Development of 6 channel portable CO_2 sampling system and its practical use

研制了便携式六通道自动采样器二氧化碳采样系统，并在落叶松人工林中进行了实际应用。该系统能提供落叶松人工林6个不同层位的CO_2浓度和流量的日变化信息。一台机器可以用两个打蛋器工作4天(对于汽车手机，12V)。该系统可以很好地工作，但我们不能确定它的重量是否减轻，防水性能的改善是否失败。这些都是需要进一步改进的重要问题。近地面CO_2浓度变化很大，白天为350ppm，日出前为489ppm。冠层CO_2浓度中午前为320ppm，夜间为410ppm。这些波动受风向和风速的影响很大。CO_2浓度的突然升高可能是由于降水增加了土壤微生物的活动。

Portable CO_2 sampling system with 6 channels auto-sampler was developed and its practical use in a larch plantation was performed. A new system can provided information of diurnal change on CO_2 concentration and flow rate at the sampling of 6 different strata in a larch plantation. A machine could work for 4 days with two batters(for auto mobiles, 12 V). This system could work well but we could not confirm the lessen its weight and fail the improvement of waterproof. These are big point for requiring further improving. CO_2 concentration near ground varied largely from 350ppm at daytime to 489ppm before sunrise. In contrast, CO_2 concentration at canopy position ranged from 320ppm before noon and 410ppm during night. These fluctuation was strongly affected by wind direction and speed. A sudden increase of CO_2 concentration may be attributed to precipitation which would increase activities of soil micro-organisms.