Carbon cycling and food web energy transfer in salinized headwater streams

盐化源头溪流中的碳循环和食物网能量转移

• 批准号: 2207923
• 负责人: Sally Entrekin
• 金额: $ 70万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2207923&HistoricalAwards=false
• 关键词: Carbon; cycling; food; web; energy

Freshwater ecosystems are becoming salinized (or “salty”) across the globe from activities associated with agriculture, road de-icing, wastewater discharge, and mining. In central Appalachia, headwater stream ecosystems are particularly vulnerable to the impacts of salinization from surface coal mining, a widespread economic activity in the region. Increased salt concentrations stress aquatic organisms and can make headwaters unlivable for some microbes and animals. This is concerning because Appalachian headwaters are home to some unique organisms and collectively, have some of the most diverse aquatic insect communities in the world. Stream insects are especially adapted to cycling nutrients and distributing food energy from the surrounding forests into aquatic food webs. There is an urgent need to understand how salinization affects the freshwater insect community, stream productivity, and food web energy transfer. The consequences of salinization on freshwater animals in headwater streams will be shared with local K-12 teachers and trainees, scientists, and regional policy makers. New metrics for stream bioassessments will also be developed and shared. This research will assess salinity effects on carbon (C) processing in headwater streams through measurements of food web C production and transfer. Enhanced weathering of mining-exposed minerals can elevate major ions and salinity in headwater streams, with documented impacts to microbial and macroinvertebrate growth and community composition. Such organismal stress responses likely have cascading effects on stream food webs and ecosystem processes like decomposition and primary production. Salinization is predicted to alleviate salt limitation in primary producers and increase gross primary production (GPP). In contrast, subsidy-stress responses are predicted in heterotrophic production. Thus, along an increasing salinity gradient, similar subsidy-stress responses in trophic transfer efficiency could ultimately decrease food web C transfer at the highest salinities. To test these hypotheses, simultaneous measurements of C pools, transfers, and transformations will be taken in nine study streams that represent a salinity gradient.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.

淡水生态系统正在通过与同意，脱水，废水排放和采矿相关的活动中盐分（或“咸”）。在阿巴拉契亚中部，源水流生态系统尤其容易受到盐水煤矿开采的影响，这是该地区的宽度经济活动。盐浓度升高，压力水生生物，可能使某些微生物和动物无法渗出源头。这是令人担忧的，因为阿巴拉契亚的源头是一些独特组织的家园，并且共同拥有世界上一些最多样化的水生昆虫群落。溪流昆虫尤其适合循环养分，并将周围森林中的食物能量分配到水生食物网中。迫切需要了解盐水如何影响淡水昆虫社区，流媒体生产力和食物网能量转移。盐水对淡水流中淡水动物的后果将与当地的K-12老师和培训人员，科学家和地区政策制定者共享。还将开发和共享用于流生物评估的新指标。这项研究将通过测量食物网C的生产和转移来评估盐水中碳（C）加工的盐度影响。增强了暴露于采矿的矿物质的风化可以提升源头水流中的主要离子和盐度，并记录在相比之下，在异营生产生中预测了补贴压力反应。沿着增加的盐梯度沿盐梯度的增加相似，相似。营养转移效率的补贴应力反应最终可以减少最高盐度的食物Web C转移。为了检验这些假设，将在代表盐度梯度的九个研究流中进行C池，转移和转换的简单测量。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准通过评估来获得支持的。