青海省柴达木盆地及其周围山地植被

THE VEGETATION OF QAIDAM BASIN AND ITS SUROUNDING MOUNTAINS

柴达木盆地位于青藏高原东北部,其植被分布规律较复杂。东部为半干旱荒漠草原地带,地带性植被为荒漠化草原;中部为干旱荒漠地带,地带性植被为灌木和矮半灌木砾漠;西部为极端干旱裸露荒漠地带,在砾石戈壁和低山基本上无植被。本区盆地底部随着地貌、土壤和地下水的变化,出现了植被环带状分布规律。从盆地边缘向中心依次发育着洪积平原灌木、矮半灌木砾漠带,冲积平原灌木沙漠带,冲积-湖积平原灌木盐漠带,湖积平原盐生草甸带,最后为裸露盐壳和盐湖。本区山地的植被垂直带自东而西明显不同。荒漠草原地带的带谱为:山地草原-山地常绿针叶林-亚高山灌丛-高寒草甸-高山稀疏植被;荒漠地带为:矮半灌木山地石漠-高寒草原-高寒草甸-高山稀疏植被;极端荒漠地带为:裸露低山石漠-矮半灌木山地石漠-高寒草原-高山稀疏植被。

The Qaidam basin is situated in the north-east Qinghai-Xizang plate-au, its distribution pattern of vegetation is very camplicated. The east-ern part of it belongs to the semiarid desert steppe zone with the zonalvegetation desert steppe. The middle part belongs to the arid desert zonewith shrubby and dwalf semi-shrubby gravelly desert. The western part isan extremely arid bare-desert without vegetation in the gravelly gobi andlow mountains. At the bottom of the basin, a ring-shaped belts of the ve-getation from the edge toward the centre shows the following sequence:flood plain-the shrubby and dwarf semi-shrubby gravelly desert belt, all-uvial plain-the shrubby and semi-arboreou sandy desert belt, alluviallacu-strive plain-the shrubby saline desert belt, lacustrine plain-the holophyticgrass and forb meadow belt, and finally, bare salt crust and salt lakes. In the mountains of the Qaidam region there is great difference in thevertical belt spectrum of the vegetation between east and west: the verti-cal spectrum in the desert steppe zone is: mountainous steppe-mountaino-us evergreen needleaf forest-subalpine shrubland-alpine meadow-alpine spa-rse vegetation; in the arid desert zone: dwarf semi-shrub mountain rockydesert-alpine steppe-alpine meadow-alpine sparse vegetation; and in thebare desert zone: bare low mountain rocky desert-dwarf shrubby mountainrocky desert-alpine steppe-alpin sparse vegetation.