Collaborative Research: Watershed Carbon Distribution and Flux Across Environmental Gradients

0404130麦格林流域碳分布和跨环境梯度的通量二氧化碳(CO2)在气候变化和土壤盐基离子去除中的中心作用已经确定。然而，集水区土壤中二氧化碳的产生和排放的时空变化仍然知之甚少。我们刚刚开始开发方法，从由通量塔或呼吸室进行的点状测量扩大到更大的空间尺度，如地块或流域。主要的二氧化碳强迫因素如何在气候、环境、生物地球化学和地形梯度上发生变化，需要加以解决。此外，对地形对碳积累的控制和溶解有机碳的动员的补充调查S对于理解流域尺度上的地形和碳循环之间的联系具有重要意义。许多关于碳的分配和迁移的研究主要集中在大气交换上，而忽略了溪水中碳的损失。最近的工作让我们深入了解了控制溪水C出口的时间和数量的过程。我们认为，了解地形控制和河流-集水区的连接对于了解来自集水区的总碳通量是不可或缺的。与水文相似相关的生物地球化学相似性概念已被认为是理解生物地球化学过程空间模式的有力工具。我们的研究将测试这一概念在土壤呼吸和DOC输出中的适用性，并将确定必要的关键测量集，以量化土壤二氧化碳产生和地表排放的一级控制中的空间和时间变异性。这些场导出的信息将通知和约束我们的模型，该模型模拟这些参数在空间和时间上的可变性。这些空间分布的数据是模拟土壤二氧化碳的产生和运输的核心。通过将广泛的野外测量和对影响土壤呼吸的因素(如土壤温度、土壤水分、土壤肥力和气候变量)的量化与数值模拟技术相结合，这项工作将为测量和模拟土壤与大气之间广泛但知之甚少的水、碳和能量交换提供一条前进的道路。本研究的目的是(1)量化二氧化碳外流，并开发和应用流域呼吸模型，包括土壤空气二氧化碳浓度、土壤水分垂直迁移溶解二氧化碳和地表二氧化碳外流，(2)探索地形可以在多大程度上解释驱动呼吸的因素所固有的变异性，以及(3)量化地形对流域土壤碳分布的控制，并在流域尺度上将土壤碳在景观中的积累、DOC迁移和河流DOC输出联系起来。拟议活动的智力价值这项工作将为开发和应用一个框架提供经验信息和基础，以了解土壤呼吸和由此产生的土壤空气CO2浓度、大气交换和溪水C输出的时空变量。拟议活动产生的更广泛的影响。将本科生和研究生纳入研究的各个方面是这项工作的主要目标。弗罗斯特堡州立大学是一所以本科生为主的机构，因此，本科生获得研究经验的机会有限。这项研究将通过弗罗斯特堡州立大学、弗吉尼亚大学和蒙大拿州立大学(EPSCoR机构)之间的合作联系，为现在和未来的弗罗斯特堡学生提供经验和机会。学生将成为研究小组不可或缺的成员，并将被鼓励通过在国家会议上发表和介绍他们的研究成果来承担他们的贡献。这项研究将通过将接近实时的数据纳入课堂练习和实地学习来加强教学活动(本科生和研究生)。这项工作还将加强弗罗斯特堡的研究基础设施，帮助提升在水文学和生物地球化学领域代表性不足的本科院校的学生和教职员工。如果获得资金，大天空科学和自然历史研究所已经同意为参加英国科学与自然学会研究生计划的一名研究生提供额外的支持。根据该计划，该研究员将接受培训，将他们的结果有效地传达给K-12社区和公众。研究员计划为研究生提供培训和交流科学的机会，鼓励年轻科学家了解他们在向公众传播科学发现方面的作用，并帮助实现BSI.的使命，即将当前的研究与基于探究的学习相结合，供所有年龄和各行各业的人使用。这项工作还将产生土壤空气二氧化碳浓度、排放、半分布式野外测量和驱动因素随时间的模拟的数据集，以及与溪水C输出的链接。我们的数据集将在网上免费提供给其他研究人员，并可以作为二氧化碳产生、通量和溪水C出口模型的测试数据集。到目前为止，(对作者而言)还没有这样的数据集。知识)，但这对于通过提供试验场和比较集来了解环境梯度上的碳积累和通量至关重要。

0404130McGlynn Watershed carbon distribution and flux across environmental gradients The central roles of carbon dioxide (CO2) in climate change and the removal of base cations from soils has been established. However, the spatial and temporal variation of CO2 production and efflux from catchment soils remains poorly understood. We are just beginning to develop the methods to up-scale from point measurements such as those made by flux towers or respiration chambers to larger spatial scales such as plots or watersheds. How the primary CO2 forcing factors vary across climatic, environmental, biogeochemical, and topographic gradients needs to be addressed. In addition, complementary investigation of the topographic controls on C accumulation and the mobilization of dissolved organic carbon (DOC) s central to understanding the links between the landscape and the C cycle at the watershed scale. Many investigations of C allocation and movement focus on atmospheric exchange, neglecting the loss of C in stream water. Recent work has given us insight into the processes controlling the timing and magnitude of stream water C exports. We believe that understanding topographic controls and stream-catchment connections are integral to understanding total C flux from catchments. The concept of biogeochemical similarity, related to hydrological similarity, has been identified as a powerful tool in understanding the spatial patterns of biogeochemical processes. Our research will test the applicability of this concept for soil respiration and DOC export and will identify the critical set of measurements necessary to quantify the spatial and temporal variability in the first-order controls on soil CO2 production and surface efflux. This field-derived information will then inform and constrain our model that simulates the variability of these parameters through space and time. These spatially distributed data are central to simulation of the production and transport of soil CO2. By combining