| Summary: | 碩士 === 國立中央大學 === 國際永續發展碩士在職專班 === 105 === Abstract
Sustainable forest management requires tools that can provide details about the development of mixed, uneven aged forest stands. For tools to be developed and implemented forest data and statistics are necessary. Data was obtained from Programme for Belize (PfB) from their 2015 - 2016 pre-harvest stock survey at the Rio Bravo Conservation and Management Area in Northern Belize. Data on ten hardwood tree species were made available for this paper. The data was visually presented and analyzed to determine the first, second and third quartiles for each species, in order to better understand growth of species in the area. Statistical techniques were used to estimate the stem-height volume. This was done in order to develop a method for preliminary estimations of standing tree volume prior to being harvested. Past studies were also reviewed to evaluate their methods of estimating tree height, in order to get a better understanding of the relationship between tree height and diameter.
Through visual analysis it was observed that the growth of stem height and diameter at breast height for the ten species did not have a pattern. However, data analysis by quartiles showed that the upper quartile for stem height ranged from 9 to 14 meters, and for diameter it ranged from 38 to 75 cm. An equation for volume estimation was developed, which provided conservative estimates of stem height volume, forming a good basis for pre-harvest estimations. Revision of two height-diameter models for height prediction led to the conclusion in order to develop an accurate model for the area a mixed-effects stochastic technique is necessary. The results of the study are presented such that they can be used as an aid in forest management and monitoring individual trees and tree stands.
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