贵阳市植被净初级生产力与景观格局时空分布及相关性研究

Study on the correlation between net primary productivity of vegetation and the landscape pattern of temporal and spatial distribution in Guiyang

为研究贵阳市的净初级生产力(NPP)及景观格局时空分布及相关性,采用CASA估算、景观格局指数、空间自相关方法对2000—2019年的遥感数据进行分析。结果表明:贵阳市净初级生产力总体水平较高,多年均值为678.1 g C·(m^(2)·a)^(-1),由421.1 g C·(m^(2)·a)^(-1)增长到894.9 g C·(m^(2)·a)^(-1),NPP的增长与各县域的空间分布相关性逐渐增强,整体呈北高南低的空间分布特点;景观格局上,贵阳市蔓延度由50.8%~67.2%降低到49.2%~66.1%,景观破碎化加深,边缘密度由24.6~50.3 m·ha^(-1)上升为24.7~51.9 m·ha^(-1),边缘逐渐复杂且不规则,斑块密度由0.4~1.8 n·99 ha^(-1)上升到0.5~2.0 n·99 ha^(-1),景观类型迭代迅速;景观丰度由3.5~5.3上升到4.2~5.5,景观源地类型逐渐增加,平均邻近度指数由147.0~527.8上升到161.0~551.6,景观连接度逐渐增加,香农多样性指数由0.7~1.2(n·100 ha^(-1))上升到0.8~1.3(n·100 ha^(-1)),景观类型的信息量随之增加,斑块相似系数由22880.3降到20177.2,斑块异质性逐渐加强,核心斑块总面积由8543.0 ha降低到8505.2 ha,核心斑块减少;基于经验贝叶斯的莫兰指数分析,平均邻近度指数、斑块相似系数、边缘密度、斑块密度与NPP相关性最强,贵阳市林地、疏林、高覆被草地增加,其斑块破碎化增加,边缘逐渐略显复杂不规则,类型逐渐增多,斑块间连接度增加,有利于NPP的迅速增加。

In order to study the temporal and spatial distribution and correlation of net primary productivity(NPP)and landscape pattern in Guiyang,the remote sensing data from 2000 to 2019 were analyzed by using CASA estimation,landscape pattern index,and spatial autocorrelation methods.The results show that:The overall level of net primary productivity in Guiyang is relatively high,with a multi-year average value of 678.1 g C·(m^(2)·a)^(-1),increasing from 421.1 g C·(m^(2)·a)^(-1) to 894.9 g C·(m^(2)·a)^(-1);The correlation between the growth of NPP and the spatial distribution of each county is gradually enhanced,and the overall spatial distribution of NPP is high in the north and low in the south;In terms of landscape pattern,the spread of Guiyang City has decreased from 50.8%~67.2%to 49.2%~66.1%,and the fragmentation of the landscape has deepened.The edge density increased from 24.6~50.3 m·ha^(-1) to 24.7~51.9 m·ha^(-1),and the edges are gradually complicated and irregular,and the patch density increased from 0.4~1.8 n·99 ha^(-1) to 0.5~2.0 n·99 ha^(-1);The landscape type iterates rapidly;The landscape abundance rises from 3.5~5.3 to 4.2~5.5;The type of landscape source gradually increases;The average proximity index rises from 147.0~527.8 to 161.0~551.6,and the landscape connectivity gradually increases;Shannon diversity index rises from 0.7~1.2(n·100 ha^(-1))to 0.8~1.3(n·100 ha^(-1)),and the amount of information of landscape types increases accordingly;The patch similarity coefficient drops from 22880.3 to 20177.2;The patch heterogeneity gradually strengthened;the total area of the core patch decreased from 8543.0 ha to 8505.2 ha.Core patches are reduced;Based on empirical Bayesian Moran index analysis,the average proximity index,patch similarity coefficient,edge density,and patch density have the strongest correlations with NPP.With the increase of the woodland,sparse forest,and covering grassland of Guiyang City,the fragmentation of woodland patches increased,the edges gradually became slightly complex and irregular;The types gradually increased,and the connectivity between patches increased,which was conducive to the rapid increase of NPP.