Study On Carbon Storage Of Forest Vegetation And Its Affecting Factors In The Region South Of Miaodao Archipelago

Island is a special terrestrial ecosystem, its ecological structure is relatively simple, andthe species richness is lower than that of the mainland. Island ecosystems still has strongability of carbon storage and plays an important role in the global carbon cycle. However, thecomprehensive estimation on carbon storage and their influencing factors in the island forestecosystem are limited, which is difficult to make needs of forest carbon fixation capabilityevaluation in China.Based on the biomass allometric equation combined with the data investigated in standsample plot, the tree and herb carbon storage of three main types of forest ecosystems (Pinusthunbergii, Robinia pseudoacacia,and Pinus thunbergii×Robinia pseudoacacia) in the regionsouth of Miaodao Archipelago in Shandong Province was estimated, respectively. The impactof different parameters in the island on arbors carbon storage were discussed, and advancescountermeasures and suggestions for improving the ability of carbon sequestration in forestecosystem. The reasults will elucidate the mechanisms underpinning carbon sequestration inisland forest, in order to offer scientific basis for carbon cycle studies. The results of the studyshowed that:(1) The results indicated that the carbon content rate in the same organs of differentspecies decreased in the order (p<0.05): P. thunbergii forest>R. pseudoacacia forest. Thecarbon content rate were quite different both in different organs of the same species. Thecarbon content rate of trunk and leaf were higher than that of the others. The average carboncontent rate in herb layer was35.83%for the P. thunbergii×R. pseudoacacia forest,32.20%for the P. thunbergii, and28.71%for the R. pseudoacacia, respectively, which are as follows:aboveground>underground. The carbon content rate of herb layer was significantly negativelycorrelated with stand density (R2=0.163, p<0.05).(2) The arbors average carbon storage was72.10t/hm2, which was higher than the herbaverage carbon stock (0.638t/hm2) in the region south of Miaodao Archipelago. The largestcarbon storage of tree layer in different forest is P. thunbergii of93.75t/hm2, followed by P.thunbergii×R. pseudoacacia (78.17t/hm2), R. pseudoacacia (44.38t/hm2). In herb layer, thecarbon storage of R. pseudoacacia forest was higher than that of the others, arriving at1.11t/hm2, followed by P. thunbergii (0.60t/hm2) and P. thunbergii×R. pseudoacacia (0.39t/hm2).Because the P. thunbergii is suitable to plant in island, it is an ideal tree species in MiaodaoArchipelago with good carbon sequestration function.(3) The sandy soil is the main forest soil types of Miaodao Archipelago, and soil erosionwas seriously. There were significant differences in different forest soil physical properties.The soil structure of P. thunbergii is superior to the others. The soil nutrient indexes weremeasured, the results showed that the contents of soil available nutrient and total potassium were relatively poor while the rest of nutrient was rich.(4) The average carbon storage of herb layer and slope and elevation showed normaldistribution. A major controlling factors to the herb carbon storage in Miaodao Archipelagoforest was disturbance of human activities from spatial differentiation characteristicresearch.(5) Based on the mathematical statistics method, the correlation between arborsaverage carbon storage and forest age, site condition and soil physical-chemical propertieswere analyzed. The arbors average carbon storage was significantly positively correlatedwith slope (R2=0.20,p<0.05) and age (R2=0.37,p<0.001); Principal Components Analysis(PCA) indicated that moisture, pH, phosphorus and potassium contents in the forest soilwere major controlling factors on the arbors average carbon storage in the region south ofMiaodao Archipelago.