Collaborative Research: The Effects of Watershed Urbanization on In-Stream Transformation of Organic Nutrients within Running Waters

城市化已经成为全球变化的一个重要组成部分，因为它目前的范围和规模。 城市化地区的河流正在从反映景观和大气沉积人为变化的流域养分运输者转变为积极改变下游N和P形式和生态效应的养分转化者。 关于沿海河流在转化营养物方面的潜在重要性以及对食物网的影响，目前的资料不足。 通过实地研究、流域评估和围隔生态系统研究，该研究将把流域城市化的变化与河流中有机形式营养物的处理率联系起来。 创新的，国家的最先进的分析方法将被用来构建质量平衡，评估生物利用度的变化，指纹的分水岭源，评估转化率，并估计潜在的流生成的不同部分的有机氮磷。与正在进行的巴尔的摩LTER计划和栖息地映射将被用来与流域特征的营养转换。 结果将有广泛的相关性，在沿海生态系统的富营养化问题，并有助于确定当溪流和河流有可能区分流产生内部的有机氮磷从外部补贴的无机氮磷作为一个结果，不断增加的城市化。 欧空局SEEDS项目的少数民族学生将参加这项研究。

ABSTRACTUrbanization has become a critical component of global change, given its current extent and magnitude. Streams in urbanizing areas are shifting from watershed nutrient transporters that reflect the anthropogenic changes in the landscape and atmospheric deposition to nutrient transformers that actively change the forms and ecological effects of N and P delivered further downstream. Insufficient information exists regarding the potential importance of coastal streams in transforming nutrients and consequent effects on foodwebs. Through field studies, watershed assessments, and mesocosm studies, the research will link changes in watershed urbanization to rates of in stream processing of organic forms of nutrients. Innovative, state-of-the-art analytical methods will be used to construct mass balances, assess changes in bioavailability, fingerprint the watershed source, assess transformation rates, and estimate the potential for in-stream generation of different fractions of organic N&P. Collaboration with the ongoing Baltimore LTER program and habitat mapping will be used to relate the nutrient transformations to watershed characteristics. Results will have broad relevance to eutrophocation problems in coastal ecosystems and help determine when streams and rivers have the potential to discriminate between streams that generate internal organic N&P from external subsidies of inorganic N&P as a result of increasing urbanization. Minority students from the ESA SEEDS project will participate in the research.