LTER: Georgia Coastal Ecosystems-III

佐治亚州海岸生态系统(GCE)LTER位于大西洋海岸三个相邻的海湾，包括潮间带沼泽和河口。气候变化、海平面上升和人类改变景观的长期驱动因素将通过改变整个景观的水量和模式，导致GCE领域内主要栖息地类型(状态变化)的转变。水输送的这些变化可以概念化为河流流入、当地径流、地下水输入和潮汐淹没的压力和脉冲，这些变化反过来又表现为盐度和该领域淹没模式的变化。GCE-III的研究旨在探讨气候变化和人为因素驱动的盐度和洪水变化如何在不同的空间和时间尺度上影响生物和生态系统的反应，并预测这些变化对整个沿海地貌的栖息地供应和碳(C)固存的后果。下一个供资周期的目标是：1)跟踪流域和邻近高地气候和人类活动的长期变化，并评估这些驱动因素对区域边界条件(河流输入、邻近高地的径流和入渗、海平面高度)的影响。这将通过对气候、水化学、海洋交换和人类在景观上的活动的长期测量来实现。2)描述区域内物理特性(如层化、河口盐入侵、停留时间)、化学特性(如盐度、营养物质、有机质倾向性)、地质特性(如沉积)和生物特性(如生物丰度和生产力)的时间和空间变异性，并评估它们如何受到河流流入和其他边界条件变化的影响。LTER研究人员将通过跟踪我们核心监测点的水和沼泽状况、遥感和水动力学模型来实现这一点。3)描述该区域3种优势生境(斯巴达纳沼泽、淡水/微咸水沼泽、高位沼泽)对盐度和淹水条件下的脉冲和压力的响应。调查人员将通过监测、大规模现场操作和建模来实现这一点，该模型旨在评估系统对斯巴迪纳沼泽淹没变化、淡水/微咸水沼泽盐度增加以及高沼泽水文连通性变化的反应。LTER人员特别感兴趣的是确定导致栖息地转变(状态变化)的阈值，以及确定这些变化的信号。4)描述GCE领域的栖息地供应、碳固存和出口的模式，并评估盐度和洪水的变化可能如何影响这些模式。这将通过使用建模和现场观测来评估海平面上升、淡水流入和沿海发展的不同情景下的栖息地供应和碳流，这些情景描述了该系统殖民前的过去条件及其在未来100年可能的未来。这些努力将被综合为对生物和生态系统对气候变化和人类活动驱动的盐度和洪水变化的反应的天气学理解，这将被用来评估生境之间的阈值和该领域状态变化的可能性。GCE校园计划是与UGA海洋推广服务合作开展的，建立在教育工作者的长期接触和指导之上。随着浪潮的到来，校园计划正在为即将出版的GCE儿童书籍制定活动和分发计划。与GCE桃子LSAMP项目的合作将为少数族裔本科生提供研究机会，跨地点跨学科课程将为研究生提供跨学科培训。GCE博士后机会将推动几位科学家的早期职业生涯。LTER与佐治亚州海岸研究理事会合作，促进沿海资源的科学管理。GCE科学家经常参加各种公共外展论坛。GCE信息也可以通过我们的网站广泛访问，该网站使用最先进的信息系统来管理和显示关于研究地点、研究、分类、数据集、出版物和项目管理的信息。

Intellectual Merit The Georgia Coastal Ecosystems (GCE) LTER is located along three adjacent sounds on the Atlantic coast and includes both intertidal marshes and estuaries. Long-term drivers of climate change, sea level rise and human alterations of the landscape will cause transitions in dominant habitat types (state changes) within the GCE domain by changing the amounts and patterns of water delivery across the landscape. These changes in water delivery can be conceptualized as presses and pulses in river inflow, local runoff, groundwater input, and tidal inundation, which will in turn manifest themselves as changes in salinity and inundation patterns in the domain. The research at GCE-III is designed to address how variations in salinity and inundation, driven by climate change and anthropogenic factors, affect biotic and ecosystem responses at different spatial and temporal scales, and to predict the consequences of these changes for habitat provisioning and carbon (C) sequestration across the coastal landscape. The goals for this next funding cycle are to: 1) Track long-term changes in climate and human actions in the watershed and adjacent uplands, and evaluate the effects of these drivers on domain boundary conditions (riverine input, runoff and infiltration from adjacent uplands, sea surface height). This will be accomplished through long-term measurements of climate, water chemistry, oceanic exchange, and human activities on the landscape. 2) Describe temporal and spatial variability in physical (e.g. stratification, estuarine salt intrusion, residence time), chemical (e.g. salinity, nutrients, organic matter liability), geological (e.g. accretion) and biological (e.g. organism abundance and productivity) properties in the domain, and to evaluate how they are affected by variations in river inflow and other boundary conditions. LTER researchers will accomplish this by tracking both water and marsh conditions at our core monitoring sites, remote sensing, and hydrodynamic modeling. 3) Characterize the responses of three dominant habitats in the domain (Spartina marsh, fresh/brackish marsh, high marsh) to pulses and presses in salinity and inundation. Investigators will accomplish this through monitoring, large-scale field manipulations, and modeling designed to evaluate system responses to changes in inundation in the Spartina marsh, increased salinity in the fresh/brackish marsh, and changes in hydrologic connectivity in the high marsh. LTER personnel are particularly interested in determining thresholds that cause habitat transitions (state changes), and in identifying signals of these changes. 4) Describe patterns of habitat provisioning and C sequestration and export in the GCE domain, and to evaluate how these might be affected by changes in salinity and inundation. This will be accomplished by using modeling and field observations to evaluate habitat provision and C flow under different scenarios of sea level rise, freshwater inflow, and coastal development that describe both the pre-colonial past conditions of the system and its likely future over the next 100 years. These efforts will be synthesized into a synoptic understanding of both biotic and ecosystem responses to variations in salinity and inundation driven by climate change and human activities, which will be used to assess thresholds between habitats and the potential for state changes in the domain.Broader Impacts The goal of GCE outreach is to enhance scientific understanding of coastal ecosystems by teachers and students, coastal managers, and the general public. The GCE Schoolyard program, run in partnership with the UGA Marine Extension Service, is built around long-term contact and mentoring of educators. The Schoolyard program is developing activities and distribution plans for the forthcoming GCE children's book, As the Tide Comes In. A partnership with the GCE Peach LSAMP program will provide research opportunities for minority undergraduates, and a cross-site interdisciplinary course will provide interdisciplinary training for graduate students. GCE postdoctoral opportunities will advance the early careers of several scientists. The LTER partners with the Georgia Coastal Research Council to promote science-based management of coastal resources. GCE scientists routinely participate in a variety of public outreach forums. GCE information is also broadly accessed via our website, which uses a state-of-the art information system to manage and display information about study sites, research, taxonomy, data sets, publications, and project administration.