雪冰孢粉记录研究进展

Review on Palynological Records in Snow and Ice

孢粉作为一种可靠的代用指标,能够反映不同时间尺度古气候和古环境的变化信息。雪冰孢粉研究以雪冰中的植物花粉和孢子为研究对象,结合雪冰研究的特性和孢粉研究的优势,为气候重建提供了一种新的手段。雪冰孢粉是古植被的直接反映,可用于重建湿度、温度和人类活动。归纳了雪冰孢粉的古环境意义,总结了雪冰孢粉研究的空间分布状况,概述了雪冰孢粉记录的研究进展。现阶段雪冰孢粉研究在源区与传播特征、季节变化特征、辅助雪冰定年和古气候重建等方面均取得了良好的进展。北极地区有区域性的雪冰孢粉现代过程研究工作,而山地地区研究主要关注单个冰帽,并有若干学者在孢粉重建古温度以及孢粉重建古湿度等方面进行了定量化尝试。目前研究表明,雪冰孢粉对湿度变化的响应较为敏感,并且在温度重建方面具有极大潜力。特别在青藏高原,藜科、蒿属、禾本科以及莎草科花粉的百分比变化能够较客观地反映湿度变化信息。此外,雪冰孢粉记录的草原、草甸和荒漠植被类型的转变能够提供温度和湿度变化信息。但是,这些孢粉指标均具有一定的局限性,且其古环境指示意义研究也并不深入。青藏高原雪冰孢粉现代过程和古气候重建等应是未来值得关注的研究内容之一。

As one of the most credible proxies, pollen and spores can be used for retrieving the paleoenvironmental change at different time scales. Palynology in snow and ice provides a new version for climate reconstruction when taking both advantages of pollen and spores, as well as snow and ice. As a direct reflection of paleo-vegetation, palynology in snow and ice can be used to reconstruct humidity, temperature variations and human activities. The paleoenvironmental significance, research sites and research status of palynology in snow and ice were summarized. Good results have been achieved in the following aspects: pollen source and spread pattern characteristics, seasonal variation characteristics, dating supplement and paleoclimate reconstruction. Regional pattern of palynology modern progress has been established in Arctic areas. However, researchers focus on specific ice cap in mountain areas, and many scholars have made quantitative attempts for temperature and humidity reconstruction in these areas. Previous research suggests that pollen and spores in snow and ice are extremely sensitive to paleo-humidity changes and have great potential for temperature reconstruction. Especially in Qinghai-Tibet Plateau, humidity information can be objectively reflected by pollen percentage changes such as Chenopodiaceae, Artemisia , Poaceae, Cyperaceae. In addition, changes among vegetation types such as steppe, meadow and desert, which are recorded by pollen and spores, can also provide information on temperature and humidity changes. However, these pollen proxies have their limitations in the aspect of paleoclimate reconstruction, and their paleoenvironmental significance are ambiguous. Finally, the prospects for future research can focus on the modern process and paleoclimatic reconstruction of palynology in snow and ice in Qinghai-Tibet Plateau.