The Carbon Sequestration Status And Potention Of Three Typical Plantations In Jiangxi Province

Absorbing the greenhouse gas was an important function of forest ecosystem to carbon sequestration. Improving the ability of forest ecosystem's carbon sequestration was an important way to slow the speed of global climate changing. Global afforestation area was about 4.5 million hm2 each year.And China was the most significant nation in the world about artificial afforestation achievement. It could improve the ability of carbon sequestration by expanding the plantation's area. Taking plantation in Jiangxi as the research object, we studyed its carbon sequestration feature and contribution to carbon sink in Jiangxi. The results showed that:(1) The carbon density of Chinese fir plantation ecosystem was 220.31 t / hm2, the carbon density of Masson pine plantation ecosystem was 114.04 t / hm2, and the carbon density of slash pine plantation ecosystem was 93.89 t / hm2. There was a very significant difference between them(P <0.01). The carbon density of three typical plantation ecosystem systems was mainly focused on soil layer and tree layer. And the proportion of forest floor litter and dead wood layer in eco-systems was less than 10%. Among them, the tree layer aboveground carbon stocks were mainly concentrated in the trunk organ, forest floor carbon stocks were mainly in the aerial part, and litter layer and dead carbon stocks were mainly concentrated in the litter layer. Organic carbon content and soil organic carbon density decreased with the soil depth's increasing, and topsoil's(0-10cm) organic carbon content was highest.(2) The carbon reserves of artificial forest was 8.76×108t in Jiangxi. The largest carbon storage was Chinese fir plantation(5.92×108t), followed by Pinus massoniana Carbon Storage(2.20×108t), and the smallest was slash pine plantations(0.64×108t). Each type of forests' carbon stocks were mainly concentrated in the young forest, middle-aged forest and mature forest.The proportion of mature forest and mature forest were less than10%. The carbon storage increased with latitude's increasing.(3) The carbon fixation rate of Chinese fir plantations, pine and slash pine plantation were 1.90Mg·hm-2·a-1,2.02Mg·hm-2·a-1, 2.04Mg·hm-2·a-1, and the differences among them was not significant(P> 0.05). Chinese Fir Plantation sequestration rate increased with the age group's increasing, Masson pine plantations and slash pine plantation tree layer carbon sequestration rate presented "M"-type movements. The difference between the carbon fixation rate of North Jiangxi,Middle Jiangxi and South Jiangxi was not significant(P>0.05). Jiangxi Plantation theoretical maximum value of carbon sequestration potential was 15.31 t. hm-2, and its economic value was up to 21.7 billion yuan.(4) The carbon density of artificial forest ecological systems increased firstly and then decreased with forest age's increasing. Forest density had no effect on forest ecosystemscarbon density systems. The mixed coniferous forest carbon density was significantly higher than that of pure forest carbon density(P <0.01).