Reynolds Creek Carbon Critical Zone Observatory

世界上大部分陆地碳以土壤碳的形式存在于临界带。事实上，土壤储存的碳大约是大气的三倍。然而，当受到干扰或经历新的环境条件或极端情况时，土壤向大气释放碳的速度是否会快于吸收碳的速度，这方面存在很大的不确定性。这些不确定性的产生是由于对控制土壤碳命运的过程的不完全理解，以及将土壤碳估算从地块扩大到景观或全球水平的挑战。研究人员正在建立雷诺溪临界区观测站（RC CZO），以解决从地块到景观尺度改善土壤碳储量预测和控制其命运的过程的巨大挑战。RC CZO将与爱达荷州西南部的雷诺兹河实验流域（RCEW）位于同一地点，该流域由美国农业部农业研究服务局（USDA-ARS）管理了50多年。由于该区在气候、植被、土壤有机碳和无机碳分布上具有很强的梯度，因此特别适合于CZO。该观测站将利用现有的科学基础设施，包括长期、空间广泛的气象和土壤监测。一个由爱达荷州立大学、博伊西州立大学和USDA-ARS组成的跨学科科学家团队将把他们的初步努力集中在广泛表征地上和地下植物生物量以及跨越分水岭的土壤碳量和特征上。沿着海拔梯度密集测量的一组站点（CORE）将包括蒸散发和相关的陆地-大气碳交换、树液通量、土壤呼吸、土壤水分、土壤温度和其他基本气候变量的测量。实验研究将包括调查规定的火和放牧对土壤碳和过程的影响。CORE站点数据将支持改进土壤-植被-大气系统建模的工作，并为合作提供丰富的数据集。一套模拟工具将用于以足够高的分辨率分布控制气候输入变量，以捕捉景观上的自然异质性，并预测整个流域土壤碳和其他关键生态和水文储量和通量的分布。这个CZO将产生一个最大的耦合土壤碳-环境变量数据集。该数据集将为开发和测试对区域和全球气候和生物地球化学建模至关重要的建模工具提供独特的校准目标。RC CZO的中尺度研究将提高我们将局部观测扩展到景观和全球的能力；这是支持精确地球系统建模的重要步骤。中等规模的模拟评估将揭示过程表示中的弱点，并允许研究人员确定关键的研究需求。CZO将成为碳循环研究和教育的社区资源，以及全球土壤模型社区研究的磁石，以解决理解土壤碳行为的巨大挑战。这个观测站还将提高人们对土地管理活动（如规定的火灾和放牧）如何在景观水平上改变土壤性质、碳输入和土壤有机碳的命运的理解。除了传统的培训外，CZO还将开发一门关于关键区域过程的实地方法课程，并开发K-12课程，以提高对关键区域土壤的认识。

Most of the world's terrestrial carbon is found in the Critical Zone as soil carbon. Indeed, soils store approximately three times more carbon than the atmosphere. Yet large uncertainties exist as to whether soils will release carbon to the atmosphere faster than they can take it up when disturbed or experiencing new environmental conditions or extremes. These uncertainties arise owing to an incomplete understanding of the processes controlling soil carbon fate and the challenge of scaling up estimates of soil carbon from the plot to the landscape or global level.Investigators are establishing the Reynolds Creek Critical Zone Observatory (RC CZO) to address the grand challenge of improving prediction of soil carbon storage and the processes governing its fate at the plot to the landscape scale. The RC CZO will be co-located with the Reynolds Creek Experimental Watershed (RCEW) in southwest Idaho, which has been administered by the United State Department of Agriculture -Agricultural Research Service (USDA-ARS) for over 50 years. The RCEW is particularly well suited for the CZO because of its strong gradients in climate, vegetation, and distributions of soil organic and inorganic carbon. The observatory will leverage existing scientific infrastructure that includes long-term, spatially extensive meteorological and soil monitoring.An interdisciplinary team of scientists from Idaho State University, Boise State University, and the USDA-ARS will focus their initial efforts on extensive characterization of above and below ground plant biomass and soil carbon amounts and characteristics across the watershed. An intensively instrumented set of sites (CORE) along an elevation gradient will include measurements of evapotranspiration and the associated land-atmosphere exchange of carbon, sap flux, soil respiration, soil moisture, soil temperature, and other essential climate variables. Experimental research will include investigation of prescribed fire and grazing on soil carbon and processes. The CORE site data will support efforts to improve modeling of the soil-vegetation-atmosphere system and provide a rich dataset for collaborations. A suite of simulation tools will be used to distribute controlling climate input variables at a sufficiently high resolution to capture the natural heterogeneity on the landscape and predict the distribution of soil carbon and other key ecological and hydrologic stores and fluxes throughout the watershed. This CZO will produce one of the largest coupled soil carbon- environmental variable datasets available. The dataset will provide a unique calibration target to develop and test modeling tools critical for regional and global climate and biogeochemical modeling. The intermediate scale research at the RC CZO will improve our ability to scale local observations to the landscape and the globe; an essential step to support accurate Earth system modeling. Evaluation of simulations at the intermediate scale will reveal areas of weakness in process representation and allow researchers to identify critical research needs. This CZO will become a community resource for carbon cycling research and education, and a magnet for global soil modeling community research to address the grand challenge of understanding soil carbon behavior. This observatory will also improve understanding of how land management activities like prescribed fire and grazing alter soil properties, carbon inputs and the fate of soil organic carbon at the landscape level. In additional to traditional training, this CZO will develop a field methods course on critical zone processes and develop K-12 curriculum to improve literacy of soils in the critical zone.