Carbon Density Of Pinus Tabulaeformis And Quercus Aliena Var. Acuteserrata Forest Ecosystems On The Southern Slope Of The Middle Qinling Mountains

In different districts where Pinus tabulaeformis and Quercus aliena var. acuteserrata iswidely distributed on the southern slope of the Middle Qinling Mountains,50Pinustabulaeformis forest sample plots and50Quercus aliena var. acuteserrata forest sample plotswere set typically. Based on field investigation and laboratory analysis, organic carbondensity of arbor layer, shrub layer, herb layer, litter layer and soil layer of Pinus tabulaeformisforest and Quercus aliena var. acuteserrata forest in this region were estimated and analyzed.And the difference of carbon density of different stand ages, elevation, gradients, slopeaspects, and slope position. Main findings were as following:1. In the Pinus tabulaeformis forest ecosystem on the southern slope of the MiddleQinling Mountains, carbon content of trunk, root, branch, bark and leaf of arbor layer were50.54%,50.28%,51.80%and48.57%; carbon content of leaf, branch and root of shrub were46.27%,46.70%,39.30%; carbon content of above and under ground part of herb layer were41.78%,34.96%; carbon content of litter layer was33.79%; carbon content of layer A, layerB and layer C of soil layer were5.87%,1.36%and0.84%.In the Quercus aliena var.acuteserrata forest ecosystem, carbon content of trunk, root, branch, bark and leaf of arborlayer were48.03%，50.57%，48.77%，46.83%and46.16%; carbon content of leaf, branchand root of shrub were45.22%,44.06%,39.39%; carbon content of above and under groundpart of herb layer were39.64%31.50%; carbon content of litter layer was30.84%; carboncontent of layer A, layer B and layer C of soil layer were4.01%,1.46%and0.69%. Biomassweighted average of carbon content of arbor layer of Pinus tabulaeformis forest was50.32%,and it was47.95%for the Quercus aliena var. acuteserrata forest. It was larger in the Pinustabulaeformis forest than that in the Quercus aliena var. acuteserrata forest.2. Carbon density of Pinus tabulaeformis forest ecosystem of this region was150.12t/hm~2, and carbon density of soil layer, arbor layer, litter layer, shrub layer and herblayer were56.74,40.79,1.77,0.43and0.27percent of the total; carbon density of layer A,layer B and layer C were50.57,39.11and10.33percent of the soil layer; carbon density oftrunk, branch, root, leaf and bark were55.82,21.25,10.29,7.35and5.29percent of arborlayer. Carbon density of Quercus aliena var. acuteserrata forest ecosystem of this region was 259.20t/hm~2, and carbon density of soil layer, arbor layer, litter layer, shrub layer and herblayer were60.88,38.27,0.50,0.23and0.12percent of the total; carbon density of layer A,layer B and layer C were55.83,29.20and14.97percent of the soil layer; carbon density oftrunk, root, branch, bark and leaf were51.85,22.36,14.77,7.61and3.41percent of arborlayer. Vegetation carbon density of Pinus tabulaeformis forest and Quercus aliena var.acuteserrata forest of this region were larger than the average vegetation carbon density inChina, and there was great carbon sequestration potential.3. There was positive correlation between carbon density of litter layer and soil layer, aswell as litter layer and soil layer. It was considered that litter layer had positive effect oncarbon sequestration of the forest, and shrub layer benefited to the accumulation of litter layer.Therefore, to enhance forest carbon sequestration, shrub and litter layer of the forest shall beprotected.4. Terrain factors had remarkable influence effect on carbon density of Pinustabulaeformis and Quercus aliena var. acuteserrata forests. To bring the ecosystem servicesof the forest ecosystem into full play, different scientific operation and management shall betaken against different terrain.