| 3. | With increase of artificial forest age , the content of soil organic matter decreased sharply . and soil physical , chemical and biological properties of forest became worsen . from soil physical properties analysis , soil silt , clay , physical clay , aggregate degree and structure coefficient in topsoil increased with increase of artificial forest age and soil sand deceased
在土壤物理性质方面，随着人工云杉林龄的增加，土壤表层粉粒、粘粒、物理性粘粒、团聚度和结构系数降低，砂粒含量增高，土壤饱和持水量、毛管持水量及总孔隙和毛管孔隙在人工云杉演替过程中表现出“ u ”型变化。 |
