宁夏沙湖自然保护区种子植物区系分析

Floristic Analysis of the Seed Plants in Sand Lake Nature Reserve

沙湖自然保护区属宁夏干旱区,共分布有种子植物47科123属161种(包括变种),47科种子植物可划分为5个分布区类型和2个变型,其中热带性分布科有12科,占总科数的57.1%(除世界分布),温带分布型的有9科,占总科数的42.9%。2种类型包含科数相差不大,说明该自然保护区是热带向温带过渡的类型。123属种子植物可划分为13个类型和9个变型,温带分布属及其变型占有主导地位,共有60属,占总属数的60.6%。研究表明,该自然保护区种子植物虽在组成上简单,以荒漠以及盐碱植物成分居多;但其植物区系地理成分复杂,具有明显的温带性质;由于人为活动的加剧,植物区系日渐脆弱。

Sand Lake Nature Reserve is located in Arid Zone of Ningxia. There are 161 species （including varieties） of the seed plants distributed in Sand Lake Nature Reserce belong to 47 families and 123 genera. These species in 47 families can be divided into 5 areal-types and 2 sub-types,and the 57. 1% of them are tropic areal-types involving 12 families,42. 9 of them are temperate areal-type involving 9 families. Two types have small difference in families,it is illustrated the area is transition of triopical to temperrate type. Further,the 123 genera can be divided into 13 areal-types and 9 sub-types,in which the temperate areal-type and sub-types involve 60 genera accounting for 60. 6 % in total, also showed a dominant floristic element in this seed flora. The investigation results demonstrated that the seed plant in the composition of simple and moiority of them are desertification and salilinazation plants;but eographical elements of the flora are comparatively complex,has a significant temperate characteristic; because of the intensification of human activities, the flora of the Sand Lake area is increasingly fragile.