ClimCellMed - Climate dynamics during the late Holocene derived from Cell structure measurements of juniper trees in the eastern Mediterranean

当今非洲的大部分地区受到全球和环境变化的严重影响，直接导致或恶化了已经存在的社会问题。由于非洲大陆过去也经历过类似的变化，因此更详细地了解区域过去的气候动态是很重要的，因为有人假设环境变化在调节人类的扩张、收缩甚至可能灭绝方面发挥了重要作用。更可靠的区域气候重建将为更全面地研究非洲人类社会内部的转变和纠缠机制提供有价值的背景信息。在世界许多地区，基于树木年轮的气候重建已经成功完成。非洲的树木年代学通常是困难的，因为不清楚，双重，缺失或楔入环边界。在某些情况下，树木年轮被用作精确确定年代的高分辨率气候代用品。从赤道以北非洲生长的树木中获得的长期重建非常罕见，我们认为这是古气候数据库中的一个关键空白。在赤道以北的非洲，由于森林面积非常有限，长期树木年轮记录的未来前景通常是黯淡的。从非洲树木中提取的可追溯到考古学年代的木材非常罕见，但从土耳其进口的木材（雪松、杜松和柏树）提取的可追溯到考古学年代的木材很常见。从树木气候学的角度来看，从土耳其南部海岸腹地的托罗斯山脉进口的杜松被认为是北非最有前途的物种。该项目的主要目标是将来自活树和考古遗址的木本刺柏材料结合起来，并首次利用最近开发的共聚焦激光扫描显微镜测量树木年轮细胞结构的方法，在公元前3000年的地中海地区建立一个长期重建。得到的细胞结构年表将被细分为几个类，每个树轮只包含一小部分细胞行。由此产生的亚年表代表了亚季节性的细胞生长模式。这些次年表将与季节气候数据相关联，并将得到额外的季节气候信息。随后的分析将检查地中海东部和非洲东北部与气候变率的大气和海洋模式（例如ENSO、NAO和季风）的关系，调查过去火山爆发的影响，并确定该地区对人类社会可能产生的气候影响。

Large parts of present-day Africa are affected severely by global and environmental change, resulting directly in or worsening already existing societal problems. Since the continent has gone through similar changes in the past, it is important to comprehend the regional past climate dynamics in more detail, since it has been hypothesised that environmental change played a significant role in conditioning human expansions, contractions and possibly even extinctions. More reliable regional climate reconstructions will be valuable background information when studying the transformations within human societies and entanglement mechanisms in Africa more comprehensively. In many parts of the world tree-ring based climate reconstructions have been accomplished successfully. African dendrochronology is often difficult because of indistinct, double, missing or wedging ring boundaries. In some instances, tree rings have been used as precisely dated high-resolution climate proxies. Long-term reconstructions derived from trees growing in Africa north of the equator are very rare, which we believe is a crucial gap in the palaeoclimate database. The future prospects for long tree-ring records in Africa north of the equator are generally bleak due to the very limited forested area. Dendroarchaeologically datable wood from African trees is very rare but dendroarchaeologically datable wood from timber (cedar, juniper and cypress) imported from Turkey is common. For dendroclimatological purposes, juniper imported from the Taurus Mountains in the hinterland of Turkey´s southern coast is seen as the most promising species in northern Africa. The main goal of the project is to combine woody juniper material from both living trees and archaeological sites, and to establish, for the first time, a long reconstruction in the Mediterranean back to 3000 BC, utilizing a recently developed method applying confocal laser scanning microscopy for measuring cell structures of tree rings. The resulting cell structure chronologies will be subdivided into several classes, containing only a fraction of cell rows per tree-ring. The resulting sub-chronologies represent sub-seasonal cell growth patterns. Such sub-chronologies will be correlated with seasonal climate data and additional seasonal climate information will be derived. Subsequent analyses will examine relationships to the atmospheric and oceanic modes of climate variability (e.g., ENSO, NAO and Monsoon) in the eastern Mediterranean and northeast Africa, investigate the impact of past volcanic eruptions and identify possible climate effects on human societies in the region.