大老岭国家级自然保护区是三峡库区重要的水源涵养林区,在改善生态环境、保护生物多样性等方面发挥了重大作用.本文结合多源遥感数据与气象观测资料,构建植被生态质量指数(vegetation ecological quality index,VEQI)模型,通过趋势分析、稳定性分析、相关分析、通径分析、灰色关联度分析等方法,探究大老岭2013-2022年VEQI时空变化及其对气候因子的响应.结果表明:(1)近十年植被平均VEQI为91.8,达极优等级,空间上南部区域好于北部.(2)VEQ1趋势变化总体表现为南部增加、北部减少,增加区域面积占25.9％.整体表现为低波动,其中南部增加区域表现为低-中低波动,中部和北部减少区域表现为中低-中波动,局地达中高波动.(3)热量因子中,VEQI与年平均气温(average temperature,TA)极显著负相关,与霜冻日期(frost date,FD)、高温日数(high temperature days,HD)极显著正相关,与暖昼日数(number of warm days,WDD)显著负相关.HD间接作用最大,FD通过TA起的间接作用最大,与冷夜日数(number of cold nights,CND)的关联度最大.(4)水分因子中,VEQI与年降水量(annual precipitation,PA)显著正相关,与年累计降水日数(annual cumulative precipitation days,PAD)、持续有雨日数(continuous rainy days,CDR)极显著正相关.RA 间接作用最大,且主要通过中雨日数(number of moderate rainy days,RMD)起间接作用,VEQI与PAD的关联度最大.研究结果加深了对大老岭植被生态质量时空变化及其气候驱动因素的认识,对大老岭甚至全国其他地区的生态文明建设具有重要意义.
Variation of Vegetation Ecological Quality in Dalaoling National Nature Reserve and Its Response to Hydro-thermal Conditions
As an important water conservation forest area in the Three Gorges Reservoir,Dalaoling National Nature Reserve plays an important role in improving the ecological environment and protecting biodiversity.The study constructed a vegetation ecological quality index(VEQI)model by multi-source remote sensing data and meteorological observation data.The Spatio-temporal varia-tion and its response to climatic factors were investigated by Theil-Sen trend analysis,stability analysis,correlation analysis,path analysis,gray correlation analysis and so on in Dalaoling from 2013 to 2022.The results show that:(1)The average annual VEQI is 91.8,reaching the excellent grade.The southern region is better than the northern region spatially.(2)The overall change of VEQI trend shows an increase in the south and a decrease in the north,with the increased area accounting for 25.9％.Overally,it shows low volatility,but in the increased southern areas low-medium-low fluctuation,in the decreased central and northern areas medi-um-low-medium fluctuation,and in some local areas medium-high fluctuation.(3)In the heat factors,VEQI was extremly signifi-cant negative correlation with annual mean temperature(TA),extremely sighificant positive correlation with frost date(FD)and high temperature days(HD),and nagative correlation with the numer of warm days(WDD).The indirect effect of HD was the greatest and the indirect effect of FD was the greatest through TA.The correlation with the number of cold nights(CND)was the highest.(4)In the water factors,VEQI was significantly and positively correlated with annual precipitation(PA),significantly and positively cor-related with the annual cumulative precipitation days(PAD)and the days of continuous rainfall(CDR).The indirect effect of RY was the largest,and the indirect effect of RY was mainly through RMD.The results deepen the understanding of temporal and spa-tial variation of vegetation ecological quality and its climate driving factors in Dalaoling,and it is of great significance to the con-struction of ecological civilization in Dalaoling and other areas of China.
万方数据
维普
