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通过在华西雨屏区苦竹(Pleioblastus amarus)人工林内建立固定样地、定期监测等方法,研究该人工林生态系统土壤呼吸各组分特征及其温度敏感性.结果表明:2010年2月—2011年1月,苦竹林平均土壤呼吸速率为1.13μmol·m-2·s-1,仲夏最高,深冬最低;凋落物层、无根土壤和植物根系对苦竹林土壤呼吸的贡献率分别为30.9%、20.8%和48.3%,各呼吸组分的季节动态均与土壤总呼吸类似,并与温度和凋落量等因素相关;苦竹林土壤总呼吸(RST)、凋落物层CO2排放(RSL)、无根土壤CO2排放(RSS)和植物根系呼吸(RSR)的年碳排放量分别为4.27、1.32、0.87和2.08Mg C·hm-2·a-1;土壤总呼吸及其各组分与凋落量呈显著正线性相关,与土壤10cm温度和气温均呈显著正指数相关;基于土壤温度计算的RST、RSL、RSS和RSR的Q10值分别为2.90、2.28、3.09和3.19,凋落物层CO2排放的温度敏感性显著低于总呼吸和其他各组分.
The characteristics and temperature sensitivity of soil respiration in this plantation ecosystem were studied by means of establishing fixed plots and regular monitoring in the Pleioblastus amarus plantation in West Huaxi.The results showed that: from February 2010 to January 2011 In January, the average soil respiration rate was 1.13μmol · m-2 · s-1, the highest in midsummer and the lowest in winter. The contribution rates of litter layer, rootless soil and plant root to soil respiration of P. bambutus were 30.9 %, 20.8% and 48.3%, respectively. The seasonal dynamics of all respiration components were similar to total soil respiration, and were related to factors such as temperature and litterfall. The total soil respiration (RST), litter CO2 emission The annual carbon emissions of root-free soil CO2 (CO2) and plant root respiration (RSR) were 4.27, 1.32, 0.87 and 2.08 Mg · hm-2 · a-1, respectively. The Q10 values of RST, RSL, RSS and RSR based on soil temperature were 2.90, 2.28, 3.09 and 3.19, respectively. The litter CO2 emission The temperature sensitivity was significantly lower than the total respiration and other components.