| The study on soil physical and chemical properties in pure forest of Cryptonmeria fortunei in Liuwan Forest Farm of
Guangxi was intended to provide scientific reference for the reasonable planting density of Cryptonmeria fortunei in Guangxi. The density of four standard plots were 1 450 plant/hm2, 1 800 plant/hm2, 2 075 plant/hm2 and 2 700 plant/hm2, respectively.The analysis on physical and chemical properties of soil which sampled from each sample plot shows that soil bulk density tended to decrease with increasing density, was closely related with the soil water retaining capacity and soil porosity in soil physical properties aspect. The nutrition contents were higher at 0~20 cm depth than at 20~40 cm depth. Nutrition of upper layer changed irregularly under different stand density. The contents of soil organic carbon, hydrolysable nitrogen and soil available potassium were in the high level under 2 075trees /hm2 stand density. However, in subsoil soil organic carbon was positively correlated with stand density, soil available potassium changed irregularly
and hydrolysable nitrogen increased at first and then decreased. Based on the soil physical and chemical properties, 2 075 plant/hm2 should be the reasonable density to g ncrease the forest yield of Cryptomeria fortunei plantation in this area. |
