Analysis of grassland biomass characteristics and its impact factors in north slope of Tianshan

The distribution of grassland biomass and impact factors in north slope of Tianshan were analyzed in this study. The biomass of different types of grassland was estimated to reveal the spatial distribution of aboveground and underground biomass and the relationship between biomass and environmental factors. The results showed that grassland biomass decreased in the order of temperate mountain meadowtemperate meadow steppealpine meadowlow saline meadowtemperate steppetemperate desert steppetemperate steppe deserttemperate desert. There was no significant variation for spatial distribution of aboveground and underground biomass within the same grassland. The aboveground biomass of lowland saline meadow was significantly higher (P0.05) than that in other types of grassland. For underground biomass and total biomass, there was significant difference between temperate mountain meadow and other types of grassland (P0.05). The root-shoot ratios of each type of grassland were mainly between 3.2 and 20.0. The aboveground biomass was correlated with annual precipitation and the extent of human using, however, the underground biomass correlated with annual precipitation, annual average temperature and landform.