Study On The Soil Water Characteristics Of Pinus Tabulaeformis Plantation Of Daqing Mountain

The soil water characteristics, the soil physical characteristics and the canopy interception of Pinus tabulaeformis plantation were studied in the middle shady slope of Daqing Mountain. The results showed that:(1) The thickness of the soil layer was 35~104cm. The soil gravel content was 59.21%～71.88% in surface layer,which was 53.24%～79.83% in A layer and 47.35%～67.13% in B layer.(2) The field capacity, the volume weight and the soil total porosity was 23.60%～26.90%, 1.21～1.31 and 53.16%～53.68% respectivitily,when the density of plant was between 2933 stubs/hm2 and 3307 stubs/hm2 , which was 22.88%～23.04%, 1.39～1.42 and 48.68%～49.37% respectivitily when the density of plant was 2202 stubs/hm2 or 4463 stubs/hm2. The soil saturated hydraulic conductivity decreased as the stand density increased in 20cm soil depth. The trend in 40cm soil depth was opposite.(3) When the density of plant was 2933～3307 stubs/hm2 , the soil water content between surface and 40cm layer was 5.87%～7.24% in dry season and 12.60%～13.00% in rain season. When the density of plant was 2202 stubs/hm2 or 4463 stubs/hm2 , the soil water content between surface and 40cm layer was 4.69%～5.98% in dry season and 14.40%～14.83% in rain season.(4) The change of the canopy interception, the precipitation in forest and the surface runoff wasn't obvious when the stand density changed. When precipitation was more than 16.3 mm, the stem flow increased with the stand density increase.