The Research On Biomass And Carbon Storage Of Forest Vegetations In Wangcheng District, Changsha

With statistics of Class II Forest Resource Inventory in Wangcheng district in2013, this thesis made an estimation on the typical forest trees biomass and average biomass of main tree species (groups), economical forest, bamboo forest in Wangcheng district. The Continuous Function Model of Biomass Conversion Factors, which is founded by Fang Jingyun to present relationship between biomass and volume, was adopted in the assessment. On the basis of Shi Junnan’s analysis on conversion from tree plants and non-tree vegetation to carbon storage, the thesis also calculate the forest carbon storage in Wangcheng. Furthermore, an assessment on the carbon sink value of typical forest vegetation in this district was formed according to the conclusion in Global Carbon Sink Price Prediction and Comparision Table. In the end, an analysis was made on spatial distribution of forest types, structure of tree species, age structure, carbon storage of typical forest vegetation in Wangcheng and the spatial distribution map was drawn.The research shows that:(1) The total territory of Wangcheng district is95446.7hm2and total forest land is26938.8hm2, within which public welfare forest covers12748.9hm2and commercial forest covers12748.9hm2. Dingzi town is the largest area of public welfare forest, with a coverage of2527.1hm2, accounting for9.38%of total forest land area in Wangcheng. Bairuopu village is the largest area of commercial forest, with a coverage of3221.5hm2, accounting for11.96%of total forest land area in Wangcheng.(2) As statistics of Class II Forest Resource Inventory in Wangcheng district in2013show, the main tree species (groups) in Wangcheng are masson pine, Chinese fir, pine abroad, poplar, broad-leaved trees, which cover an area of22600.6hm2together with an volume of1287315m3. Broad-leaved tree is main tree specie, its area and volume covering56.11%and53.63%of that of total tree forest in the district respectively.(3) With review of age structure, young and middle-aged forest is primary, its area and volume accounting for93.47%of total forest area and84.98%of total forest volume in the district. It is worth mentioned that the area of middle-age forest accounts for78.50%of total forest area and its volume accounts for6.48%of total volume of forest in the district.(4) The total biomass of Wangcheng district is1421.273X103t, among which the biomass of tree species (group), as the primary subject of forest biomass in this district, is1383.105X103t, accounting for97.45%of total forest biomass. The biomass of economical forest is20.524X103t, accounting for1.69%of total forest biomass, while the biomass of bamboo forest is8.644X103t, account for0.86%of total forest biomass.(5) The total biomass of main tree species (group) in Wangcheng district is1383.105×103t, and the average biomass is61.198t/hm2, among which biomass of slow-growing broad-leaved trees leading by camphor is587.454×103t, accouting for42.44%of total biomass of main tree species (group), which is absolutely dominating.Biomass of other species is shown as follows:ordinary-growing broad-leaved trees (341.844×103t)> Chinese fir (232.790×103t)> pine abroad (107.468×103t)> masson pine (82.663×103t)> poplar (20.515×103t)> fast-growing broad-leaved trees (10.371×103t)。(6) The total carbon storage of Wangcheng district is712.897×103t, among which carbon storage of tree species (group) is698.313×103t, accounting for97.95%of the total. Carbon storage of economical forest is10.262X103t, accounting for1.44%of the total while carbon storage of bamboo forest is4.322X103t, account for0.61%of the total. The carbon density of tree species (group) is30.898t/hm2, lower than the national and global average level, which are35-39t/hm2and86t/hm2respectively, which shows that there is a large space of carbon storage development in Wangcheng district. Carbon storage of other species is shown as follows:slow-growing broad-leaved trees (290.026×103t)> ordinary-growing broad-leaved trees (168.768×103t)> Chinese fir (124.682×103t)> pine abroad (56.936×103t)> masson pine (42.522×103t)> poplar (10.257×103t)> fast-growing broad-leaved trees (5.120×103t)(7) Forest with a carbon density of21-30t/hm2,31-40t/hm2、41-50t/hm2.51-60t/hm2district is the most-widely distributed in Wangcheng district, almost existing in all of the villages and towns. Forest with carbon density of0-10t/hm2is mainly distributed in Heimifeng Forest Park in the northeast and sporadically distributed in some other villages and towns. Forest with carbon density of11-20t/hm2is mainly distributed in Leifeng Town in the south of the district and sporadically distributed in some other villages and towns. Forest with carbon density above60t/hm2is mainly distributed in Heimifeng Forest Park in the northeast and Bairuopu village and Wushan town in the south.(8) The total carbon sink value of Wangcheng district is4365.492x104yuan, among which carbon sink value of tree species (group), economical forest and bamboo forest are4276.187×104yuan,62.841×104yuan, and26.464×104yuan respectively.Carbon sink value of other tree species (groups) are as follows:slow-growing broad-leaved trees (1776.004×104yuan)> ordinary-growing broad-leaved trees (1033.469×104yuan)> Chinese fir (763.504×104yuan)> pine abroad (348.656×104yuan)> masson pine (260.388×104yuan)> poplar (62.812×104yuan)> fast-growing broad-leaved trees (31.354×104yuan)(9) After analyzing the distribution of forest resource in Wangcheng district, we conclude that the adjustment of forest vegetation should achieve the goal-structure with subtropical evergreen broad-leaved forest mainly and Coniferous forest and economic forest secondarily.