Vegetation succession and climate changing since the Late Pliocene in Tianzhu Region in Beijing
Yao YifengYe ChaoKou XiangyuXu Jingxian Jia SanmanDu NaiqiuLi Chengsen
1 Institute of Botany, Chinese Academy of Sciences, Beijing100093
2 Institute of Earth Environment, Chinese Academy of Sciences, Xian710075，Shaanxi
3 Hydrogeology and Engineering Geology Group of Beijing,Beijing100037
4 Beijing Normal University, Beijing100875
5 Beijing Museum of Natural History, Beijing100050
6 Graduate School, Chinese Academy of Sciences, Beijing100039
研究了北京天竺TZ01钻孔岩心孢粉样品239块，孢粉组合反映了北京天竺晚上新世以来(约3.580 Ma BP)植被演替和气候变迁大致经历了10个发展阶段：(1) 3.580～3.050 Ma BP：以针叶林植被为主，气候寒冷偏湿；(2) 3.050～2.555 Ma BP：植被为落叶阔叶和常绿阔叶混交林—草原类型，该阶段开始升温，但气候较为温暖湿润；(3)2.555～2.300 Ma BP：植被为温凉偏干的疏林草原，湿度开始下降；(4) 2.300～1770 Ma BP：植被类型仍为疏林草原，该阶段温度上升，但幅度并不大，湿度基本不变，气候温凉干爽；(5) 1.770～1.070 Ma BP：植被类型为针阔混交林—草原，气候温暖湿润；(6) 1.070～0.922 Ma BP：植被演替为较暖湿略干的针阔混交林—草原；(7)0.922～0.800 Ma BP：植被为较寒冷干燥的疏林草原，温度降低，降水减少；(8) 0.800～0.650 Ma BP：植被为温暖偏干的以松为主的疏林草原，温度有所上升，但湿度变化较小；(9)0.650～0.160 Ma BP：植被为温凉湿润的针阔叶混交林—草原；(10) 0.160 Ma BP至今：植被以针阔叶混交林—草原为主，前期气候冷湿，后期较为温暖湿润。
Totally 239 palynological samples from TZ01 borehole in Tianzhu Region in Beijing were studied. The palynological assemblages show that the vegetation succession and the changing pattern of climate in Tianzhu Region in Beijing during the past 3580 million years experienced ten stages: (1) From 3.580 to 3.050 Ma BP, the vegetation was dominated by needleleaved forest with the cold and humid climate conditions; (2) From 3.050 to 2.555 Ma BP, the vegetation changed into deciduous and evergreen broadleaved mixed forests and grassland, and climate became warm and humid； (3) From 2.555 to 2.300 Ma BP, the vegetation was arid grassland with sparse forest, and humidity began to decline； (4) From 2.300 to 1.770 Ma BP, the vegetation was grassland with sparse forest, but temperature began to rise and humidity changed little; (5) From 1.770 to 1.070 Ma BP, the vegetation transferred into grassland along with needle and broadleaved mixed forests with the warm and humid climate conditions； (6) From 1.070 to 0.922 Ma BP, the vegetation had the same type as the previous stage, but climate was a bit arid; (7) From 0.922 to 0.800 Ma BP, the vegetation was grassland with sparse forest in cold and arid climate, while temperature declined and precipitation decreased; (8) From 0.800 to 0.650 Ma BP, the vegetation was arid grassland with sparse forest, and temperature rose again, but humidity changed little; (9) From 0.650 to 0.160 Ma BP, the vegetation was grassland along with mixed needle and broadleaved forest; (10) From 0.160 Ma BP to present, the vegetation was dominated by needle and broadleaved forests, while climate was warmer and more humid during the late phase of this stage.
