不同密度的湿地松生长过程研究

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

通过对5种密度的湿地松人工林生长现状的调查,选取标准木进行树干解析,分析不同林分密度的湿地松胸径、树高和材积的生长规律。结果表明:湿地松胸径、树高前期生长快,6 a或9 a后生长趋缓,材积年均生长量随树龄增大逐渐增加,连年生长量在第3或第4龄阶达最大值,此后连年生长量逐渐减小。密度越小,胸径生长越快;树高受造林密度的影响不明显,且随着树龄的增加,树高的密度效应在逐渐减小;单株材积随密度减小而增大。保持合理的造林密度才能获得最大的林分蓄积量和最好的经济效益。

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.