基于土地利用变化的广东省生境质量时空演变特征

Spatio-temporal characteristics of habitat quality based on land-use changes in Guangdong Province

生境质量的高低成为测度地区生态健康及可持续状态的关键因子。广东省生态质量及退化过程复杂,目前对该领域的研究较为薄弱。利用FLUS-InVEST耦合模型,对广东省1980—2020年生境质量变化及未来2020—2035年生境质量趋势进行研究。得出以下主要结果:(1)林地、耕地为广东省的主要土地利用类型,构成了地表覆盖景观基质;建设用地增加迅速,40年间面积翻了1.2倍;耕地锐减,面积比由27.1%减到22.8%;如果继续保持历史变化趋势,未来15年间建设用地面积将继续增加,耕地面积则减少至不足22%。(2)林地集中连片区域主要在北部生态发展区,耕地集聚分布于东西两翼,除几个大的水库图斑外,湿地在整个研究区都有分布;北部生态发展区域内的林地表现出破碎化特征,部分区域耕地、湿地都有减小和破碎化趋势。(3)过去的40年,生境质量变好的区域面积占比最大(44%),其次是未变化(29%)和减小的区域(27%),其中,约79%的区域指数值增减在-0.1—0.1之间;未来15年里,质量指数继续增大的区域面积比例将减少到39%,继续减小的比例将增大到31%;粤港澳大湾区局部低级别生境有连片的趋向。(4)即使没有土地利用类型转换变化,部分区域的生境质量也有增加或减小的变化;但存在土地利用类型变化的区域,生境质量变化的强度更大。以上结果说明,广东省生境质量总体较好,但局部有变差的态势,土地利用类型变化与生境质量的响应关系较为复杂。认知区域生态环境的特征,加强土地利用变化与生境质量响应关系及其机理的探究,可为目前正在实施的生态修复工作提供研究支持。

On one hand,habitat quality has become a main factor to measure regionally ecological health and sustainable state.On the other hand,the ecological quality and degradation process in Guangdong Province are complex though solid researches were rarely recorded.Therefore,this paper used the FLUS-InVEST coupling model to study the habitat quality changes in Guangdong Province from 1980 to 2020 and forecasted the future trends from 2020 to 2035.The main results are as follows:(1)Forest land and cultivated land were the main land uses in Guangdong Province,which constituted the landscape matrix of land cover.Construction land has increased rapidly,with the area of 1.2 times in the past 40 years.The area of cultivated land has dropped sharply,with the ratio decreased from 27.1%to 22.8%.The area of construction land was expected to increase and the area of cultivated land would decrease to less than 22%in the next 15 years if following the trends.(2)Forest land was mainly in the northern ecological development area.The cultivated land was concentrated in the east and west wings of Guangdong Province.Except for several large reservoir spots,wetland distributed throughout the study area.The forest land in the northern ecological development area has shown the characteristics of fragmentation,and the cultivated land and wetland in some areas had a trend of decreasing and fragmentation.(3)In the past 40 years,the area of improved habitat quality accounted for the largest proportion(44%),followed by areas that remained unchanged(29%)and decreased(27%).Approximate 79%of regional habitat quality indices increased or decreased between-0.1 and 0.1.In the next 15 years,the proportion of area where habitat quality continued to increase will decrease to 39%.The proportion will increase to 31%,and the low-level habitat patches in the core area of the Pearl River Delta were expanding.(4)Without land-use changes,there were still diverse habitat-quality changes in some areas.But habitat-quality changes were greater in areas where land uses have been transferred from one to another.The results concluded that the habitat quality in Guangdong Province had the characteristics of overall good advantages and prominent local deterioration,which was the regional characteristics that needed to be recognized in the present ecological restoration work.Relationship between land-use change and habitat-quality effect were much more complex,which needed further reveal in the future studies.