A Study On Biomass And Carbon Storage Of The Five Specise Plantations In Subtropical China

In the last century, the global are undergoing with a warming climate. The increasing of the concentration of green house gas, especially the concentration of CO₂, in the atmosphere plays the main role. The forests have the function of absorbing CO₂ and fixed carbon which plays an important role in regulating the global carbon cycle and climate change mitigation. Thus, afforestation and reforestation are widely accepted to be the most economic, real and effective way to resolve the global warming.This paper selected Michelia macclurei, Castanopsis hystrix, Mytilaria laosensis, three broad-leaved tree species and Pinus massoniana and Cunninghamia lanceolata, two coniferous tree species that are widely planted in Guangxi area. The site, which of the same field conditions and near mature forest in 21～24, was selected in Tropical Forestry Experiment of the Chinese Academy of Forestry Science in Guangxi, Pingxiang, Fubo. Through the investigate of field survey, sample collection and experimental analysis, this paper established the 23 years old Michelia macclurei biomass regression equation, and got the vegetation layer components of biomass and the vegetation layer, soil layer components of the carbon content, carbon storage of five kinds of artificial forest. The conclusions are as follows:（1） Through determination the biomass of each organ of Michelia macclurei and Cunninghamia lanceolata, using W=a （D²H）^b model, established the biomass regression equation of each organ Michelia macclurei and Cunninghamia lanceolata, the results reached extremely significant level, high degree fitting.（2） The amount of tree layer biomass of five forest types order is:Cunninghamia lanceolata Forest (198.244 t·hm^-2)>Mytilaria laosensis (186.047 t·hm^-2)>Castanopsis hystrix forest (147.791 t·hm^-2)> Pinus massoniana forest (140.606 t·hm^-2)> Michelia macclurei forest (132.389 t·hm^-2).（3） Biomass in the spatial distribution of forest in the 5 forest types are not the same. The three broad-leaved tree species shared the same law of spatial distribution of forest biomass, that: the tree layer （98.29-99.16%）> the litter layer （0.42-0.95%）> shrub layer （0.39-0.70%）> herb layer （0.004-0.06%）. However, the spatial distribution of forest biomass of the two coniferous tree species are not all the same. The Pinus massoniana forest is in the form of space: the tree layer （97.73%）> shrub layer （1.03%）> the litter layer（0.71%）> herb layer （0.53%）. But foe the Cunninghamia lanceolata shows that:the tree layer （98.35%）> shrub layer （0.76%）> herb layer （0.50%）> the litter layer （0.38%）.（4）The litter carbon content rate of the 5 kinds of forest is:Mytilaria laosensis （49.341%）> Pinus massoniana （49.172%）> Castanopsis hystrix （48.751%）> Cunninghamia lanceolata （47.611%）> Michelia macclurei （46.963%）.（5）The soil carbon content of the 5 kinds of forest decreased with soil depth increasing and decreasing, but the decreasing rate shows different. The rate of carbon containing horizontal comparison of the results were obtained as follows: stand the same soil carbon rate in Mytilaria laosensis forest and Michelia macclurei plantation were the highest with 0-10 and 10～30 cm layer of soil, and Castanopsis hystrix forest is on the center, Pinus massoniana forest and Cunninghamia lanceolata forest minimum; 30～50 and 50～100 cm layer of soil is:Cunninghamia lanceolata forest> Mytilaria laosensis fores> Pinus massoniana forest> Michelia macclurei forest> Castanopsis hystrix forest.（6）The vegetation carbon storage order of the 5 types of forest is:Mytilaria laosensis Plantation （102.683 tC·hm^）-2))> Cunninghamia lanceolata Plantation (99.944 tC·hm^-2)>Pinus massoniana Plantation (76.177 tC·hm^-2)> Castanopsis hystrix Plantation (75.434 tC·hm^-2)> Michelia macclurei Plantation (63.691 tC·hm^-2). Carbon storage is the largest level of tree layer,5 kinds of tree layer carbon storage order: Mytilaria laosensis Plantation (101.929 tC·hm^-2)> Cunninghamia lanceolata Plantation (98.527 tC·hm^-2)> Pinus massoniana Plantation (74.656 tC·hm^-2)> Castanopsis hystrix Plantation (74.203 tC·hm^-2)> Michelia macclurei Plantation (62.874 tC·hm^-2).（7）The soil carbon storage order of the 5 kinds of forest is: Mytilaria laosensis Plantation (179.489 tC·hm^-2)> Michelia macclurei Plantation (174.892 tC·hm^-2)>Pinus massoniana Plantation (149.054 tC·hm^-2)> Cunninghamia lanceolata Plantation (143.365 tC·hm^-2)> Castanopsis hystrix Plantation (138.653 tC·hm^-2).（8）The carbon storage of the 5 kinds of forest is:Mytilaria laosensis Plantation (282.173 tC·hm^-2)> Cunninghamia lanceolata Plantation (243.309 tC·hm^-2)> Michelia macclurei Plantation (238.585 tC·hm^-2)> Pinus massoniana Plantation (225.231 tC·hm^-2)> Castanopsis hystrix Plantation (214.087 tC·hm^-2).