慕士塔格冰芯中近百年来细菌数量与气候环境变化的关系

应用流式细胞技术分析了取自青藏高原西部慕士塔格冰川73m冰芯上部56.27m中细菌的数量变化,在1907~2000年的93年中,细菌年平均数在0.66×103ml(1982年)至6.91×103个/ml(1912年)之间变化,平均2.59×103个/ml。细菌数量的变化可分为10个不同的阶段,其中6个高峰期和4个低峰期,分别与氧同位素所反映的高温和低温期有较好的对应。冰芯中细菌数量除温度影响外,还受人类活动和陆源粉尘的影响。慕士塔格冰芯中细菌的数量远低于位于高原中部的各拉丹冬冰芯中细菌的数量,且慕士塔格冰芯中细菌数量受陆源粉尘的影响也小于各拉丹冬冰芯,可能是因为慕士塔格冰芯所处荒漠带植物稀少和土壤中细菌数量少所致,慕士塔格和各拉丹冬冰芯中细菌数量的不同反映了冰芯细菌对所处的不同生态环境的响应。

BACTERIAL ABUNDANCE VARY IN MUZTAGATA ICE CORE AND RESPOND TO CLIMATE AND ENVIRONMENT CHANGE IN THE PAST HUNDRED YEARS

We used flow cytometry to analysed the bacterial abundance in top 56.27m of 73m Muztagata ice core which was drilled from accumulating zone(6300m above sea level; 38°17'N, 75°06'E) at Muztagata Glacier located on the western of the Tibetan Plateau.Bacterial abundances of 292 samples obtained from the ice core ranged from 0.43×103 cells/ml to 13.32×103 cells/ml,with an average value 2.64×103 cells/ml.Date of the 56.27m long ice core was determined according black carbon concentration and spanned from 1907 to 2000.The results presents annual bacterial abundances deposited in Muztagata ice core over the past 93 years.The bacterial abundance varied from 0.66×103 cells/ml (1982)to 6.91×103 cells/ml (1912),with average value 2.59×103 cells/ml. Ten periods of bacterial abundance,6 peak periods and 4 low value periods,respond to the high and low temperature stages which indicated by the oxygen isotope ratios,respectively.Bacterial abundance significently correlated to oxygen isotope ratios,Na+,NH4+,K+,Mg2+,Ca2+,Cl-,and NO3- concentration.Temperature,anthropogenic and dust influence the bacterial abundance in the Muztagata ice core.The bacterial abundance in the Muztagata ice core are lower than that in Geladangdong ice core located on the central of the Tibetan Plateau,and are less influence by dust.It is possibely due to the Muztagata ice core located in the barren desert region,while the Geladangodng ice core located in the alpine steppe region.The different bacterial abundance between the two ice cores imply that the bacteria in ice core are sensitively respond to the ecosystem environment where they surround.