Structural Features And Soil Characteristics Of Artificial Forest Of Different Ages Robinia Pseudoacacia

Stand structure is the basis of stand features, analysis and reconstruction of stand structure is an important basis for the establishment of stand growth model, but also to develop the premise of rational forest management programs. Forest soils for plant growth to provide the material basis, the amount and proportion of nutrients in forest soils, on plant growth, diameter, height, crown diameter, cover, etc. have a direct influence, and thus affect the amount of resources and community succession process.In this study, Yongshou, Shaanxi Province Huai Pinglin field 5a,17a and 22a of Locust Plantation for the study, research and analysis of different ages locust plantation structure and soil characteristics differences, providing a scientific basis for acacia plantations Health Assessment and Management. The results are as follows:(1) Stand structure:5a Locust Plantation diameter classes focused 4-8cm, skewness and kurtosis of the distribution are greater than 0, indicating that the DBH Distribution of Locust Plantation 5a students left side that is the main stage and stand in the path differentiation small.17a Locust Plantation diameter classes mainly in 4-12cm, most of the distribution skewness is greater than 0, the peak is less than 0, indicating that the DBH Distribution of Locust Plantation 17a that is the left side of the trail order based.22a Locust Plantation diameter classes focused on 10-14cm, distribution of skewness is less than 0, the peak is greater than 0, indicating that the right side 22a Locust Plantation diameter that is large diameter class-based.3 DBH stand age distribution of basic arithmetic mean diameter of the peak, then gradually reduced diameter classes to both sides; height distribution and distribution have substantially the same diameter, the number of trees in the middle of the most high profile, two level in order to reduce the number of trees, but the asymmetry trails order of the number of trees than the large diameter class.(2)Soil physical properties:the water content in 0-40cm layer increases with increasing stand age, and among three forest age reached a significant difference (P<0.05),40-60cm fluctuating change and 5a,17a and 22a reach significant differences (P<0.05). Soil bulk density in the surface layer (0-20cm) increased with increasing stand age,20-60cm obvious trends in density in 0-60cm layers and three forest age were significant differences (P<0.05); soil total porosity, capillary porosity, non-capillary porosity in 0-40cm, total water holding capacity showed trend volatility.(3) Soil chemical properties:organic matter increased with increasing stand age at the surface (0-20cm) and 5a,17a and 22a reach a significant difference (P<0.05),20-60cm trend is not obvious, but 5a and 22a reach significant differences (P<0.05); total nitrogen content increased in 0-20cm layer increases with stand age,20-60cm fluctuating change, and in 0-40cm layer 5a,17a and 22a reach a significant difference (P<0.05); available phosphorus content in 0-40cm layer showed the lowest 17a of locust Plantation,40-60cm increase and decrease with the forest age, and in the 0-60cm layer three stand ages have reached a significant difference (P<0.05); K content in 0-60cm layer increases with increasing stand age, and in the 0-40cm layer 5a,17a and 22a reach a significant difference (P<0.05).These results suggest that,5a, stand structure and soil properties 17a and 22a acacia plantations have significant differences, when conducting health assessment and system management measures take full account of these differences, acacia plantations for different age characteristics, the development of scientific and rational the evaluation and management of technical measures.