RAPID: Effect of wildfire on stream mercury and organic carbon in a southern Appalachian forested watershed

汞以低浓度存在于环境中，但可以在食物链中积累，并可能对人类和野生动物造成神经损伤。 汞在水生环境中的动态与这些环境中的碳循环相关联。 碳和汞在河流生态系统中的移动受到河流所经过的陆地环境的影响，当流域发生野火时，从土地转移到河流中的碳和汞的数量可能会增加。2016年4月和5月，弗吉尼亚州谢南多厄国家公园内的落基山野火完全烧毁了Twomile Run周围的分水岭。 自1987年以来，该溪流一直在监测水质，并将与附近的一条溪流配对，这条溪流是一个未燃烧的森林流域，潘恩运行，在为期一年的研究中，评估野火对河流生态系统中碳和汞运输的影响。 这项工作的结果将与公园内的土地管理人员分享，因为这可能有助于他们将火灾作为一种管理工具。该研究将为本科生提供测量运输中碳和汞的现场和实验室技术培训。该研究的目标是确定火灾对大西洋中部森林流域碳和汞通量的影响。排放燃烧过的分水岭的Twomile Run的碳和汞通量将与排放未燃烧分水岭的潘恩Run的碳和汞通量进行比较。将在12个月的时间内从两个流域收集手动抓取样本和自动高流量样本。 将分析样品的pH值、碱度、阴离子、阳离子、溶解有机碳、紫外吸收、总悬浮沉积物、挥发性固体和汞。 将利用对河流流量的连续估计来计算两个流域的碳和汞通量，这些数据还将提供这些输出的空间和时间动态的详细特征。 到目前为止，还没有关于河流生态系统的研究探讨了火灾对碳和汞迁移的影响，这项研究将填补这一知识空白。由于野火后立即发生的风暴预计会引起高水平的碳和能源动员，因此需要快速供资，以便能够迅速取样。

Mercury is present in the environment in low concentrations, but can accumulate in food chains and can cause neurological damage to humans and wildlife. The dynamics of mercury in aquatic environments are coupled to the cycling of carbon in those environments. The movement of carbon and mercury in stream ecosystems is influenced by the terrestrial environment through which the stream passes, and when wildfires occur in the watershed, there can be increases in the amounts of carbon and mercury that are transferred from the land to the stream. In April and May of 2016, the Rocky Mountain wildfire within the Shenandoah National Park, Virginia, completely burned the watershed surrounding Twomile Run. That stream has been monitored for water quality since 1987 and will be paired with a nearby stream draining an unburned forested watershed, Paine Run, in a year-long study to assess the influence of wildfire on the transport of carbon and mercury from stream ecosystems. The results of this work will be shared with land managers within the Park as it may help inform their use of fire as a management tool. The research will provide training for an undergraduate student in field and laboratory techniques for measuring carbon and mercury in transport.The research has the goal of determining the impacts of fire of the fluxes of carbon and mercury from forested watersheds in the mid-Atlantic region. The fluxes of carbon and mercury from Twomile Run that drains the burned watershed will be compared with those from Paine Run that drains an unburned watershed. Manual grab samples and automated highflow samples will be collected from the two watersheds over a 12-month period. The samples will be analyzed for pH, alkalinity, anions, cations, dissolved organic carbon, UV absorbance, total suspended sediments, volatile solids and mercury. Continuous estimates of stream flow will be used to calculate the flux of carbon and mercury from both watersheds and the data will also provide a detailed characterization of the spatial and temporal dynamics of those exports. To date, no studies of stream ecosystems have explored the impacts of fire on carbon and mercury transport, and this study will fill that knowledge gap. Because storms that occur immediately after a wildfire are expected to induce high levels of carbon and energy mobilization, RAPID funding is needed to make prompt sampling possible.