岩溶山区不同岩性和地貌类型下景观斑块分布与多样性分析

以研究区2000 年TM影像、1:50 000 地形图和1:250 000DEM为基础数据源, 运用景观斑块 分布与多样性特征指数, 测算了黔西南中低山丘原盆谷区不同岩性和地貌类型下景观格局特征。结 果表明: ①灌木林地、疏林地、中覆盖度草地占据着景观中的优势地位, 是明显的景观基质, 控制着 区域景观生态格局及其发展。景观斑块类型在不同岩石和地貌类型区存在较明显差异; ②在连续性 灰岩区、灰岩与碎屑岩互层区和灰岩夹碎屑岩区形成的山间盆地和高原台面上以及北部水热丰富 的河谷地带, 水田、旱地、疏林地、低覆盖度草地集中分布, 浅中切割低山类型中有林地和灌木林地 集中分布; ③在连续性白云岩区形成的深切割( 低、中和高) 丘陵、浅切割( 低、中和高) 丘陵, 低覆盖 度草地和灌木林地集中分布; ④从岩溶石漠化、土壤侵蚀、森林退化的空间格局及其组合来看, 在形 成生态环境的区域差异过程中, 岩性和地貌的空间组合结构起着显著的控制作用。

The Distribution and Diversity of Landscape Patches in Different Lithology-Landform Types in Karst Mountainous Areas

Abiotic environmental spatial variations and various disturbances were main divers,which resulted in landscape heterogeneity.Spatial patterns of landscape elements were dominantly enslaved to landform characteristics and disturbances.The objective of this study was to use Landsat TM data at a spatial resolution of 30m,1:50 000 topographic map and 1:250 000 DEM in 2000 to determine the distribution of landscape patches and the relations among the distribution of landscape patches,lithologic types and landform types basing on patch distribution and diversity index across middle-low mountains,hills,basins and valleys from southwestern Guizhou province,China.The results indicated that in the study site,shrubbery land,sparse-forest land and moderate coverage grassland were dominant landscape types.They were obvious landscape matrixes,and controlled landscape patterns and their evolvements.Moreover,there was an evident difference of landscape patches in different lithology-landform areas.Paddy,dryland,sparse-forest land and sparsely covered grasslands are distributed primarily in intermontane basins and plateau surface of homogenous limestone,limestone/clastic rock alternations and limestone interbedded with clastic rock areas,and river valley zone,which are rich in water and heat and are located at north of the study area.Forestland and shrubbery land occurred mainly in shallow and moderate dissected low mountains.Sparsely covered grassland and shrubbery land were detected mainly on low,middle and high hills,which are dissected deeply or shallowly in homogenous dolomite areas.Seen from spatial patterns and assemblages of karst rock deserti-fication,soil erosion and forest degradation,lithology and landform played pronounced roles in controlling the processes of eco-environmental heterogeneity.