Density Effects on the Growth of Eucalyptus urophylla × E.grandis Plantation in Yunan County, Guangdong Province
The effects of different planting densities ( 1470, 1250, 1000, 833 trees · hm-2 ) on the preservation rate, tree height, DBH, individual tree volume and stand volume of Eucalyptus urophylla × E. grandis plantation aged at 0.8 to 7.8 years in Xijiang Forest Farm of Yunan county, Guangdong province were studied by arranging a trial treated with four spacings of 1.7 m × 4 m, 2.0 m × 4 m, 2.5 m × 4 m and 3.0 m × 4 m through the randomized block experiment. The results showed that different planting densities had significant influences on the preservation rate, tree height, DBH, individual tree volume and stand volume. Except for the age of 0.8 years, the preservation rate of stand aged at other years decreased with the increasing planting density, among which there were significant differences between 1470 trees · hm-2 and other three types of planting density. The planting density also had eminent effects on tree height, but the difference was relatively small. The mean values of DBH and individual volume decreased gradually with the increasing of plant density, and there were significant differences in the two indicators between 1470, 1250 trees · hm-2 and other two types of planting density for the stand aged at 2.8 to 7.8 years. At 7.8 years old, the volume of stand planted with 1250 trees · hm-2 was the highest with the value of 195.0 m3 · hm-2, which increased by 16.28%, 5.86%, 14.37% compared with the planting density of 1470, 1000 and 833 trees · hm-2. Therefore, the planting density between 1000 to 1250 trees · hm-2 was recommended to obtain the highest stand volume of E. urophylla × E. grandis plantation.
Eucalyptus urophylla × E. grandisplantationgrowthplanting density
NETL
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万方数据
维普
