Study on the Growth Process of Pinus elliottii Forests with Different Density

Based on investigation of current growth situation of Pinus elliottii artificial forests with 5 density.The standard trees were chose to analyze the trunk,and the growth rules of DBH,height and volume of P.elliottii with different density were analyzed.The results showed that: DBH and height of P.elliottii grew rapidly at early period,the growth slowed down after six or nine years,annual increment of volume increased with tree age increases,current annual increment was up to maximum on third or fourth age gradations,current annual increment decreased from then on.The stand density was smaller,the DBH grew faster;Planted density had little effect on height,the effect of density waned with tree age;Stem volume increased with the density decreased.Maintain reasonable planting density can get the maximum stand volume and the best economic efficiency.