植物生态学报 ›› 2015, Vol. 39 ›› Issue (11): 1053-1061.DOI: 10.17521/cjpe.2015.0102

所属专题: 遥感生态学

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塔里木河下游河岸带植被的空间结构特征

朱绪超1,2, 袁国富1,*(), 邵明安1,4, 易小波3, 杜涛1,2   

  1. 1中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室, 北京 100101
    2中国科学院大学, 北京 100049
    3西北农林科技大学资源环境学院, 陕西杨凌 712100
    4西北农林科技大学资源环境学院, 陕西杨凌 712100
  • 出版日期:2015-11-01 发布日期:2015-12-02
  • 通讯作者: 袁国富
  • 作者简介:# 共同第一作者
  • 基金资助:
    基金项目 国家自然科学基金(41271050)

Spatial pattern of riparian vegetation in desert of the lower Tarim River basin

ZHU Xu-Chao1,2, YUAN Guo-Fu1,*(), SHAO Ming-An1,4, YI Xiao-Bo3, DU Tao1,2   

  1. 1Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
    3State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A & F University, Yangling, Shaanxi 712100, China
    4College of Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712100, China
  • Online:2015-11-01 Published:2015-12-02
  • Contact: Guo-Fu YUAN
  • About author:# Co-first authors

摘要:

揭示我国内陆河流域下游河岸带植被的空间结构特征, 对于了解我国西北干旱区荒漠河岸带植被的空间分布规律、指导荒漠化治理和内陆河水资源管理具有重要意义。该研究基于野外大范围植被调查数据支持下的遥感监督分类方法, 利用Landsat-8 OLI遥感数字图像, 辨识了塔里木河下游柽柳(Tamarix spp.)灌丛、胡杨(Populus euphratica)疏林和芦苇(Phragmites australis)草地3类主要的河岸带植被, 并利用建立的叶面积指数(LAI)遥感反演经验模型反演了研究区柽柳灌丛和胡杨疏林的叶面积指数, 旨在从区域尺度和总体趋势上分析荒漠河岸带植被的空间结构和分布特征。结果表明: 在有详细地物资料的基础上, 遥感监督分类可以作为一种干旱区荒漠河岸带植被分类的有效方法; 遥感分类结果显示塔里木河下游胡杨疏林分布面积约336.4 km2, 柽柳灌丛约为405.3 km2, 胡杨疏林总体更靠近河道, 柽柳灌丛分布范围更广; 河岸带植被LAI整体很低, 柽柳灌丛和胡杨疏林平均LAI值分别为0.253和0.252, LAI小于0.5的植被对应面积分别占柽柳灌丛和胡杨疏林总面积的92.4%和90.1%, 表明了塔里木河下游荒漠河岸植被空间上稀疏分布的特征; 统计结果显示, 河岸带植被结构存在巨大的空间变异性, 其中胡杨疏林比柽柳灌丛的空间变异性更大; 河岸带植被LAI随距河道距离呈现显著负指数分布规律, 在离河道1 km范围内LAI随离河道距离快速下降, 而1 km外区域叶面积指数普遍低于0.1, 表明植被主要分布在河道两侧1 km范围内。整体稀疏的空间分布、显著的空间变异性, 以及由LAI体现的植被盖度随距河道距离的负指数下降规律是荒漠河岸带植被空间结构的3个基本特征。

关键词: 极端干旱区, 河岸带植被, 叶面积指数, 空间分布, 监督分类, 塔里木河下游

Abstract:

AimsRevealing the spatial pattern of riparian vegetation in hyper-arid regions can improve our understanding on the water relations of riparian vegetation in the desert watershed ecosystem, and also can provide valuable scientific guidance for desertification control and water resources management of watershed of the arid region in northwestern China. This research objective is to show the spatial distribution and structures of typical riparian vegetation in hyper-arid desert watershed from regional and overall perspective.Methods Based on Landsat-8 OLI remote sensing images and a large number of field vegetation surveys, the supervised classification method was used to distinguish three main vegetation categories in the lower Tarim River basin: Tamarix thicket, Populus euphratica woodland, and Phragmites australis grassland. The leaf area index (LAI) of Tamarix thickets and Populus euphratica woodlands were inverted by using the remote-sensed LAI inversion empirical model that we developed.Important findings Supervised classification supporting abundant information of ground objects by remote sensing was an effective method to determine desert riparian vegetation categories in arid desert regions. The area was 336.4 km2 for the Populus euphratica woodlands and 405.3 km2 for the Tamarix thickets, respectively. The Tamarix thickets had a wider distribution range while the Populus euphratica woodlands grew near the river channel. The overall LAI of the riparian vegetation was low. The average LAI value was 0.253 for the Tamarix thickets and 0.252 for the Populus euphratica woodlands. The areas of vegetation with the LAI value of less than 0.5 accounted for 92.4% and 90.1% of the total area of the Tamarix thickets and the Populus euphratica woodlands, respectively. The statistic results showed that large spatial variability of the riparian vegetation LAI existed. The spatial variability of the Populus euphratica woodlands was larger than that of the Tamarix thickets. The LAI values of the riparian vegetation had a significant negative exponential relationship with the distances away from the river channel. The LAI values declined rapidly within the distance of 1 km from the river channel and they were generally lower than 0.1 when the distances beyond 1 km, which indicated that the riparian vegetation was mainly distributed within 1 km from both side of the river. This research indicated three basic characteristics of the spatial pattern in riparian vegetation from hyper-arid desert regions, including overall sparse spatial distribution, high spatial variability and negative exponential relationship between LAI and distance away from the river channel.

Key words: hyper-arid region, riparian vegetations, leaf area index, spatial pattern, supervised classification, lower Tarim River basin