245 / 2023-09-29 22:46:38

The spatio-temporal variation law of vegetation net primary productivity in low-strength mining area

vegetation carbon sequestration capacity; Net primary productivity; Evolution law; Low intensity mining; Mann-Kendall test

Based on existing research, the scale of ecological environment measurement in mining areas is not precise enough, and the combination with coal mining conditions is not sufficient. In order to study the spatiotemporal evolution characteristics of Net Primary Productivity (NPP) of vegetation in mining areas under low intensity mining conditions, as well as the correlation between its influencing factors, this paper calculates the net primary productivity of vegetation in the Datai Mining Research Area, Control Area, and Mentougou Area from 2013 to 2020 based on the improved Carnegie Ames Stanford Approach (CASA) model; The spatiotemporal evolution characteristics of vegetation carbon sequestration capacity in mining areas were studied by combining M-K test and slope trend analysis；According to analyze the correlation between vegetation NPP and its influencing factors in mining areas based on Pearson correlation coefficient，The results indicate that:① From 2013 to 2020, the annual average NPP of vegetation in Mentougou District showed a fluctuating upward trend, with the minimum and maximum values being 268.5gC · m-2 and 295.2gC · m-2, respectively; The maximum annual vegetation NPP values of the Datai Mining Research Area and the Control Area are 601.1 gC · m-2 and 534.1 gC · m-2, respectively; The monthly variation pattern of vegetation NPP in the research area and control area of Datai Mine is basically consistent; ② In terms of space, the NPP values of vegetation in the eastern part of Mentougou District from 2013 to 2020 were lower than those in other regions, and the high NPP values of vegetation were mostly distributed in the southwest region; In the past 8 years, 54.3% of the areas in Mentougou District have remained basically unchanged in vegetation NPP, while 31.8% have slightly increased in vegetation NPP; The trend of vegetation NPP changes in the research area and control area of the Datai Mine is basically consistent. The overall area of vegetation NPP slightly decreased accounts for 46.7%, while the area of vegetation NPP slightly and significantly increased accounts for 37.4% ;③There is a significant correlation between vegetation NPP changes and annual cumulative precipitation changes in Mentougou District, with a maximum correlation coefficient of 0.96, which is also significantly related to annual temperature changes; ④ The correlation coefficients between vegetation NPP and annual coal output in the study and control areas are relatively close, with values of -0.79 and -0.83, respectively. Based on the spatiotemporal distribution characteristics of vegetation NPP in the study and control areas, it can be concluded that the mining activities of Datai Mine from 2013 to 2019 did not have a significant impact on the vegetation NPP of the mining area during this period.