摘要
黄土高原上水热自东南向西北有规律递减,在旱中生和中旱生植物组成的草甸草原背景上,稀疏的分布着一些旱中生矮乔木,称疏林草原,这类群落乔木覆盖度一般不超出20%,通常10%左右,有时低于5%.大致420—520mm 隆水量是决定黄土高原森林草原存在的主要因素.
The Loess Plateau is situated at 33°3'-40°6'N,100°5'-114°3'E. It is covered with loess of 50-150 m thick. As it is eroded by flowing water for a long time,it formed alone yuan,beam-ridges and hill-gullies topography. Humidity and heat decrease gradu-ally from southeast to northwest in the Loess Plateau. The forest is replaced by the steppe, and an obvious transition zone formed between them, it is a forest steppe. Its characteristic is that stunted exro-mesophilous trees are distributed sparsely on the meadow steppe. The meadow steppe mainly consists of xero-mesophytes and meso-xero-phytes,the trees cover degree is usually less than 20%,generally about 10%,sometimes below 5%. Precipitation of about 420-520 mm is a decisive factor of the existence of the forest-steppe in the Loess Plateau.
出处
《地理科学》
CSSCI
CSCD
北大核心
1994年第2期152-156,共5页
Scientia Geographica Sinica
关键词
草原
森林草原
黄土高原
疏林草原
The Loess Plateau
Forest steppe
Open forest steppe
Meadow steppe
