应高寒生态学与生物多样性重点实验室梁尔源研究员邀请，德国纽伦堡-爱尔兰根大学地理系Achim Bräuning教授将前来青藏所交流并做学术报告。

　　报告题目：Linking atmospheric circulation systems with tree-ring proxies - a global perspective for paleoclimate research

　　时间: 2016年3月4日（周五）下午2:00-4:00

　　地点：青藏高原所 915会议室

　　主持人：梁尔源  研究员

报告人简介：     Dr. Achim Bräuning，德国纽伦堡-爱尔兰根大学地理系教授，我所“中科院海外特聘人才”项目高级访问学者。现任国际树轮研究会主席，欧盟COST-action FP1106计划首席。自1992年以来，他在青藏高原地区开展了大量的树轮同位素、密度、细胞结构等方面的研究，发起和参与多项与青藏高原地区气候变化有关的研究项目。

　　报告摘要：

　　The climate of High Asia and the Tibetan plateau is closely linked to various global atmospheric circulation systems, including the Asian summer and winter monsoons, the westerlies via the North Atlantic Oscillation (NAO), and the tropical El Niño-Southern Oscillation (ENSO). Tree rings provide sensitive and precisely dated climate proxies with annual and even sub-annual resolution that record variation of various climate factors, like temperature, precipitation, or humidity. Different tree-ring parameters like ring width, wood density, vessel or tracheid characteristics, or stable isotopes are sensitive for specific climate factors and can be used in combination to get a more complete picture on climate variability. On the other hand, large-scale tree-ring networks provide the opportunity to link regional tree-ring derived climate reconstruction over wide areas and to reconstruct the dynamics of large-scale circulation systems, for example to link High Asia with the NAO region, with the tropical Pacific area (ENSO, or with tropical regions affected by the southwest Asian summer monsoon in East Africa. However, although tree-ring analyses in tropical regions have made large progress in the past years, there are still challenges to overcome in tropical dendroclimatology. The lecture provides an overview of methods and results of analyzing tropical tree rings and provides perspectives for large-scale tree-ring networks linking regions under different atmospheric circulation systems.