Study On Spatio-temporal Evolution And Influencing Factors Of Land Use Carbon Emissions In Black Soil Area Of Northeast China

Global warming is becoming more and more serious,reducing carbon emissions and promoting the construction of ecological civilization have gradually become a consensus.Since the industrial revolution,under the influence of human activities,land use/land cover in different time and space scale rapid change,thus dramatically change the surface cover state,cause the ecosystem material cycle and energy flow huge changes,directly affect the land ecosystem carbon regulation process,but also become one of the important driving factors of global climate change.Therefore,carbon emissions caused by land use change is one of the important influencing factors of global warming.Related land-use changes are considered the second largest contributor to global atmospheric CO2 increases.In recent decades,the increase in global carbon emissions has caused a series of environmental problems,such as global climate anomalies,sea level rise and frequent extreme weather events,which have greatly affected human production and life.Adhering to the responsibility of a big country,China has put forward the strategy of carbon peak carbon neutrality,pointing out that carbon emissions should peak by 2030 and carbon neutrality by 2060.In this context,the efficient use of land and the reduction of carbon emissions have gradually become the focus of attention.The change of land use affects carbon emissions to a large extent.Exploring the change mechanism of land use carbon emissions and analyzing the influence and mechanism of relevant influencing factors on this mechanism can help promote the realization of carbon peak carbon neutrality goals and promote the establishment of low-carbon cities.The black soil area in Northeast China is a traditional agricultural and heavy industrial base in China.It consumes a lot of energy and has a large space to reduce carbon emissions.Based on this,this paper studies the black soil region in Northeast China,selects the data of the black soil region in Northeast China and its 96 county-level administrative units from 1990 to 2020,and takes the whole region and the county as a unit respectively.The change law of carbon emissions in the use of land in the region reveals the mechanism of the relevant influencing factors,and puts forward reasonable suggestions on how to reduce carbon emissions in the region,hoping to help the region reduce emissions and ultimately achieve green and high-quality development.The main results of this study are as follows:(1)Cultivated land and forest land are the main land use types in the black soil area of Northeast China,accounting for more than 70%of the total land area.From 1990 to 2020,the area of forest land,grassland and water area showed a decreasing trend,and the area of cultivated land,construction land and unused land showed an increasing trend.The overall change of cultivated land and forest land is relatively stable due to the large area base.The area of cultivated land increased from 1938.33 km2in 1990 to 2220.88 km2in 2020,with an average annual growth rate of only 2.43%.The area of forest land decreased by 108.07 km2,with an average annual change rate of only-1.03%.Due to the small area base,the overall change of grassland is obvious,and the area is reduced by more than half.The area of construction land gradually increased but the overall change was small.Cultivated land and woodland and grassland are transformed into each other in a large area.Construction land and cultivated land are transformed into each other due to village merging and urban expansion.(2)From 1990 to 2020,the net carbon emissions of land use in the black soil region of Northeast China showed an increasing trend,from 11.91×10~4t to 253.29×10~4t,with an annual growth rate of 4.53%.Cultivated land dominated by agricultural activities was the main carbon source,accounting for 76.82%of the total carbon source from 1990 to 90.01%in 2020.Forest land is the main carbon sink,accounting for 96%of the total carbon sink.The total carbon emissions of most counties in the black soil area of Northeast China showed a continuous increasing trend.The total carbon emissions of Dehui City,Nehe City and Changchun City were the largest,accounting for 42.23%of the total carbon emissions in the black soil area of Northeast China.Oroqen Autonomous Banner,Zhalantun City,Daqingshan County and other counties and cities are completely carbon absorption.In addition,the spatial distribution of land use carbon emissions in the study area is concentrated,but the spatial agglomeration phenomenon is gradually weakening,and the emission gap between regions is gradually narrowing.(3)In general,the most important factor affecting the carbon emissions of land use in the black soil region of Northeast China from 1990 to 2020 was the income level,which increased the carbon emissions by 1398.35×10~4t.The impact of land use structure,land carbon emission intensity and population size on carbon emissions is also positive,which increased carbon emissions by 213.44×10~4t,186.26×10~4t and 173.95×10~4t,respectively.Land use efficiency has an inhibitory effect on net carbon emissions,and the reduction value of land use carbon emissions is1730.63×10~4t.