extensive field measurements and quantification of the factors influencing soil respiration such as soil temperature, soil moisture, soil fertility, and climatic variables with numerical modeling techniques, this work will provide a way forward for measuring and modeling the extensive but poorly understood exchange of water, C, and energy between soils and the atmosphere. The objectives of this research are (1) to quantify CO2 efflux and to develop and apply a model of catchment respiration, incorporating soil air pCO2, vertical soil water transport of dissolved CO2, and surface CO2 efflux, (2) to explore the extent to which topography can be used to explain the variability inherent in the factors driving respiration, and (3) To quantify the topographic controls on the distribution of soil C in the watershed and link C accumulation in the landscape, DOC transport, and stream DOC export at the watershed scale. Intellectual merit of the proposed activity This work will provide empirical information and the foundation for development and application of a framework for understanding the spatial and temporal variably of soil respiration and resultant soil air CO2 concentration, atmospheric exchange, and streamwater C export. Broader impacts resulting from the proposed activity. The inclusion of undergraduates and graduate students in all aspects of research is a primary goal of this work. Frostburg State University is a predominantly undergraduate institution, and as such, has limited opportunities for undergraduates to obtain research experience. This research will provide Frostburg students, both now and in the future with experience and opportunities through collaborative linkages made between Frostburg State University, The University of Virginia, and Montana State University (EPSCoR institution). Students will be integral members of the research team and will be encouraged to take ownership of their contributions through publication and presentation of their findings at national meetings. This research will enhance teaching activities (undergraduate and graduate) through inclusion of near real-time data in class exercises and field-based learning. This work will also strengthen the research infrastructure at Frostburg, helping to advance students and faculty from undergraduate institutions that are underrepresented in the fields of hydrology and biogeochemistry. If funded, the Big Sky Institute for Science and Natural History has agreed to provide additional support for participation of a graduate student in the BSI Graduate Fellows Program. Under that program, the Fellow would receive training in effective communication of their results to K-12 communities and the public. The fellows program provides graduate students training and opportunities to communicate science, encourages young scientists to understand their role in disseminating scientific findings to the public, and helps fulfill BSI.s mission of combining current research with inquiry-based learning for people of all ages and all walks of life. This work will also produce a dataset of soil air CO2 concentrations, efflux, semi-distributed field measurements and simulations of driving factors through time, and links to streamwater C export. Our datasets will be made freely available on the web to other researchers and can serve as a test data set for models of CO2 production, flux, and streamwater C export. To date, no such dataset is available (to the authors. knowledge), yet this is critical to understanding C accumulation and flux across environmental gradients by providing a testing ground and comparison set.