Spatio-temporal Evolution Characteristics About Carbon Storage In Terrestrial Ecosystems Of The Yangtze River Economic Belt Under The Perspective Of Land Use

There are large amounts of carbon stored in terrestrial ecosystems,and land use directly impacts the carbon cycling process between the land ecosystem and the atmospheric environment.Improper land use can cause a significant amount of stored carbon in the terrestrial ecosystem to be released into the atmosphere,increase CO2concentrations,and aggravate the greenhouse effect.Scientific land use planning and ecosystem stability can promote regional development.This article evaluates the characteristics of regional land use and carbon storage changes to reveal the spatiotemporal patterns of land use and carbon storage,providing a basis for regional ecological and economic development planning in the context of carbon reduction.This article focused on the nine provinces and two municipalities in the Yangtze River Economic Belt as the research object.ENVI5.3 and Arc GIS10.2 software were used to interpret and classify five-phase Landsat remote sensing images from 2000,2005,2010,2015,and 2020.Through geographic spatial analysis,the spatiotemporal characteristics of the land use structure in the Yangtze River Economic Belt were analyzed.By reviewing previous literature on the area,carbon density data in the Yangtze River Economic Belt was obtained.Using the In VEST model and combining land use change data,the carbon storage of the terrestrial ecosystem in the region was calculated and visualized,revealing the spatiotemporal characteristics of the carbon storage in the terrestrial ecosystem.The spatial correlation analysis was used to analyze the clustering effects of regional carbon storage.The Markov-FLUS coupling model was used to simulate land use changes in the Yangtze River Economic Belt under the natural development scenario and the ecological protection scenario,and its impact on carbon storage was analyzed.The following conclusions were drawn:(1)The spatial distribution of land use types in the Yangtze River Economic Belt differs significantly,with forest land being the largest land use type,concentrated in the middle and upper reaches of the Yangtze River Economic Belt,accounting for more than 50%.The second largest land use type is arable land,accounting for more than30%,mainly distributed in the Sichuan Basin in the upper reaches of the Yangtze River and the plain area in the middle and lower reaches of the Yangtze River.Between 2000and 2020,the area of cultivated land transferred out was the largest,followed by grassland,with 23,018.02 km~2 and 15,776.88 km~2,respectively.The area of construction land transferred in was the largest,with an increase of 33,065.03 km~2 or89.6%from 2000 to 2020.It is the land type with the highest attitude towards land use.(2)The carbon storage of the terrestrial ecosystem in the Yangtze River Economic Belt was 25,049.24 Tg,25,032.78 Tg,25,011.05 Tg,24,961.36 Tg,and 24,986.53 Tg in 2000,2005,2010,2015,and 2020,respectively.The carbon storage of the terrestrial ecosystem in the Yangtze River Economic Belt first decreased and then increased,with carbon loss reaching its highest point between 2010 and 2015,after which carbon storage began to recover.The sum of carbon storage in the upper reaches of the Yangtze River was as high as 58%,making it an important carbon sink in the Yangtze River Economic Belt.There are differences in the spatial distribution of carbon storage in the terrestrial ecosystem in the Yangtze River Economic Belt,which generally decreases from west to east.High-carbon storage areas have a significant clustering effect,while low-carbon storage areas also exhibit significant clustering.The results of driving factors of geographical exploration of carbon storage show that altitude and socio-economic factors are the main driving factors of regional carbon storage,and the interactive driving of factors is stronger than that of single factor,and the interactive driving of normalized vegetation index(NDVI)is stronger.(3)The Markov-FLUS coupling model results:Under the simulation scenario of natural development and ecological protection,the area of arable land,forest land,grassland,and water area decreases,while the area of construction land and unused land increases.Compared with natural development scenarios,the reduction in ecological protection scenarios is relatively small,and green resources such as forests and grasslands are more protected.Under the natural development scenario,the decrease of carbon storage is mainly caused by the increase of construction land area,while under the ecological protection scenario,the difficulty of conversion of forest land types with high carbon storage increases,the area of forest land conversion to farmland and construction land decreases,and the regional carbon storage decreases.However,with the conversion of low carbon storage farmland,unused land and grassland to high carbon storage forest land,the decline of regional carbon storage slows down,and some provinces’carbon storage slightly recovers.