Development of Individual Tree Mortality Equations for Four Coniferous Species by Using Distance-Independent Competition Index

摘要

This study was carried out to develop individual tree mortality equations by using competition index for four coniferous species such as Pinus densiflora in Gangwon province, Pinus dcnsiflora in the central Korea, Pinus koraiensis and Larix leptolepis. The competition index was estimated by distance-independent model developed by Schroder and Gadow and then used as an independent variable for developing adequate individual tree mortality model by coniferous species. Seven candidate models for individual tree mortality by species were compared and evaluated based on three evaluation statistics such as mean difference(MD), standard deviation of difference(SDD) and standard error of difference(SED). It was found that each species has different model forms for the most appropriate mortality estimation. That is, Pinus densiflora. in Gangwon province is best fit to model II , Pinus densiflora in the central Korea is best fit to model IV, Pinus koraiensis is best fit to model V and Larix leptolepis is best fit to model VII. The estimated fit indices for the mortality equations of each species ranged from 0.70 to 0.83, which is relatively high in terms of mortality estimation. Therefore, it is concluded that the mortality equations developed in this study could be useful and applicable for the estimation of tree mortality by species.