尾巨桉萌芽更新不同密度处理对林分初期生长的影响

对尾巨桉不同处理更新3.2a生林分的生长调查,分析结果表明:在密度1 110株/hm2时,植苗更新林分平均胸径比萌芽更新林分高6.8%;平均单株材积比萌芽更新高11.4%;萌芽更新林分平均胸径随保留密度的增大而减小,方差分析结果表明不同处理尾巨桉林分胸径生长有极显著差异。萌芽更新林分平均单株材积随保留密度的增大而减小,萌芽保留1 110株/hm2平均单株材积比2 100株/hm2减小26.5%。在相同密度1 110株/hm2时,植苗更新林分每公顷蓄积比萌芽更新高23.1%。萌芽更新林分单位面积蓄积随密度的增大而增大,林分密度2 100株/hm2的林分每公顷蓄积量比密度1 110株/hm2高53.7%。

Influences of Eucalyptus urophylla x E.grandis Sprout Regeneration in Different Density Treatments on Primary Growth of Forest Stand

The result of the growth survey about 3.2 year-old regeneration forest stand of Eucalyptus urophylla × E.grandis in different treatments showed that transplanting seedlings regeneration forest stand average breast diameter is 6.8% more than sprout regeneration's and the average single-tree volume of transplanting seedlings regeneration is 11.4% more than that of sprout regeneration.Sprout regeneation forest stand average breast diameter decreases with the increase of reserved density.In different density treatments,differences in sprout regeneration forest stand average breast diameter of Eucalyptus urophylla × E.grandis are remarkable according to variance analysis.Sprout regeneration forest stand average single-tree volume decreases with the increase of reserved density.Sprout regeneration forest stand average single-tree volume in the reserved density of 1110·hm-2 is 26.5% less than that in 2100·hm-2.In the same density of 1110·hm-2,transplanting seedlings regeneration forest stand volume per hectare is 23.1 % more than sprout regeneration's.Sprout regeneration forest stand volume per hectare increases with the increase of reserved density,and forest stand volume per hectare in forest stand density of 2100·hm-2 is 53.7% more than that in 1110·hm-2.