Collaborative LTREB Proposal: Will increases in dissolved organic matter accelerate a shift in trophic status through anoxia-driven positive feedbacks in an oligotrophic lake?

LTREB 协作提案：溶解有机物的增加是否会通过寡营养湖泊中缺氧驱动的正反馈加速营养状态的转变？

• 批准号: 1754276
• 负责人: Craig Williamson
• 金额: $ 12.64万
• 依托单位: Miami University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1754276&HistoricalAwards=false
• 关键词: Collaborative; LTREB; Proposal; Will; increases

Lakes provide many services to society, such as clean drinking water and productive fisheries. Many lakes, however, are now experiencing increased input of carbon and nutrients, warming temperatures, and declining ice cover, which may reduce water quality or cause blooms of potentially harmful algae. Specifically, many lakes across the United States are experiencing increased browning due to high loading of organic matter leached from land plants. Browning reduces water clarity and interferes with drinking water management practices. In addition, it can cause other changes that may lead to rapid long-term declines in water quality. This research will test the hypothesis that browning may reduce oxygen concentrations in lakes. Low oxygen can cause nutrient release from lake sediments that may increase algae blooms, leading to lake eutrophication. Understanding the effects of browning will increase knowledge of lake ecosystems, and improve forecasts of how lakes will change as their surrounding environments change. This research will also train graduate and undergraduate students, and will lead to better public understanding of threats to lake water quality.Ecological tipping points are of vital interest as anthropogenic activities rapidly transform natural ecosystems. Changes in dissolved organic matter (DOM) represent one important potential driver of tipping points in aquatic ecosystems. This project will investigate whether increases in terrestrial DOM loading can push clear-water oligotrophic lakes beyond a critical tipping point by stimulating hypolimnetic anoxia and sediment DOM and phosphorus release, which may initiate a positive feedback loop of decreasing water clarity, stronger thermal stratification, and enhanced hypolimnetic anoxia. This feedback loop accelerates ecological change and ultimately may shift lake trophic status toward greener, mesotrophic to eutrophic as well as browner, dystrophic conditions. This project will extend a long-term data set of water quality variables sampled since the late 1980s in two lakes in or near the Lacawac Sanctuary and Biological Field Station, located in northeastern Pennsylvania. Complementing these long-term observations, experiments and modeling will be carried out to understand feedbacks associated with browning and enhancing understanding of broader patterns of change in inland water bodies. The project will support a regional lake monitoring network in Pennsylvania and closely interface with GLEON, the Global Lake Ecological Observatory Network.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.

湖泊为社会提供许多服务，例如清洁饮用水和生产渔业。但是，许多湖泊现在正在经历碳和养分的投入增加，温度变暖以及冰盖下降，这可能会降低水质或引起潜在有害藻类的开花。具体而言，由于从土地植物中浸出的有机物的高负载，美国的许多湖泊正在经历褐变的增加。褐变降低了水的清晰度，并干扰了饮用水管理实践。此外，它可能导致其他变化，可能导致水质长期下降。这项研究将检验以下假设：褐变可以降低湖泊中的氧气浓度。低氧可能导致湖泊沉积物的营养释放，从而增加藻类开花，从而导致富营养化湖。了解褐变的影响将增加对湖泊生态系统的了解，并改善随着周围环境的变化的变化预测。 这项研究还将培训毕业生和本科生，并将对湖水质量的威胁有更好的公众了解。随着人为活动迅速改变自然生态系统，生态临界点具有至关重要的兴趣。溶解有机物（DOM）的变化代表了水生生态系统中临界点的一个重要驱动力。该项目将通过刺激降低缺氧缺氧和沉积物DOM和磷释放来调查陆生DOM负载的增加是否可以将透明水的贫营养湖泊推向关键转化点，这可能会引发降低水的积极反馈回路，较强的热层和增强的低分性缺氧性强氧。这种反馈循环加速了生态变化，最终可能会将营养状况转移到绿色，中营养性的富营营养和褐色，营养不良状态。自1980年代后期以来，该项目将延长所采样的长期数据集，以自1980年代后期在宾夕法尼亚州东北部的Lacawac Sanctuary和Lacawac Sanctuary和生物野外站的两个湖泊中采样。将进行补充这些长期观察，实验和建模，以了解与褐变相关的反馈，并增强对内陆水体变化更广泛模式的理解。该项目将支持宾夕法尼亚州的区域湖泊监测网络，并与Gleon紧密接触Gleon，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通过评估来支持的。

项目成果

Habitat-Mediated Responses of Zooplankton to Decreasing Light in Two Temperate Lakes Undergoing Long-Term Browning

两个经历长期褐变的温带湖泊中浮游动物对光照减弱的栖息地调节反应

• DOI: 10.3389/fenvs.2020.00073
• 发表时间: 2020
• 期刊: Frontiers in Environmental Science
• 影响因子: 4.6
• 作者: Williamson, Craig E.;Overholt, Erin P.;Pilla, Rachel M.;Wilkins, Keiko W.
• 通讯作者: Wilkins, Keiko W.

Attenuation of photosynthetically active radiation and ultraviolet radiation in response to changing dissolved organic carbon in browning lakes: Modeling and parametrization

光合有效辐射和紫外线辐射的衰减响应褐宁湖中溶解有机碳的变化：建模和参数化

• DOI: 10.1002/lno.11753
• 发表时间: 2021
• 期刊: Limnology and Oceanography
• 影响因子: 4.5
• 作者: Pilla, Rachel M.;Couture, Raoul‐Marie
• 通讯作者: Couture, Raoul‐Marie

The effects of dissolved organic matter from a native and an invasive plant species on juvenile Daphnia survival and growth

本地和入侵植物物种溶解的有机物对幼年水蚤生存和生长的影响

• DOI: 10.1093/plankt/fbaa027
• 发表时间: 2020
• 期刊: Journal of Plankton Research
• 影响因子: 2.1
• 作者: Wilkins, Keiko W;Overholt, Erin;Williamson, Craig
• 通讯作者: Williamson, Craig

Key rules of life and the fading cryosphere: Impacts in alpine lakes and streams

• DOI: 10.1111/gcb.15362
• 发表时间: 2020-10-19
• 期刊: GLOBAL CHANGE BIOLOGY
• 影响因子: 11.6
• 作者: Elser, James J.;Wu, Chenxi;Saros, Jasmine E.
• 通讯作者: Saros, Jasmine E.

Widespread deoxygenation of temperate lakes

• DOI: 10.1038/s41586-021-03550-y
• 发表时间: 2021-06-03
• 期刊: NATURE
• 影响因子: 64.8
• 作者: Jane, Stephen F.;Hansen, Gretchen J. A.;Rose, Kevin C.
• 通讯作者: Rose, Kevin C.