LTREB: Baltimore Urban Watershed Studies

在美国，城市、郊区和远郊生态系统都很重要，并且在不断增加。分水岭方法允许在水文定义的流域中对水、营养物质和其他物质的输入和输出进行量化，在过去的50年里，它一直是生态系统生态学的核心，允许评估不同面积和土地利用区域的生态系统结构和功能。这种方法对于分析扰动的影响（例如，砍伐森林）特别有用，而且对于长期分析对诸如水文气候变率和大气沉积等环境变化较微妙方面的反应也特别有用。在巴尔的摩生态系统研究（BES）中，该研究小组使用分水岭方法作为比较城市生态系统与生态学家传统研究的人类主导较少的生态系统的基础，并作为问题生成，假设检验和模型开发的迭代循环的平台。本研究对BES的森林参考、农业参考以及一系列城市和郊区生态系统进行了长期监测。这种对流域投入产出预算和趋势的分析提供了关于城市水文、氮、磷、氯化物、病原体和金属和药物化合物等污染物的基本数据。这些研究增加了我们对城市生态系统的结构和功能的基本理解，它们与其他生态系统类型的比较，以及确定影响生态系统功能和服务以及污染物的命运和运输的关键因素。这项研究继续进行长期研究，包括基于流域的监测、实验和建模之间的相互作用，这些研究有可能显著提高我们对城市和非城市生态系统的理解。这项研究的更广泛的影响包括更好地了解影响巴尔的摩多样化人类社区的环境条件，并与历史悠久的黑人机构Coppin州立大学合作，培训野外和实验室环境生物学的本科生。本项目侧重于城市流域环境生物学的长期研究。该项目将延续巴尔的摩生态系统研究（BES）城市长期生态研究（LTER）项目20多年的研究成果。BES沿着城乡梯度建立了8个长期流域监测站，以捕捉城市生态系统结构的生物、物理、建筑和社会方面对流域动态的综合影响。自1998年以来，收集了河流阶段和流量的连续数据，以及每周用于分析硝酸盐、磷酸盐、总氮、总磷、氯化物、硫酸盐、浊度、温度、溶解氧和pH值的水样，这些数据来自于流入巴尔的摩市区然后流入切萨皮克湾的较大流域。核心数据包括20多年的连续流数据和来自14000多个水样的多个元素，收集的样本的物理档案，以及为流域研究提供机制支持的长期地块尺度数据。这些生物物理数据与定期的住宅住户和治理调查相结合，以汇集人类居民对环境质量的看法。BES LTER研究的资金将于2021年9月结束，因此需要LTREB的资金。从长期数据中产生的三个假设需要继续收集长期数据进行检验，这些假设将在拟议的《热带气候变化研究计划》十年研究计划中加以处理。这些假设探讨了气候、流域特征、人类知识、价值观和流域管理努力之间的相互作用将如何影响未来20年城市河流水文的变化，以及氮、磷、盐和金属的浓度和输出。该奖项反映了美国国家科学基金会的法定使命，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。

Urban, suburban, and exurban ecosystems are important and increasing in the U.S. The watershed approach, which allows for the quantification of inputs and outputs of water, nutrients, and other substances in hydrologically defined basins, has been central to ecosystem ecology for the past 50 years, allowing for evaluation of ecosystem structure and function over areas of differing size and land use. This approach has been particularly useful for analysis of the effects of disturbances (e.g., clear cutting of forests) but also for long-term analysis of responses to more subtle aspects of environmental change such hydroclimate variability and atmospheric deposition. In the Baltimore Ecosystem Study (BES), this research team used the watershed approach as a basis for comparing urban ecosystems with the less human-dominated ecosystems that have been more traditionally studied by ecologists and as a platform for iterative cycles of question generation, hypothesis testing, and model development. This research sustains long-term monitoring of forested reference, agricultural reference, and a range of urban and suburban ecosystems in the BES. Such analysis of watershed input-output budgets and trends provides fundamental data on urban hydrology, nitrogen, phosphorus, chloride, pathogens, and contaminants such as metals and pharmaceutical compounds. These studies increase our fundamental understanding of the structure and function of urban ecosystems, how they compare with other ecosystem types, and identification of key factors influencing ecosystem functions and services and the fate and transport of pollutants. This research continues long-term studies that include interactions between watershed-based monitoring, experiments, and modeling that have the potential to significantly improve our understanding of both urban and non-urban ecosystems. The broader impacts of this research include a better understanding of environmental conditions affecting the diverse Baltimore human community, and a partnership with a historically black institution, Coppin State University, to train undergraduates in field and laboratory environmental biology.This project emphasizes Long Term Research in Environmental Biology (LTREB) on urban watersheds. The project would continue 20+ years of studies carried out by the Baltimore Ecosystem Study (BES) urban Long Term Ecological Research (LTER) project. BES established eight long-term watershed monitoring stations along an urban-rural gradient that capture the integrated influence of the biological, physical, built, and social aspects of urban ecosystem structure on watershed dynamics. Since 1998, continuous data on stream stage and discharge as well as weekly water samples for analyzing nitrate, phosphate, total nitrogen, total phosphorus, chloride, sulfate, turbidity, temperature, dissolved oxygen, and pH have been collected for the larger watershed that drains into urban Baltimore and then into Chesapeake Bay. The core data comprise 20+ years of data of continuous streamflow and multiple elements from over 14,000 water samples, a physical archive of collected samples, and long-term plot-scale data that provide mechanistic support for the watershed studies. These biophysical data have been paired with periodic residential household and governance surveys to pool human residents of their views on environmental quality. Funding for the BES LTER studies is ending in September 2021, creating a need for LTREB funding. Three hypotheses that have emerged from the long-term data, which require continued long-term data collection to test, will be addressed in the proposed LTREB Decadal Research Plan. These hypotheses address how interactions between climate, watershed characteristics, and human knowledge, values, and efforts to manage watersheds will affect the flashiness of urban stream hydrology, and the concentrations and exports of nitrogen, phosphorus, salt, and metals over the next 20 years.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.