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本文于2003年5月至10月在长白山森林生态系统定位站内研究了高浓度CO2(500和700靘olmol-1)对红松幼苗土壤呼吸以及根系呼吸对土壤呼吸的贡献。经过4个生长季高浓度CO2的处理,利用LI-6400-09土壤呼吸室对红松幼苗土壤总呼吸和根系呼吸进行了测定。为了区分根系呼吸对土壤总呼吸的贡献,本文采用了PVC管断根法,即每种处理下将三根PVC管插入土壤中30cm以切断根系,从而终止了植物冠层对根系碳水化合物的供应。分别于6月16日、8月20日和10月8日对管内外土壤呼吸进行了测定。结果表明大气和土壤5cm温度都存在明显的日变化,但不同处理之间没有显著差别(P>0.05)。土壤总呼吸和断根土壤呼吸也有明显的日变化和季节变化。不同处理之间土壤总呼吸和断根土壤呼吸差异显著(P<0.01)。6月16日、8月20日和10月8日不同处理下土壤总呼吸和根系呼吸的贡献的平均值分别为3.26、4.78和1.47靘olm-2s-1以及11.5%、43.1%和27.9%。图5表1参38。
In this paper, from May to October 2003 in Changbai Mountain Forest Ecosystem Positioning Station studied the high concentration of CO2 (500 and 700 靘 olmol-1) on Korean pine seedlings soil respiration and root respiration contribution to soil respiration. After 4 high-concentration CO2 treatments for 4 growing seasons, total soil respiration and root respiration of Pinus koraiensis seedlings were determined using LI-6400-09 soil respiration chamber. In order to distinguish the contribution of root respiration to total soil respiration, a PVC root-cutting method was used in this paper. Three PVC pipes were inserted into the soil for 30 cm in each treatment to cut off the root system, thus terminating the plant canopy supply of root carbohydrates. Soil respiration inside and outside the pipe was measured on June 16, August 20 and October 8, respectively. The results showed that there was a significant diurnal variation in air and soil temperature of 5cm, but there was no significant difference between different treatments (P> 0.05). Soil total respiration and root resuming soil respiration also have obvious diurnal and seasonal changes. The total soil respiration and root resuming soil respiration differed significantly among different treatments (P <0.01). The average contributions of soil total and root respiration under different treatments on June 16, August 20 and October 8 were 3.26, 4.78 and 1.47 靘 olm-2s-1 and 11.5, 43.1 and 27.9% respectively, . Figure 5 Table 1 reference 38.