Characterization Of Grassland Landscape In Shanxi Plateau

Grassland landscape is an important part of the natural landscape. Grassland ecological system is well known as the ecological barrier owing to its irreplaceable role in the adjustment of ecological environment. Research on grassland landscape pattern has become one of the hot topics of modern ecology. In the present thesis, an attempt has been made to investigate the spatial patterns of grassland landscape in Shanxi Plateau. It may have important bearing on the comprehensive understanding of the distribution patterns of the vegetation for the pleteau as a whole, and would provide usefull information for the environment management and the scientific research in future.Based on the "Map of Grassland Types of Shanxi Province"(1:500000),"Map of Administritive Divisions of Shanxi Province"(1:500000) and "Map of Soil Types of Shanxi Province"(1:500000)", the characteristics of the grassland landscape patterns in Shanxi plateau were examined on the landscape and association levels, respectively, using the Mapgis software and the quantitative community classification method TWINSPAN and ordination method DCA.The results indicated three basic characteristics of grassland distribution in Shanxi Pleateau.(1) The diversity of the grassland types changed from low to high, and then to low again from the south to the north across the plateau.(2) The number of the grassland patches showed following trend from the south to the north across the plateau:smallâ†'largeâ†'smallerâ†'larger.(3) The distribution of grassland and the amount of grassland patches were closely related to altitudianal change.Results of TWINSPAN showed that all the1127grassland sample plots could be classified into31association groups, which were related to the longitude, latitude, altitude, rainfall, air temperature and slope aspect. The result of DCA for all the grassland sample plots showed that the horizontal axis represented the change of altitude which decreased gradually from left to right, and consequently the number of grassland association increased firstly, and then reduced. The vertical axis reflected the soil water content that gradually increased from top to bottom, and thus the number of grassland association and the distribution density of the grassland association gradually increased. The first dominant association group was divided into12areas, which appeared like the letter "V" in the figure of DCA. The second dominant association group was classified into six areas, i.e. areas Wutai Mountain, Guandi Mountain, the northeast of Taiyue Mountain, Xizhou Mountain, Luya Mountain and Yunzhong Mountain. The result of DCA for44dominant associations showed that the horizontal axis represented the change of temperature which decreased gradually from left to right, and consequently the types of the associations decreased, while the vertical axis represented the change of altitude that increased from top to bottom, and correspondingly the types of the associations decreased gradually.