Studies On Grassland Agroecosystem And Spectral Characteristics Of Vegetation And Soil In Sanjiaocheng Sheep Breeding Farm

Characteristics of climate, soil, vegetation, and pasture stockbreeding production in Qinghai Sanjiaocheng sheep breeding farm were investigated and analyzed. TM image materials were combined for systematical analysis. The main results are:1. Vegetation distribution characteristics and soil hygroscopic water conditionsDominant species and sub-dominant species that represent different grassland types in different altitudes (from 3100m to 3700m) are as follows: Triglochin maritimum, Potentilla anserine→Achnatherum splendens, Festuca ovina→Poa crvmophila, Stipa purpurea→Kobresia humilis, Kobresia humilis. Vertical distribution zonation of grassland type was clearly showed here; higher the elevation is, lower plant height and aboveground biomass are, it is certified that fierce environment condition in high altitude puts special stress on grassland productivity. The equilibrium of hygroscopic water in different soil level is not reached simultaneously at different altitude. Higher the elevation is, earlier this equilibrium is reached. It is proved that there are remarkable differences in hygroscopic water content within a small area due to elevation events.2.Reflection characteristics of TM image bands for different objectsTen objects were chosen for their band comparison, including rocky mountain glacier, saline and alkaline area, reservoir, bare land, alpine steppe, alpine, meadow, river, artificial grassland, lake and swamp. Three vegetation types were also selected for plant band comparison, such as alpine steppe, alpine meadow and mountain meadow. The results showed: among TM1, TM2, and TM3 bands, spectral reflectance of bog and lake is much higher than that of other objects. There is no significant difference among these three types of vegetation. While within band 4, spectral reflectance of green plants is different from each other, therefore, band 4 is good at distinguishing different vegetation. As for band 5, spectral reflectance of alpine meadow, bare land and alpine grassland is much higher than other objects. As for band 6, there is no distinctive variation for all objects.3. Analysis on characteristics of TM imagery's 7 bandsGray intensities of 10 objects in 7 bands were statistically analyzed. The results showed: standard deviation of TM5 is highest and its band scope is widest; standard deviation of TM5 is lowest and its band scope is narrowest. It shows that TM5 contain more information,...