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Pollen-based Biome Reconstruction at Middle Holocene (6 ka BP) and Last Glacial Maximum (18 ka BP) in China Members of China Quaternary Pollen Data Base


Biome (vegetation) reconstruction of the Middle Holocene ((6 000±500) a BP) and the Last Glacial Maximum ((18 000±2 000) a BP) in China was accomplished based on pollen data from “China Quternary Pollen data Base" and biomesation procedure. There are 116 pollen data used for 6 ka BP biome reconstruction. The 6 ka BP Biome shows the following differences as compared with the present vegetation: 1. Forests of eastern China expanded westwards to the steppe area. 2. Temperate deciduous forests shifted about 4 degrees latitudinally northwards and replaced by cool temperate mixed forest and taiga at present. 3. Tundra in Tibet Plateau was greatly shrunken. 4. Seasonal rainforest was replaced by rainforest in southern China. All these changes must be attributed to the increasing temperature and humidity during Middle Holocene, except some areas of southwestern and tropical areas of southern China where climate might be even cooler, but more humid than nowadays. Biome of 18 ka BP based on 39 pollen data displayed: 1. Steppe and desert expanded southwards and eastwards reaching the northern margin of the present evergreen broad-leaved forest. 2. Evergreen broad-leaved forest retracted southwards to the present tropical zone and the tropical forest banished completly. The vegetation changes must be resulted from cold and dry climate during the Last Glacial Maximum.

中国中全新世(6Ka  BP)和末次盛冰期(18 Ka BP)生物群区的重建
中国第四纪孢粉数据库小组*

摘要:利用中国第四纪孢粉数据库提供的116个6ka BP(±500年)和39个18kaBP(±2ka)的花粉数据,根据生物群区化方法(biomization)重建了中国中全新世(6ka BP)和未次盛冰期(18ka BP)两个关键时段的生物群区。结果表明,中全新世东部森林系统地向北推进,温带落叶阔叶林向北推进约4个纬度。大部分森林明显向草原区推进,青藏高原的冻原大面积退缩,在西南地区局部和热带地区气候较今略为冷湿,热带季雨林转变为热带雨林。末次盛冰期,草原大面积向南扩张,抵达现代的常绿阔叶林区的北缘,热带森林消失,常绿阔叶林退缩到现代热带区域边缘。
关键词: 花粉;生物群区;中全新世;末次盛冰期;中国


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