Wood carbon content and basic density of Taiwan red cypress (Chamaecyparis formosensis) trees grown under different thinning treatments in the Liouguei area.

Abstract

Understanding the wood carbon content and basic density is important for accurately assessing forest carbon sequestration. The effects of different thinning treatments on the wood carbon content and basic density of Taiwan red cypress (Chamaecyparis formosensis) trees were investigated. The results revealed that the average wood carbon contents under different thinning treatments showed no statistically significant differences. However, trees from heavily thinned plantations (basal area, 30 m^2 ha^(-1)) had lower wood basic density than those from plantations with medium, light, and no thinning. Significant differences in the wood carbon content and basic density were observed among cambium of various ages. The effects of ring characteristics on the wood carbon content of Taiwan red cypress were examined. The wood carbon content increased with increasing ring width parameters and decreasing ring density parameters. In our analyses, the carbon content was affected by various ring characteristics; moreover, both the latewood width and latewood percentage in a ring were the best predictors. The results suggest that using a moderate (≤ medium thinning) plantation density will have no effects on the wood carbon content or wood basic density; however, different tree ages should be considered for calculating carbon sequestration.