Stand Structure Analysis of a Pinus yunnanensis Juvenil Plantation in Lufencun Forestry Farm

In order to analyze structures and characteristics of diameter classes, tree heights, basal areas and important values (Ⅳ), etc., the investigation was conducted in a 10-year-old Pinus yunnanensis plantation which established by uneven row spacing of the 1 m ×2 m ×5 m at Jianshan Forest zone of Lufengcun Forestry Farm. The results showed as followings: mean diameter at breast height (DBH) of the stand was 8.3 cm with the DBH ranges of 1.7-14.7 cm, among the DBH range, tree stem sequence (TSS) of the 5.0-11.0 cm was 83.3%, based on 2 cm as a diameter class (DC), the TSS of the 8 cm and 10 cm DC had 2/3 in total stand trees, it was presented normal distribution between the TSSs and different DCs. Mean height of the stand was 4.5 m with mean ranges of 2.6-5.3 m for the different DCs, there was linear regression equation of y=1.891ln (x) + 0.593 3 between the height and the DBH. Total basal areas and the IVs of the different DCs were 4.3-2 057.3 cm² and 0.2%-23.0%, respectively, which also presented normal distribution with the DCs. According to the differentiation of the stand DBHs and heights, it was proposed that the first time tending thinning should be implemented.