火烧对荒漠化草原土壤性质的影响

Effects of fire on soil properties in desertified steppe of Northwest China.

火烧是荒漠生态系统重要的干扰因子,对植被-土壤系统有显著的影响,是生态系统管理的重要影响因素。采用人为放火的方法研究了火因子对荒漠化草原土壤含水量、养分含量的影响。结果表明:火烧对表层土壤含水量的影响与降水事件有关。在降水事件频发的阶段,火烧样地土壤水分含量有升高的趋势,而在无降水期则降低;火烧当年土壤全氮、有机质含量高于对照样地,第二年则低于对照样地;火烧对土壤全磷、全钾含量和pH值影响不显著。研究表明,火烧干扰对荒漠化草原土壤理化性质产生了一定影响,该研究结果可为我国荒漠化草原的火烧管理提供依据。

Fire is a crucial disturbance factor in desert ecosystem, which has significant eitects on vegetation-soil system, playing a key role in ecosystem management. By the artificial burning in spring, this paper studied the effects of fire on the soil moisture and nutrient contents in a de- sertified steppe of Northwest China. The effects of the fire on the topsoil moisture content were re- lated to precipitation events. The topsoil moisture content in burnt plots had an increasing trend at the stages of the frequent occurrence of precipitation, but decreased during the period of no precipitation. The soil total N and organic matter contents increased in the current year of burn- ing, but decreased in the next year. Fire had no significant effects on soil total phosphorus and total potassium content and soil pH. These findings indicated the definite effects of fire on the soil physical and chemical properties in desertified steppe, and provided reference for the fire man- agement of our desertified steppe.