• Title/Summary/Keyword: stem voulme table

Search Result 2, Processing Time 0.018 seconds

Estimating Stem Volume Table of Quercus Acutissima in South Korea using Variable Exponent Equation (변량지수식을 이용한 전국 상수리나무의 입목수간재적표 추정)

  • Ko, Chi-Ung;Kim, Dong-Geun;Kang, Jin-Taek
    • Journal of Korean Society of Forest Science
    • /
    • v.108 no.3
    • /
    • pp.357-363
    • /
    • 2019
  • This study was conducted to develop a stem volume table for Quercus acutissima in Korea by using Kozak's stem taper equation. In total, 2700 tree samples were collected around the country, and growth performance was investigated through compiling data on diameters by stem height and stem analysis. In order to test the stem taper equation's fitness, the fitness index (FI), bias, and mean absolute deviation (MAD) were analyzed. The fitness of the equation was estimated at 97%, bias as 0.017, and MAD turned out to be 1.118, respectively. Furthermore, there was a statistically significant volume difference between the current volume table and the new volume table (p = 0.0008, <0.005). The result indicates that using the new volume table that reflects the actual forest will reduce the loss when assessing wood resources and will improve the accuracy of forest statistics for national and local governments. A stem volume table, the main result of this research, which is utilized in the estimated stem taper equation, will provide growth information for Quercus acutissima, one of the main broadleaf species in Korea, and will function as a management indicator for rational forest management.

Development of a Stem Taper Equation and a Stem Table for Criptomeria japonica Stands in South Korea (삼나무의 수간곡선식 및 입목수간재적표 개발)

  • Ko, Chi-Ung;Lee, Seung-Hyun;Lee, Sun-Jung;Kim, Dong-Geun;Kang, Jin-Taek
    • Journal of Korean Society of Forest Science
    • /
    • v.109 no.4
    • /
    • pp.461-467
    • /
    • 2020
  • The aim of this study was to utilize Kozak's stem taper model to develop both a stem taper equation and a stem volume table for Criptomeria japonica, a tree species distributed across Korea. A total of 1,000 sample trees were cut and collected across the country to measure their diameters by stem height. The equation was then used to estimate examine their stem shapes. Our results show that the Fitness Index for the equation was 98.7%, the Mean Absolute Deviation (MAD) was -0.0142, and the MAD was 1.1640, thus indicating a high level of fitness. A statistically significant difference (p < 0.05) was also found from the analysis of discrepancies between a current table and the new table used in this study. It is therefore suggested that the new table-with data from actual stands-will contribute to enhancing the accuracy of national and municipal forest statistics and reducing losses caused by imprecise data on available forest resources.