摘要
若尔盖ＲＭ孔上部６３７ｃｍ的花粉分析研究表明，在２２０００－１８０００ａＢ．Ｐ．，植被以高山草甸和荒漠草原为主，气候较现在寒冷干燥；１８０００－１３０００ａＢ．Ｐ．，主要是高山、亚高山草甸，出现亚高山灌丛，气温趋于升高，但仍干燥；１３０００－１１０００ａＢ．Ｐ，植被以亚高山禾草草甸为主；亚高山灌丛发展，可能已出现亚高山常绿针叶林，气温进一步上升，到后期己接近现在，湿度有所增加；１１０００－７０００ａＢ．Ｐ．，亚高山常绿针叶林扩张，亚高山灌丛在地方性植被中的比重又有所增加，草甸除禾草草甸外，可能出现亚高山莎草草甸或沼泽草甸，气温和湿度均比前期增高，西南季风在１１０００ａＢ．Ｐ．前后侵入本区；７００００－３３００ａＢ．Ｐ．，亚高山常绿针叶林大规模扩张，亚高山灌丛基本上被其取代，地方性植被主要是禾草草甸和莎草草甸或沼泽草甸，气候温暖潮湿；３３００－１９００ａＢ．Ｐ．，亚高山常绿针叶林退缩，禾草草甸可能被杂草草甸所取代，仍有莎草草甸或沼泽草甸，气温下降，湿度下降，西南季风逐渐减弱；１９００－１４００ａＢ．Ｐ．；针叶林进一步退缩，且冷杉在针叶林中的含量大于云杉，莎草草甸或沼泽草甸的规模扩大，气温进一步下降；１４００ａ?
The pollen record of 637cm in the upper part of 310m core RM from Zoige shows the occurrence of alpine meadow and desert-steppe in 22000-18 000aB.P.,which indicates a much colder and drier climate than that at present.From 18 000aB.P.to 13000aB.P.,alpine and subalpine meadow dominated,with the appearance of subalpine shrubbery;the temperature was still cold,but began to rise gradually.In 13000 -11000aB.P.,subalpine grass meadow was the dominant vegetation,with the development of subalpine shrubbery and the disappearance of alpine meadow,while subalpine evergreen coniferous forest began to appear,indicating that the temperature continued to rise and the humidity increased.From 11000aB.P.to 7000aB.P.,subalpine evergreen coniferous forest expanded and subalpine Cyperaceae meadow and/or swamp meadow appeared except the dominant subalpine grass meadow in local vegetation,temperature and humidity were higher than that of the previous period,and Southwest Monsoon began to invade the region by 11000aB.P.During 7000-3300aB.P.,subalpine evergreen coniferous forest went on expanding and local vegetation was dominated by subalpine grass meadow and Cyperaceae meadow and/or swamp meadow,representing a warm and wet climatic condition and a strengthened Southwest Monsoon.From 3300aB.P.to 1900aB.P.,subalpine evergreen coniferous forest decreased and grass meadow was replaced by weed meadow,but with the existence of Cyperaceae meadow and/or swamp meadow,temperature and humidity decreased and Southwest Monsoon began to weaken gradually.In 1900-1400aB.P.,coniferous forest was further reduced,whereas Cyperaceae meadow and/or swamp meadow expanded ,indicating a drop in temperature.From 1400aB.P.to 1000aB.P.,coniferous forest increased slightly,but Cyperaceae meadow and/or swamp meadow declined, showing a slight rise in temperature.
出处
《微体古生物学报》
CSCD
北大核心
1996年第4期401-406,共6页
Acta Micropalaeontologica Sinica
基金
国家八五攀登计划青藏项目
