Vegetation changes during the last 400 years in norhern Yakutia, Arctic Russia: Evidence from pollen analysis and vegetation modeling

这项建议的主要目标是利用植被代用方法和植被模型，探讨气候变化对北极植被的影响，特别是过去400年和未来100年雅库特北方的树线动态。根据最初提出的前三个月的工作计划，我们分析了现代沉积物样品的花粉和大型化石（以及硅藻和枝角类）。所获得的生物组合与现代植被和气候参数有统计学显著相关。我们还准备了驱动BIOME 4和LPJ植被模型的输入数据。初步模拟了雅库特地区的植被现状和历史变化，基本揭示了北极植被的结构和功能。为了实现我们的最终目标，在植被代用数据重建过去400年的植被变化方面还需要做更多的工作（花粉/硅藻/枝角类）;改进植被模型并将古植被模拟、植被代用品结果和古气候模拟联系在一起;根据过去的变化预测植被变化并评估世纪区域风险。

The main objective of this proposal is to explore the impacts of changes in climate on arctic vegetation, with special respect to treeline dynamics in northern Yakutia during the last 400 years, and in the future 100 years, using both vegetation proxy methods and vegetation modelling. In accordance with the originally proposed working programme for the first three month, we analyzed modern sediment samples for pollen and macrofossils (and additionally for diatom and cladocera). Obtained organism assemblages are statistically significantly related to modern vegetation and climate parameter. We have also prepared input data for driving both the BIOME4 and the LPJ vegetation model. The current vegetation patterns and historical vegetation changes were preliminarily simulated in Yakutia, which revealed basically the arctic vegetation structure and functions. In order to achieve our final aims more works are needed in terms of reconstructing vegetation changes during the past 400 years from vegetation proxy data (pollen/ diatoms/cladocera) in northern Yakutia; improving the vegetation models and linking palaeovegetation simulation, vegetation proxy results and palaeoclimate modelling together; and predicting vegetation change and assessing the regional risk for the 21st Century in the context of past changes.