冀北辽河源森林景观格局特征及破碎化研究

Analysis of the landscape patterns and forest fragmentation trend in Liaohe Source Area,Hebei

基于辽河源2012年7月分辨率为10 m的遥感影像图及1∶5万的地形图、森林资源二类清查数据和GPS地面真实采集点,在地理信息系统软件ArcGIS、ENVI和景观指数分析软件Fragstats支持下,利用主成分分析方法降维选取对破碎化贡献最大的斑块形态指标,分析了冀北辽河源森林景观格局特征和破碎化程度。结果表明,各景观组分中阔叶林、油松面积最大,是辽河源地带性植被,分布集中,破碎化较小;华北落叶松、疏林地、居民地、道路和未成林地面积小,呈零散分布,破碎化程度较高,人为干扰程度大。各景观类型的平均分维数均接近1。景观整体破碎化水平较低,景观多样性指数为2.068 6,说明景观多样性丰富,异质性高;均匀度指数为0.783 8,说明景观类型分布均匀。各景观类型的边界褶皱程度均较低,整个景观的边界形状较为简单。

This paper is aimed at introducing our analysis of the landscape pattern and the forest fragmentation trend in Liaohe Source Area, Hebei. Our analysis has been made on the data gained based on the remote sensing results with a resolution of 10 m in the Liaohe River source area with the precision of 1：50 000 large-scale topographic map and the data of the forest survey inventory published in July, 2012. In this paper, we have made an estimate of the characteristic patterns of the landscape and the degree of fragmentation by choosing the patch shape index with the principal component analysis method via the geographic information system software known as ArcGIS, ENVI and landscape index analysis software Fragstats. To make our estimate more close to the reality, we have chosen indicators of plaque morphology of the biggest fragmentation contributive factors by dimensionally reducing our analysis and mainly focusing on the analysis of the forest landscape pattern and the degree of fragmentation of the area. While trying to keep the stability of the region＇s ecosystem and the biodiversity conservation, our analysis attempts to offer a down-to-earth reference to the decision-making of the forest management. In the places where wide-leaf trees and pinus tabulaeformis take the dominant proportion of the forest, 42% of the total area of the entire landscape is covered with such wide-leaf trees with few fragmentations. This part of landscape can be said to be the zonal thickly vegetated area of the main Liaohe River source, the area of Larix principis-rupprechtii, the open forest land, or the region with the well-settled space, scarcely seen large roads or immature forests. However, there are all the signs indicate that in the river source area, there is still a vast scattered distribution and a high degree of fragmentation, which indicate serious human interference or disturbance, though the fractal dimension of all the landscape types seems low, that is, close to 1. The results also reveal a low fragmentation of the overall landscape, and its diversity index can reach 2.068 6, rich in high heterogeneity. In addition, the evenness index of the region has reached 0.783 8, which indicates the distribution of landscape types is nice, whereas the boundary fold of all the landscape types remains low with the boundary division of the entire landscape being relatively simple.