Collaborative Research: BoCP-Design: US-Sao Paulo: The roles of stochasticity and spatial context in dynamics of functional diversity under global change

合作研究：BoCP-设计：美国-圣保罗：随机性和空间背景在全球变化下功能多样性动态中的作用

• 批准号: 2225098
• 负责人: Kurt Anderson
• 金额: $ 6.55万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2225098&HistoricalAwards=false
• 关键词: Collaborative; Research; BoCP; Design; US

In the race to understand, anticipate, and counter the effects of global change, no systems are more at-risk than freshwater ecosystems. However, managing or mitigating the effects of global change requires three elements: 1) a basic understanding of how an ecosystem functions; 2) a method for estimating how changes in climate can translate to changes in an ecosystem; and 3) a method for extrapolating to future climate scenarios. This research contains those elements with respect to stream ecosystems. Previous research has highlighted the importance of the physical structure of a stream network on a stream’s function. The current project extends that work to incorporate an additional element: the size of an aquatic community. Smaller communities of species are composed of smaller populations. Also, those small populations tend to have higher variation in important vital rates like births, deaths, and local extinctions. Ultimately, that variation can translate into variation in ecosystem functioning. However, the size of a community is not random with respect to the structure of stream networks. Larger streams provide more area for habitat, and thus generally larger population sizes. This research investigates how the relationship between community size and stream network structure affect the functioning of stream ecosystems. Finally, the project will use modeling to extrapolate the results of these investigations into predictions of how stream ecosystems will respond to future global change. This project creates unique opportunities for ecology education at the graduate and undergraduate levels, including from under-represented groups, and allows students to participate in the international relationships that are inherent in the work. This work will explicitly address the following hypotheses. First, owing to temperature-dependent differences in population growth rates and densities, the degree of demographic stochasticity in shaping community assembly is higher in tropical streams compared to temperate ones. Second, the balance between demographic stochasticity and environmental selection as drivers of community assembly depends on the interaction between network position, community size, and dispersal. Third, higher stochastic community assembly in tropical streams and dispersal-limited headwaters result in higher variability in functional composition. To understand how the community size by network position interaction functions in diverse climates, we will conduct intensive surveys of both resident and dispersing macroinvertebrates at multiple positions in a river network. These surveys will be performed in parallel in both the US and Brazil. This North versus South comparison will ultimately allow for extrapolation to future-climate scenarios.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在理解、预测和应对全球变化影响的竞赛中，没有什么系统比淡水生态系统面临的风险更大。然而，管理或减轻全球变化的影响需要三个要素：1）对生态系统如何运作有基本的了解。 2）一种估计气候变化如何转化为生态系统变化的方法；以及3）一种推断未来气候的方法。的结构当前的项目扩展了这项工作，纳入了一个额外的要素：较小的物种群落由较小的种群组成，而且这些小种群的重要生命率往往有较大的变化。最终，这种变化会转化为生态系统功能的变化，但就河流网络的结构而言，群落的规模并不是随机的，因此可以提供更多的栖息地。这项研究调查了通常较大的人口规模。最后，该项目将使用模型来推断这些调查的结果，以预测河流生态系统将如何应对未来的全球变化。这项工作将明确解决以下假设：首先，由于人口的温度依赖性差异。增长率和密度，程度与温带溪流相比，热带溪流在塑造群落聚集方面的人口随机性更高，作为群落聚集驱动因素的人口随机性和环境选择之间的平衡取决于网络位置、群落规模和分散之间的相互作用。热带溪流和分散有限的源头的群落聚集导致功能组成的更大变异性为了了解群落规模如何通过网络位置相互作用在不同的气候中发挥作用，我们将对常驻和分散的大型无脊椎动物进行深入调查。这些调查将在美国和巴西同时进行，最终将能够推断出未来的气候情景。该奖项反映了 NSF 的法定使命，并被认为是值得的。通过使用基金会的智力优势和更广泛的影响审查标准进行评估来提供支持。