The vegetation spatiotemporal evolution and the response to geographical environment of Qian-Gui region in 20 years
[Objective]The aims of this study are to examine the spatiotemporal changes of vegetation in the Qian-Gui region and its response to the geographical environment,and to provide the scientific reference for the benefit assessment of regional ecological restoration projects and further restoration efforts.[Methods]Based on NDVI data,combined with the baseline and trend of vegetation,regional vegetation was categorized into nine status types.The response of vegetation in different status types to geographical characteristics such as lithology,topography,soil,and topographic position index was analyzed by using the Normalized Difference Vegetation Index(NDVI).[Results](1)From 2001 to 2020,the annual mean NDVI exhibited a fluctuating increase,with an average trend rate of 1.8 X10-3 per year.The vegetation areas in recovery,degradation,and stable states accounted for 30.8％,9.1％,and 60.1％,respectively.(2)The proportion of stable vegetation types gradually decreased across low,medium,and high coverage vegetation,while the proportions of degraded and recovering types increased sequentially.(3)On pure carbonate rocks,the normalized area index for high coverage vegetation was below the mean,and for low coverage vegetation,it was above the mean,whereas clastic rocks showed the opposite pattern.(4)The response of vegetation to red soil and paddy soil was correlated with the background coverage degree.(5)Low coverage stable vegetation was concentrated in karst gorge areas,with high coverage vegetation showing a clear advantage in peak cluster depressions.(6)The response relationship between low coverage vegetation and topography was significant,while the influence of topography on medium coverage vegetation was less pronounced.[Conclusion]The vegetation in the Qian-Gui region generally shows an improving trend,with uneven spatial distribution across different vegetation states types.The vegetation on lateritic red soil and karst canyons is relatively stable,while the high coverage vegetation in the yellow soil areas and peak forest plains shows a more noticeable unidirectional degradation.High coverage and low coverage vegetation are concentrated in areas of medium and low topographic values,respectively.
万方数据
维普
