黄河首曲草地气候变化及生态效应

Climate Changes and Ecological Effects of the Grasslands in the First Meander of the Yellow River

利用黄河首曲草地气候资料和生态观测资料,分析了黄河首曲草地气候变化特征及其生态效应.结果表明:黄河首曲大部分区域降水量年际变化呈下降趋势,存在2～4 a、6～7 a和10～11 a的年周期振荡特征.气温年际变化呈上升趋势,增温速度均大于全国增温速度.1983年之前气温距平以偏冷为主,1984年之后持续偏暖.草地年干燥指数变化呈显著上升趋势,20世纪80年代末至2004年明显趋于干旱化.气候变化是草地生态退化的自然诱发因素,而超载过牧,滥采乱挖,人为破坏,生物链失衡等环境蠕变是造成生态退化的人为因素,二者共同作用导致黄河首曲草地水资源锐减、生物多样性减少及生态退化.

Using the main meteorological and ecological data observed in the grasslands of the first meander of the Yellow River, the climate changes and eco-environment effects of the grasslands in the first meander of the Yellow River were analyzed. The results show that in the first meander of the Yellow River, the annual precipitation tended to decrease and fluctuated with three periods： 2～4 years , 6～7 years and 10～11 years. The annual mean temperature was remarkably warmer than that in other regions of China; the departure of annual temperature was low before 1983 and high after 1984. The annual mean aridity index of the grasslands tended to increase. There are many serious ecological problems in this area at the present time. fearful degeneration of ecological, desertification of grassland, obvious shortage of water resources, and quick decrease of bio-diversity. All of these are caused by both climate changes and human activity.