关键词: 土壤呼吸, 根呼吸, 凋落物层CO2释放, 无根土壤CO2释放, Q10值, 温度敏感性

Abstract: To understand the characteristics of soil respiration components and their temperature sensitivity in a Pleioblastus amarus plantation in the Rainy Area of West China, a one-year periodic monitoring was conducted in a fixed plot of the plantation from February 2010 to January 2011. In the plantation, the mean annual soil respiration rate was 1.13 μmol·m–2·s–1, and the soil respiration presented a clear seasonal pattern, with the maximum rate in mid-summer and the minimum rate in late winter. The contribution rates of the respiration of litter layer, root-free soil, and root to the total soil respiration of the plantation accounted for 30.9%, 20.8% and 48.3%, respectively, and the respiration of the components had a similar seasonal pattern to the total soil respiration, being related to temperature and litterfall. The annual CO2 efflux from the total soil respiration, litter layer CO2 release, root-free soil CO2 release, and root respiration was 4.27, 1.32, 0.87 and 2.08 Mg C·hm–2·a–1, respectively. The total soil respiration and its components had significant positive linear correlations with litterfall, and significant positive exponential correlations with air temperature and the soil temperature at depth 10 cm. The Q10 values of total soil respiration, litter layer CO2 release, root-free soil CO2 release, and root respiration calculated based on the soil temperature were 2.90, 2.28, 3.09 and 3.19, respectively, suggesting that the temperature sensitivity of litter layer CO2 release was significantly lower than that of the total soil respiration and of its other components.

Key words: soil respiration, root respiration, litter layer CO2 release, root-free soil CO2 release, Q10 value, temperature sensitivity