Flow of CO2 from soil may not correspond with CO2 concentration in soil

The relationship between CO2 flow from soil and soil CO2 concentration was investigated at 72 permanent sampling points at two forested post-mining sites in the northwest of the Czechia. Based on the entire data set (72 points sampled monthly during the growing season), CO2 flow from the soil was positively correlated with soil CO2 concentration. CO2 concentration in deeper soil layers was positively correlated with root biomass and negatively correlated with soil microbial respiration. In individual sampling points relationship between CO2 flow and soil CO2 concentration varied from being significantly positive (30% of points) to significantly negative (7%) but mostly being non-significant (63%). The positive correlation occurred at points with high root biomass in deeper soil layers, while the negative correlation occurred at points with high soil microbial respiration per cm3 of soil. Laboratory experiments showed that the CO2 produced by microbial respiration can reduce microbial re...本研究在捷克西北部两处造林型采矿废弃地的72个永久性采样点（permanent sampling points），探究了土壤二氧化碳（CO₂）通量与土壤二氧化碳浓度之间的关联。基于完整数据集（生长季期间每月采样的72个点位），土壤二氧化碳通量与土壤二氧化碳浓度呈正相关关系。深层土壤中的二氧化碳浓度与根系生物量呈正相关，而与土壤微生物呼吸（soil microbial respiration）呈负相关。在单个采样点位中，土壤二氧化碳通量与浓度的相关性存在显著差异：30%的点位呈显著正相关，7%的点位呈显著负相关，其余多数点位（63%）的相关性未达显著水平。正相关关系出现于深层土壤根系生物量较高的点位，而负相关关系则出现于单位体积土壤微生物呼吸强度较高的点位。室内实验表明，微生物呼吸产生的二氧化碳可降低微生物……