Research On Carbon Sequestration Ability Of Main Afforestation Tree Species In Central And Southern Shanxi, China

Forest carbon-sink plays an important role in the levels of greenhouse gases in the atmosphere and affects carbon "source" and "sink" because of the has been the hot research area for a long time. In this article, we studied the biomass, carbon density and rate of carbon sequestration of different organs of main forests in central and southern Shanxi with the combination of forest inventory data and sample-plot survey. The results will be used as the reference for the carbon sequestration capacity of the forests. It showed that the carbon content of different tree organs were:Larch51.58%, Quercus liaotun-gensis47.15%, Chinese pine46.83%, Locust46.40%, Aspen45.99%; the average carbon content of the3broad-leaved forest and the2coniferous foest were46.51%and51.33%, and the carbon content of coniferous foest organs were higher than the organs of broad-leaved forest seeing from tree morpho-logical chara-cterristics’angle. So correspondent carbon content data of different forests’different organs should be used when estimate the carbon content. In this study, the variable coefficient of the organs’carbon content of each forest were0.72%-3.38%, and the number were3.18%-7.2%among trees. The bio-masses of main forests were:Quercus liaotungensis (136.28t/hm2)> Chinese pine (111.10t/hm2)>Locust (98.48t/hm2)>Larch (76.93t/hm2)>Aspen (43.59t/hm2). The biomass differences of the same organs in different forests were big, and the amount of variation of the same organs’proportion except the Chinese pine was relatively stable; the biomass was mostly in the trunk and then the root, branch, leaf. There was a proportional relation in the biomass allocation of aboveground part and underground part of different forests, while the aboveground part biomass was about70%-80%of the total biomass, and the underground part occupied around20%-30%. The carbon contents of the forests in this study were:Quercus liaotungensis (64.26t/hm2)>Chinese pine (52.03t/hm2)>Locust (45.69t/hm2)>Larch (39.68t/hm2)>Aspen (20.05t/hm2).There were big carbon content differences in the same organs of different forests, which showed similar law with that of biomass and carbon content. The proportion of carbon density of different organs in the same forest was: Chinese pine1.61%-54.10%, Aspen6.78%～63.04%, Quercus liaotungensis5.24%-42.42%, Larch1.76%-58.74%, Locust1.09%～41.37%. The proportion of carbon density of the same organs in different forests was trunk> root>branch>leaf, however the varied range was big. According to gathered data of the4th,5th,6th forest inventory, we reached that the carbon density of main forests in Shanxi showed a trend of increase, which explained the quality of forests in Shanxi was stable. The carbon density would relatively increase with the continuous improvement of forests’structure. So the forests in Shanxi is a giant potential carbon pool. Furthermore, more tending measures towards the existing forests should be enhanced, so that the carbon sink function of the forest ecosystem in Shanxi can be brought into full play. The rates of carbon sequestration of the5forests were:Quercus liaotungensis (20.56tC/hm2/a)> Locust (18.31tC/hm2/a)> Chinese pine (17.23tC/hm2/a)> Aspen (10.02tC/hm2/a)>Larch (6.02tC/hm2/a).