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选择降水利用效率(RUE)作为评价指标,对河西走廊代表性草地类——温性荒漠、高寒草甸、温性草原进行生态评价研究。通过植被指数提取、降水Co-Kriging插值、图层叠加,得到河西走廊区域2006—2010年的RUE(NDVI)、RUE(PVI)、RUE(TSAVI)数据,并与地上生物量进行相关分析,筛选出适合不同草地类的RUE作为该区域生态评价的指标。结果表明:1)温性荒漠区RUE(PVI)与草地生物量风干重正相关性最高(R~2=0.879),高寒草甸区RUE(NDVI)与草地生物量风干重的正相关性最高(R~2=0.876),温性草原区RUE(TSAVI)与草地生物量风干重的正相关性最高(R2=0.895)。2)温性荒漠区、温性草原区生态均处于退化过程,高寒草甸区处于恢复过程。研究认为选择合适的RUE值可作为不同草地类生态评价指标,并具有理论的可行性和实践的可靠性。
The RUE was chosen as the evaluation index to study the ecological evaluation of the representative grassland in Hexi Corridor - temperate desert, alpine meadow and temperate steppe. The RUE (NDVI), RUE (PVI) and RUE (TSAVI) data of Hexi Corridor region from 2006 to 2010 were obtained through vegetation index extraction, precipitation Co-Kriging interpolation and layer overlay. RUE suitable for different grassland class as an indicator of ecological evaluation of the region. The results showed that: 1) RUE (PVI) had the highest positive correlation with air dry weight of grassland biomass (R ~ 2 = 0.879); the positive correlation between RUE (NDVI) and air dry weight of grassland biomass in alpine meadow (R ~ 2 = 0.876). The positive correlation between TSAVI and grassland biomass dry weight was the highest (R2 = 0.895). 2) In the temperate desert zone and the temperate grassland zone, the ecology is in the process of degeneration and the alpine meadow zone is in the process of recovery. The research suggests that selecting suitable RUE value can be used as an index of ecological evaluation of different grassland types and has theoretical feasibility and practical reliability.