Long-term vegetation dynamics along altitudinal and longitudinal gradients in the Hyrcanian forest region (northern Iran) and the role of climate, sea level change, fire and anthropogenic impacts during the late Quaternary

伊朗的赫卡尼亚森林分布在阿尔博尔斯山脉和塔利什山脉北坡820公里长的狭长地带，占伊朗国土面积的6%。这个小地带有3234种植物，包括约500种特有植物，占植物多样性的44%。与安纳托利亚北部的森林一起，海卡尼亚森林构成了最重要的避难所，也是第四纪之前覆盖北半球温带的阔叶落叶森林的最后遗迹。该地区拥有许多Arcto-Tertiary和印度-马来西亚植物群的遗迹，被认为是具有全球重要性的生物多样性中心。今天，原始植被分布在从海岸到阿尔博尔斯和塔利什高地的垂直地带。由于该地区北受里海限制，南受高原限制，由于温度波动、降雨情况变化和里海海平面变化，上部森林线和沿海植被分别在空间和时间上发生了显著变化。此外，在过去的几个世纪里，人为的力量已经广泛地改变了植被。在如此多变的环境条件下，研究海卡尼亚的环境史，包括植被、植物多样性、气候、火灾、人类影响和海平面变化，具有至关重要的意义。迄今为止，海卡尼亚地区仅有少量的古生态记录。吉兰省是研究最少的省份，但其重要性很高，因为：i)吉兰具有广阔的森林和湿地，是开展古生态学研究的适宜区域；ii)吉兰是连接孤立的南海岸和欧亚大陆西部的走廊，其植被历史可以为欧亚大陆西部温带落叶林的避难假说提供新的见解；iii)吉兰是海卡尼亚省中最潮湿的省份，其古生态允许比较过去的东西降水梯度。4)吉兰是伊朗已知最古老的人类居住地，5)拥有最大的沿海河流森林遗迹。本项目将采用创新性的沉积物岩心多代理研究（花粉、孢子、木炭、地球化学分析等）和创新性的现代花粉雨研究（DNA元条形码），在海拔梯度上研究吉兰的环境历史。此外，还可以对东部和西部海卡尼亚地区的环境史进行比较。本研究还将为该生物多样性中心的保护和管理提供背景资料，其结果对自然保护、森林和牧场管理、农业、考古学和可持续发展等领域具有重要意义。

The Hyrcanian forests of Iran occurs in a 820 km long narrow belt on the northern slopes of Alborz and Talysh Mountains and occupies 6% of the area in Iran. This small belt hosts 3234 plant species including ca. 500 endemic plants and accounts for 44% of plant diversity. Along with the forests of northern Anatolia, Hyrcanian forests constitute the most important refugia and the last relicts of broad-leaved deciduous forests that covered the temperate zones of the northern hemisphere before the Quaternary. Hosting many remnants of the Arcto-Tertiary and Indo-Malaysian flora, the area is considered as a centre of biodiversity with global importance. Today, the original vegetation is distributed in altitudinal zones from the coast to the Alborz and Talysh highlands. Since the area is restricted by the Caspian Sea (CS) to the north and highlands to the south, the upper forest line and coastal vegetation have been subjected to pronounced changes due to temperature fluctuations and changes in the rainfall regime and CS sea level changes respectively, in space and time. In addition, anthropogenic forces have extensively modified the vegetation in the last centuries. Occurring in such changeable environmental conditions, investigating the Hyrcanian environmental history including vegetation, plant diversity, climate, fire, human impact and sea level change are of crucial importance. So far only a few palaeoecological records are reported from the Hyrcanian region. The Gilan province is the least studied province and is of high importance because: i) Gilan with extensive forests and wetlands is an appropriate area to carry out palaeoecological studies, ii) Gilan is the corridor that connects the isolated southern coast of the CS to western Eurasia and its vegetation history can provide new insights into the refugium hypothesis for the west Eurasian temperate deciduous forest, iii) Gilan is the wettest among the Hyrcanian provinces and its palaeoecology allow the comparison on an east-western precipitation gradient during the past, iv) Gilan is home of the most ancient known human settlements in Iran and v) has the largest remnant of coastal fluvial forest. This project will apply innovative multi-proxy studies (pollen, spores, charcoal, geochemical analysis, and others) of sediment cores and innovative (DNA meta-barcoding) modern pollen rain study on altitudinal gradients to investigate the environmental history of Gilan. Furthermore, a comparison between environmental history of eastern and western Hyrcanian region will be possible. This study will also provide background information for conservation and management of this centre of biodiversity and the results are of high importance for such as nature conservation, forest and rangeland management, agriculture, archaeology and sustainable development.