Abstract: Based on the forest inventory data in 2009 and plot survey, and using allometric equation and vegetation type method, this paper estimated the carbon density and carbon storage of different components of  forest ecosystems in mountainous region of east Liaoning. In this region, the forest ecosystem carbon density was 300.050 Mg·hm^-2, with 63.237 Mg·hm^-2 in arbor layer, 0.558 Mg·hm^-2 in shrub layer, 0.274 Mg·hm^-2 in herbaceous layer, 3.529 Mg·hm^-2 in litter layer, and 232.452 Mg·hm^-2 in soil profile. The carbon density of arbor layer increased with increasing stand age, while that of shrub layer was in adverse. No obvious patterns were observed in the carbon density in soil, herbaceous layer, and litter layer among different aged stand groups. Overall, the forest ecosystem carbon storage in the mountainous region of east Liaoning (with an area of 305.852×10⁴ hm²) was 917.709 Tg C, of which, soil carbon storage (710.959 Tg C) was 3.44 times of biomass carbon storage (206.75 Tg C). Through the comparison of our results with previous studies, it was found that due to the underestimation of the carbon density of young forests, the forest inventory data greatly underestimated the carbon storage of arbor layer. Meanwhile, in previous studies, the use of a simple conversion factor overestimated the carbon density of understory vegetation, but greatly underestimated the carbon density of soil.

Key words: gel, bareroot seedling, fine root, nitrogen metabolism, nitrogen use efficiency.