Effect Analysis on the Different Planting Densities of Pinus elliottii

The influence of planting density and resin tapping on forest growth was analyzed by using 19and 21-year-old Pinus elliottii with different planting densities as materials. The results indicated that DBH and preservation rate declined with the increasing of planting density,while the volume of wood and number of small stands increased with the increasing proportion of volume. The reservation rate with different planting densities declined and the other growth indices rose with the increasing of tree age. The height had no significant difference with different densities at 19-year-old,while at 21-year-old,the difference was obvious. Tapping tests showed resin yield of single tree was lower with the higher planting density,but the resin yield of unit area increased. The differences of height,DBH and volume were obvious with the densities of 1 080 strain /hm2and 1 680 strain /hm2by resin tapping. By correlation analysis,volume and DBH had high correlation,while hight had low. More middle and small stands were cultivated with 2 520 strain /hm2. It was suitable for cultivating large and middle stand with 1 080 strain /hm2and 1 320 strain /hm2.