Investigation of grassland resource in Subei County,Gansu

Investigation of grassland resources in Subei County was carried out by the combination of 3S technique, fixedsampling site and route survey. The grassland types, area, distribution and species composition were investigated, and the grassland coverage, height and production were measured. The result showed that: 1)There was 5 181 889 hm2 grassland in Subei County, which was classified into 9 classes embracing 17 subclasses, 29 types of 19 forms; 2）The forage yield of different grassland was 5 093 kg/hm2 in meadow,3 094 kg/hm2 in temperate steppedesert,2 561 kg/hm2 in alpine meadow,1 933 kg/hm2 in alpine shrubmeadow,1 822 kg/hm2 in alpine desert, 1 665 kg/hm2 in temperate desertsteppe,1 183 kg/hm2 in temperate desert,1 143 kg/hm2 in alpine steppe, and 760 kg/hm2 in temperate steppe,respectively; 3)The total yield of fresh froage in Subei was 88 609.171 t/a (30 476.385 t/a as winddried forage), and the theoretic grazing capacity in the grassland should be 1.354 2 million sheepunits; and the livestock in Subei County was 0.407 5 million sheepunits; 4)Plant resources in Subei County were very abundant, 210 plant species (belonged to 129 genera of 42 families)were distributed in the Qilian Mountains region in the southern party of Subei County, in which 185 species were the medium quality forage，25 species was the good quality forage;86 plant species (belonged to 54 genera of 23 families) were distributed in Mazongshan Mountains region, in which 70 speices were the good quality forage.