气候变化对东祁连山禾草-嵩草草甸生产力的影响

摘要

In this study, the relation between climate change and grassland yield was analysed in Grass-Ko-bresia type of alpine meadow of Jinqiang River region in Tianzhu County. The results showed that the gradient changes of temperature was 0. 286℃ during 10 years,the annual average temperature was 0. 899℃ from 2000 to 2006. The average precipitation was 408. 3 + 52. 4 mm from 1980 to 2006 and it reached the peak in 1988 and then it declined. The average moisture index (K Value) was 2. 778±0. 475,which reduced 0. 003 per year. The grassland type still belong to cold temperate humid taiga forest class according to Integrated Orderly Classification System of Grassland(IOCSG). Although the precipitation declined slowly,but the yield of grassland reduced obviously,which means the grassland degradation was caused by overgrazing under the human being behavior.%通过对金强河高山草原定位试验站气候变化和禾草-嵩草草甸生产力分析,探讨了气候变化和草地退化的关系.结果表明,自从1980～1998年,金强河流域大气温度10年间变化梯度约为0.286℃;2000～2006年平均温度为0.899℃,温度增幅加大;平均降水量408.3±52.4 mm,在1988年达到峰值后,降水量有减小趋势;草原湿润度K平均值2.778±0.475,减少幅度约为每年0.003,在草原综合顺序分类法中仍为“寒温潮湿寒温性针叶林类”草地,尚未改变草原类型中类的划分.降水量减少趋势缓慢,但草产量变化表现出明显的下降趋势,这种降水量持平、草产量快速下降的事实也说明了人为因素造成的牲畜超载过牧是加速高寒草甸退化的主导因子,即该草地生产力降低的主要原因是由人为过度利用造成.