中国岩溶2023，Vol.42Issue(5)：1117-1130,14.DOI:10.11932/karst2023y037
广西喀斯特地区植被生态质量多尺度时空演变分析
Multi-scaled analysis of spatial-temporal evolution of vegetation ecological quality in the karst area of Guangxi
摘要
Abstract
The karst area in Guangxi is characterized by its extensive and typical landform development,covering a total area of 8.334 million hectares,18.9％of the total karst area in Southwest China and 35.1％of the total land area in Guangxi.This area is marked by poor and shallow soil,dominated by shrubs,shrub-grass,and grasslands as its vegetation.Therefore,it is subject to climate changes and meteorological disasters with a weak disaster-bearing capacity.The area is a typical ecologically vulnerable region in the southwest of China,and it is also the focus area for the Guangxi government to carry out ecological protection and restoration and rural revitalization.The scientific and rational assessment of vegetation ecological quality and its spatial-temporal evolution in the karst area is crucial for ecological restoration and governance,and the achievement of the"dual-carbon"goal. In order to monitor and assess the status of vegetation ecological quality in karst areas more objectively,and to clarify the spatial-temporal heterogeneity of vegetation ecological quality at different time scales,this study took the vegetation in the karst area of Guangxi as object.Based on the principle of"similar habitat"for vegetation ecological restoration,the"3S"technology was used to monitor and assess the vegetation ecological quality in the study area at different spatial and temporal scales.Firstly,the climate data was used to calculate the multi-year moisture index(MI)of the study area and delineate the climate gradient.Secondly,the maximum net primary productivity(NPPm)of the vegetation in the corresponding period was calculated.The correlation between MI and NPPm of the vegetation was analyzed,and the NPPm edge function of different vegetation types was constructed to determine the natural"baseline"of the potential productivity of vegetation within the climate gradient.Then a comprehensive vegetation quality model(MQI)for the karst area of Guangxi was built.Finally,the ecological quality index of vegetation was respectively calculated at monthly,quarterly,annual,and interannual scales to conduct a multi-scaled analyze of spatial-temporal evolution of vegetation ecological quality in the study area from 2000 to 2019. The results showed that:(1)There were obvious differences in the potential of vegetation ecological restoration under different climatic conditions in the karst area of Guangxi.The NPPm was a dynamic value that changes with climatic conditions,and different vegetation types responded differently to climatic conditions.Among these types,farmland vegetation was the most sensitive,followed by shrub-grass,and forest was the least affected.(2)There were significant temporal and spatial differences in the vegetation ecological quality at monthly,quarterly,annual,and interannual scales in the karst area of Guangxi.Temporally,the ecological quality indexes of vegetation at monthly and quarterly scales followed a parabolic pattern,and the annual index showed an increasing trend with fluctuation.The interannual evolution of vegetation ecological quality experienced four stages:slow growth,gradual growth,rapid growth,and significant growth.Spatially,vegetation ecological quality gradually increased from the northeastern to the southwestern part and from the northern to the southern part of the study area,with an overall high ecological quality.(3)There was a significant improvement in vegetation ecological quality in the karst area of Guangxi.From 2000 to 2019,the index of vegetation ecological improvement was 0.71/20a in the study area,with 98.83％of the regional vegetation ecological quality showing an upward trend over the 20-year period.Most of the improvement of regional vegetation ecology was favorable,primarily attributed to the national policies of returning farmland to forests,projects of rocky desertification control,and the favorable climate conditions in Guangxi.(4)The model for vegetation ecological quality of the study area exhibits high regional suitability and is able to finely and accurately reflect the spatial-temporal evolution characteristics of vegetation ecological quality in the study area.关键词
植被生态质量/植被净初级生产力/时空演变/湿润指数/广西喀斯特地区Key words
vegetation ecological quality/net primary productivity/spatial-temporal evolution/humidity index/the karst area of Guangxi分类
资源环境引用本文复制引用
莫建飞,陈燕丽,莫伟华..广西喀斯特地区植被生态质量多尺度时空演变分析[J].中国岩溶,2023,42(5):1117-1130,14.基金项目
广西重点研发计划项目(桂科AB23026052 （）
桂科AB17292051) （）
广西气象科研计划重点项目(桂气科2023Z03) （桂气科2023Z03）
