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キーワード:
Pollen data
Plant functional types
Biomes
Vegetation changes
China
Mid-holocene
Last glacial maximum
Basin western tibet
Environmental-change
Loess plateau
Bp
Records
Biomes
要旨:
Pollen data from China for 6000 and 18,000 C-14 yr BP Were compiled and used to reconstruct palaeovegetation patterns, using complete taxon lists where possible and a biomization procedure that entailed the assignment of 645 pollen taxa to plant functional types. A set of 658 modern pollen samples spanning all biomes and regions provided a comprehensive test for this procedure and showed convincing agreement between reconstructed biomes and present natural vegetation types, both geographically and in terms of the elevation gradients in mountain regions of north-eastern and south-western China. The 6000 C-14 yr BP map confirms earlier studies in showing that the forest biomes in eastern China were systematically shifted northwards and extended westwards during the mid-Holocene. Tropical rain forest occurred on mainland China at sites characterized today by either tropical seasonal or broadleaved evergreen/warm mixed forest. Broadleaved evergreen/warm mixed forest occurred further north than today, and at higher elevation sites within the modern latitudinal range of this biome. The northern limit of temperate deciduous forest was shifted c. 800 km north relative to today. The 18,000 C-14 yr BP map shows that steppe and even desert vegetation extended to the modem coast of eastern China at the last glacial maximum, replacing today's temperate deciduous forest. Tropical forests were excluded from China and broadleaved evergreen/warm mixed forest had retreated to tropical latitudes, while taiga extended southwards to c. 43 degreesN. [References: 134]
