基于InVEST模型的芜湖市固碳能力及影响因子研究

A Study on Carbon Fixation Capacity and Its Influencing Factors Based on InVEST Model at Wuhu City

[目的]研究安徽省芜湖市2011—2021年碳储量时空分布格局,同时探究生态环境因子、地形因子、气象因子和土地利用程度对其固碳能力的影响变化,为芜湖市土地资源管理及绿色农业发展提供参考依据。[方法]以芜湖市2011,2015,2021年土地利用数据,利用InVEST模型Carbon storage模块定量评估研究碳储量空间分布,探究土地利用程度、地形、气象、土壤侵蚀等因子影响,并根据相关性分析叠加计算碳储量热点区域。[结果](1)近年,芜湖市因土地利用变化碳储量减少了4.14×10^(5) t,呈逐年减少趋势;固碳能力:草地<耕地<林地,林地为5 488.97 t/km^(2)且耕地碳储量高达7.39×10^(6) t。(2)在自然因素中,用地类型、海拔、坡度及土地利用程度是影响碳储量空间分布主要原因,随海拔、坡度升高而逐级缓慢增加,碳储量整体呈“北低南高”分布情况。(3)在生态环境因素中,碳储量与土壤保持为显著正相关,相辅相成互为协同关系;相反,与土壤侵蚀互为权衡关系。(4)南部碳储量呈现“高—高集聚”占18.77%,北部为“低—低集聚”仅为2.73%;碳储量热点区域因资源开发利用影响呈逐年减少趋势,优良区域占11.95%,集中于南部山林地带,局部较弱需重点保护管理优化。[结论] 2011—2021年芜湖市固碳总量逐年减少,固碳速率呈现逐年减弱趋势,固碳能力较稳定。芜湖市北部固碳能力相对较弱,可通过土地管理优化以提升其固碳能力。

[Objective]The spatial and temporal distribution pattern of carbon storage at Wuhu City,Anhui Province from^(2)011 to 2021 were analyzed,and the influence of ecological environmental factors,topographic factors,meteorological factors,and land use degree on carbon sequestration capacity were determined in order to provide a reference for land resource management and green agricultural development at Wuhu City.[Methods]The carbon storage module of the InVEST model was used to quantitatively determine the spatial distribution of carbon storage,to explore the effects of land use degree,topography,meteorology,soil erosion,and other factors,and to calculate the hot spots of carbon storage based on correlation analysis superposition using land use data from^(2)011,2015,and 2021 at Wuhu City.[Results]①Carbon storage at Wuhu City has declined by 4.15×10^(5) t in recent years due to land use changes,with an annually decreasing trend.The carbon sequestration capacity of grassland was lower than that of cultivated land.The carbon storage capacity of cultivated land was 7.41×10^(6) t,while that of forest land was 5489.01 t/km^(2).②Land use type,elevation,slope,and land use degree were the most important natural factors determining the spatial distribution of carbon stocks,which increased gradually step by step with altitude and slope.The overall distribution of carbon stocks was“lower in the north and higher in the south.”③Carbon storage and soil conservation were significantly and positively associated,mutually reinforcing,and synergistic among ecological and environmental variables;yet,there was a trade-off with soil erosion.④Carbon storage in the south showed a pattern of“high-high accumulation”,accounting for 18.77%of the total carbon accumulation,whereas carbon storage in the north showed a pattern of low-low accumulation,accounting for just 2.73%of the total carbon accumulation.The hotspots of carbon storage declined over time as a result of the effect of resource development and usage,with 11.95%of the area classified as excellent concentrated in the southern mountain forest.Certain areas were found to be vulnerable and will need to be conserved and optimized.[Conclusion]From^(2)011 to 2021,the total amount of carbon sequestration at Wuhu City decreased year by year,and the carbon sequestration rate showed a trend of weakening over time,while carbon sequestration capacity was relatively stable.Carbon sequestration capacity in the northern part of Wuhu City was relatively weak,and could be increased through land management optimization.