摘要
为更客观监测评估喀斯特地区植被生态质量状况及阐明植被生态质量不同时间尺度的时空异质性特征,基于多年植被净初级生产力(NPP)、湿润指数(MI),建立植被净初级生产力极大值(NPPm)边缘函数,并结合植被覆盖度,构建出广西喀斯特地区植被综合生态质量模型(MQI),以分析2000—2019年该地区植被生态质量多尺度时空演变特征。结果表明:(1)植被NPPm是随气候条件变化的动态值,不同植被类型生产潜力对气候条件的响应不同,其中农田植被响应最敏感,灌草次之、森林最弱;(2)广西喀斯特地区月份与季度植被生态质量指数呈抛物线形式,年度植被生态质量指数呈波动式增加,年际植被生态质量发展经历了缓慢增长、逐步增长、迅速增长、显著提升4个演变阶段,且植被生态质量由广西喀斯特地区东北部向西南部、北部向南部逐渐递增,总体良好;(3)2000—2019年,广西喀斯特地区植被生态改善指数为0.71/20 a,98.83%的区域植被生态质量在20 a期间呈上升趋势,大部区域植被生态改善良好,这主要得益于退耕还林、石漠化治理工程和良好气候条件;(4)此植被生态质量模型区域适宜性较高,能精细化、精准化反映广西喀斯特地区植被生态质量的时空演变特征。
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.
作者
莫建飞
陈燕丽
莫伟华
MO Jianfei;CHEN Yanli;MO Weihua(Guangxi Institute of Meteorological Sciences,Nanning,Guangxi 530022,China;Guangxi Ecological Meteorology and Satellite Remote Sensing Center,Nanning,Guangxi 530022,China)
出处
《中国岩溶》
CAS
CSCD
北大核心
2023年第5期1117-1130,共14页
Carsologica Sinica
基金
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)。
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
vegetation ecological quality
net primary productivity
spatial-temporal evolution
humidity index
the karst area of Guangxi
