Study On Carbon Fixation, Sequestration Rate And Potential In Vegetation Of Pinus Massoniana Nature Forest

This paper mainly discussed the biomass and carbon storage in different standstructures changed with different age groups, based on investigating the biomass and thedetermination of carbon content rate on different age groups of Pinus massoniana natureforest in Ji’an city Jiangxi province. The rate of forest vegetation carbon sequestration wasestimated according to the forest resource inventory date for management, discussed themost proper method for estimation of forest vegetation carbon sequestration potentialanalyzed by the methods of maximum, light use efficiency, regression model of netprimary productivity and growth, then estimated the forest vegetation carbon sequestrationpotential by using it. The results showed as follows:（1）The biomass of Pinus massoniana nature forest about each organ of tree layerand single tree was on the rise with the increase of stand age. Biomass about each organ ofsingle tree at different age groups accounted for the proportion of the total biomass wasdifferent, biomass distributing sequence of different organs in young forest and middle-ageforest was: trunk>root>branch>leaf>bark; in near-mature forest, mature forest andovermature forest was: trunk>branch>root>bark>leaf；Biomass of understory vegetationand litter layer did not show the variation of rising with the increase of stand age.（2）The carbon density in tree layer was rising with the increase of stand age, thecarbon density in5age groups were15.58t·hm-2、22.54t·hm-2、28.27t·hm-2、33.87t·hm-2and66.14t·hm-2respectively; the average carbon storage in shrub and herb under forestwere3.18t·hm-2and2.37t·hm-2; the average carbon storage of litter in undecomposedlayer and half-decomposed layer were0.43t·hm-2and0.37t·hm-2; The distributions ofcarbon storage in tree layer, understory vegetation and litter layer were80.92%,16.80%and2.28%respectively.（3）The rate of forest carbon sequestration in tree layer at5age groups were2.03t·hm-2·a-1,2.95t·hm-2·a-1,3.18t·hm-2·a-1,1.09t·hm-2·a-1and1.01t·hm-2·a-1respectively.（4）The method of maximum suitable for stand had some limitation to estimate theforest vegetation carbon sequestration potential; the method of light use efficiency hadgreater uncertainty; the method of regression model of net primary productivity wasreliable and helpful, but the workload was larger; the method of according to the standgrowth to estimate the forest vegetation carbon sequestration potential was reliable andsimple, improved the accuracy and efficiency. The average estimation of carbonsequestration potential in tree layer at5age groups were1.60,1.47,1.48,1.56and1.25t·hm-2·a-1, respectively.