近50年黑河流域潜在植被的演替及生态环境变化研究

Vegetation succession and ecological changes in the Heihe River watershed over the past 50 years

本研究以综合顺序分类法(IOCSG)为基本理论方法,在GIS的支持下,利用黑河流域14个气象站点1961-2010年间50年的气候数据模拟出黑河流域潜在植被的演替过程,在此基础上耦合植被对气候变化的动态响应,分析不同气候条件下黑河流域潜在生态环境的变化。结果表明:1)黑河流域潜在植被类型在逐渐减少,到c时期(1991-2010)时仅有11种植被类型,并且在空间分布上差异性很大,下游额济纳旗地区植被类型非常单一。2)黑河中上游气候暖湿化,潜在植被向暖湿的植被类型发展,但变暖的速度大于变湿的速度,使植被类型不断退化;而下游额济纳旗地区,气候逐渐暖干化,潜在植被向暖干的植被类型发展,荒漠化较为严重。3)随着气候的变化,全流域植被类型逐渐减少,潜在生态环境逐渐恶化,近年来下游额济纳旗地区植被生态环境的严重恶化是气候变化和人为因素共同导致的结果。

Potential vegetation succession processes in the Heihe River watershed were simulated over a 50 year period from 1961 to 2010 using integrated sequence classification.The simulation was supported by GIS infor-mation and climate data from 14 weather stations covering this time period.Linking the dynamic response of vegetation to climate change was achieved by analyzing the potential ecological environment changes in the Heihe River watershed under different climate conditions.The results show that：1）Potential vegetation types gradually reduced in the Heihe River watershed with only 11 types remaining by the 1991 to 2010 period,and with significant differences in spatial distribution.2）In the upper and middle reaches of the Heihe River water-shed the climate is predicted to become wetter and warmer and the potential vegetation influence indicates a change toward warm and wet adapted species but with a more rapid change to warm than wet adapted species. In contrast,the climate becomes drier and warmer with a corresponding change in the potential vegetation type to warm and dry in the downstream mesozoic-cenozoic region,aggravating desertification.3 ）As the climate changes,vegetation types gradually reduce in the entire drainage basin and the potential ecological damage in-creases.Climate change and human factors have resulted in serious deterioration of the ecological environment in downstream mesozoic-cenozoic areas.