• Title/Summary/Keyword: Minimum and the maximum values for DBH

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Development of Estimation Equation for Minimum and Maximum DBH Using National Forest Inventory (국가산림자원조사 자료를 이용한 최저·최고 흉고직경 추정식 개발)

  • Kang, Jin-Taek;Yim, Jong-Su;Lee, Sun-Jeoung;Moon, Ga-Hyun;Ko, Chi-Ung
    • Journal of agriculture & life science
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    • v.53 no.6
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    • pp.23-33
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    • 2019
  • In accordance with a change in the management information system containing the management record and planning for the entire national forest in South Korea by an amendment of the relevant law (The national forest management planning and methods, Korea Forest Service), in this study, average, the maximum, and the minimum values for DBH were presented while only average values were required before the amendment. In this regard, there is a need for an estimation algorithm by which all the existing values for DBH established before the revision can be converted to the highest and the lowest ones. The purpose of this study is to develop an estimation equation to automatically show the minimum and the maximum values for DBH for 12 main tree species from the data in the national forest management information system. In order to develop the estimation equation for the minimum and the maximum values for DBH, there was exploited the 6,858 fixed sample plots of the fifth and the sixth national forest inventory between in 2006 and 2015. Two estimation models were applied for DBH-tree age and DHB-tree height using such growth variables as DBH, tree age, and height, to draw the estimation equation for the maximum and the minimum values for DBH. The findings showed that the most suitable model to estimate the minimum and the maximum values for DBH was Dmin=a+bD+cH, Dmax=a+bD+cH with the variables of DBH and height. Based on these optimal models, the estimation equation was devised for the minimum and the maximum values for DBH for the 12 main tree species.