Study On The Change Of Forest Resources And The Dynamics Of Carbon Storage Of Dominant Tree Species In Shanxi

Climate change has been one of the hot points of human's concern.The CO2 absorbing and accumulating ability of forestry vegetation can slow down the rising of greenhouse gases like CO2.Therefore,estimating the biomass and carbon storage of forest ecosystem in an area scientifically,describing and analyzing its current situation and dynamic changes quantificationally and revealing the inherent law of forest ecosystem can provide supports for regional ecological construction and typical vegetation protection.Utilizing the data from the 8th and 9th national forest census in Shanxi Province,this study analyzes the changes of the arbor forests' area and accumulation.Using the biomass(regression)experience model estimating method,combined with the carbon content of different tree species,the study analyzes the distribution factor of biomass,carbon storage and carbon density of dominant tree species in Shanxi forest ecosystem.Combined with remote sensing image data,using stepwise regression,partial least squares and neural network to build pinus tabulaeformis forest carbon storage estimating model,the study discusses the carbon storage estimating method using remote sensing image and ground easy test factor.The research results indicate that:(1)Shanxi forest land resources in 2015,the forest area net increase is 28.43?104hm2,volume increase is 3184.25?104m3;shelter forest accounts for the largest area in forest,up to 73.20%;the forest area ingcrase mainly due to natural changes and afforestation,contributing to 17.83% and 10.23% of the overall area net increase respectively,and the area reducing reason mainly due to tree-cutting and natural disaster;in terms of dominant tree species;pinus tabulaeformis area and volume increase 0.75?104hm2 and 346.67?104m3 respectively;the other three species are characterized by area decrease and volume increase;under different forest ages,all the age groups' volume are increased except for nearly ripe forest;the natural forest consumption decreases,the main artificial consumption comes from the cutting of young and middle aged forests,the increase of tree mortality also contributes to the consumption.(2)Use biomass experience regression model and the dominant species' carbon content to obtain carbon storage.Within four types of tree species,oak carbon storage accounts for the largest,with an increase of planted forest of 48.08%,followed by pinus tabulaeformis,aspen and larch,the pinus tabulaeformis natural forest contributes the largest,but the planted forest increase accounts for 54.59%,the planted pinus tabulaeformis forest's effect begin to highlight;Carbon stocks of young forest all decreased in different degree,reflected the cutting consumption augmented and various tree species' carbon shocks maximized in the middle age forest and mature forest.By different canopy level,canopy density secondary has topmost carbon shocks.It will make the growth of carbon shocks maximum that high canopy density and low canopy replanting maintain canopy density 0.4 to 0.6.With the increase of altitude and slope,four species generally showed increased first and then decreased,slope in 6 to 45,pine and oak in the altitude of 1400 to 1600 meters,larch in 2000 to 2200 meters,aspen under the 1000 meters,all kinds of tree species' carbon shocks maximized.(3)Based on the remote sensing image and the ground measurement factor,constructing model which estimates carbon storage of Pinus tabulaeformis forest and comparing fitting reading through the stepwise regression,partial least squares method and neural network method.The results show using BP neural network that inspection accuracy is 82.13%,using multiple stepwise regression is 76.73% and partial least squares regression is 77.09%.Having a higher precision with the neural network model,its academic consequence closes the theoretical results,which indicate it can reflect a certain species of carbon shocks.This study preliminary showed the dynamic growth change about Shanxi province forest resources in arbor forest nearly ten years,and konwn the intrinsic reason of dominant tree species' carbon storage dynamic changes in different terrain,ground and environment factor index,also constructed the fast estimation method of carbon shocks with the remote sensing image and ground factor measurement,provided a reference value for the study of forest carbon shocks,provide guidance for forest management and afforestation in Shanxi province.