Carbon Accumulation And Carbon Sinking In Carbon Forest Ecosystem Under Different Afforestation Patterns In Subtropical Forests In China

Carbon sink forests can fix atmospheric carbon dioxide and play an important role in mitigation of global warming.They study the accumulation of organic carbon in the carbon sink forest ecosystems of different afforestation models in the South subtropical region,and provide a carbon sink carbon sink function evaluation for different afforestation models.Scientific basis.Using a single-factor randomized block design,a carbon sink was established for the three research afforestation models based on new afforestation(I),closed-to-mount afforestation(II),replanting(III),and three afforestation models.The advantages and disadvantages of afforestation model in terms of accumulation and carbon sequestration.Therefore,research provides a scientific basis for screening carbon sinks and afforestation models.research shows:(1)Carbon sink soil carbon accumulation: There was a significant difference in soil organic carbon content among the three afforestation models at different stages(p<0.05).Among them,the difference in soil organic carbon stock changes between the new and intercropping systems was extremely significant(p<0.01).In other words,the effects of three afforestation models on soil organic carbon storage in 0-60 cm soil were not significant(P>0.05),but significant differences were observed in top soil(0-20 cm).In the five years of carbon sinking and afforestation,the soil carbon stocks of the three afforestation models increased significantly,and the soil organic carbon stocks of the three afforestation models were in order of replanting,interplanting,new afforestation,and closing hills for afforestation,that is,at the early stage of carbon sink afforestation,the replanting model.In the next study area,the soil organic carbon stocks are the most,whilethe model of reforestation based on natural regeneration has the lowest soil organic carbon reserves,indicating that artificial building methods in the study area are superior to natural building methods in the short term.However,the soil carbon stocks of new afforestation and closed forestation are significantly lower than that of the original zonal forest(control ground),indicating that carbon sinks still have great carbon sink potential.From the perspective of the increase in soil carbon stocks,with the increase of time,compared with the new afforestation and replanting modes,the closure of the mountain to afforestation will have a larger soil carbon stock and a greater advantage in increasing soil carbon.(2)Carbon sink forest carbon accumulation: The distribution patterns of three afforestation patterns in the study area showed arbor> shrubs> litters,and the accumulation of carbon sinks in vegetation layer was dominated by arbors,and the effect of carbon sinks was significant.In the five years of carbon sinking and afforestation,the total vegetation carbon stocks of the three afforestation models increased significantly,and the organic carbon stocks in the vegetation layer were in order of replanting,interplanting,new afforestation,and closing mountains and afforestation.The replantation pattern remained the highest in the vegetation layer,but From the increase in vegetation carbon stocks,it can be seen that the carbon sink afforestation model adopting the new afforestation model is more advantageous for increasing the amount of vegetation carbon sinks.(3)Carbon sink and forest carbon sink function: The total carbon stocks of the carbon sink forests of the three afforestation models are increasing with the increase of forest age.The carbon stocks of the three afforestation model carbon sinks at the initial stage(5 years)are the largest and the lowest carbon reserves in order.Planting and interplanting> New afforestation> Closing the mountain to cultivate forests.From the perspective of the increase in carbon stocks,the carbon stocks in the new afforestation model have the fastest growth rate,followed by the replanting and interplanting model,indicating that the growth rate of the carbon sink function using the new afforestation and replanting models is betterthan closing the mountain to afforestation.In summary,the carbon accumulation of soil and vegetation in the carbon sink forests of the three afforestation models has their own advantages.In the future,the carbon accumulation rules of carbon sinks and forests under more afforestation models in different regions should be studied,so as to greatly increase the forest ecosystem.Carbon reserves increase the function of carbon sink services in forest ecosystems,so as to provide a basis for selecting appropriate afforestation models for the establishment of carbon sink forests with different objectives.