LTREB: Thirty-Four Years of Tidal Marsh Response to Environmental Change

LTREB：三十四年潮汐沼泽对环境变化的反应

• 批准号: 2051343
• 负责人: Jonathan Langley
• 金额: $ 60万
• 依托单位: Smithsonian Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-15 至 2026-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2051343&HistoricalAwards=false
• 关键词: LTREB; Thirty; Four; Years; Tidal

Coastal wetlands are some of the most productive ecosystems on Earth, and are critical transition zones between terrestrial and marine habitats. Salt marshes, hotspots of biological activity, have a remarkable ability to sustain themselves, largely due to their vegetation, and maintain coastlines as sea level changes. However, the annual loss of thousands of hectares of low-lying coastal wetlands to open water each year threatens fisheries, wildlife habitat, water quality, soil carbon stocks, and adjacent human infrastructure. The objective of this project is to learn how coastal wetlands, salt marshes in particular, will respond to intensifying environmental change. This project plans to extend experiments examining the influence of rising atmospheric CO2, nutrient pollution, invasive species, and sea level rise on the structure and persistence of salt marsh vegetation. It aims to take advantage of an unparalleled thirty-four year record of plant, microbe and soil responses to global change to identify the most important factors for marsh survival. These results should be relatable to other coastal ecosystems, and are likely to improve predictions of future marsh loss as well as inform management strategies for maintaining wetlands. Data from the project will be incorporated into undergraduate classes at two institutions, undergraduates will assist with data collection and use data from the project for senior theses, and the general public will be given tours of research site and given the opportunity to participate in citizen science initiatives.This project includes three complementary, long-term field experiments that manipulateatmospheric CO2 and N enrichment in different plant communities, that leverage the inter-annual variability in other critical factors such as sea level, salinity and precipitation. The team plans to test the hypothesis that sea level rise, as the ultimate driver of change in coastal wetlands, will cause the two plant species with the highest flood tolerance (native sedge and invasive Phragmites australis) to replace those with lower flood tolerance (C4 grasses) over the next decade. Because the sedge and Phragmites also respond strongly to elevated CO2, the team predicts that plant community composition will initially shift and increase the ecosystem-scale CO2 response, but it will ultimately decline due to increasing flooding stress. The marsh is expected to cross a threshold in the next decade as rates of relative sea level rise accelerate to the point that the marsh becomes unstable due to declining productivity. However, the areas dominated by Phragmites, particularly plots with added N, yield the greatest productivity on the marsh, and have the best chance to keep up with accelerating sea level. Finally, the team hypothesizes that an increase in methane emissions expected with increased flooding will be offset initially by higher rates of rhizosphere methane oxidation from the flood-tolerant sedge. The results from this experiment can continue to inform models and global change syntheses. The site and extensive dataset are used as a hands-on case study in ecology courses at Villanova University and Bryn Mawr College. This project plans to train researchers at all levels, to engage the public in the long-term and forward-looking science that arises from this LTREB site, and to promote the application of this basic science to support coastal wetland protection, conservation, and restoration.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.

