Temporal dynamics and spatial variations of forest vegetation carbon stock in Liaoning Province,China

There are many uncertainties in the estimation of forest carbon sequestration in China, especially in Liaoning Province where various forest inventory data have not been fully utilized. By using forest inventory data, we estimated forest vegetation carbon stock of Liaoning Province between 1993 and 2005. Results showed that forest biomass carbon stock increased from 68.91 Tg C in 1993 to 97.51 Tg C in 2005, whereas mean carbon density increased from 18.48 Mg·ha^?1 C to 22.33 Mg·ha^?1 C. The carbon storage of young- and middle-aged forests increased by 22.1 Tg C and 5.95 Tg C, but that of mature forests has decreased by 0.25 Tg C. The carbon stock and density of forests in Liaoning Province varied greatly in space: larger carbon storage and higher carbon density were primarily found in the east area. The spatial distribution of carbon density was determined by many factors, of which human activities played an important role. The forests in Liaoning Province played a positive role as a sink of atmospheric carbon dioxide. The carbon fixation ability of forests in this area was primarily derived from forest plantation and the total forest carbon sequestration can be enhanced by expanding young- and middle-aged forests.