Current stocks and potential of carbon sequestration of the forest tree layer in Qinghai Province,China

Aims Our objective was to estimate the carbon storage in the forest tree layer in Qinghai Province, China.Methods Based on forest resource inventory data and field investigation data, we estimated the carbon storage, sequestration rate and potentials in the forest tree layer in the Qinghai Province.Important findings The carbon density and total carbon storage of forest tree layer in Qinghai Province was 76.54 Mg·hm ^-2 and 27.38 Tg, respectively, of which four forest types (Picea spp. forest, Cupressus funebris forest, Betula spp. forest and Populus spp. forest) accounted for 86.67% while their areas were 96.23% of total forest areas in Qinghai. The carbon density and carbon storage of Picea spp. forest was 106.93 Mg·hm ^-2 and 14.78 Tg, respectively, which was the largest among all forest types. The carbon storage of the forest tree layer at different stand ages followed the sequence of over-mature forest > middle-aged forest > mature forest > near-mature forest > young forest. In addition, the carbon storage of forest tree layer in the province increased from 23.30 Tg in 2003 to 27.38 Tg in 2011. The average annual growth of carbon and carbon sequestration rate were 0.51 Tg and 1.06 Mg·hm ^-2·a ^-1, respectively. The maximum and minimum of carbon sequestration rate were respectively found in Cupressus funebris forest (0.44 Mg·hm ^-2·a ^-1) and Betula spp. forest (-1.06 Mg·hm ^-2·a ^-1). The mean carbon sequestration potential reached 8.50 Tg in 2011, with the highest value found in Picea spp. forest (3.40 Tg). These findings suggested high carbon sequestration potential of forest tree layer in Qinghai Province. Therefore, the carbon storage in Qinghai Province could be increased through better forest management and utilization.