Climatic Influences to Cryosphere-Biosphere in Siberian Permafrost

1994年夏季，与俄罗斯冻土研究所和雅库茨克生物研究所的研究人员合作，在东西伯利亚进行了两个考察组(冻土组和生物组)的野外工作。永久冻土研究小组的目标是在长期和短期内调查永久冻土对气候变化的反应。根据气候变化的长期影响，对多年冻土中的地面冰进行了分析，以恢复过去的古环境。类似于大陆冰盖，丰富的古气候信息被存储在EDOMA中。利用专门设计的便携式GC系统对伊多玛的气泡气体浓度进行了现场测量。在伊多玛中发现了异常高浓度的甲烷，表明伊多玛的起源是同生冰楔。采集了沉积物中的有机物质，并用名古屋大学的AMS系统进行了放射性碳测年。…的结果进一步的测年结果表明，伊多玛形成于30,000~40,000 yBP的卡尔金斯基中期，除对伊多玛进行化学分析外，还研究了氧的等量特征。氧的同位素浓度分布结果也反映了过去海区的温度变化。在当前全球变暖的趋势下，东西伯利亚低地地区发生了伊多玛的大范围解冻。根据卫星图像和以前的测量数据估计了伊多玛的总损失。伊多玛融化产生的甲烷通量计算为每年1000万吨。夏季发育的冻土带湿地具有良好的生态环境，是理想的甲烷来源。在不同地点观测了湿地甲烷的排放通量。建立了甲烷通量与夏季融化层温度(活跃层)和活跃层深度的重要方程。将该方程应用于野外条件，确定湿地甲烷年排放通量为1Tera g。甲烷气体是当今大气中主要的温室效应气体之一。根据解冻的伊多玛湿地和现有湿地的估算通量，多年冻土被认为是未来全球气候变暖的主要因素。多年冻土对气候变化的响应不仅是被动的，而且是主动的。生物小组对苔原和泰加地区的植被类型进行了调查。对细辛鹿蹄草和格兰花鹿蹄草的形态变异进行了研究。物种的变异性比以前报道的要大，这表明气候变化的影响。对泰加和苔原地区果蝇的空间分布进行了研究。本文报道了11个果蝇新种。所有信息都于1995年3月底在雅库茨克与对应的研究人员进行了讨论。较少

In 1994 summer season, two groups (Permafrost and Biology) of the expedition were conducted the field works at eastern Siberia cooperating with Russian researchers from Permafrost Institute and Yakutsk Biological Institute. Peramfrost group aimed to survey the permafrost response to climatic change in both long and short terms. In relation to long term influence of climatic change, ground ice in permafrost, which is locally termed as Edoma, was analyzed as to reconstruct paleo-environmet in the past. Analogus to continental ice sheet, profound information of the paleo-climate were stored into Edoma. On-the-sopt survey of gas concentration of air bubbles in Edoma was done by means of specially desinged portable GC sysytem. Exceptionally high concentration of methane in Edoma was traced indicating the origin of Edoma as Syngenetic Ice-wedge. Organic materials from sediments were collected and were subjected to Radio-carbon dating measurements by AMS system at Nagoya University. Results o … More f dating suggested that Edoma was formed at the time of Karginsky interstadial dated ranges between 30,000yBP and 40,000yBP.In addition to the chemical analysis of Edoma, isotoic caharacters of Oxygen was examined. Temperature changes of the past wrere also traced from the results of isotope concentration profile of Oxygen.Under present trend of global warming, large scale thawing of Edoma occurrs in lowland area of eastern Siberia. The total loss of Edoma was estimaed based on Satellite images and previously measured data. Methane flux from thawing Edoma was caluculated as 10 Mega ton per year. The tundra wetlands developted in summer season is an ideal source of methane because of anaboric environment. The flux of methane from wetland were observed at various locations. The emphirical equation of methane flux was performed with temperatures in summer thaw layr (active layr) and depth of active layr. Adopting this equation to the field conditions, annual flux of methane from wetland was determined as 1 Tera g. Methane gas is one of the major green house effect gases in present atmospher. Based on the estimated fluexes from both thawing Edoma and present wetlands, permafrost is considred as major role of future warming of global climate. Permafrost response to climatic change is not only passive but active manners.Biological group conducted the surveys of vegetation types in tundra and taiga regions. The morphological variability of Pyrola Asarifolia and P.Grandiflora were surveyed. The variability of thiis species were rather larger than prevously reported indicating the influences of climatic change. The spacial distribition of Drosophila was examined at Taiga and Tundra. 11 new species of Drosophila were reported in this field study. All infoamtion was discussed with counterpart reseachers at Yakutsk at the end of march, 1995. Less