OPUS:CRS: Synthesis of decadal changes in controls, trajectories, & tipping points in vegetation cover, spatial structure, & marsh platform elevation in Great Sippewissett Marsh

盐沼是沿海环境的共同特征。它们提供基本服务，如维持水质、稳定海岸线，并为重要渔业提供选择的栖息地。在世界各地，盐沼正受到人类活动的长期影响的威胁。这些问题包括营养物质负荷增加、海平面加速上升以及气温和降水增加。这些变化可能正在达到临界点，超过这个临界点，这些服务可能会停止。该项目使用了一个49年的盐沼对氮素添加的响应和其他外部驱动因素的数据集，以增加对盐沼结构和功能的理解。了解盐沼对这种变化的反应对于更好地管理这些关键生态系统是必要的。这一研究结果将对盐沼生态的基本问题做出重大贡献，并将对负责湿地管理的利益相关者有所帮助。这项研究产生的完整数据库将通过DataONE(地球数据观测网络)免费提供给任何未来的用户。该项目建议对马萨诸塞州科德角具有代表性的新英格兰盐沼大西佩维塞特沼泽的长期研究得出的丰富数据库进行综合。核心数据库包括a)高清晰度(10x10厘米)的植被镶嵌记录，以及b)高清晰度(±1-3毫米)的微海拔空间分布，两者都是在49年前建立的重复的10米半径试验田中测量的。这些地块经过了长期处理，包括四种不同水平的营养输入，与世界上河口发现的富营养化范围相当。在条件发生实质性变化的同时，富营养化仍在继续：因此，这项工作将评估暴露在大范围富营养化环境中的盐沼将如何应对海平面上升、温度和降水的交互和平行变化。这一独一无二的数据库的合成将允许定义主要驱动变量的交互影响，促进对盐沼响应和不断变化的条件下的十年轨迹的理解，并从理论上理解外部与内部控制、稳定状态、临界点和十年植被轨迹的可变性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Salt marshes are common features of coastal environments. They provide fundamental services, such as maintaining water quality, stabilizing shorelines, and providing choice habitats for important fisheries. Across the world, salt marshes are under threat from the long-term effects of human activities. These include increased nutrient loading, accelerating sea level rise, and increased temperature and precipitation. These changes may be reaching tipping points beyond which these services may cease. This project uses a 49-year dataset on salt marsh responses to nitrogen addition and other external drivers to increase understanding of salt marsh structure and function. Knowledge about the response of salt marshes to such changes is necessary for better management of these critical ecosystems. Results from this research will lead to substantial contributions to basic questions about ecology of salt marshes and will be useful to stakeholders responsible for wetland management. The full database generated from this research will be made freely available to any future users through DataONE (Data Observation Network for Earth).The project proposes a synthesis of a rich database derived from long-term research in the Great Sippewissett Marsh, a representative New England salt marshes in Cape Cod, MA. The core database includes a) a high-definition (10x10 cm) record of a mosaic of vegetation, and b) a high-definition (±1-3 mm) spatial distribution of micro-elevations, both measured within replicated experimental 10-m radius plots established 49 years ago. These plots have been subject to chronic treatments, including four different levels of nutrient inputs, comparable to ranges of eutrophication found in the worlds’ estuaries. The enrichments continued while conditions changed substantially: this work therefore will assess how salt marshes exposed to a wide range of eutrophication will respond to interactive and parallel changes in sea level rise, temperatures, and precipitation. Synthesis of this one-of-a-kind database will allow definition of interactive effects of major driving variables, advance understanding of salt marsh responses and decadal trajectories under changing conditions, and develop theoretical understanding of external vs internal controls, stable states, tipping points, and variability of decadal vegetation trajectories.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.