华北泥河湾盆地植被、气候与早期人类生存环境研究进展

The Vegetation, Climate and Early Human Habitat Changes in the Nihewan Basin, North China: a Review

中国北方泥河湾盆地可以与非洲奥杜威峡谷相媲美,它们具有十分相似的地质演化过程,这里河湖相沉积发育,并且蕴藏着丰富的古生物化石和大量古人类遗迹,是研究东亚早期人类生存环境变化的重要区域。基于前人积累的晚上新世以来植被、气候及早期人类生存环境的大量研究资料,经分析发现在大约2.6Ma(百万年),泥河湾盆地的植被由阔叶林转变为以针叶林为主;大约1.92 Ma以后,植被以温带森林-草原(主要是松属、蒿属及藜科)/温带草原(主要是蒿属和禾本科等)为主。通过对比发现,晚上新世以来中国北方从西部到中部,由森林转变为以森林-草原为主的植被类型出现的时段呈现明显的阶梯型。此外,泥河湾盆地气候出现了13个冷暖旋回,15个干湿旋回,显著的冷干事件发生在2.8 Ma、2.6 Ma、1.92 Ma及143.8 ka(千年),湿润事件发生在43、32和6.6 ka。早期人类生活在森林-草原或以草原为主的植被环境中,气候冷暖干湿波动较大,水源丰富,大量哺乳动物共存。建议在建立泥河湾人类遗址更为精细地层的年代框架下,开展古气候温度与降水参数的定量化研究,将有助于精准重建古人类生存环境及揭示其变化规律。

Nihewan Basin in North China is endowed with ‘the Olduvai Gorge in East Africa’. Both basins have a similar geological evolution with well-developed fluvial and lacustrine deposits, rich fossil and a large number of remains of early humans. Undoubtedly, it is a key area to study the changes of habitats of early humans in East Asia. Compiling the literatures, we sketched the changes in vegetation, climate and early human habitats in the Nihewan Basin since the late Pliocene and noticed that the first vegetation shift from broad-leaved forest to coniferous forest occurred at ~2.6 Ma(Mega annum);the second important change of vegetation succession occurred at about 1.92 Ma. After that time, the vegetation was mainly temperate forest-steppe(covering Pinus, Artemisia, Chenopodiaceae)/temperate steppe(mainly Artemisia and Poaceae). By comparison, it is found that the vegetation change from forest to forest-steppe appeared gradually from west to central throughout northern China since the late Pliocene. In addition, at least 13 cold-warm cycles and 15 dry-wet cycles were recorded. Significant cold-dry events occurred at 2.8 Ma, 2.6 Ma, 1.92 Ma, and 143.8 ka(kilo annum), while humid events took place at 43, 32, and 6.6 ka. Early humans lived in forest-steppe or steppe environment with rich water resources where cold-warm and dry-wet climate fluctuated periodically, and co-existed with other mammals. In the future,under the chronological framework of establishing a more fine stratum of Nihewan human site, quantitative research on temperature and precipitation parameters of paleoclimate will benifit accurate reconstruction of the habitat of hominins and reflection of the law of change.