| The increasing of atmospheric CO2 concentration and temperature are the main characteristics of global climate change, which changes the structure and functions of terrestrial ecosystem, threatens to the survival of human health and safety, Forest as the main part of terrestrial ecosystem, its function of absorbing and storing CO2 get more and more attention from governments and scientists. Because China owns the largest plantation in the world, the effective management and nurturing these plantations not only can improve the ecological environment, but also can increase CO2 fixation and carbon sink, slow global warming. pinus massoniana spread widely in China, its area is 1434.43 million hectares, ranking first for coniferous forest. The research of the carbon cycle dynamic of pinus massoniana under different managements is useful for scientific and reasonable management as well as the carbon storage. of pinus massoniana forest .This research employ FORECAST model to simulate the different sites, different rotations and felling the carbon cycle characteristics of pinus massoniana under different cutting ways.The results show:1)The site is better, the carbon storage of plant in the aboveground is greater; In the same site, the rotational period is the longer, the carbon storage of plant in the aboveground is greater. For the first rotation, the carbon storage of the ground vegetation in the way of whole tree cutting are less than that in the stem cutting. The carbon storage of above ground in the rotation length of ten years decreases with increasing the number of rotations, and the tendency is more obvious for the whole tree cutting than stem cutting. The carbon storage of above ground plant in first four rotations under different site conditions showed a sharp decline. The carbon storage of above ground in the rotation length of twenty years decreases with increasing the number of rotations, and the tendency is more obvious for the whole tree cutting than stem cutting; The carbon storage of above ground under different site conditions declined obviously in the second rotation. For the way of stem cutting ,the carbon storage of above ground in the rotation length of fifty years increases with increasing the number of rotations in the poor site, the whole tree cutting decrease obviously; In medium site, two logging showed that the carbon storage of above ground decreases with increasing the number of rotations, but the whole tree cutting reduced significantly; In a good site, the carbon storage of above ground changes slightly with increasing the number of rotations. 2)soil organic carbon content increased with the site conditions becoming better; soil organic carbon content in the short length of rotation is less than that in the long length of rotation;soil organic carbon content in the whole tree cutting is less than that in stem cutting .For the rotation length of ten years, soil organic carbon content decreased significantly in the first four rotation. For the rotation length of twenty years, soil organic carbon content changed significantly in the first two rotation , While for the rotation length of fifty years, soil organic carbon content changed slightly.(3)In the same length of rotation, total carbon of ecosystem increasing with site becoming better; In the same site, total carbon of ecosystem increasing with length of rotation becoming longer.(4) The simulation results showed that short rotation length in good site is benefit for obtaining more forest production. |
