西伯利亚南部旧石器时代晚期哺乳动物群动态学

旧石器时代晚期至全新世发生了广泛而迅速的动物群更替,为研究动物群对快速环境变化的反应提供了有益的信息。自中新世以来中亚地区一直是欧亚大陆向更开阔和干旱环境转变的焦点。利用已发表的俄罗斯贝加尔湖和阿尔泰山区域旧石器时代晚期的文献资料,通过对大型食草动物臼齿齿冠高度、食性和体型大小的分析,绘制了环境变化图。结果表明,在旧石器时代最晚期(晚冰期),平均齿冠高度、平均体型大小均有所减小,食物取向从食草向食树叶转变,这意味着气候变得温暖,降雨量增加,森林也有可能扩展。常见种(出现于超过25%的地点)更强烈地表现出这一趋势。齿冠高度随海拔高度而增大,提示降雨量减少。从齿冠高度得出的降雨量数值与根据其他指标所估算的数值之间的偏差可能随海拔高度而增大。影响西伯利亚南部猛犸象动物群消亡的主要变化可能开始于末次冰期冰盛期(LGM)之后。猛犸象和奇蹄动物出现频率的降低与大型哺乳动物的绝灭相一致,它们和偶蹄类的差异则反映了气候的变化。人类的过度开发可能给区域环境带来了更大的压力,使得哺乳动物的种群数量下降,导致它们更迅速地绝灭。

DYNAMICS OF THE MAMMALIAN FAUNA IN SOUTHERN SIBERIA DURING THE LATE PALAEOLITHIC

The extensive and rapid faunal alteration occurring at the late Pleistocene-Holocene is an informative period for studying faunal responses to rapid environmental change. Since the Miocene Central Asia has been the focal point of the transformation in Eurasia towards more open and dry environment. Here I use published literature data on the late Palaeolithic of Lake Baikal and Altai Mountains region in Russia to map environmental changes through molar crown height ( hypsodonty),diet and body size in large herbivores. The results demonstrate a decrease in mean hypsodonty, mean body size, and the shift in dietary preferences from grazing towards browsing during the latest late Palaeolithic or Late Glacial (LG) , which implies climatic warming, precipitation increase and, probably, spread of forests. Common species, present in ≥ 25 per cent of localities, produced these trends more strongly and responded faster to changing environments. Hypsodonty increased with altitude, which suggests precipitation decrease. Deviation between precipitation values derived from hypsodonty and estimated from other paleoindicators might be increasing with altitude. The major change that influenced the demise of the mammoth fauna in southern Siberia was probably initiated after the Last Glaciation Maximum (LGM). Decrease in mammoth and perissodactyl commonness is consistent with large mammal extinctions and different from artiodactyls response to climatic change. Human overexploitation could regionally add more stress to the declining mammalian populations and lead quicker to their extinction.