隆务河流域植物区系研究

Study on the Floristic Characteristics in Longwu River Valley

隆务河流域共有种子植物 6 5科、 32 9属、 970种。区系特征如下 :(1)本区系是在高寒类型和寒温、干旱类型兼具的生态环境下形成的。 (2 )以多年生草本为主、木本植物和一年生植物为辅的植物种类比较丰富。 (3)以北温带成分为主的温带性质明显。 (4)区系具有年轻性和衍生性质。 (5 )本区的中国特有种是以我国西南、西北和华北地区为集中分布区或分别为分布中心的种为基础组成的。 (6 )本区系具有促使物种分化的“过渡生境”的性质和作用 ,或可称之为“过渡区效应”。区系分析表明 ,本区系应属与横断山和甘肃南部区系联系密切的青藏高原区系范围 ,并且在以高原、高山区系成分为主的基础上兼有我国西北寒旱区的荒漠旱生成分。建议是否可在其周围区系更进一步研究的基础上重新确定唐古特地区的界线。

There are 970 species,329 genera,65 families of seed plants distributed in this area (34°50′-35°55′N and 100°40′-102°30′E).Its floristic characteristics are as follows:(1)The flora is formed under the influence of alpine arctic and xeric ecological environment.(2)The floristic composition consists mainly of perennial herbs only accompanied with few trees and annuals.(3)The north temperate elements are superior than the old world temperate elements and others in numbers.(4)The flora belongs to young and derivative.(5)The endemic species coincide with some of those distributed in SW,NW and N China.(6)The flora is situated in the area with a transitional habitat for species differentiation,viz.the flora is influenced by the transitional area effect.By analyzing the floristic composition abounded with alpine and xeric elements,it is clear that the flora belongs to the Qinghai Tibet plateau flora and closely related to those of Hangduan mountains and S Gansu.It is suggested that the boundary of the Tangute Region of flora slauld be redefined based upon the further study of the flora existed in this area and its adjacent areas.