| In this study,Larix gmeliniilarch forest was taken as the research object.T hrough the field investigation and sample measurement,the changes of biomass and carbon storage of Larix gmelinii at different developmental stages were cal culated,and the forest stand factor,vegetation carbon stock and soil layer were calculated.The relationship between carbon stocks and ecosystems was analyze d.Estimating the carbon fixation rate in the vegetation tree layer,estimatingth potential for carbon sequestration in the vegetation layer by estimating themaxi mum value method,productivity regression method,and growth process method and performing variance analysis on the results calculated by the three methods.The potential for soil carbon sequestration was estimated using the maximum method,and the potential for carbon sequestration in the Larix gmelinii ecosyst em was explored.The results of the study are as follows:(1)The total biomass of stands increased with the increase of forest age.The total biomass of young forest,medium forest,near-mature and mature forests were 108.43 t·hm-2,129.33 t·hm-2,232.44 t·hm-2 and 274.63 t·hm-2,respectively.In the vertical structure,the biomass of the tree layer in the total biomass of the stands was between 95.49% ~ 98.05%;the proportion of the undergrowth vegetation layers was between 1.36% and 3.61%;the litter layers accounted for the stand The proportion of total biomass was the smallest,and the percentage of litter layer biomass was between 0.60% ~ 0.91%.(2)The total carbon storage of ecosystems gradually increases with the increase of forest age.The proportion of soil carbon storage between different age groups was between 53.37 and 67.95%.There was no obvious change in the proportion of carbon storage with age group;the proportion of total carbon storage in the vegetation layer was 31.79~ 46.38%.Litter layer carbon storage ratio between 0.23 ~ 0.36%.There was a negative correlation between the carbon stocks in the vegetation layer,soil layer and ecosystem and the stand density,and there was a positive correlation with the forest age.(3)The annual average carbon fixation rate in the tree layer was 1.36 t·hm-2·a-1 for young forests>1.20 t·hm-2·a-1for near-mature forest>1.09 t·hm-2·a-1for middle forests.> mature forest(0.92 t·hm-2·a-1).The maximum value method and the growth process method have similar results for estimating the carbon sequestration potential of different age groups,with no significant difference(P>0.05).The carbon fixation potential estimated by the productivity regression model method was significantly higher than that of the other two estimation methods,and there was a significant difference(P<0.01).The soil carbon sequestration potential ranged from 111.1 t·hm-2 to 129.82 t·hm-2.The potential for soil carbon sequestration did not change significantly with the increase of forest age.(4)The potential for carbon sequestration in forest ecosystems in this study consists of the carbon sequestration potential of the vegetation layer and the potential for carbon sequestration in the soil layer.The young plant had the lowest potential for carbon fixation and the value was 0.01 t·hm-2·a-1.However,the potential for carbon fixation in the soil layer was 129.82t·hm-2.The highest potential of carbon sequestration in mature vegetation was 0.47 t·hm-2·a-1,while that of medium-aged forest was the lowest,with a value of 103.20 t·hm-2. |
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