黄土丘陵沟壑区坡沟植被生态序列研究

The vegetation series along slopes on the Hilly-gullied Region of Loess Plateau

植被生态序列是小地形对植被空间分布影响的反映。采用样线法,对安塞纸坊沟支沟拐沟中南北向短坡面深沟谷和长坡面浅沟谷断面进行植被调查,分析其植被生态序列特征、物种组成及物种多样性。结果表明:短坡面深沟谷序列主要以灌乔木等演替后期物种为主,而长坡面浅沟谷序列则主要为草本物种;同一序列中,阴坡、沟谷地具有比阳坡、沟间地复杂的演替后期群落;序列中物种主要由菊科(Compositae)、豆科(Leguminoseae)和禾本科(Gramineae)构成,生活型主要为多年生草本,生态型以旱生、中旱生为主。α多样性指数在阴坡和短坡面深沟谷序列较高,β多样性指数在地形变化活跃的沟缘线区较高。研究结果可为黄土丘陵沟壑区植被建设人工调节提供参考依据。

Vegetation series explains influence of micro-landform on the vegetation distribution. Two north- south sections, a short slope with deep gully section and a long slope with shallow gully section, in Guaigou of Zhifanggou watershed in Ansai county were investigated by line transection. Then, the characters of vegetation series, composition and diversity of vegetation were analyzed. The main results are as follows： there are more herbs on the long slope with shallow gully section, while, on the short slope with deep gully section, there are more shrubs and trees, which are the main species of later community. And on the same section, the communities of the shade and gully region are more complex. Species of Compositae, Leguminoseaea and Gramineae composite of all most species, perennial herbs is the dominant life-form, and xerophyte and mesoxerphyte are the main water ecotype. The α diversity of the shade slope and the short slope with deep gully section is higher, while the β diversity is higher at erosion front of gully. Based on all above, suggestions of vegetation restoration are given.