若尔盖国家公园评估区种子植物区系特征

Flora characteristics of seed plants in the evaluation area of Zoige National Park

为探讨若尔盖国家公园种子植物区系性质和特征,以川、甘两省拟建国家公园评估区(面积23338.49 km2)为研究对象,地理坐标位于101°1′49″—103°24′52″E,32°9′34″—34°32′25″N之间,通过实地调查,了解若尔盖国家公园评估区种子植物组成,并进行区系特征分析。结果表明:(1)评估区有种子植物96科454属1757种,其中大科(50种以上)有9个,共计908个种,占种子植物总种数的51.68%;菊科、禾本科、蔷薇科属于广布的世界科,在本区系中占优势地位;单种属(仅1种)有220个,占种子植物总属数的48.46%,表明本区系年轻和衍生的进化性质。(2)科的分布区可划分为8个类型和7个变型,除世界广布类型外,温带性质有32个科,占比为64.00%,温带性质明显;东亚特有科有1个,即星叶草科Circaeasteraceae,表明与东亚古老植物区系有关。(3)属的分布区可划分为14个类型和15个变型,除世界分布和外来属以外,温带性质的属占比为90.38%,其中北温带占比为44.81%,具有从北温带向中温带过渡的性质。(4)评估区内有中国特有种763种,高原特化现象明显,其中甘肃和四川省分布的狭域特有植物有24种。

This study focuses on the evaluation area of the planned national park in Sichuan and Gansu provinces,covering an area of 23,338.49 km2,to explore the characteristics and features of seed plant flora in Zoige National Park.The geographical coordinates were located between 101°1′49″E—103°24′52″E,32°9′34″N—34°32′25″N.The composition of seed plants and flora characteristics in the evaluation area of Zoige National Park were analyzed based on field investigation.The results showed that:(1)There were 1757 species of seed plants in 96 families and 454 genera in the evaluation area,including 9 large families(over 50 species)with 908 species,accounting for 51.68%.Compositae,Gramineae,and Rosaceae belonged to Widespread while occupying a dominant position in this region.There were 220 genera singly(only 1 species),accounting for 48.46%,indicating the young and derived evolutionary properties.(2)The distribution of the family can be categorized into 8 types and 7 variants.Apart from Widespread,there were 32 temperate families,accounting for 64.00%,indicating that temperate properties were prominent.There was one East Asian endemic family,namely Circaeasteraceae,with a bearing on ancient flora.(3)The genus distribution could be divided into 14 types and 15 variants.Except for Widespread and Foreign,temperate genera took 90.38%(northern temperate 44.81%),indicating a transition from northern to middle temperate.(4)There were 763 Chinese endemic species,with an apparent specialization from the plateau,including 24 narrow endemic species distributed in Gansu and Sichuan provinces.