Collaborative Research: TERRG: Thresholds in ecosystem responses to rainfall gradients

合作研究：TERRG：生态系统对降雨梯度响应的阈值

• 批准号: 2039228
• 负责人: Christopher Patrick
• 金额: $ 83万
• 依托单位: College of William & Mary Virginia Institute of Marine Science
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-08 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2039228&HistoricalAwards=false
• 关键词: Collaborative; Research; TERRG; Thresholds; ecosystem

The biology and chemistry of streams change in response to changes in temperature and rainfall patterns. Changes in temperature and precipitation may lead to predictable changes in the biology and chemistry of streams, while other changes are abrupt and unpredictable. In the face of environmental change, we need to understand the environmental conditions that result in predictable and abrupt responses to both the biology and chemistry of streams. This award will support research on understanding biological controls and environmental constraints on the structure and function of streams in South Texas. The research will take advantage of a semi-arid to mesic rainfall gradient that features an abrupt shift in stream community composition and ecosystem functioning at 85 cm rainfall/yr. The research will consist of a mix of field observations, manipulative experiments, and modeling. Training of undergraduate (including minority) and graduate students and outreach via an established K-12 program will contribute to the project?s broader impacts.This project will advance our understanding of why subtle shifts in the environment can result in the significant and abrupt reorganization of ecological communities. Spatial patterns in structure and function of ecosystems along precipitation gradients indicate that threshold effects are common and widespread. Therefore, understanding the mechanisms that drive these patterns is essential for forecasting which regions of the world will undergo rapid ecosystem shifts under future environmental change. Stream ecosystems are particularly sensitive to changes in precipitation, but multiple mechanisms can be invoked to explain observed threshold effects in streams. These mechanisms include: 1) Changes in the quantity, quality, temporal stability, and predictability of the resource base, which cascade up to higher trophic levels; and conversely, 2) Changes in the temporal stability, predictability, and average environmental conditions impacting community structure, which then cascade down to ecosystem processes. By exploring these alternate and potentially simultaneously operating mechanistic hypotheses in a set of streams along a precipitation gradient in South Texas, the research will capitalize on an ideal natural experiment along with a strong foundation of preliminary data collected by the principal investigators. The results of this study will in turn inform our understanding of how similar processes operate in stream ecosystems around the world, and the basic principles will enhance our understanding of these processes in all ecosystems. The award will support training of undergraduate, graduate, postdoctoral scholars, and early career faculty at both a Hispanic Serving Institution and a primarily undergraduate institution serving 40% minorities. Undergraduates will conduct independent research and present the results at professional meetings. K-12 outreach and adult education will be conducted through the SIU Center for Ecology and Graduate Research Assistants Supporting Science (GRASS) program.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.

流的生物学和化学随着温度和降雨模式的变化而变化。 温度和降水的变化可能会导致流的生物学和化学变化，而其他变化是突然且不可预测的。面对环境变化，我们需要了解对溪流生物学和化学的可预测和突然反应的环境条件。该奖项将支持有关了解南德克萨斯州流的结构和功能的生物控制和环境限制的研究。这项研究将利用半干旱的介质降雨梯度，其在85 cm降雨/年中的流社区组成和生态系统功能突然变化。该研究将包括现场观测，操纵实验和建模的混合。对本科生（包括少数民族）和研究生的培训以及通过既定的K-12计划进行宣传的培训将对该项目的更广泛的影响做出贡献。该项目将促进我们对为什么环境中的细微转变会导致生态社区的重大和突然重组。生态系统沿降水梯度的结构和功能的空间模式表明阈值效应是普遍且广泛的。因此，了解推动这些模式的机制对于预测世界哪些地区将在未来的环境变化下进行快速生态系统转变。流生态系统对降水的变化特别敏感，但是可以调用多种机制来解释流中观察到的阈值效应。这些机制包括：1）资源基础的数量，质量，时间稳定性和可预测性的变化，这些变化升级到较高的营养水平；相反，2）时间稳定性，可预测性和影响社区结构的平均环境条件的变化，然后级联到生态系统过程。通过探索沿德克萨斯州南部降水梯度的一组流中的这些替代且潜在的机械假设，该研究将利用理想的自然实验，以及由主要研究人员收集的强大初步数据的基础。这项研究的结果反过来又将为我们对世界各地的流生态系统中类似过程的运作方式的理解提供了信息，基本原理将增强我们对所有生态系统中这些过程的理解。该奖项将支持西班牙裔服务机构和主要为40％少数民族服务的本科机构的本科，研究生，博士后学者和早期职业教师的培训。本科生将进行独立的研究，并在专业会议上介绍结果。 K-12宣传和成人教育将通过SIU生态学和研究生研究助理支持科学计划（GRASS）计划进行。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评估标准来通过评估来支持的。

项目成果

Structure and functional composition of macroinvertebrate communities in coastal plain streams across a precipitation gradient

• DOI: 10.1111/fwb.13968
• 发表时间: 2022-07
• 期刊: Freshwater Biology
• 影响因子: 2.7
• 作者: F. Carvallo;Bradley A. Strickland;Sean Kinard;B. Reese;J. D. Hogan;C. Patrick