Collaborative Research: Impact of Climate Warming and Ocean Carbonation on Eelgrass (Zostera marina L.)

知识价值：过去几十年积累了越来越多的证据，表明人类活动对整个地球的基本生物地球化学过程产生了深远的影响，特别是在支持多种高产生态系统（包括珊瑚礁、海草草甸和河口）的沿海环境中。海草的生态意义很大程度上是由于它们对水下水生生存的显著适应程度。然而，尽管有许多成功的适应，海草对光的需求很高，这使它们容易受到人为干扰。这种矛盾的脆弱性很大程度上是因为它们高度依赖溶解的含水二氧化碳进行光合作用。人们早就认识到，大气中二氧化碳浓度上升可能对全球气候产生重大的变暖影响，但“另一种二氧化碳问题”（也称为海洋酸化）的潜在影响，直到最近才开始受到重视。与气候变化的其他影响一样，世界海洋中溶解的含水二氧化碳[CO2 (aq)]浓度的增加将在生物中引起消极和积极的反应，最终使生态输家和赢家受益。本项目将结合操作实验、生理/生化调查和数学模型，探索大鳗草对沿海海洋变暖背景下二氧化碳（aq）增加的反应。研究人员推测，CO2（aq）的升高将通过改善光合作用相对于呼吸作用的Q10响应来提高植物的高温耐受性，从而提高植物的生长速度，提高营养芽在高温下的存活率，甚至提高开花产量和种子产量。该项目将研究对这些至关重要的海洋被子植物的光需求和碳平衡动态具有负（海洋变暖）和正（海洋碳化）影响的环境参数之间的关键关系。通过关注大西洋沿岸大叶藻分布的南部边界附近的切萨皮克种群，研究人员将获得预测性的见解，了解气候变化如何改变这种至关重要的物种在其他沿海环境中的地理分布，这些环境可能受到较小的温度压力，但海洋碳酸化水平相似。更广泛的影响：这项工作将为联合项目负责人Victoria Hill博士提供植物生理学和生物化学方面的培训，并将在4年的研究过程中支持至少两名研究生的论文研究。与弗吉尼亚水族馆和海洋科学中心的合作将促进该项目的教育解释和节目的发展，该项目将专门针对每年参观水族馆的65万至70万人。

Intellectual Merit: The past few decades have accumulated mounting evidence of profound anthropogenic effects on fundamental biogeochemical processes across the planet, especially in coastal environments that support a diverse array of highly productive ecosystems including coral reefs, seagrass meadows, and estuaries. The ecological significance of seagrasses is largely due to the remarkable degree of adaptation they exhibit to a submerged aquatic existence. Despite numerous successful adaptations, however, seagrasses have high light requirements that make them vulnerable to anthropogenic disturbances. The paradoxical vulnerability results largely from their high reliance on dissolved aqueous CO2 for photosynthesis. The potential for rising atmospheric CO2 concentrations to have significant warming impacts on the global climate has long been recognized, but the potential impacts of the "other CO2 problem", also known as ocean acidification, have only recently begun to be appreciated. As with other impacts of climate change, the increased concentrations of dissolved aqueous CO2 [CO2 (aq)] in the oceans of the world will elicit both negative and positive responses among organisms, ultimately potentiating ecological losers and winners. This project will explore the response of eelgrass to increased CO2 (aq) within the context of a warming coastal ocean using a combination of manipulative experiments, physiological/biochemical investigations and mathematical modeling. The investigators hypothesize that rising CO2(aq) will increase the high temperature tolerance of plants by improving the Q10 response of photosynthesis relative to respiration, thereby leading to higher growth rates, improved survival of vegetative shoots at high temperature, and even flowering output and seed production. This project will investigate the key relationships between environmental parameters that have both negative (ocean warming) and positive (ocean carbonation) impacts on the light requirements and dynamics of carbon balance in these critically important marine angiosperms. By focusing on Chesapeake populations growing near the southern limit of eelgrass distribution on the Atlantic coast, the investigators will gain predictive insight into how climate change may alter the geographic distribution of this critically important species in other coastal environments that may be subjected to less temperature stress but similar levels of ocean carbonation.Broader Impacts: This work will provide training in plant physiology and biochemistry to the co-PI, Dr. Victoria Hill and will support the dissertation research of at least two graduate students over the course of the 4-year study. Collaboration with the Virginia Aquarium and Marine Science Center will facilitate the development of educational interpretation and programming from this project that will be specifically targeted to the 650,000 to 700,000 people that visit the Aquarium each year.