The effects of thinning on carbon stocks and fluxes in a Chinese arborvitae plantation

China has extensive areas of forest plantations that sequester and store large quantities of carbon. However, the rate of carbon sequestration by Chinese arborvitae (Platycladus orientalis Linn. Franco) is unknown. This research looks at carbon stocks and fluxes in forest vegetation, soil and litter seven years after thinning Chinese arborvitae in order to evaluate the effect of thinning levels on carbon sequestration. At 22 years, the plots were reduced from 5900 to 4100 and 3000 trees per hectare in three replicates. Carbon stocks of above-ground tree materials were lowest in the heaviest thinned plots and highest in the control plots. Above-ground shrub carbon pools were the opposite, i.e., largest in the heaviest thinned plots and lowest in the controls. Soil and litter carbon stocks were not affected by thinning treatment. Results suggest that thinning may positively affect vegetation carbon sequestration in the short term, an important observation for forest managers using thinning to optimize carbon sequestration capacity.