沿海湿地是地球上最具生产力的生态系统之一，是陆地和海洋生境之间的重要过渡区。 盐沼，生物活动的热点，有一个显着的能力，以维持自己，主要是由于他们的植被，并保持海岸线的海平面变化。然而，每年有数千公顷的低洼沿海湿地流失到开放水域，威胁着渔业、野生动物栖息地、水质、土壤碳储量和邻近的人类基础设施。该项目的目标是了解沿海湿地，特别是盐沼，将如何应对日益加剧的环境变化。 该项目计划扩大实验，研究大气中二氧化碳浓度上升、营养污染、入侵物种和海平面上升对盐沼植被结构和持久性的影响。它旨在利用植物，微生物和土壤对全球变化的反应的无与伦比的34年记录，以确定沼泽生存的最重要因素。这些结果应与其他沿海生态系统，并有可能改善未来沼泽损失的预测，以及为维护湿地的管理战略提供信息。 来自该项目的数据将被纳入两个机构的本科生课堂，本科生将协助收集数据并将来自该项目的数据用于高级论文，公众将获得图尔斯参观研究现场并有机会参与公民科学倡议。长期的实地实验，控制不同植物群落的大气CO2和N富集，利用海平面、盐度和降水等其他关键因素的年际变化。该团队计划测试这样一个假设，即海平面上升作为沿海湿地变化的最终驱动力，将导致两种具有最高洪水耐受性的植物物种（原生莎草和入侵芦苇）在未来十年内取代那些具有较低洪水耐受性的植物（C4草）。由于莎草和芦苇对CO2浓度升高也有强烈的反应，研究小组预测，植物群落组成最初会发生变化，并增加生态系统规模的CO2响应，但由于洪水压力的增加，它最终会下降。由于相对海平面上升的速度加快，沼泽地由于生产力下降而变得不稳定，预计沼泽地将在未来十年内跨越一个门槛。然而，芦苇占主导地位的地区，特别是添加N的地块，在沼泽中产生最大的生产力，并有最好的机会跟上海平面的加速。最后，研究小组假设，随着洪水的增加，预计甲烷排放量的增加最初将被耐洪水的莎草根际甲烷氧化率较高所抵消。这项实验的结果可以继续为模型和全球变化综合提供信息。该网站和广泛的数据集被用作维拉诺瓦大学和布林莫尔学院生态学课程的实践案例研究。该项目计划培训各级研究人员，让公众参与这个LTREB网站产生的长期和前瞻性科学，并促进这一基础科学的应用，以支持沿海湿地保护，养护，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Rapid plant trait evolution can alter coastal wetland resilience to sea level rise

• DOI: 10.1126/science.abq0595
• 发表时间: 2023-01
• 期刊: Science
• 影响因子: 56.9
• 作者: M. Vahsen;M. Blum;J. Megonigal;S. Emrich;J. Holmquist;B. Stiller;K. Todd-Brown;J. McLachlan

Do tradeoffs govern plant species responses to different global change treatments?

• DOI: 10.1002/ecy.3626
• 发表时间: 2021-12
• 期刊: Ecology
• 影响因子: 4.8
• 作者: J. Langley;Emily Grman;Kevin J Wilcox;Meghan L. Avolio;K. Komatsu;S. Collins;S. Koerner;Melinda D. Smith;A. Baldwin;W. Bowman;N. Chiariello;A. Eskelinen;H. Harmens;M. Hovenden;K. Klanderud;R. McCulley;V. Onipchenko;C. Robinson;K. Suding

Rapid evolution of a coastal marsh ecosystem engineer in response to global change

沿海沼泽生态系统工程师响应全球变化的快速演变

• DOI: 10.1016/j.scitotenv.2022.157846
• 发表时间: 2022
• 期刊: Science of The Total Environment
• 影响因子: 9.8
• 作者: Mozdzer, Thomas J.;McCormick, Melissa K.;Slette, Ingrid J.;Blum, Michael J.;Megonigal, J. Patrick
• 通讯作者: Megonigal, J. Patrick

Impacts of Phragmites australis Invasion on Soil Enzyme Activities and Microbial Abundance of Tidal Marshes

• DOI: 10.1007/s00248-018-1168-2
• 发表时间: 2018-03
• 期刊: Microbial Ecology
• 影响因子: 3.6
• 作者: Sung-Hyun Kim;Sung-Hyun Kim;Jiyoung Kang;J. Megonigal;Hojeong Kang;J. Seo;W. Ding

Reproductive Responses to Increased Shoot Density and Global Change Drivers in a Widespread Clonal Wetland Species, Schoenoplectus americanus

• DOI: 10.1007/s12237-023-01249-z
• 发表时间: 2023-09
• 期刊: Estuaries and Coasts
• 影响因子: 2.7
• 作者: Aoi Kudoh;J. Megonigal;J. A. Langley;G. Noyce;Toshiyuki Sakai;D. Whigham