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为了解改变碳源输入方式对土壤呼吸速率及土壤温湿度的影响,于2014年5-12月,在吉林省蛟河红松阔叶混交林地表无雪期间,利用LI-8100土壤CO_2通量全自动测量系统测定不同处理(对照处理、去凋处理、加倍凋落物处理、切根处理及去凋切根处理)土壤呼吸速率及5 cm处温、湿度.结果表明:不同处理之间5 cm深度土壤温度的差异性不显著(P>0.05),土壤湿度差异显著(P<0.05).整个观测期间对照、去凋、加倍凋落物、切根和去凋切根处理的土壤呼吸速率平均值分别为3.35μmol m~(-2) s~(-1)、3.54μmol m~(-2) s~(-1)、4.22μmol m~(-2) s~(-1)、2.11μmol m~(-2) s~(-1)和2.45μmol m~(-2) s~(-1),不同处理土壤呼吸速率的变化幅度不相同.去凋、加倍凋落物处理使土壤呼吸速率增加,整个观测期平均增加了1.98%和24.81%.切根、去凋切根处理使土壤呼吸速率降低,整个观测期平均降低了36.49%和28.64%.对照、去凋、加倍凋落物、切根及去凋切根处理的Q_(10)值分别是3.32、3.35、3.38、2.59和3.13,切根处理显著低于其他处理.不同处理的土壤呼吸速率与土壤温度之间均呈显著指数相关(P<0.001),但与土壤湿度之间相关关系不显著(P>0.05).土壤温度和土壤湿度的双变量复合模型能够更好地解释土壤呼吸的季节变化,决定系数R~2值为62%-95%.本研究结果证明改变碳源输入是影响森林CO_2通量的重要因子.
In order to understand the influence of carbon source input on soil respiration rate and soil temperature and humidity, during May to December 2014, during the period of snow-free surface of Pinus koraiensis-broadleaf mixed forest in Jiaohe, Jilin Province, The soil respiration rate and the temperature and humidity at 5 cm were measured by automatic measurement system under different treatments (control treatment, des-witching treatment, double litter treatment, root cutting treatment and descaling root cutting treatment) .The results showed that: The differences in soil temperature were not significant (P> 0.05), but significant differences in soil moisture (P <0.05). The mean values of soil respiration rate of control, de-withered, double litter, Were 3.35μmol m -2 s -1, 3.54μmol m -2 s -1, 4.22μmol m -2 s -1, 2.11μmol m -1 respectively, ~ (-2) s ~ (-1) and 2.45μmol m ~ (-2) s ~ (-1), respectively, and the changes of soil respiration rate in different treatments were not the same.Drying and doubling litter treatments increased the soil respiration rate , And increased by 1.98% and 24.81% on average during the whole observation period.The root respiration rate and root cutting rate decreased by 36.49% and 28.64% The Q_ (10) values of litterfall, root cutting and unwaxing treatments were 3.32, 3.35, 3.38, 2.59 and 3.13, respectively, and the root cutting treatments were significantly lower than those of other treatments.The values of soil respiration rate and soil temperature (P <0.001), but no significant correlation with soil moisture (P> 0.05) .Bi-variable composite model of soil temperature and soil moisture can better explain the seasonal variation of soil respiration, and determine the coefficient The value of R ~ 2 is 62% -95% .The results of this study show that changing the input of carbon source is an important factor affecting the CO 2 flux in forest.