Abstract: The authors estimated aboveground biomass in 6 grasslands of Xinjiang according to data composed of 460 plots from 92 sites in Xinjiang Uigur Autonomous Region. Meanwhile, the authors evaluated the relationship between aboveground biomass and environmental factors. The primary results are summarized as follows: (1) Aboveground biomass density varies significantly in different grassland type. In the steppe, desert steppe has the minimum, temperate steppe and alpine steppe has the medium, while meadow steppe has the maximum. In the meadow, montane meadow has higher aboveground biomass density than alpine meadow. (2) The total aboveground biomass in 6 grasslands of Xinjiang is 14.65 Tg C, which accounts for about 10% of China’s grassland biomass. The grassland aboveground biomass is distributed primarily in alpine steppe and alpine meadow, which accounts for 41.7%. (3) Aboveground biomass of steppe grassland is controlled by annual precipitation, while aboveground biomass of meadow grassland is determined by mean annual temperature. (4) Aboveground biomass of steppe grassland is mediated by soil moisture and soil total N content. However, no significant correlation is found between soil resource availability and aboveground biomass in meadow grassland.

Key words: Xinjiang, grassland, aboveground biomass, climatic factors, soil moisture, soil total N content

摘要： 2004年对新疆地区的草地地上生物量进行了大范围的调查，据此估算了新疆6种主要草地类型的地上生物量密度和总量，并探讨了草地地上生物量与环境因子的关系。结果表明，草原类型中，荒漠草原的地上生物量密度最小 (34.9 g C·m^-2)，草甸草原最大 (87.3 g C·m^-2)，而典型草原 (53.2 g C·m^-2)和高寒草原 (47.7 g C·m^-2)介于两者之间；草甸类型中，山地草甸 (117.4 g C·m^-2)的地上生物量密度显著高于高寒草甸 (58.1 g C·m^-2)。6种草地的地上生物量总量为14.65 Tg C，约占全国的10%。地上生物量主要集中于高寒草原和高寒草甸，两者占总量的41.7%；其次是典型草原、山地草甸和荒漠草原，分别占19.0%、18.3%和14.6%；草甸草原因分布面积小而使得其地上生物量最小，仅占总量的6.4%。草原和草甸地上生物量的控制因子存在差异：草原地上生物量主要受降水控制，而草甸地上生物量则与温度相关。除受气候影响外，草原地上生物量还与土壤含水率、土壤总氮含量正相关，而草甸地上生物量与土壤含水率、土壤总氮含量均不相关。

关键词: 新疆, 草地, 地上生物量, 气候, 土壤含水率, 土壤总氮含量