黄土高原豆科植物区系的研究

STUDY ON THE FLORA OF LEGUMINOSAE IN LOESS FLATEAU

本区豆科植物共49属,217种,分别为中国豆科植物总数的22.5%和14.6%。在区系组成中,古地中海成分48种,占22.1%;东亚成分42种,占19.4%;中国喜玛拉雅成分21种,占9.7%;欧亚温带—黄土高原—青藏高原成分23种,占10.6%;特有成分22种,占10.1%;广布成分38种,占17.5%;归化成分23种,占10%。因此,本区是以古地中海成分和东亚成分为主。在自然景观中,旱生的草木和灌木起着重要作用,占有自然植被中的重要优势,是森林草原和草原的重要组成。

Loess plateau is located between asiatic inland and eastern Asia. It is generally known as a famous area with the deepest loess deposit in the world. For this reason, the flora of Leguminosae in this area are provided with transitional charactors, the floristic elements came from the other regions during past historical period. There are about 172 genera with 1485 species of Leguminosae in China; in Loess plateau alone there are 49 genera with 217 species(14.6%)of the total 1485 sp. In these elements of Leguminosae, the Tethys element is 48 species(22.1%); Eastern asiatic element is 42 species (19.4%); Sino-Himalaya element is 21 species (9.7%); Eurasian temperature-Loess plateau-Qingzang plateau element is 23 species(10.6%); Endemic element is 22 species(10.6%); Cosmopolitan element is 38 species(17.5%); Natural element is 23 species (10.6%) . Therefor it shows that the flora of Leguminosae in Loess plateau is mainly consist of the Tethys element and eastern asistic element, the other are secondary. Among the floristic elements of Leguminosae, the xerophilous herbs and shrubs play a important rule or have a conspicuous dominancy in the natural vegetations, which reflect the xerophytic ladscope of the steppe and forest-steppe. In addition, most of the species of Leguminosae have important ecological and economical values, so that these resources utilized fully in the future.