The Research Of Carbon Storage Of Different Mixed Roportions In Masson Pine Mixedwood

Vegetation plays an important role in global carbon balance and potential carbon storage. It is closely related to global climate change. Recent years, southern area, where has a rapid development of industrial,an increasing of carbon dioxide emission and higher forest coverage rate, have got a significant impact on climate change and carbon balance in Anhui province.The quality of carbon sink forests, to some extent, deeply influences the capacity of forests carbon sequestration.The sample stands located in Zongyang County, Anqing City, southern Anhui Province, where belongs to the southeastern edge of the Dabie Mountains, the lower reaches of the north Yangtze River. The main vegetation type is mixedwood which mixed by conifer and broadleaf trees, including Masson pine, fir, maple, dyetree and german oak. In this research, we try to study five different mixed proportions (0-20%、21-40%、41-60%、61-80%和81-100%)of masson pine and broadleaf trees, The biomass and carbon storage of tree layer, shrub layer, herb layer(including moss), litterfall and coarse woody debris in five proportions as well as soil carbon density will be compared to build regression modles between different organs and carbon storage, mixed proportions and carbon storage in different layers of forest vegetation,as well as mixed proportions and carbon storage. The main findings are as follows:(1) The biomass which distributes in different organs of Masson pine shows the following trends:trunk>root>branch>leaf. The proportion of Masson pine have a significant impact on biomass and carbon content of tree layer, stand biomass can also be obviously different among these mixed proportions. The proportion which Masson pine accounts for41-60%could get the maximum biomass, up to83.17t·hm-2,while the proportion which Masson pine accounts for81-100%have got the minimum biomass, only74.62t·hm-2.(2) The mixwoods with different proportions of Masson pine have obviously vertical distribution of vegetation. The understory vegetation has an increasing trend as broadleaf trees reduced in tree layer. This phenomenon shows broadleaf trees have a impact on biomass of understory vegetation. The biomass of shrub layer also changes among different mixed proportions. it can get the maximum where Masson pine accounts for41-60%and60-80%, and the minimum appears in the proportion of0-20%, which only have0.6t·hm-2. Biomass in herb layer gets a maximum of0.049t·hm-2among15sample stands. It changed by niche in stands. The biomass in stand which Masson pine accounts for61-80%almost gets twice as much than which mixed proportion is0-20%. The litterfall layer gets a minimum biomass of3.097t·hm-2in which proportion is81-100%. However, there is no difference in other mixed proportions. The coarse woody debris appears in the9th plot where biomass is1.045t·hm-2.(3) The carbon content in various organ of Masson pine are as follows: root>stem>branch>leaf. In15sample plots, the tree layer have got the highest carbon content, up to47.906%; the second is the shrub layer, which up to44.343%; the carbon content of the herb layer is the lowest, only43.067%. The carbon content of litterfall is43.983%, slightly higher than the carbon content of the herb layer; carbon content of coarse woody debris is44.988%. Using statistical analysis, the result shows that the carbon content will increase and reduce at high speed in shrub and herb layer. The proportions of mixedwoods has a significant influence on all layers of forest vegetation, especially for shrub, herb and litterfall. The results of this study shows the carbon storage of the five proportions of mixedwoods in the sample plots are39.970t·hm-2,37.895t·hm-2,41.980t·hm-2,40.239t·hm-2and37.320t·hm-2.(4) The stands where masson pine accounts for60%can get soil organic carbon density as high as28.46kg·m-2. the organic carbon density of soil layer is9.80kg·m-2in the depth of0-10cm,9.59kg·m-2in the depth of10-20cm and9.07kg·m-2in the depth of20-30cm.The lowest soil carbon density is14.99kg·m-2, accounts for52.67%of carbon density in the stand where the proportion of masson pine is61.9%. Carbon density of Soil layer in0-10cm and10-20cm are7.88kg·m-2and7.11kg·m-2. The relationship of soil carbon density in different mixed proportions are as follows:41-60%>61-80%>21-40%>81-100%>0-20%。The results shows mixedwoods proportions between41-60%have ideal carbon storage since it can be better for carbon sequestration. The results also proved that Masson pine can coordinate growth with other mixedwood species in this proportion,and the ability of carbon sink is significantly higher than other mixedwood proportions in this condition.