Based On LUCC Daqing Area Analysis Of Soil Organic Carbon Change In Recent 35 Years

Soil organic carbon pool is the largest carbon pool of terrestrial ecosystem.Soil organic carbon storage is affected by land use/cover area change and land type organic carbon density change.Based on the spatial analysis of geographic information system.this study ended in 2019.Respectively to build daqing city in 1984 and in the initial stage of afforestation project ending stage in 2009 as the research start time,through the remote sensing image to obtain land use/cover change data in the study area,using a variety of parameter quantitative analysis of land use/cover change in different time scales the intensity and direction,combined with the field sampling analysis on the influence of soil organic carbon,Using geographic detectors and spatial analysis of geographic information system,different natural and social factors were selected to explore the relationship between driving factors behind soil organic carbon storage,and the following conclusions were drawn:(1)The intensity and direction of land use/cover will be significantly different at different time scales,and the succession direction of different land use/cover is a complex process.Compared with 1984,560548.563 hm2 of land type changed in 2019,and marshes dominated the total area of change,and the marshes were mainly replaced by grassland and arable land,accounting for 63.25%of the loss area of marshes.Compared with 2009,there were 78913.72 hm2 land type changes in 2009,and the decrease of grassland area accounted for the main position of area change during this period,and grassland was mainly replaced by arable land and saline-alkali land.In recent 10 years and in recent 35 years,the area of marsh and grassland showed a decreasing trend.(2)The change of soil organic carbon density showed a curve from decreasing to rising.According to one-way anova.0-20cm soil organic carbon content is significantly different from land use/cover type,and surface soil organic carbon is more susceptible to land use/cover change,and soil organic carbon density is also different due to different time scales.From 1984 to 2019,soil organic carbon density decreased from high to medium level.The change rate of soil organic carbon in marsh decreased the most,reaching 0.191kg/(m2·a),while that in grassland decreased the least,and tended to be constant.From 2009 to 2019,the soil organic carbon density showed an overall trend of recovery and partially recovered to a high level.The increase rate of swamp was 0.353 kg/(m2·a).which was the land use/cover type with the largest change range,and the change range of forest land was the smallest.(3)compared with 1984,soil organic carbon storage in 2019 decreased by 1.19×1010kgC;Compared with 2009,soil organic carbon storage in 2019 increased by 8.06×109kgC,and the driving factors behind this complex combination of soil organic carbon storage.In the past 35 years,grassland was the main reason for the decrease of soil organic carbon storage,and grassland accounted for 91.08%of soil organic carbon storage due to area reduction.In recent 10 years,forest land was the main reason for the increase of soil organic carbon storage,and forest land was the dominant area,contributing 93.83%.By exploring different natural and social factors through geographical detectors,it was found that temperature and precipitation were the main factors affecting soil organic carbon storage in the study area in recent 35 years,and the interaction of different driving factors had different degrees of impact on the explanatory power of soil organic carbon storage.