Soil Physical Characteristics of Main Vegetation Types in Daqing Mountains

The soil physical characteristics of five main vegetation types in Daqing Mountains were studied.Results indicated that in 0—100 cm soil layer,gravel content(particle fraction≥1 mm)and soil bulk density increased with the increase in soil depth;and soil total porosity,field capacity,and maximum moisture capacity decreased with the increase in soil depth.Besides the mixed forest of Quercus liaotungensis and Ostryopsis davidiana,gravel content and soil bulk density in arbor forest were less than those in shrub land.Soil total porosity,field capacity,and maximum moisture capacity in arbor forest were higher than those in the shrub land.The order of vegetation types,in terms of the average saturated soil hydraulic conductivity,was:Ostryopsis davidiana shrubs Populus davidiana natural forest Betula platyphylla natural forest Pinus tabulaeformis plantation mixed forest of Quercus liaotungensis and Ostryopsis davidiana.The maximum water storage in 0—60 cm soil layer in Populus davidiana natural forest was the highest among the five vegetation types and its value reached 3 550.36 t/hm2.The mixed forest of Quercus liaotungensis and Ostry opsis davidiana and Ostryopsis davidiana shrubs had the lower values of 2 319.85 and 2 271.87 t/hm2,respectively.