最近12 000年来青藏高原植被的时空分布

青藏高原30个点湖泊的孢粉记录综合研究显示: 在进入全新世之前(12 ka BP以前),除最东南部外,高原从东到西均发育为荒漠草原植被.全新世早期(12.0-9.0 ka BP)高原东南部(104°-98° E)为落叶阔叶林/针阔叶混交林; 中部(98°-92° E)为草甸或灌丛草甸,再向西至80° E左右为草原植被; 全新世中期(9.0-3.2 ka BP)高原由东向西古植被依次发育为针阔混交林和硬叶阔叶林(104°-98° E)→针阔混交林(98°-94° E)→灌丛草甸(94°-92° E)→草原(92°-80° E);全新世晚期(3.2 ka BP以后)由东向西古植被依次为硬叶阔叶林→针阔混交林→草甸→草原→荒漠.

Temporal-Spatial Distribution of Vegetation in the Qinghai-Xizang Plateau During the Past 12 ka BP

Comprehensive studies on the basis of pollen records from lake cores at 30 sites in the Qinghai Xizang Plateau have been used to reconstruct temporal spatial distributions of Holocene vegetations. Before the Holocene (prior to 12.0 ka BP) desert steppe vegetation was developed from the east to the west in the most parts of the Plateau, with a few exceptions in the extreme southeastern appeared. During the early Holocene (12.0-9.0 ka BP),deciduous broad leaved forest/coniferand broad leaved deciduous mixed forest were distributed in the east of Plateau(104° -98°E). Meadows or shrub meadow appeared in the middle of the Plateau (98° -92°E). Farther west to about 80°E, a steppe landscape was present. During the middle Holocene (9.0-3.2 ka BP), the palaeovegetations were sequentially conifer and broad leaved deciduous mixed forest and sclerophyllous broad leaved forest (104°-98°E)-conifer and broad leaved deciduous mixed forest (98°-94°E)-shrub meadow (94°-92°E)-steppe (92°-80°E). During the late Holocene (after 3.2 ka BP), the palaeovegetations were sequentially sclerophyllous broad leaved forest-conifer and broad leaved deciduous mixed forest-meadow-steppe-desert from east to west of the Plateau.