| As the most important carbon reservoir in the global carbon cycle,the total carbon storage of terrestrial ecosystem is about four times of the atmospheric carbon storage,so accurate assessment of the carbon sequestration service function of terrestrial ecosystem has gradually become a research hotpot of global climate change.As an important part of the ecosystem,land use change is an essential reason for the change of carbon storage.It further impacts the terrestrial carbon cycle by affecting the allocation of carbon storage in the terrestrial ecosystem,which is the main human factor leading to the increase of greenhouse gas emissions,second only to fossil fuel combustion.Taking the Hexi Corridor,a typical arid and semi-arid area in northwest China,as an example,based on the five periods of land use data of the Hexi Corridor in 2000,2005,2010,2015 and 2020,this paper analyzes the land use change in the Hexi Corridor and its impact on regional ecosystem carbon storage by combining ArcGIS and InVEST model,and reveals the influencing factors of spatial heterogeneity of carbon storage in the Hexi Corridor.On this basis,the GMOP-PLUS model is used to simulate the land use change trend and the temporal and spatial evolution characteristics of carbon storage under the natural development scenario and ecological protection scenario in the future 2035.The main conclusions of the study are as follows:(1)The land use in the Hexi Corridor shows obvious spatial differentiation characteristics,with unused land being the main type of land use,and the spatial distribution changes of grassland and unused land are significant.From the perspective of various land use types in the Hexi Corridor,the area size is respectively unused land>grassland>cultivated land>forest>water area>construction land.The land use structure is relatively single,the unused land area accounts for more than 70%of the total area of the region.From 2000 to 2020,about 32155.76 km~2of land in the Hexi Corridor has changed,accounting for 7.7%of the total area.The land use of the Hexi Corridor is trending towards a positive transfer,and the ecosystem is gradually stabilizing.(2)The carbon storage of Hexi Corridor in 2000,2005,2010,2015 and 2020 are152.73×10~6、155.26×10~6、159.43×10~6、161.47×10~6、161.78×10~6t,showing an increasing trend year by year,with a cumulative increase of 9.05×10~6t.Among them,the fastest increase was from 2005 to 2010,with an increase of 4.17×10~6t.Grassland is the most important carbon pool in the Hexi Corridor,contributing about 46.93%of the carbon storage.The increase of carbon storage in the Hexi Corridor is mainly due to the transformation between different land use types,which indicates that the positive evolution of the ecosystem makes the carbon storage in the Hexi Corridor continue to increase.From the perspective of spatial distribution,the spatial distribution pattern of carbon storage in the Hexi Corridor is generally characterized by"belt in the west-flaky in the southeast",but the spatial distribution of carbon storage changes little,and carbon storage in most regions remains unchanged.(3)The results of the influencing factors of carbon storage show that the main driving factors affecting the spatial differentiation of carbon storage in the Hexi Corridor are natural factors,and the influence degree of natural factors is greater than that of human factors.The factor detection results showed that vegetation coverage,precipitation,and soil type were the main factors.The interaction of any two factors has a greater impact on the carbon storage of the Hexi Corridor than that of a single factor,and both of them show two relationships of dual-factor enhancement and nonlinear enhancement.Especially in the nonlinear enhancement relationship,mainly the interaction of natural factors and human factors.(4)Under the two scenarios in 2035,the land use structure and spatial pattern of the Hexi Corridor are better than the current land use distribution pattern in 2020.Moreover,the land use structure and spatial pattern of the ecological protection scenario are better than those of the natural development scenario.The carbon storage showed an increasing trend under both the natural development scenario and the ecological protection scenario in 2035.Compared with 2020,the carbon storage under the natural development scenario increases by 5.12×10~6 t,and the carbon storage under the ecological protection scenario increases by 14.28×10~6 t.In general,the increase of carbon storage under the ecological protection scenario is significantly higher than that under the natural change scenario,which is mainly due to the different change trends of grassland and cultivated land area. |
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