Research On Change Of Time And Space And Potentiality Prediction Of The Forest Carbon Sink And Its Economic Value In China

Under the vision of carbon neutrality,quantification of forest carbon sink is conducive to formulating forest carbon strategy and carbon trading mechanism,enhancing resilience against climate change,and playing an important role in safeguarding national ecological security,achieving carbon neutrality and mitigating global warming.Based on the data from the third to the ninth forest inventory in China,this paper estimated the forest carbon storage in China by using the biomass conversion factor continuous function method and the average biomass density method,and then obtained the forest carbon sink in each period.The trend of carbon storage and carbon sink in different age groups,species and origin of arbor forest over time was analyzed.The natural breaks method and spatial autocorrelation analysis were used to study the spatial distribution and change characteristics of forest carbon storage and carbon sink.Based on linear regression analysis,principal component analysis and vector autoregression model,the effects of average annual temperature,average annual precipitation,average altitude,forest area,forest fire area,forest pest area,GDP per capita and wood yield on forest carbon storage were revealed.Carbon tax law and market value method were used to estimate the economic value of forest carbon sink.The GM(1,1)model and the Logistic growth equation model between the stock per unit area of the dominant tree species of different origin(natural or artificial)and the age of the forest in China were used to predict the carbon sequestration potential of Chinese tree forests in 2030.The aim is to provide data support and theoretical reference for improving forest carbon sink and its economic value and realizing carbon peak and carbon neutrality as soon as possible in China.The main conclusions are as follows:(1)China’s forest carbon reserves were on the rise during 1984-2018,accounting for 78.36%～80.44% of China’s forest carbon reserves.From 1989 to 2018,the carbon sequestration of Chinese arbor forests showed a fluctuating upward trend.In the study period,the average carbon sink of mature forest was the largest,and broad-leaved mixed forest was the main contributor of forest carbon sink,accounting for 49.31% of the total carbon sink of tree forest.With the enhancement of afforestation,the proportion of carbon sink of artificial forest increased.(2)From 1984 to 2018,the spatial distribution of forest carbon storage in China was higher in northeast China and Southwest China,and slightly lower in central China.The areas with higher carbon sinks were concentrated in southern China.The Moran’s I value of forest carbon storage in China from 1984 to 2018 showed an overall trend of fluctuation and increase,and mainly showed high-high and low-high concentrations in local space.The spatial distribution of carbon sinks in Chinese arbor forests was different in each inventory period,and the distribution range of carbon sinks in the low level area was the largest from 1999 to 2003.From 1984 to 2018,the Moran’s I value of Chinese forest carbon storage showed a trend of first increasing and then decreasing.In the local space,there were mostly high-high and low-high accumulation areas,and only low-low accumulation areas appeared in 1994-1998 and 1999-2003.(3)Average annual precipitation,average altitude,forest area,per capita GDP and wood yield had positive correlations with forest carbon stocks,while average annual temperature,forest fire area and forest pest area had negative correlations with forest carbon stocks.The factors were divided into different sources.The forest stand factor had the greatest impact on forest carbon storage,followed by environmental factor,and human factor had the least impact.When analyzing the contribution rate of each influencing factor,forest carbon storage was affected most by itself,and showed a trend of decreasing gradually.In the long run,the change of forest carbon storage is affected by 79.48% of individual factors,0.07% by average annual temperature,0.17% by average annual precipitation,0.13% by average altitude,0.48% by forest area,0.39% by forest fire area,and 0.08% by forest pest area.16.29% was affected by GDP per capita and 2.90% by timber production.(4)The change trend of forest carbon sink economic value obtained based on carbon tax law and market value method is consistent,and the analysis is based on the estimated result of carbon tax law.From 1989 to 2018,the economic value of forest carbon sinks in China showed a fluctuating upward trend,with an average annual growth rate of 5.95%.Affected by the fluctuation of exchange rate,the average economic value of carbon sink in the near mature forest was the highest,which was3.902 billion yuan /a,and the proportion of the economic value of carbon sink in the plantation forest increased.As a whole,the high and medium high levels of forest carbon sink economic value in China during 1989-2018 were mainly concentrated in the northeast and southern coastal areas of China.Tibet Autonomous Region has the highest average carbon sink economic value of forest.(5)Based on GM(1,1)model and Logistic growth equation,the carbon stocks of Chinese trees in 2030 were predicted respectively.Compared with 2015,the predicted values of carbon stocks increased by 31.42% and 22.71%,respectively.At this time,the carbon sinks of forest were 260.60 Tg C/a and 153.32 Tg C/a,respectively,and the economic values of carbon sinks were 27.269 billion yuan /a and 16.043 billion yuan /a,respectively,indicating that the carbon sinks of Chinese forest had high growth potential and economic value.