Study On Forest Carbon Stock In Beijing Of China

The carbon cycle of forest ecosystems has some functions of control and adjustment to the global climate changes,is an important part of the global carbon cycle which is one of the core issues of the global climate changes researches.The estimation of forest organic carbon pool has been hotspot questions of the researches on forest ecosystems.The present study is primarily focused on nine major forest types in Yanqing County,Beijing, China.In this paper,biomass of different stands was estimated,carbon storage of the dominant species of the tree layer and the shrub layer was measured,and carbon storage of the forest ecosystem in the local area was calculated.In addition,the dynamics of carbon pool of the local forest ecosystem was analyzed.The results were mainly concluded as follows:By using the wet combustion method,foundation of tree layer biomass model with compatibility, organic carbon ratio measures of tree layer,shrub layer,and the evaluations of the density and size of regional forest ecosystem carbon storage were studied among nine forest stands of Mountains in Beijing(Yanqing County):Pinus tabulaeformis,Larix principis-rupprechtii,Platycladus orientalis, Populus davidiana,Quercus liaotungensis,Juglans mandshurica,Robinia pseudoacacia,Betula platyphyll,Broadleaf mixed forests,Shrub and so on.Firstly,the carbon content of nine dominant forest species in Yanqing Mountain,Beijing by using the wet combustion method,and the mean tissues' carbon contents of these species were 0.5308,0.5210, 0.5104,0.4824,0.4801,0.4514,0.4640,0.5031,0.4824,0.4777 respectively for nine stands and one shrub above.The mean carbon content of the conifer species(0.5207) was higher than broadleaf species (0.4772),and the carbon content of conifer stands was also higher than that of broadleaf stands.Secondly,the density of carbon storage of nine main forests in Yanqing Mountain were 69.5224,30.2855,49.9849,34.4055,43.9550,57.6091,43.8971,53.6560,55.1286 t·hm-2 in sequence,in addition,the carbon storage of nine dominant forest species was0.1051,0.0729,0.05650,1.1458,0.0019,0.0931,0.5240,0.2460,0.3807 Tg respectively.The density of mean carbon storage of tree layer of nine stand in Yanqing County was 49.0774 t·hm-2,total carbon storage of of tree layer of nine stand in Yanqing County was 2.6073Tg,that of shrub layer was 5.8526 t·hm-2 and 0.0121 Tg.Thirdly,based on the data of national forest survey of 3756 quadrats from Yanqing County,the result showed that there was a prominent linear relationship between the tree biomass(W) and the mean DBH(DBH),the mean height of trees(H) and the density of trees(D),tree biomass(W) and the wood volume(V).It was proved theoretically that the forest biomass linear estimation model could be applied on the regional scale directly.Fourthly,according to the data of the fourth-times sub-forest management inventory form 1990 to 2005,the carbon storage was estimated as 587.022 10-2 TC in 1990,617.548 10-2 TC in 1995,790.622 10-2 TC in 2000 and 878.596 10-2 TC in 2005.The average growth rate of carbon storage was 10.61% per 5 years,and 10.79%per 5 year for biomass.It played the role of the carbon sink well.