SGER: An opportunity to study the impact of nutrient pulsing in an oligotrophic forest stream in South Dakota

河流作为陆地流域营养物质的运输者的重要性正在增加，因为人类对营养物质的日益沉积往往超过了许多陆地生态系统吸收它们的能力。这项研究将评估营养脉冲对南达科他州一条低营养(少营养)森林溪流的影响。急流溪是一条泉水溪流，其特点是营养物质浓度非常低。它一直在经历一次令人讨厌的藻类水华。这种现象很不寻常，因为典型的藻类水华与人为营养负荷直接相关，但这种藻类的水华--一种硅藻(Didymphenia Giate)--往往与营养不良的水域有关。由于这种硅藻可以显著影响溪流生态系统的结构和功能，并影响渔业，南达科他州猎物、鱼类和公园部门正在Rapid Creek添加缓释肥，试图防止金丝藻的水华。为了评估这种营养负荷对这条河流的生物和非生物成分的影响，这项研究将研究投药地点上下游的营养动态。由于硅藻的生长对重要营养元素的最佳比例很敏感，因此本研究将集中在碳、氮、磷和二氧化硅等营养物质，以及酶活性、溶解氧和叶绿素产生的变化等生物反应方面。这些措施将提供对生态系统健康状况的洞察。该项目还加强了学生的研究、培训和教育，同时产生了可广泛应用于其他生态系统的有价值的数据。

The significance of streams as transporters of nutrients from terrestrial watersheds is growing as the increasing deposition of nutrients by humans often exceeds the capacity of many terrestrial ecosystems to absorb them. This study will evaluate the impact of nutrient pulsing in a low-nutrient (oligotrophic) forest stream in South Dakota. Rapid Creek is a spring fed creek characterized by very low nutrient concentrations. It has been experiencing a nuisance algal bloom. This phenomenon is unusual because typically algal blooms are directly related to anthropogenic nutrient loading, yet blooms of this algae?a diatom (Didymosphenia geminate)?are often associated with nutrient-poor waters. Since this diatom can significantly impact stream ecosystem structure and function and impact fisheries, the South Dakota Game, Fish, and Parks Department is adding slow-release fertilizer to Rapid Creek in an attempt to prevent the bloom of D. geminata. To evaluate the impact of this nutrient loading on the biological and abiotic components of this stream, this study will examine nutrient dynamics upstream and downstream of the dosing site. Since the growth of diatoms is sensitive to the optimal ratio of important nutrient elements, this study will focus on nutrients such as carbon, nitrogen, phosphorus and silica; and on biological responses such as changes in enzyme activity, dissolved oxygen and chlorophyll production. These measures will provide insights into the health of the ecosystem. This project also enhances student research training and education while generating valuable data that will be broadly applicable to other ecosystems.