摘要
植被在生态系统中具有不可替代的作用,深入探讨植被覆盖的空间变化及影响因素对研究区的生态保护及政策落实具有重要意义。植被覆盖变化是多因素综合作用的结果,而前人研究主要集中于气候变化或地形变化等单一因素对植被的影响研究,缺乏对气候条件、地形变化及人口特征等多因素对植被综合作用影响的研究,不利于对植被覆盖变化主要驱动因素的客观判断。为深入了解祁连山NDVI的变化规律及驱动机制,本文以祁连山南坡这一典型区域为例,基于2000—2020年NDVI数据及气象、土壤、植被、地貌、地形、人口等要素,运用重心迁移模型及地理探测器模型对研究区植被时空变化特征及影响因素进行分析。结果表明:(1)祁连山南坡近20年植被覆盖呈逐渐变好趋势;(2)在不同土地利用类型中,未利用土地植被覆盖重心迁移距离最大,为319.77 m,迁移速率为15.23 m/a;其次,草地植被覆盖重心迁移距离为116.12 m,迁移速率为5.23 m/a,林地与耕地植被重心迁移距离最小,分别为4.66 m与1.30 m,迁移速率分别为0.22 m/a与0.66 m/a;(3)通过地理探测器分析,影响祁连山南坡植被覆盖最主要的因素为年均温、DEM、土壤类型及植被类型,评价指标交互组合表现出6.67%的独立现象、35.56%的双因子增强的现象、57.77%的非线性增强的现象;(4)祁连山南坡植被生长最适宜范围为平均温度为0.6℃~2℃、相对湿度为43.91%~48.74%、坡度为0°~7.27°、降雨为204.03~335.97 mm、人口密度为133.98~204.03人/km2、土壤类型为棕黑毡土、植被类型为高寒禾草、苔草草原、地貌为中起伏低山、DEM为3005~3263 m及坡向为北坡时。本研究有助于深入了解干旱半干旱区植被生长与植被恢复情况,并为生态工程及修复工程的实施提供一定理论依据。
Vegetation plays an irreplaceable role as environment indicator in ecosystem. The change of vegetation coveris is a result of combined effect of multiple factors. In-depth discussion on vegetation coverage in an ecosystem-concerned area regarding to their spatial changes or associated influencing factors is of great significance for ecological protection and policy-making. Past studies mainly aimed to the influence of a single factor on vegetation, such as climate change or topographic modification, but they ignored the influences of non-climatic factors, including population density on vegetation, and also lacked proper comments on the comprehensive effects of climate, topographic features, and population on vegetation change, therefore making the past findings in vegetation coverage less applicable as expected.In order to deeply understand the change law and driving mechanism of NDVI in the Qilian Mountains, taking the typical area on the south slope of the Qilian Mountains as an example, this paper analyzed the temporal and spatial change characteristics and influencing factors of vegetation by center of gravity migration model and geographical detector model based on NDVI data from 2000 to 2020 and other factors such as meteorology, soil,vegetation, landform, topography and population. The results show that:(1) The vegetation coverage on the southern slope of the Qilian Mountains has gradually improved in recent 20 years;(2) Among different land use types, the distance of gravity center of vegetation cover in unused land was the largest, which was 319. 77 m, and the migration rate was 15. 23 m/a;Secondly, the migration distance of barycenter of vegetation cover in grassland was 116. 12 m, and the migration rate was 5. 23 m/a, while the migration distance of barycenter of forest land and cultivated land was the smallest, which was 4. 66 m and 1. 30 m, and the migration rate was 0. 22 m/a and0. 66 m/a, respectively;(3) According to the analysis of geographical detectors, the main factors affecting vegetation coverage on the southern slope of the Qilian Mountains were average annual temperature, DEM, soil type and vegetation type. The interactive combination of evaluation indexes showed 6. 67% independent phenomenon,35. 56% double factor enhancement phenomenon and 57. 77% nonlinear enhancement phenomenon;(4) The most suitable range of vegetation growth on the south slope of the Qilian Mountains was the average temperature of0. 6 ℃ ~ 2 ℃, relative humidity of 43. 91% ~ 48. 74%, slope of 0 ~ 7. 27, rainfall of 204. 03 ~ 335. 97 mm,population density of 133. 98 ~ 204. 03 persons per kilometers, soil type of brown-black felt soil, vegetation type of alpine grass and Carex grassland, landform of middle undulating low mountain, DEM of 3005 ~ 3263 m and slope aspect of north slope. This study is helpful to understand the vegetation growth and vegetation restoration in arid and semi-arid areas, and provides a theoretical basis for the implementation of ecological engineering and restoration engineering.
作者
童珊
曹广超
闫欣
刁二龙
张卓
TONG Shan;CAO Guangchao;YAN Xin;DIAO Erlong;ZHANG Zhuo(College of Geographical Sciences,Qinghai Normal University:Xining 810008,China;Qinghai Key Laboratory of Natural Geography and Environmental Process,Qinghai Normal University:Xining 810008,China;Key Laboratory of Earth Surface Processes and Ecological Conservation of the Ministry of Education,Qinghai-Tibet Plateau,Xining 810008,China)
出处
《山地学报》
CSCD
北大核心
2022年第4期491-503,共13页
Mountain Research
基金
青海省2020年第二批林业改革与发展基金湿地保护与恢复项目(QHTX-2020-043-02)~~。
关键词
植被覆盖
时空变化
迁移特征
地理探测
祁连山
vegetation cover
temporal and spatial variation
migration characteristics
geographic exploration
the Qilian Mountains
作者简介
童珊(1995-),陕西西安人,博士研究生,主要研究方向:环境地表过程与生态响应。E-mail:1661143102@qq.com;通讯作者:曹广超(1971-),山东苍山人,博士,教授,主要研究方向:青藏高原地区环境变化与地理信息系统应用。E-mail:Caoguangchao@qhnu.edu.cn。
