Study On Biomass And Carbon Sequestration Benefits For Understory Shrubs And Herbs Of Forests In Beijing MiaoFengShan Forest Farm

It is the basis for accurate determination of the biomass of many ecological and forestry problems. Understory shrubs and herbs are important components of the forest ecosystem, and play an important role in maintaining nutrient cycling of forests. It is significant to research on soil and water conservation and species diversity of forest. This paper is involved in approaches to estimate understory biomass of the understory shrubs and herbs in three forest types, including Pinus tabulaeformis forest, Quercus Variabilis forest and Mixed coniferous forest in Beijing Forestry University Experimental. The shrub layer was divided into arbor and typical shrub. We surveyed the height,basal diameter, crown range and wet ratio,then constructed the organs and the whole plant biomass models, with plant crown area (A), champions league volume (V), base diameter and plant height product(DH), base diameter square and plant height product (D2H) as the independent variable. And the largest R2and smaller SEE model were choosed as the optimal model. The understory shrubs biomass was studied via using the optimal model with the survey data of sample plots. Herbs biomass was used the method of harvesting all quadrat. On the basis of biomass, we calculated the carbon fixation and oxygen values of nutrients of shrub species and herbs in the three forest types. The results show that:(1) The optimal biomass models of organs from a single species are mostly cubic equation, power function, quadratic equation and simple equation. The optimal model are cubic equation of arbor leaf and biomass, typical shrub mostly are power function. Besides the shrub branch optimal model is power function, the rest are cubic equation. The dry biomass of the optimal model of arbor shrub mostly are cubic equation, and typical shrub mostly is power function. The root biomass of the optimal model of arbor shrub mostly are cubic equation, and typical shrub mostly is power function and cubic equation. The organ model of shrub species are not always superior to the whole plant model.(2) The independent variable and models of different shrub species are not the same. The independent variable for the each organ are usually V, D2H, DH and A. The independent variable of type trees shrubs and typical shrub plants biomass model are V, the leave of arbor are V and DH, the leave of typical are V and D2H. The independent variable of branch of arbor are D2H, the independent variable of branch of typical are V. The independent variable of dry of arbor are D2H and DH, the dry of typical are DH. The independent variable of root of arbor are V and D2H,the roof of typical are DH and A.(3) It is calculated that the total biomass of Pinus tabulaeformis forest, Quercus Variabilis forest and Mixed coniferous forest, they are respectively1622.05,1652.66and2008.12kg·hm-2. There is a big difference in the composition of shrubs and herbs biomass of different forest. The shrubs biomass is:Pinus tabulaeformis forest> Quercus Variabilis forest>Mixed coniferous forest; The herbaceous biomass:Mixed coniferous> Quercus Variabilis fores>Pinus tabulaeformis forest. Aboveground biomass under different forest types herbaceous layer is greater than below-ground biomass, and the shrubs layer biomass is greater than the herbaceous layer biomass.(4) We estimate the value of carbon sequestration under shrubs and herbaceous shrub biomass of three forest types. They are610660.5,223124.2,711056.2yuan of Pinus tabulaeformis, Quercus Variabilis and Mixed coniferous forest.