冰楔是反映多年冻土区古气候（温度）变化的标志物，冰楔不同叶理的稳定氧同位素（δ18O）浓度可反映冰楔发育过程中的古温度变化过程.20世纪80年代末，在伊图里河地区发现了不活动冰楔，这是迄今北半球发现纬度最南的冰楔，它具有重要的气候和环境意义.采用稳定同位素分析、荧光显微计数和流式细胞术，对伊图里河冰楔δ18O浓度与微生物数量进行了分析.结果表明：伊图里河冰楔发育过程中有3次小周期的气温波动，不同叶理的微生物数量也出现了3次波动.温度变化与微生物数量之间的相关性分析表明，冰楔叶理的成冰温度降低，冰楔中存活的微生物数量也随之降低，且温度越低，微生物数量越少.
Ice-wedge is an indicator of paleoclimate change. The δ18O concentration in different layers could reflect the change of paleotemperature during ice-wedge growth. In the late 1980s, inactive ice wedges were found in Yitulihe, Northeast China, which were the south-most ones so far and were important in climatic and environmental research. In this paper, the δ18O concentration and microbial number in the inactive ice-wedges were analyzed by using stable isotope, fluorescence microscopy counting, and flow cytometer (FCM). During the ice-wedge growth in Yitulihe area, there were three short-term paleotemperature fluctuation, and three times of fluctuation in microbial amount in different ice-wedge layer. Correlation analysis indicated that there was a converging relationship between the temperature change and microbial amount in the ice-wedges. The lower the temperature when ice-wedge layer formed, the less the microbes survived in the layer.