Growth dominance pattern of hybrid eucalyptus stands at Northeastern province of Quang Ninh
Keywords:
Gini coefficient, growth dominance, hybrid Eucalyptus, Lorenz curve.Abstract
At a given age, the main contribution of dominant or smaller trees for the stand growth will determine the stand growth dominance pattern. Based on the dominance pattern a given silvicultural practice, such as thinning would be proposed for the stand. In this paper, the five-year-old hybrid Eucalyptus (E. urophylla E. grandis) stands reached to an average diameter of 12.5cm, the height of 16.0m, and the biomass of 118m3/ha, respectively. Trees at the bottomhill and the tophill showed the higher growth than those at middlehill
area. Lorenz curves of all stands aged from 2 to 5 years old at three position dropped above the basic line (so-called “1:1 line”). This reflects that all stands are bearing the “reverse” growth dominance patterns; that means smaller (non-dominant) trees are contributing a greater part into the stand growth than the dominant ones no matter which age and/or growing position. This result is
out of research hypothesis that a “positive” growth pattern was expected in this period of the stands. Low planting density and extensive techniques are probably considered as the dynamics of the stands. Therefore, it is not necessary to apply a thinning process at the present.
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