细叶桢楠天然林幼苗人工移植造林成效

Performance of Undergrowth Seedlings Transplanted From Natural Forest of Phoebe hui

在湖南省龙山县红岩溪镇白果村石灰岩发育的石灰土及页岩发育的山地黄壤上开展细叶桢楠天然林幼苗(苗龄4a、苗高80~120 cm)移植造林试验。结果表明:细叶桢楠在山地黄壤上生长比石灰土上好,14 a细叶桢楠胸径年生长量0.56 cm、树高年生长量0.36 m、冠幅3.96 m^2。14 a细叶桢楠胸径年平均生长量持续上升,连年生长量7 a前持续上升,7~14 a波动明显;树高年平均生长量6 a前明显上升,6 a后缓慢下降,连年生长量6 a前波动上升,6 a后快速波动下降,年平均生长量与连年生长量相交于7 a;材积年平均生长量持续上升,连年生长量8 a前缓慢上升,8 a后快速波动上升,平均生长量与连年生长量差距逐年扩大;细叶桢楠胸高形数稳定在0.66~0.51之间。受硕蝽危害,58.4%的植株抽生多主梢。石灰土中84.0%的细叶桢楠根系分布在距地表20 cm土层范围内,山地黄壤中87.7%的细叶桢楠根系分布在距地表30 cm土层范围内。

A sylviculture experiment of transplanting natural Phobe hui seedling of 4 years old with height of 80 cm to 120 cm was made at Hongyanxi town,Longshan county.Results of investigation showed that,Phobe hui seedling grew better on mountain yellow soil developed from shale rock than that on lime soil developed from limestone.The annual increment of diameter at breast height （DBH） of individual young Phobe hui trees of 14 years old was 0.56 cm,and its annual increment of height was 0.36 m,the average crown projective plane area was 3.96 m^2.The average annual increment of DBH of individual young trees of 14 years old grow up continually,while,the average annual increment of height grow up continually before 7 a,and fluctuate obviously during 8 a to 14 a.The average increment of height of tree younger than 6 a was rising rapidly,while rising slower for trees elder than 6 a.The annual increment amount of height was rising fluctuated before 6 a,but got a fluctuant and fast descending after 6 a.The curves of average annual increment and annual increment of height crossed at 7 a.Average increment of timber volume was rising continually for whole survey time,while annual increment of tree volume rising slowly before 8a,but rising rapidly yet fluctuant after 8a,and the difference between curves of average and annual increment enlarged yearly.Besides,the form coefficient of trunk of Phoebe hui based on DBH were 0.66 ^ 0.51.Additional investigation showed that bifurcating rate of leading shoot was 58.4% for whole individuals because of being damaged By Eurostus Dallas.Moreover,84.0% of root system distributed in the range of 20 cm below soil surface for trees grew on limestone soil,while,87.7% of root system distributed in the range of 30 cm below soil surface for trees grew on mountain yellow soil.