Studies On Carbon Sequestration Of Larix Gmelinii Virgin Forest And Restoration Forest After Cutting

This paper researched the carbon sequestration of Larix gemilinii virgin forest and restoration forest after cutting at the Inner Mongolia Daxinganling Mountains Forest Ecosystem Research Station, based on community types and different cutting methods. There were Ledum palustre—Larix gmelinii virgin forest, Grass—Larix gmelinii virgin forest, Bryaceae—Larix gmelinii virgin forest, Betulafruticosa—Larix gmelinii virgin forest and gradually cut and clear cut forest in the year of 1987. In order to accurately estimating size of carbon storage, trees, shrubs, herbs, mosses, litters biomass were estimated by investigation of plots, the carbon content rates(CCRs) of trees, Shrubs, herbs, mosses, litters and soil were measured by Potassium Dichromate (K2Cr2O7)—Heating method, then analysis on ecosystem each part of carbon density distribution characteristics was done. The result showed that:(1) Among the trees, the sequence of different organ carbon content of Larix gmelinii is bark>leaf>trunk>branch>root, the mean carbon content is 49.96%; for betula platyphylla, it is: bark>root>trunk>branch>leaf, mean carbon content is 50.18%. Among the shrubs, Ledum palustre, Vaccinium vitis-idaeamean are the evergreen plants, but Betula fruticosa is deciduous plant, the mean organs carbon content were 51.05% and 43.91%, it is about 40.66%, 45.85% and 44.35% for grasses, mosses and litters. For forest soil, the mean organic carbon content was: Ledum palustre-Larix gmelinii forest 73.680g·kg-1; Grass-Larix gmelinii forest 68.880g·kg-1; Bryaceae-Larix gmelinii forest 242.661g·kg-1; Betula fruticosa-Larix gmelinii forest 234.140 g·kg-1,the carbon content of soil reduced with increasing of the soil depth.(2) The carbon storage is: Betula fruticosa-Larix gmelinii forest > Ledum palustre-Larix gmelinii forest>Bryaceae—Larix gmelinii forest>Grass—Larix gmelinii forest, it is 435.565 t·hm-2, 307.711 t·hm-2, 248.048 t·hm-2 and 169.293 t·hm-2 for each types of forest. For components of ecosystem carbon pool, it showed: soil>vegetation>litters. Soil is the key carbon pool in whole ecosystem. The ecosystem mean carbon storage of Larix gmelinii virgin forest is 290.176 t·hm-2.(3) Since 1987, the gradually cut and clear cut forest ecosystem total carbon storage are 176.060t·hm-2 and 114.916t·hm-2, it reduced about 27.77%, 52.85% respectively, which compared with virgin forest. The disturbance of different cutting operations could lead to decrease of the forest ecosystem carbon storage. For the above ground carbon pool, it had been reduced about 53.6% and 81.2% after gradually cut and clear cut respectively, for the underground carbon pool, it about 18.1% and 43.1%. We have seen that, cutting operations have negative effects on vegetation carbon pool, which is higher than the soil carbon pool. So gradually cut will beneficial for maintain and restoration forest ecosystem carbon sinks.