植被是陆地生态系统的主体,其演化对全球气候变化及碳循环有着至关重要的影响。重建过去典型增温过程中植被的变化,是评估全球变暖背景下植被响应的关键之一。末次冰盛期(LGM)是末次冰期中距今最近的气候最冷、冰川规模最大的时段。LGM...植被是陆地生态系统的主体,其演化对全球气候变化及碳循环有着至关重要的影响。重建过去典型增温过程中植被的变化,是评估全球变暖背景下植被响应的关键之一。末次冰盛期(LGM)是末次冰期中距今最近的气候最冷、冰川规模最大的时段。LGM以来,气候经历了从末次冰盛期到全新世的逐渐增温和后续降温过程。本研究综合公开发表的东北地区的69条孢粉序列,通过生物群区化方法定量重建了LGM以来其植被分布格局变化。结果表明,21~12 ka B.P.,森林仅分布在东部边缘山地,该时期森林类型点位比例最低,仅25%,研究区大面积被草原和荒漠占据;12~9 ka B.P.,森林向西、北方向扩张,草原被迫向内蒙古高原地区迁移,森林-草原分界线逐渐向西移动;9~5 ka B.P.,森林成为主要植被类型,在东北地区广泛分布,森林点位比例在6 ka B.P.达到最大值,约65%以上。温带落叶林分布范围与现代相比,最北界向北扩张大约7°~8°。草原仅分布在松嫩平原东部和内蒙古高原北部。全新世大暖期(6±0.5 ka 14C),森林-草原分界线大致分布在现代300 mm年等降水量线附近;5 ka B.P.以来,草原再次扩张。森林向东部边缘山地迁移。森林-草原分界线向东迁移。此外,温带落叶林出现的海拔变化显示,LGM以来其逐渐上升至全新世早中期开始下降,与全球温度变化类似。进一步分析表明,LGM以来,降水或有效湿度可能是控制东北地区森林整体比例变化的主要驱动因素。此外,5 ka B.P.以来,人类活动对植被分布格局的影响是不可忽视的。展开更多
Biomization provides an important way to assign pollen taxa to biomes and to simulate palaeo-vegetation patterns, so that pollen data can be mapped to reconstruct biogeography and climate. The authors have tested the ...Biomization provides an important way to assign pollen taxa to biomes and to simulate palaeo-vegetation patterns, so that pollen data can be mapped to reconstruct biogeography and climate. The authors have tested the applicability of this procedure to assign modern pollen surface samples from China to biomes. The procedure successfully delineated the major vegetation types of China. When the same procedure was applied to 6 ka B.P. fossil pollen samples, the reconstructions showed that the forest zones were systematically shifted northwards ca. 300\500 km beyond their present northern limits in eastern China; the area of desert and steppe vegetation was reduced compared to the present in northwestern China; the area of tundra was reduced largely on the Tibetan Plateau. This research is a contribution to the project of BIOME 6000 in Pacific-Asian regions.展开更多
Vegetation evolution in the northern South China Sea region since 40 500 a BP is reconstructed using biomization procedure based on pollen data from deep sea core 17940. The result shows that, it is feasible to recons...Vegetation evolution in the northern South China Sea region since 40 500 a BP is reconstructed using biomization procedure based on pollen data from deep sea core 17940. The result shows that, it is feasible to reconstruct palaeovegetation using biomization procedure, when pollen, particularly Pinus pollen, transported by mind over long distance is excluded. Results from factor analysis suggest that humidity and temperature are the two main factors determining vegetation evolution on land around the northern South China Sea. From 40 500 a BP to 11 100 a BP, broad-leaved evergreen forest (WAMF), and montane conifers(MGRF) occurred on hills and low mountains; while steppe (STEP) predominated on the exposed shelf. The main feature of the vegetation evolution is the frequent alternation between MGRF (or WAMF) and STEP, implying abrupt changes in millennium scale between humid/cold and dry/temperate climate. All abrupt climate events could be broadly correlated with Henrich events and Dansggard-Oscherge events. One of the events around 12 700 a BP, sees the occurrence of MGRF, suggesting that climate turned humid and cold rapidly. This may be correlated with the Younger Dryas event; Broad-leaved evergreen (WAMF) predominates since 11 000 a BP. During the early Holocene and late Holocene tropical rainforest (TRFO) or tropical seasonal forest (TSFO) occurred several times.展开更多
