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2007年6月至2009年10月,采用静态箱/气相色谱法测定了不同采伐干扰(皆伐后农作、皆伐后造林、50%强度采伐、25%强度采伐和对照)条件下,东北地区典型次生林的土壤CH4通量.结果表明:研究样地的土壤均为CH4的吸收汇.采伐干扰降低了土壤的CH4吸收能力,不同处理样地土壤的CH4吸收通量大小依次为:对照(-85.03μg CH4·m-2·h-1)>50%强度采伐(-80.31μg CH4·m-2·h-1)>25%强度采伐(-70.97μg CH4·m-2·h-1)>皆伐后农作(-65.57μg CH4·m-2·h-1)>皆伐后造林(-62.02μg CH4·m-2·h-1).各处理样地土壤CH4吸收通量的季节动态相似,均表现为生长季吸收值较高,冬季较低.采伐干扰后各处理的土壤温度、土壤湿度、土壤硝态氮和铵态氮含量均增加,而土壤CH4吸收通量与土壤温度呈显著二次相关,与土壤含水量呈线性负相关.次生林采伐后土壤含水量、土壤铵态氮和硝态氮含量的增加是土壤CH4吸收通量降低的重要控制因子.
From June 2007 to October 2009, static box / gas chromatography was used to determine the effects of different cutting disturbances (clear-cut farming, clear-cut afforestation, 50% intensity harvesting, 25% intensity harvesting and comparison) The results showed that all the soils in the study area were CH4 absorption sinks, and the harvesting disturbance reduced the CH4 absorption capacity of soils. The CH4 fluxes in the soils from different treatments were as follows: -85.03 μg CH4 · m-2 · h-1)> 50% intensity harvest (-80.31 μg CH4 · m-2 · h-1)> 25% intensity harvest (-70.97 μg CH4 · m -2 · h -1 )> Clear-cut farming (-65.57μg CH4 · m-2 · h-1)> clear-cut afforestation (-62.02μg CH4 · m-2 · h-1) .The soil CH4 uptake flux The results showed that the seasonal variation of soil water content, soil moisture, soil nitrate nitrogen and ammonium nitrogen content were all increased after the cutting disturbance, while the soil CH4 uptake flux and Soil temperature was significantly quadratically related and negatively correlated with soil moisture content.The increase of soil water content, soil ammonium nitrogen and nitrate nitrogen content in the secondary forest after harvesting was the important factor to reduce the soil CH4 flux Control factor.