CCZO -- Soil Gas -- Research areas 1, 4, 7 -- (2015-2017)

Zachary Brecheisen, with help from Dan Richter, Will Cook, Alex Cherkinsky, Jay Austin, and others, have augered and installed soil gas wells at 4 depths at 15 locations in the Calhoun CZO. Most installation occurred in the summer of 2015 and completed in summer 2016. Gas sampling of existing wells commenced 7-31-15 and has proceeded approximately every 3 weeks since then. The gas wells target 3 different land forms: flat uplands, mid-slopes, and steeper slopes in 3 different land use comparisons. The land uses consist of 3 reference hardwood forests minimally degraded by human activity, 3 old-field secondary succession pine forests >60 years old, and 1 pseudo-replicated agricultural plot which has been, to the best of our knowledge, continually cultivated from the 1930s at the latest. The goal of this sampling is to identify anthropogenic biogeochemical signals in the deep soil profile of cultivated lands and to evaluate their persistence or lack thereof in old-field pine forests relative to reference hardwoods. Soil gas is analyzed in the field for O2 using an Apogee oxygen meter and CO2 with a Vaisala meter. Other (greenhouse) gasses are brought back to the lab, where they are analyzed on a Varian gas chromatograph with known concentration standards.
Date Range Comments: samples collected and analyzed approximately every 3 weeks; ongoing

在Calhoun区域控制点（CZO）内，Zachary Brecheisen在Dan Richter、Will Cook、Alex Cherkinsky、Jay Austin等人的协助下，于15个地点的4个深度钻孔并安装了土壤气体井。大部分的安装工作发生在2015年夏季，并在2016年夏季完成。自2015年7月31日起，对现有井的气体采样开始进行，此后大约每3周进行一次。这些气体井针对三种不同的地表形态进行目标采样：平坦的高地、中等坡度和更陡峭的斜坡，分别在三种不同的土地利用比较中进行。土地利用包括三个受人类活动最小程度退化的参考硬木森林、三个大于60年的老农田次生松树林以及一个伪复制的农业地块，据我们所知，该地块自20世纪30年代以来一直持续耕作。本采样的目标是识别耕作土地深层土壤剖面中的人为生物地球化学信号，并评估其在老农田松树林相对于参考硬木森林中的持久性或缺乏持久性。使用Apogee氧气计在野外对土壤气体中的氧气进行现场分析，使用Vaisala计对二氧化碳进行分析。其他（温室）气体则带回实验室，在那里使用已知浓度标准在Varian气体色谱仪上进行分析。日期范围注释：样品大约每3周收集和分析一次；持续进行。