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: 2225096
• 负责人: Bryan Brown
• 金额: $ 30.02万
• 依托单位: Virginia Polytechnic Institute and State University
• 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=2225096&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，预期和反对全球变化的影响的竞赛中，没有任何系统比淡水生态系统更高风险。但是，管理或减轻全球变化的影响需要三个要素：1）对生态系统的运作方式的基本理解； 2）一种估计气候变化如何转化为生态系统变化的方法； 3）一种推断未来气候场景的方法。这项研究包含有关流生态系统的这些元素。先前的研究强调了流网络在流函数上的物理结构的重要性。当前的项目扩展了这项工作，以结合附加要素：水上社区的大小。较小的物种社区由较小的种群组成。同样，这些小人口在重要的生命率（例如出生，死亡和局部延伸）中往往会有更高的差异。最终，这种变化可以转化为生态系统功能的变化。但是，相对于流网络的结构，社区的大小不是随机的。较大的溪流为栖息地提供了更多区域，因此总体人口规模较大。这项研究调查了社区规模和流网络结构之间的关系如何影响流生态系统的功能。最后，该项目将使用建模来推断这些投资的结果，以预测流生态系统将如何应对未来的全球变化。该项目为研究生和本科级别的生态教育创造了独特的机会，包括来自代表性不足的群体，并允许学生参加工作中固有的国际关系。这项工作将明确解决以下假设。首先，由于温度依赖人口增长率和密度的差异，与温度相比，在热带流中塑造社区组装的人口统计学程度更高。其次，作为社区组装驱动力的人口随机性与环境选择之间的平衡取决于网络位置，社区规模和分散之间的相互作用。第三，在热带流和分散限制的源头中，较高的随机社区组装导致功能组成的差异更高。为了了解潜水员气候中网络位置相互作用的社区规模如何起作用，我们将对居民进行深入调查，并在河网络中多个位置分散大型无脊椎动物。这些调查将在美国和巴西平行进行。该北方与南方比较最终将允许推断到未来气候的情况下。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响评估标准来评估而被视为珍贵的支持。