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区。事实上，土壤储存的碳大约是大气的三倍。然而，土壤在受到干扰或经历新的环境条件或极端情况时，是否会比吸收碳的速度更快地向大气释放碳，仍然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归宿的过程的不完全了解，以及将土壤碳的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)，以解决改善土壤碳储量预测及其在地块景观尺度上支配土壤碳归宿的过程这一重大挑战。RC CZO将与爱达荷州西南部的雷诺溪实验分水岭(RCEW)位于同一地点，该分水岭由美国农业部-农业研究服务局(USDA-ARS)管理已有50多年。RCEW特别适合于CZO，因为它在气候、植被以及土壤有机和无机碳分布方面具有很强的梯度。天文台将利用现有的科学基础设施，包括长期的、空间上广泛的气象和土壤监测。来自爱达荷州立大学、博伊西州立大学和美国农业部-ARS的科学家组成的跨学科团队将最初的工作重点放在广泛表征整个流域的地上和地下植物生物量和土壤碳量和特征上。沿海拔梯度密集测量的一组站点(核心)将包括蒸散量的测量以及与之相关的碳、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陆地-大气交换。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。核心站点数据将支持改进土壤-植被-大气系统建模的努力，并为合作提供丰富的数据集。将使用一套模拟工具以足够高的分辨率分配控制气候输入变量，以捕捉景观上的自然异质性，并预测整个流域的土壤碳和其他关键生态和水文储量和通量的分布。该CZO将产生现有最大的土壤碳-环境变量耦合数据集之一。该数据集将提供一个独特的校准目标，以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。RC CZO的中等尺度研究将提高我们将当地观测扩大到地貌和地球的能力；这是支持准确的地球系统建模的关键一步。对中等规模的模拟的评估将揭示过程表示的薄弱领域，并使研究人员能够确定关键的研究需求。该CZO将成为碳循环研究和教育的社区资源，并吸引全球土壤建模社区研究，以应对了解土壤碳行为的重大挑战。该观测站还将提高对土地管理活动(如规定的火和放牧)如何改变土壤属性、碳输入和土壤有机碳在景观水平上的去向的理解。除了传统的培训外，CZO还将开发一门关于临界区过程的实地方法课程，并开发K-12课程以提高临界区土壤的扫盲能力。

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.