Earticle

This study was carried out to compare the growth of diameter at breast height (DBH) between artificial coniferous forest and natural broad-leaved forest. Data was collected from permanent monitoring plots in Research Forest of Kangwon National University, which is located at Chuncheon-si, Gangwon province of Korea. For artificial coniferous forest, 8 plots with 20 m x 20 m size were investigated in 1996, 2001, 2008, and 2014. For natural broad-leaved forest, 8 plots with the same plot size were investigated in 1996, 2001, 2008, 2014, and 2018. Before and after first measurement, silvicultural treatment was operated with various thinning intensity of 40~81% based on the number of trees. After thinning, the density ranged 500 ~ 2,500 trees/ha for natural broad-leaved forest and 800 ~ 3,200 trees/ha for artificial coniferous forest. As a result, periodic annual increment was higher in artificial coniferous forest than in natural broad-leaved forest as compared based on similar stand density. When the upper 10% dominant trees and the lower 10% recessive tree compared, the growth difference was apparently shown between artificial coniferous forest and natural broad-leaved forest. In addition, the periodic annual increment according to stand density was higher in artificial coniferous forest and it decreased as time went by. Overall, when the stand characteristics such as stand density and average DBH was similar, DBH growth was superior in artificial coniferous forest.

This study was conducted to introduce the concept and major finding of long term monitoring focusing on major coniferous tree species. Permanent monitoring plots were installed in 38 sites of Pinus densiflora(Pd), 45 sites of Pinus koraiensis(Pk) and 45 sites of Larix kaempferi(Lk) from 2012~2015. Each plot consists of three square plots; non-thinning plot (20 m × 20 m), light thinning plot (25 m × 25 m) and heavy thinning plot (30 m × 30 m). From low intensity thinning and high intensity thinning plots were planned to be removed 20% and 40% of total basal area respectively. Thinning intensity was shown to have an effect on the DBH increment of Pd and Pk species. The DBH increments for 3 years were non-thinning < light thinning < heavy thinning in order. ANOVA analysis also showed that there was a significant difference (P<0.001) in DBH increments among thinning intensities. The growth patterns of major coniferous trees species (Pinus densiflora (Pd), Pinus. koraiensis (Pk) and Larix kaempferi (Lk)) in South Korea were analyzed and compared numerically and using stem analysis. The result showed that the mean DBH growths of Pk and Lk showed no difference as the trees age, while the one of Pd was lower than those of Pk and Lk. The mean height and volume growths were found to be Lk>Pk>Pd. Five theoretical growth functions, Logistic, Korf, Gompertz, Charpman-Richard and Weibull functions were applied to the growth data on dbh, height, basal area and volume of individual trees. The results showed that Korf function fitted the DBH, height basal and volume of Pinus koraiensis and Larix kaempferi best and expressed the growths very well. Meanwhile Chapman-Richard function fitted the growth of Pinus densiflora best.