| Summary: | 碩士 === 國立屏東科技大學 === 森林系所 === 99 === Forest management is a sustainable work. Permanent plot establishment for regular supervision is necessary. This research is based on data obtained by Forestry Bureau from 668 permanent plots during 1997 to 2007. The subjects included Chamaecyparis formosensis, Pinus taiwanensis Hayata, Cunninghamia lanceolata, Cryptomeria japonica, and Taiwania cryptomerioides. The percentage of basal area of these five conifers was applied to distinguish the forest type and to calculate the stock volume, increment, and mortality (per ha.). Further, it was utilized to uncover the relations between increment, mortality and age class, diameter class, stand density, and elevation. Results show that C. lanceolata presents a significant difference in the relation between increment and age class (20, 40 yr. respectively), also between increment and diameter (20, 30 cm respectively). As for the relation between density and increment, P. taiwanensis Hayata (1,000-2,500), C. japonica (1,000-2,500), and T. cryptomerioides (1,000-2,000) have the significant difference. As for the relation between elevation and increment, C. lanceolata (1,000-2,000 m) and C. japonica (1,000-2,500 m) have the significant difference. However, there is no significant difference between increment/ mortality and elevation in all of these five conifers. The results of this research can be used to predict forest increment and mortality.
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