太岳山油松人工林土壤呼吸对抚育强度的响应

为了解不同抚育强度下土壤呼吸速率的差异及土壤温湿度对土壤呼吸速率的影响,利用LI-8100土壤CO2排放通量全自动测量系统测定山西太岳山油松人工林不同强度抚育后土壤呼吸速率,同时测量土壤表层10 cm处的温度和湿度.4块油松人工林样地的抚育强度分别为20%、30%、40%和50%,对4块抚育样地及1块对照样地进行3种处理:切根去凋、去凋和对照.结果表明:切根去凋处理条件下抚育样地与对照样地土壤呼吸速率无显著差异(P>0.05);去凋处理条件下抚育样地与对照样地土壤呼吸速率呈显著差异(P<0.01),抚育强度为20%、30%和40%样地6、7月的土壤呼吸速率显著高于对照样地(P<0.01);对照处理条件下,抚育样地与对照样地土壤呼吸速率呈显著差异(P<0.01),抚育强度为30%和40%样地6、7、8月的土壤呼吸速率显著高于对照样地(P<0.01).土壤温度和湿度与土壤呼吸速率显著相关(P<0.01),且共同解释了土壤呼吸速率变化的30%～74%,是影响土壤呼吸速率变化的重要环境因子.

Response of Soil Respiration in Pinus tabulaeformis Plantation to Tending Intensities in the Taiyue Mountain,China

For understanding the effects of tending intensities,soil temperature and moisture on soil respiration rates,the soil respiration rate,soil temperature,and soil moisture at depth of 10 cm were measured in a Pinus tabulaeformis plantation in the Taiyue Mountain of Shanxi Province,China.The plots were tended of woods with different intensities(20%,30%,40% and 50%,respectively) before the measurements.The results showed: 1) The soil respiration rates without litter and root had no significant difference(P > 0.05) among the wood tending treatments,while the soil respiration rates with root had significant difference(P < 0.01).2) The soil respiration rates of the treatments with 20%,30% and 40% tending intensities were significant higher than those in the control plots(P < 0.01) in June and July.3) The soil respiration rates with litter and root also had significant difference(P < 0.01) among the wood tending treatments.The soil respiration rates under tending intensities of 30% and 40% were significant higher than those in the control plots(P < 0.01) in June,July and August;4) The soil temperature and moisture were significantly correlated with the soil respiration rate(P < 0.01),and the two together explained 30%~74% of the soil respiration rate changes.