| A comparative study was conducted on the index of physical and chemical characteristics of soil in Eucalypt plantation (the second generation and the first generation) and conifer-broadleaved forest (10~11a and 5~7a) in southern subtropical region, aimed to understand the effects of tree species on the physical and chemical characteristics of soil. The results showed that the soil bulk density, total porosity, capillary porosity, non-capillary porosity and soil aeration capacity of the second generation of Eucalypt plantation increased in varying degrees compared with the first generation of Eucalypt plantation, while the first generation and second generation Eucalypt plantation had no significant difference in bulk elensity and porosity, and the soil organic matter, total N, total P, total K and hydrolysable N of the second generation of Eucalypt plantation declined in varying degrees, while pH, available K and available P increased compared with the first generation of Eucalypt plantation. The soil bulk density, natural moisture content, total porosity, capillary porosity of Eucalypt plantation were lower than those of conifer-broadleaved forest, and the soil of Eucalypt plantation showed smaller effective water storage capacity. While non-capillary porosity and aeration capacity of Eucalypt plantation were higher than that of conifer-broadleaved forest, and the soil of Eucalypt plantation hadthe higher ability to accept precipitation and reduce surface runoff compared with young conifer-broadleaved forest. The content of soil organic matter, total N, total P and hydrolysable N of Eucalypt plantation were lower than that of conifer-broadleaved forest, and soil organic matter consumption of Eucalypt plantation was higher than that of conifer -broadleaved forest. Soil organic matter, total N, hydrolysable N, available P showed a significant positive correlation and soil organic matter showed the highest correlation with total N and hydrolysable N, and had an important impact on the content of total N and hydrolysable N. The principal component analysis (PCA) results showed that soil fertility was the order of conifer-broadleaved forestI〉conifer -broadleaved forest Ⅲ〉Eucalypt plantation Ⅱ〉Eucalypt plantationⅣ . |
