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...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/conifer and broad-leaved deciduous mixed forest were distributed in the east of Plateau (104degrees - 98degrees E). Meadows or shrub, meadow appeared in the middle of tire Plateau (98degrees - 92degrees E). Farther west to about 80degrees 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 (104degrees - 98degrees E) - conifer and broad-leaved deciduous mixed forest (98degrees - 94degrees E) - shrub meadow (94degrees - 92degrees E) - steppe (92degrees - 80degrees 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.展开更多
文摘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/conifer and broad-leaved deciduous mixed forest were distributed in the east of Plateau (104degrees - 98degrees E). Meadows or shrub, meadow appeared in the middle of tire Plateau (98degrees - 92degrees E). Farther west to about 80degrees 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 (104degrees - 98degrees E) - conifer and broad-leaved deciduous mixed forest (98degrees - 94degrees E) - shrub meadow (94degrees - 92degrees E) - steppe (92degrees - 80degrees 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.