| This paper takes the different scales of satellite data which SPOT, MSS,TM and ETM as major remote sensing information sources and in combination of surface-truth field trip data, ground location survey data with the last 40 years grassland resources investigation materials to analyze dynamic changing of grassland type boundary line and distribution of different grassland types, changing of distribution area, species composition, quantity and quality of biomass yields of major communities in which Filifolium sibiricum grassland, Leymus grassland ,Artemisia grassland and Stipa grassland, changing of sandy vegetation distribution and its area, developing trends of grassland landscape and basic conditions, grassland degeneration and desertification of Xilinguole grassland resources depend on the techniques of remote sensing, geographical information system and global position system. At the same time, the quantitative analysis for the dynamics of Xilinguole grassland from the view of species, community, landscape, health situation are made by author for the first time and resulted as follows:1. There is a local variation of the zonal distribution boundary of Xilinguole grassland, and the zonal distribution boundary lines are moved to east. At the same time, the areas of meadow steppe and dry steppe are approximately decreased 14% and 12% respectively, however, the areas of desert steppe and desertification steppe are approximately increased 11% and 100% respectively. In addition, the extension speed of desert steppe and desertification steppe are accelerated obviously in recent 20year. The increasing speed of sandy vegetation area is averaged approximately 9% each year. Otherwise, the grassland types had changed in different levels, in which the types of moist-steppe were decreased and disappeared year after year , and the types of sandy-vegetation and xerophytic vegetation were increased obviously.2. Distribution area, height of communities, abundance of plants had obviously decreased with the steppe of Filifolium sibiricum, Stipa baicalensis, Leymus chinesis and the species composition ratio of community has also changed, but they did not cause the decreasing of evaluation degree of grassland quality. The steppe of Stipa grandis had a trend in increasing of distribution range, but the height of forage grasses, coverage of plants, biomass yields and its quality, the abundance of plants of this steppe had decreased with the speed of 1% every year, and quality evaluation degree had fallen approximately one level. The distribution range of Stipa krylovii steppe, Artemisia frigida steppe, Stipa klemenzii steppe and Caragana microphylla steppe have a trend in extension and the height of grasses, abundance of species, biomass yield were decreased clearly. At the same time, the quality of grasses and its coverage had appearance to decrease during 60'S—80'S and began to increase at the end of 80'S—90'S, and the evaluation degree of forage grasses had fallen approximately one degree level.3. The structure of grassland landscape has changed obviously, in which, the continuous and homogeneous distributed patch structure has decreased and the diversification trend of grassland landscape structure is that changing from single, well-distributed, continuous whole structure to complicate, heterogeneity, discontinuous patch structure.4. Situation of grassland health status was descended from the eastern part to the western part of Xilinguole grassland, and the health status level of different types of grasslands are as follows: Leymus chinensis,Stipa baicalensis grassland is in excellent situation , Stipa krylovii,Cleistogenes squrrosa grassland is in fine situation, Artemisia frigida,Stipa krylovii grassland is in good situation and Stipa klemenzii,Clestogenes songgorica grassland is in middle situation. 5．It is taken a representative example to study the situation of grassland resources degeneration in Xiang huang Banner of Xilinguole grassland , and resulted that more than 91% o...
|
PDF Full Text Request