Collaborative Research: How are estuarine carbon and alkalinity dynamics influenced by macrobiota?

合作研究：河口碳和碱度动态如何受到宏观生物群的影响？

• 批准号: 2148949
• 负责人: Raymond Najjar
• 金额: $ 99.21万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2148949&HistoricalAwards=false
• 关键词: Collaborative; Research; How; estuarine; carbon

The global carbon cycle consists of the processes that transform and transport carbon on Earth. Interest in the global carbon cycle stems from its intimate connection with ecological processes and its control on atmospheric carbon dioxide, an extremely important greenhouse gas. A key feature of the global carbon cycle is the transport of carbon from land to the open ocean. Before reaching the open ocean, the carbon carried by rivers must past through estuaries, where significant transformations take place, including the interconversion of organic forms (such as carbohydrates, proteins, and lipids) and inorganic forms (carbon dioxide, bicarbonate, and carbonate) through photosynthesis and respiration. In addition to carbon, alkalinity is another important chemical quantity that is relevant to climate and life on Earth. The alkalinity is the capacity of a water body to neutralize acid and determines the extent to which carbon dioxide reacts with water to create chemical species that do not interact directly with the atmosphere. While many transformations of carbon and alkalinity in the ocean are dominated by microscopic life, like phytoplankton and bacteria, these transformations are also influenced by macroscopic life (macrobiota), such as oysters, clams, salt marshes, mangroves, and seagrasses. However, macrobiota are generally ignored in conceptual and computational models of carbon transformations in estuaries. The overall objective of this project is to improve understanding of the role that macrobiota play in estuarine carbon and alkalinity dynamics. The research will also support numerous undergraduate students, two graduate students and three post-doctoral scholars.The proposed research will be carried out through a coordinated program of field measurements, laboratory experiments, historical data analysis, and numerical modeling. Two contrasting tidal tributaries of the Chesapeake Bay, the Potomac River Estuary and the York River Estuary, will be sampled because they span much of the range of carbon and alkalinity dynamics found in estuaries worldwide and hence will facilitate the generalization of the project findings. The interdisciplinary research team will evaluate four hypotheses: (1) Tidal wetlands, such as marshes and mangroves, are a source of alkalinity to estuaries and this source increases with salinity, tidal wetland productivity, and tidal range. (2) Alkalinity sinks in estuaries are favored when riverine alkalinity is high and when benthic fauna (e.g., clams and oysters) or submerged aquatic vegetation (e.g., seagrasses) are present in sufficient quantities. (3) Alkalinity sources and sinks in estuaries are highly seasonal, with summer fluxes dominated by net calcification (due to benthic fauna and submerged aquatic vegetation, an alkalinity sink) and sulfate reduction (due to tidal wetlands, an alkalinity source) and winter fluxes due to net CaCO3 dissolution (an alkalinity source). (4) Estuaries with high-alkalinity rivers and low tidal marsh areas are sinks of alkalinity and sources of atmospheric carbon dioxide while those with low-alkalinity rivers and high tidal marsh areas are sources of alkalinity and sinks of atmospheric carbon dioxide. The research plan includes seven main elements: (1) carbonate system measurements, (2) benthic fauna distribution measurements, (3) measurements of macrobiota carbon and alkalinity fluxes, (4) development of macrobiota carbon and alkalinity flux maps, (5) historical analysis of carbonate system measurements, (6) 3-D numerical modeling, and (7) a meta-analysis that extend findings to other systems. Mentoring and inclusion will occur through the development of a research affinity group of at least eight students that will connect existing regional undergraduate research programs. Students will present their research to managers and policy makers from the Chesapeake Bay Program during annual summits and we will engage estuarine managers through presentations on macrobiota influence on biogeochemistry. This research will advance the understanding of how macrobiota influence estuarine carbon and alkalinity dynamics and, ultimately, the large-scale marine cycles of carbon and alkalinity.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.

全球碳循环由在地球上转化和运输碳的过程组成。对全球碳循环的兴趣源于其与生态过程的紧密联系以及对大气二氧化碳的控制，这是一种极为重要的温室气体。全球碳循环的一个关键特征是将碳从陆地运输到开阔的海洋。在到达敞开的海洋之前，河流携带的碳必须通过河口经过，那里发生了重大转化，包括有机形式的相互作用（例如碳水化合物，蛋白质和脂质）和无机形式（二氧化碳，碳酸氢盐和碳酸盐和碳酸盐）通过光合照相和呼吸器。除碳外，碱度是与地球气候和生命有关的另一个重要化学量。碱度是水体中和酸的能力，并确定二氧化碳与水反应的程度，以产生不直接与大气相互作用的化学物种。尽管海洋中碳和碱度的许多转化都以微观生命为主，例如浮游植物和细菌，但这些转化也受到宏观生命（Macrobobiota）的影响，例如牡蛎，蛤，蛤，盐妈，玛斯，曼格斯群岛和海格拉斯。然而，在河口的碳转化的概念和计算模型中，大分子通常被忽略。该项目的总体目的是提高对大型生物群在河口碳和碱度动力学中发挥作用的理解。这项研究还将支持众多本科生，两名研究生和三名博士后学者。拟议的研究将通过协调的现场测量，实验室实验，历史数据分析和数值建模进行。将对切萨皮克湾，波托马克河河口和约克河河口的两个形成鲜明的潮汐支流进行采样，因为它们涵盖了全球河口中发现的许多碳和碱性动态范围，因此将促进项目发现的普遍化。跨学科研究团队将评估四个假设：（1）潮汐湿地，例如沼泽和红树林，是对河口的碱度来源，这种来源随盐度，潮汐湿地生产率和潮汐范围而增加。 （2）当河流碱度很高时，河口中的碱度下水道受到青睐，而底栖动物（例如蛤and鼠）或淹没的水生植被（例如海草）的数量足够足够数量。 （3）河口中的碱度来源和下沉是高度季节性的，夏季通量由净钙化（由于底栖动物群和水生植物植被，碱度下沉）和硫酸盐的减少（由于潮汐湿地，碱度来源）和冬季滤过，由于净caco3 caco3的源（一个Alkal sivation a ankal源）。 （4）具有高未度河流和低潮汐沼泽地的河口是碱度和大气二氧化碳来源的水槽，而那些河流低的河流和高潮汐河流和高潮汐沼泽地区是碱度和大气中的二氧化碳水槽的来源。研究计划包括七个主要要素：（1）碳酸盐系统的测量，（2）底栖动物的分布测量值，（3）测量大分子碳和碱度通量，（4）开发大分子碳和碱性磁通图的发展其他系统的发现。指导和包容性将通过开发至少八个学生将连接现有区域本科研究计划的研究亲和力小组进行。学生将在年度首脑会议期间向切萨皮克湾计划的经理和政策制定者展示他们的研究，我们将通过对Macrobiota对生物地球化学的影响的介绍与河口经理互动。这项研究将促进对大分子如何影响河口碳和碱度动态的理解，并最终，最终，碳和碱度的大规模海洋循环。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和更广泛影响的评估来评估的支持，并被认为是值得的。