Collaborative Research: Watershed Carbon Distribution and Flux Across Environmental Gradients

0404130 McGlynn流域碳分布和跨环境梯度通量二氧化碳（CO2）在气候变化和土壤中盐基阳离子去除中的核心作用已经确立。 然而，空间和时间变化的CO2生产和流出集水土壤仍然知之甚少。 我们刚刚开始开发从点测量（如通量塔或呼吸室）到更大空间尺度（如地块或流域）的方法。 主要的CO2强迫因子如何在气候、环境、地球化学和地形梯度上变化需要解决。 此外，补充调查的地形控制C积累和动员溶解有机碳（DOC）的中央了解景观和C循环之间的联系在流域尺度。 许多关于C在大气中的分配和迁移的研究都集中在大气交换方面，而忽略了C在河流中的流失。 最近的工作使我们深入了解控制溪流C出口的时间和幅度的过程。 我们认为，了解地形控制和河流集水区的连接是不可或缺的理解总C通量集水区。 与水文相似性相关的水文地球化学相似性概念是理解水文地球化学过程空间格局的有力工具。 我们的研究将测试这一概念对土壤呼吸和DOC输出的适用性，并将确定量化土壤CO2生产和地表流出的一阶控制的空间和时间变异性所需的关键测量集。 然后，这些来自场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变化。 这些空间分布的数据是中央模拟土壤CO2的生产和运输。 通过结合广泛的实地测量和量化土壤呼吸的影响因素，如土壤温度，土壤湿度，土壤肥力和气候变量与数值模拟技术，这项工作将提供一种方法来测量和模拟广泛的，但知之甚少的交换水，碳，和能量之间的土壤和大气。 本研究的目的是：（1）量化CO2排放量，并开发和应用集水区呼吸模型，包括土壤空气pCO 2、溶解CO2的垂直土壤水分输送和地表CO2排放量;（2）探索地形在多大程度上可以用来解释驱动呼吸的因素的内在变异性，（3）定量研究地形对流域土壤碳分布的控制作用，并在流域尺度上将景观碳积累、DOC输送和河流DOC输出联系起来。 这项工作将为开发和应用一个框架提供经验信息和基础，以了解土壤呼吸的空间和时间变化以及由此产生的土壤空气CO2浓度、大气交换和河水C输出。 拟议活动产生的更广泛影响。本科生和研究生在研究的各个方面的包容性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为主的大学，因此，本科生获得研究经验的机会有限。 这项研究将提供弗罗斯特堡的学生，无论是现在和未来的经验和机会，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。 学生将成为研究小组的组成成员，并将鼓励他们通过在国家会议上发表和介绍他们的研究结果来掌握自己的贡献。 这项研究将通过在课堂练习和实地学习中纳入近实时数据来加强教学活动（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，帮助推进在水文学和地球化学领域代表性不足的本科院校的学生和教师。 如果获得资助，大天空科学与自然历史研究所已同意为研究生参与BSI研究生研究员计划提供额外支持。根据该计划，研究员将接受培训，有效地将他们的结果传达给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中的作用，并帮助实现BSI的使命，即将当前的研究与面向所有年龄段和各行各业的人的探究式学习相结合。 这项工作还将产生一个土壤空气CO2浓度数据集，流出，半分布式现场测量和模拟的驱动因素，通过时间，并链接到溪流C出口。 我们的数据集将在网络上免费提供给其他研究人员，并可以作为CO2生产，通量和溪流C出口模型的测试数据集。 到目前为止，没有这样的数据集（作者）。知识），但这是至关重要的理解C积累和通量跨越环境梯度提供了一个测试地面和比较集。

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.