林火干扰对土壤理化性质的影响

通过实地调查与实验室测定，分析林火干扰对昆明近郊云南省森林自然中心华山松和柏木人工林林地土壤理化性质的影响。结果表明，火烧后，华山松林下土壤密度比未过火区增加11.48％，土壤自然含水量、饱和持水量、毛管持水量、总孔隙度以及毛管孔隙度分别下降32.38％、16.21％、18.71％、9.94％、22.44％；柏木林地土壤密度比未过火区增加10.38％，自然含水量、饱和持水量、毛管持水量、总孔隙度以及毛管孔隙度分别下降23.55％、10.77％、23.22％、5.38％、12.91％。过火区华山松林下土壤pH、有效磷含量比未过火区分别增加5.81％、130.25％，全氮、全磷、全钾、水解氮和速效钾含量分别下降53.30％、28.30％、22.60％、39.74％、25.32％；过火区柏木林下土壤pH、有效磷含量比未过火区分别增加12.33％、176.34％，全氮、全磷、全钾、水解氮和速效钾含量分别减少了31.28％、31.25％、67.09％、40.66％、51.21％。火烧后林地土壤更加板结，土壤养分含量降低，不利于土壤肥力的改善。

Effect of Forest Fire Disturbance on Soil Physical and Chemical Properties

With field researching and laboratory determinating,analyzing the effect of forest fire disturbance on Soil physical and chemical properties of Pinus armandii and Cupressus plantation,in Yunnan Forest Nature Center on the outskrits of Kunming.After forest fire,soil density of Pinus armandii has increased by 11.48%,while soil non-capillary porosity,saturation moisture capacity,capillary water holding capacity,total soil porosity,and capillary porosity in soil have decreased by 32.38%,16.21%,18.71%,9.94%,22.44%,respectively.In Cupressus plantation,after forest fire,soil density has increased by 10.38%,while soil non-capillary porosity,saturation moisture capacity,capillary water holding capacity,total soil porosity,and capillary porosity in soil have decreased by 23.55%,10.77%,23.22%, 5.38%,12.91%,respectively.Moreover,compared to control,soil pH and available P in Pinus armandii have increased by 5.81%,130.25%,respectively,while soil organic materials,total N,total P,total K,hydrolysable N and rapidly available K have reduced by 53.30%,28.30%,22.60%,39.74%,25.32%,respectively.After forest fire,soil pH and available P have increased by 12.33%,176.34%,respectively.And the soil organic materials,total N,total P, total K,hydrolysable N and rapidly available K have reduced by 31.28%,31.25%,67.09%,40.66%,51.21%, respectively.Forest fire would result in soil hardening,decrease soil nutrient content,reduce improve soil fertility.