干旱区研究 ›› 2022, Vol. 39 ›› Issue (2): 510-521.doi: 10.13866/j.azr.2022.02.19

• 植物与植物生理 • 上一篇    下一篇

绿洲-沙漠过渡带植被覆盖动态变化及其驱动因素——以新疆策勒为例

曹永香1(),毛东雷1,薛杰2,3(),苏松领1,开买尔古丽·阿不来提1,蔡富艳4   

  1. 1.新疆师范大学地理科学与旅游学院,新疆干旱区湖泊环境与资源重点实验室,新疆 乌鲁木齐 830054
    2.中国科学院新疆生态与地理研究所,荒漠与绿洲生态国家重点实验室,新疆 乌鲁木齐 830011
    3.新疆策勒荒漠草地生态系统国家野外科学观测研究站,新疆 策勒 848300
    4.乌鲁木齐职业大学应用工程学院,新疆 乌鲁木齐 830002
  • 收稿日期:2021-08-17 修回日期:2021-12-13 出版日期:2022-03-15 发布日期:2022-03-30
  • 通讯作者: 薛杰
  • 作者简介:曹永香(1995-),女,硕士研究生,主要从事风沙地貌及荒漠化防治方面的研究. E-mail: 1298668601@qq.com
  • 基金资助:
    新疆维吾尔自治区自然科学基金项目(2021D01E01);中国科学院基础前沿科学研究计划项目(ZDBS-LY-DQC031);国家自然科学基金项目(42071259);国家自然科学基金项目(41601595);荒漠与绿洲生态国家重点实验室开放基金项目(G2018-02-08);中国科学院青年创新促进会项目资助(2019430)

Dynamic changes and driving factors of vegetation cover in the oasis-desert ecotone: A case study of Cele, Xinjiang

CAO Yongxiang1(),MAO Donglei1,Xue Jie2,3(),SU Songling1,Kaimaierguli Abulaiti1,CAI Fuyan4   

  1. 1. College of Geography Science and Tourism, Xinjiang Normal University, Xinjiang Laboratory of Lake Environment and Resources in Arid Zone, Urumqi 830054, Xinjiang, China
    2. State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
    3. Cele National Station of Observation and Research for Desert-Grassland Ecosystem in Xinjiang, Cele 848300, Xinjiang, China
    4. College of Application Engineering, Urumqi Vocational University, Urumqi 830002, Xinjiang, China
  • Received:2021-08-17 Revised:2021-12-13 Online:2022-03-15 Published:2022-03-30
  • Contact: Jie Xue

摘要:

绿洲-沙漠过渡带是绿洲与沙漠生态系统之间的生态缓冲区,对维持绿洲稳定与防风固沙具有重要的生态功能。以策勒绿洲-沙漠过渡带为例,选取1993—2017年Landsat遥感影像数据、气象与社会经济数据,采用归一化植被指数(Normalized Difference Vegetation Index)、像元二分模型和主成分分析方法,探讨小尺度区域长时间序列的植被变化及其驱动因素。结果表明:(1) 在近25 a来,策勒绿洲-沙漠过渡带的年均NDVI呈逐年增加的趋势,高NDVI主要分布在其东南部,而低NDVI主要分布在其西与西北部;(2) 多年平均植被覆盖度为0.23,其中1993年、1998年、2008年、2011年、2014年、2017年这6期的FVC(Fractional Vegetation Coverage)分别为0.20、0.18、0.19、0.23、0.27、0.28,植被覆盖度在不断增加;(3) 植被覆盖度总体以中等和低覆盖为主,分别占研究区总面积的30.73%、21.47%,其次为低、较高、高和极低覆盖植被,分别占研究区总面积的21.48%、20.39%、20.12%、7.26%。植被覆盖明显变好区域所占面积较小且主要集中在中部和东南部及策勒河流域周边,其余变化等级的植被覆盖分布较分散;(4) 在年际时间尺度上,人类活动是影响策勒绿洲-沙漠过渡带植被变化的主导因素,植被对降水量和大气相对湿度的敏感度大于气温,其中人工造林、耕地面积、人口数量、防护林面积分别在第一主成分分析中占0.850、0.810、0.853、0.779,大气相对湿度、降水量和牲畜存栏数分别占第二主成分分析的0.845、0.753、-0.608,气温占第三主成分分析的0.883。本研究为进一步认识绿洲-沙漠过渡带的植被变化、影响因素、植被保育及恢复提供理论依据。

关键词: 归一化植被指数, 植被覆盖度, 绿洲-沙漠过渡带, 影响因素, 主成分分析

Abstract:

The oasis-desert ecotone is an ecological buffer zone between the oasis and desert ecosystems,playing an important ecological role in maintaining oasis stability, preventing wind, and fixing sand. Based on Landsat remote sensing image data taken from 1993 to 2017, and meteorological and socioeconomic data, we used the normalized vegetation index (NDVI), the pixel dichotomy model, and the principal component analysis method to investigate long-term vegetation changes and their driving factors in small-scale regions. The results show that (1) the average annual NDVI of the Cele oasis-desert ecotone has been increasing yearly in the last 25 years. The high-value area of the NDVI is mainly distributed in the southeast, whereas the low-value area is mainly distributed in the west and northwest of study area; (2) the annual mean fractional vegetation coverage (FVC) was 0.23, and the FVC in 1993, 1998, 2008, 2011, 2014, and 2017 were 0.20, 0.18, 0.19, 0.23, 0.27, and 0.28, respectively, indicating that vegetation coverage has continuously improved; (3) regional vegetation coverage was mainly medium and low, accounting for 30.73% and 21.47% of the total area of the study area, respectively. Low, high, higher, and very low vegetation coverage accounted for 21.48%, 20.39%, 20.12%, and 7.26% of the total study area, respectively. The areas with improved vegetation coverage were relatively small and mainly concentrated in the middle and southeast of the Cele River basin, whereas the distribution of other vegetation cover types was scattered; and (4) on the interannual timescale, human activities are the dominant factor affecting vegetation change in the oasis-desert ecotone, and vegetation is more sensitive to precipitation than to air temperature. Artificially forested land, cultivated land, populated areas, and shelter belt areas accounted for 0.850, 0.810, 0.853, and 0.779 of the first principal component, respectively. Atmospheric relative humidity, precipitation, and livestock inventory accounted for 0.845, 0.753, and -0.608 of the second principal component, respectively, but air temperature accounted for 0.883 of the third principal component. This study provides a theoretical basis to further understand vegetation change, the analysis of influencing factors, and vegetation conservation and restoration in the oasis-desert ecotone.

Key words: normalized difference vegetation index, vegetation coverage, oasis-desert ecotone, influencing factors, principal component analysis