摘要
高山林线作为一条重要生态界限，是长时间气候变化和多因素综合作用的结果，一直以来备受关注。本研究借助遥感手段，选取垂直地带性最为显著的“三江并流区”，采用面向对象分类方法获得土地利用/土地覆被数据，得到林地空间分布图；基于DEM数据提取山顶点信息，采用距离分析方法，提取距离山顶点最近距离的林线点集，进一步通过目视确定林线点数据集，并系统分析林线分布与坡度、坡向、纬度、经度4个地理因子的关系。研究表明：①三江并流区的林线分布高度范围是3521～4650m；②林线主要分布在15°～35°的急坡和陡坡上，很少分布在〈2°或〉55°坡度上；最高林线分布在急陡坡上，坡度太低或太高都不适于林线的存在；林线分布明显表现为西坡高于东坡，北坡高于南坡的特征，林线海拔高程的最大值出现在西北方向，最小值出现在东南方向；③林线分布与经度之间不存在相关关系，但与纬度高度相关，林线高度表现出随纬度升高而不断上升的特征。三江并流区的林线高度受地势差异、水分、热量等条件的综合影响。
As an important ecological boundary, and because of climate change, alpine timberlines have received much attention. The Three Parallel Rivers region is characterized by conspicuous vegetation vertical zonality and is therefore the ideal area to study alpine timberlines in China. Using remote sensing, we obtained classification maps of land use and land cover for the Three Parallel Rivers. The distribution of forest land was extracted from these maps for the alpine timberline. Alpine timberline datasets were checked by visual interpretation and used to analyze the relationship between the spatial pattern of alpine timberline and four geographical factors （slope, aspect, latitude and longitude） systematically. The results showed that the elevation range of alpine timberline in the Three Parallel Rivers was 3 521-4 650m. The alpine timberline was mainly distributed on slopes 15-35°, and rarely occurred in areas with slopes less than 2° or more than 55°. The highest timberline was on acute steep slopes. The spatial pattern of alpine timberline showed significant characteristics： western aspects with higher elevations than eastern aspects, and northern aspects higher than southern aspects. The maximum elevation of the alpine timberline appeared on the northwest aspect; the minimum was the southeast. There was no correlation between the longitude factor and the alpine timberline spatial pattern. However, the spatial pattern was highly correlated with latitude and as latitude increased, the alpine timberline rose. Topographical factors and water and heat conditions were typical impact factors and combined to affect the spatial pattern of the alpine timberline.
出处
《资源科学》
CSSCI
CSCD
北大核心
2014年第2期259-266,共8页
Resources Science
基金
国家科技部基础性工作专项(编号:2008FY110300)
中国科学院地理科学与资源研究所"一三五"战略科技计划项目(编号:2012SJ008)
关键词
高山林线
遥感识别
地理因子
空间格局
三江并流区
alpine timberline
remote sensing identification
geographical factor
spatial pattern
Three Parallel Rivers
