关键词: 土壤呼吸, 137Cs示踪, 5cm土壤温度, 土壤水分, 侵蚀坡地

Abstract: We measured the soil respiration of an eroded hillslope in the Chinese Loess Plateau by using Automated Soil CO2 Flux System.The soil erosion/deposition on the slope was determined by the measurements of137Cs inventory.The results indicated that soil respiration rates were significantly lower at non eroded sites on the summit than that at deposition sites on the slope bottom,but no significant differences were observed for the middle slope sites as compared with the leveled summit.The curves of daily rate of the soil respiration among different positions were similar.The soil temperature at the soil depth of 5 cm was a key factor controlling the soil respiration rate,and the temperature effect decreased with the decline of soil water contents.There existed a significant positive correlation between the soil respiration and the soil water contents,the correlation coefficients were 0.891,0.878 and 0.892(p=0.043,0.050,0.042)for the summit,middle and lower slope respectively.There was no linear or exponential correlation between the soil temperature and the soil respiration rate.

Key words: Soil respiration, Soil respiration, 137Cs technique, Soil temperature, Soil water content, Eroded slope