火烧木管理方式对土壤特性和土壤呼吸的影响

EFFECTS OF FIREWOOD MANAGEMENT ON SOIL PROPERTIES AND SOIL RESPIRATION

为揭示不同火烧木管理方式对土壤特性和土壤呼吸的影响,在2014年兴安落叶松林火烧迹地上对不同火烧木管理方式下(未伐、择伐、皆伐)的样地进行土壤呼吸及土壤特性的测定,同时再附加未火烧区为对照样地,利用LI-8100土壤CO2排放通量自动测量系统,同时测定了土壤温度和含水量,探讨了不同火烧木管理方式土壤特性和土壤呼吸的变化。结果表明:(1)土壤有机质、全氮含量在火烧后增加,并且显著超过火烧前的水平,而不同火烧木管理之间差异不显著。火烧对土壤全效磷、速效磷含量没有明显影响,基本保持未受干扰的水平。不同火烧木管理方式土壤全效钾含量比对照地低,而速效钾含量比对照地高。(2)不同火烧木管理方式土壤温度呈单峰趋势,而土壤含水量的变化趋势与土壤温度变化不同,呈双峰趋势。未伐样地与对照样地变化趋势趋于平缓,择伐样地与皆伐样地变化幅度较大。(3)不同火烧木管理方式土壤呼吸速率均呈单峰趋势,与土壤温度变化趋势相同。生长季峰值出现在8月份,整体特征表现为皆伐地>未伐地>对照地>择伐地。(4)土壤呼吸与土壤5cm温度呈极显著相关,与土壤含水量未达到显著水平,与其他土壤特性相关性不显著。

In order to reveal the effects of different firewood management practices on soil characteristics and soil respiration, soil respiration monitoring was conducted on the burned sites of Larix gmelinii forest in 2014 under different firewood management （not cutting, selective cutting and clear cutting） In addition, an unburned area was set up as a reference site. The system of LI -8100 soil COeemission flux automatic measurement was used. Simultaneously, the soil temperature and water content were measured, and the soil characteristics and soil respiration of different firewood management were discussed. The results showed that： ①The content of soil organic matter and total nitrogen increased after fire and significantly exceeded the level before fire, but the difference between different firewood management was not significant. Fire on the soil available phosphorus, available phosphorus content had no signifi- cant effect, the basic remained undisturbed level. Different firewood management methods soil total available potassium content lower than the control, and available potassium content higher than the control. ② The soil temperature of different firewood management showed a single peak trend, while the change trend of soil moisture content was different from the soil temperature, showing a double peak trend. The trend of the trend of flattening and un - cuttings tended to be gentle, while that of the selective cutting and clear cut- ting varied greatly. ③The soil respiration rate of different firewood management showed a single peak trend, which had the same trend with soil temperature. The peak of the growing season appeared in August, and the overall characteristics were clear - cut land 〉 un -cut land 〉 control land 〉 selective cut land. ④soil respiration and soil temperature 5cm was significantly correlated, and the soil moisture did not reach a significant level, and other soil properties was not significant correlation.