摘要
通过同步观测耕层土壤空气CO2 浓度廓线、土壤温度和土壤含水量 ,主要研究和讨论了华东地区典型稻麦轮作农田旱地阶段的土壤空气CO2 浓度的变化规律 ,及土壤温度和含水量对它的影响。结果表明 :麦田土壤空气CO2 浓度与植物生长密切相关。土壤空气CO2 浓度受土壤温度的影响较为显著 ,且深层的相关性要明显大于浅层。观测阶段的麦田土壤含水量介于 30 %和 44%之间 ,与土壤空气CO2 浓度有较好的相关性 (相关性R2 =0 61 ,统计显著性p<0 0 0 1 )。土壤空气CO2 浓度与土壤含水量呈正相关性的原因可能是 :高土壤含水量导致的低充气孔隙度降低了土壤空气CO2 扩散速率 ,从而导致土壤空气CO2聚积 ,浓度升高。在 0～ 30cm土层中 ,上层土壤气体中的CO2 向上垂直扩散要比下层土壤快。土壤温度对土壤空气CO2 浓度的影响大于土壤含水量。
Changes in non-waterlogged soil air carbon dioxide (CO 2) concentration were studied in a rice-wheat rotation ecosystem of southeast China. Based on the synchronous measurement of CO 2 concentration in soil profiles and soil temperature and moisture. By analyzing the experimental data in detail, some results could be outlined as follows: The relationship between soil air CO 2 concentration and soil temperature showed remarkably correlation, and it changed with the wheat upgrowth. When water content was between 30% and 44%, it was positive correlative with the CO 2 concentration in soil profiles (R2=0.61, p<0.001). Soil CO 2 concentration of Wuxi wheat land and soil water content were presenting close correlation. The reason can be explained: High soil water content and low porosity had reduced diffusivity of soil air CO 2, thus causing soil air CO 2 to be accumulated, and the concentrations rises. Within 0～30 cm in soil depth, CO 2 in the pores of the upper soil layers vertically diffused upwards much more quickly than that in the lower soil layers; soil temperature and concentrations represented remarkably correlation, and the effect of soil water content on soil air CO 2 took second place.
出处
《气候与环境研究》
CSCD
2004年第4期584-590,共7页
Climatic and Environmental Research
基金
国家自然科学基金资助项目 40 1 75 0 3 0
中国科学院创新工程项目KZCX2 40 8和KZCX1 SW 0 1共同资助
