Long-term effect of typhoon disturbance on carbonstorage capability in an old-growth forest dominated byChamaecyparis obtusa in central Japan

This study analyzed the carbon density dynamics of trees in two stands over the period 1989 to 2008. One stand was damaged by the Isewan Typhoonin 1959, while the other had grown in natural succession without disturbance. The total carbon densities of the trees in the damaged and control forests in 1989, 2000, and 2008 were 252.8±24.4, 262.7±26.9, and 272.7±24.1 and 369.9±41.9, 377.6±40.8, and 384.6±40.5 ton/ha, respectively. A T-test indicated that the total carbon density of the typhoonforest was significantly lower than that of the control forest. However, the opposite trend was observed for the regeneration of carbon density in the stands. On an annual basis, no significant difference in the carbon density of the total stand was recorded between the two forests, but in the regeneration layer, carbon density was lower in the control forest than in the damaged forest. Although the carbon density of the total stand for the control forest increased significantly over the study period, the densities of Thujopsisdolabrata (Asunaro) and broad-leaved treespecies, which are dominant in the regeneration layer, exhibited negative trends of approximately 0.11 and -0.05 ton/ha/yr, respectively. In the damaged forest, the carbon densities of the total stand and the regeneration layer both increased over time. This study indicates that typhoondisturbance not only significantly improved the carbon sinkcapability of Thujopsisdolabrata and broad-leaved treesbut also promoted the recruitment of Chamaecyparisobtusa (Hinoki) 30 years after the typhoonevent.