文摘植被是陆地生态系统的主体,其演化对全球气候变化及碳循环有着至关重要的影响。重建过去典型增温过程中植被的变化,是评估全球变暖背景下植被响应的关键之一。末次冰盛期(LGM)是末次冰期中距今最近的气候最冷、冰川规模最大的时段。LGM以来,气候经历了从末次冰盛期到全新世的逐渐增温和后续降温过程。本研究综合公开发表的东北地区的69条孢粉序列,通过生物群区化方法定量重建了LGM以来其植被分布格局变化。结果表明,21~12 ka B.P.,森林仅分布在东部边缘山地,该时期森林类型点位比例最低,仅25%,研究区大面积被草原和荒漠占据;12~9 ka B.P.,森林向西、北方向扩张,草原被迫向内蒙古高原地区迁移,森林-草原分界线逐渐向西移动;9~5 ka B.P.,森林成为主要植被类型,在东北地区广泛分布,森林点位比例在6 ka B.P.达到最大值,约65%以上。温带落叶林分布范围与现代相比,最北界向北扩张大约7°~8°。草原仅分布在松嫩平原东部和内蒙古高原北部。全新世大暖期(6±0.5 ka 14C),森林-草原分界线大致分布在现代300 mm年等降水量线附近;5 ka B.P.以来,草原再次扩张。森林向东部边缘山地迁移。森林-草原分界线向东迁移。此外,温带落叶林出现的海拔变化显示,LGM以来其逐渐上升至全新世早中期开始下降,与全球温度变化类似。进一步分析表明,LGM以来,降水或有效湿度可能是控制东北地区森林整体比例变化的主要驱动因素。此外,5 ka B.P.以来,人类活动对植被分布格局的影响是不可忽视的。
文摘Biomization provides an important way to assign pollen taxa to biomes and to simulate palaeo-vegetation patterns, so that pollen data can be mapped to reconstruct biogeography and climate. The authors have tested the applicability of this procedure to assign modern pollen surface samples from China to biomes. The procedure successfully delineated the major vegetation types of China. When the same procedure was applied to 6 ka B.P. fossil pollen samples, the reconstructions showed that the forest zones were systematically shifted northwards ca. 300\500 km beyond their present northern limits in eastern China; the area of desert and steppe vegetation was reduced compared to the present in northwestern China; the area of tundra was reduced largely on the Tibetan Plateau. This research is a contribution to the project of BIOME 6000 in Pacific-Asian regions.
文摘Vegetation evolution in the northern South China Sea region since 40 500 a BP is reconstructed using biomization procedure based on pollen data from deep sea core 17940. The result shows that, it is feasible to reconstruct palaeovegetation using biomization procedure, when pollen, particularly Pinus pollen, transported by mind over long distance is excluded. Results from factor analysis suggest that humidity and temperature are the two main factors determining vegetation evolution on land around the northern South China Sea. From 40 500 a BP to 11 100 a BP, broad-leaved evergreen forest (WAMF), and montane conifers(MGRF) occurred on hills and low mountains; while steppe (STEP) predominated on the exposed shelf. The main feature of the vegetation evolution is the frequent alternation between MGRF (or WAMF) and STEP, implying abrupt changes in millennium scale between humid/cold and dry/temperate climate. All abrupt climate events could be broadly correlated with Henrich events and Dansggard-Oscherge events. One of the events around 12 700 a BP, sees the occurrence of MGRF, suggesting that climate turned humid and cold rapidly. This may be correlated with the Younger Dryas event; Broad-leaved evergreen (WAMF) predominates since 11 000 a BP. During the early Holocene and late Holocene tropical rainforest (TRFO) or tropical seasonal forest (TSFO) occurred several times.
