非加性作用，因此，基于单个压力源的已知效应总和不容易预测。因此，极端的气候变化与其他压力源通常会产生令人震惊的“生态惊喜”。我已经开发了一种影响多个压力源的多营反应的生态机制的概念模型。 The model is based on three operating hypotheses: 1) stressors exert more pronounced synergistic impacts on top predators than on plants because animals are less tolerant of rapid environmental change, 2) tolerant plant species more than top predators are able to readily colonize stressed ecosystems and functionally compensate for extinct species, and thus, 3) differences in tolerances among top predators, herbivores, and plants result in their interactions (e.g.,捕食和草食生态系统中的捕食和草食生态系统会深刻改变。我的研究小组通过在加拿大落基山脉的自然无鱼高山湖泊中进行实验来检验这些假设，这些落基山脉越来越受到极端气候事件的影响，引入了入侵物种和空气污染。因此，这些高度敏感的物种生态系统是研究多种应激源对营养复杂性的影响的绝佳场所。我们通过使用潜水的温室中心将全食网，单营养基团及其相互作用的反应及其相互作用进行了研究。我们还研究了宽容物种的分散和定殖的重要性，作为缓冲高山食物网的一种手段，以抵抗快速环境变化的影响。我通过比较高山湖泊中的实验和天然食物网，改进并升级了我的模型，这些湖泊暴露于相同的压力源组合中。我们的发现将有助于更好地解释为什么我们应该期望将来的全球变化产生意外。