Climate response of tree growth in Ethiopia along an altitudinal transect and implications on local climate and regional atmospheric circulation dynamics

埃塞俄比亚沿海拔样线树木生长的气候响应及其对当地气候和区域大气环流动态的影响

• 批准号: 42082865
• 负责人: Professor Dr. Achim Bräuning
• 金额: --
• 依托单位: Institut für Geographie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/42082865?language=en
• 关键词: Climate; response; tree; growth; Ethiopia

With the following extension proposal we intend to finalize ongoing studies on the seasonal growth dynamics of native and exotic tree species in the tropical mountain forest of Munessa, Ethiopia. High-resolution dendrometer measurements of stem diameter variations indicated different growth dynamics of evergreen conifer species (Pinus radiata, Podocarpus falcatus) und evergreen and deciduous broadleved tree species (Prunus africana, Celtis africana), respectively. Trees released from competition showed a strong stimulation of stem growth. The knowledge about seasonal wood formation and growth dynamics form the basis for the interpretation of long tree-ring series of ring width and latewood density and of the analysis of annual variations of stable isotopes of 13C and 18O in wood cellulose. Chronologies of stable isotopes of ca. 400 year-old Podocarpus-trees shall be used for the reconstruction of past variations of precipitation. In combination with an extensive tree-ring network from Asia, they shall further be used to analyse variations in the variability of the summer monsoon variability over the Indian Ocean. Furthermore, stable 13C analyses shall provide information on the physiological reaction of the studied tree species (changes of the ‚water use efficiency‘) on extreme drought events, which provides important information for the development of sustainable forest management options under climate change scenarious of increased rainfall variability.

通过以下扩展建议，我们打算完成正在进行的关于埃塞俄比亚Munessa热带山地森林中本地和外来树种季节性生长动态的研究。高分辨率测树仪测量的茎直径变化表明，不同的生长动态的万年青针叶树种（辐射松，罗汉果）和万年青和落叶阔叶树种（李非洲，朴树非洲）。从竞争中释放的树木表现出强烈的刺激干生长。有关季节性木材形成和生长动态的知识形成的基础上解释长的树轮系列的轮宽度和晚材密度和木材纤维素的13 C和18 O的稳定同位素的年度变化的分析。钙的稳定同位素年代学。应使用400年树龄的罗汉柏树重建过去降水量的变化。与亚洲广泛的树木年轮网络相结合，它们将进一步用于分析印度洋夏季风变率的变化。此外，稳定的13 C分析将提供关于所研究树种对极端干旱事件的生理反应（“水分利用效率”的变化）的信息，这为在降雨量变异性增加的气候变化下制定可持续森林管理方案提供了重要信息。