西藏特有种子植物多样性、分布格局及区系特征

Diversity,distribution patterns,and floristic characteristics of seed plants endemic to Tibet,China

基于西藏特有种子植物名录,结合物种自然地理分布信息,对西藏特有种子植物科属种多样性组成特征、物种生活型多样性、垂直海拔分布及县域尺度分布格局、属水平植物区系性质进行了分析,并对特有种热点地区进行了识别。结果显示,西藏特有种子植物有1079种,隶属89科297属,特有性高,其中含20种以上的科为19个,含特有种最多的科为菊科;含10种以上的属有24个,含特有种最多的属为翠雀属(Delphinium)和小檗属(Berberis)。多年生草本植物在特有种中占绝对优势(66.4%)。从区系成分来看,温带性质的属占主导(61.6%)。东南部的墨脱县含特有种数量最多(271种)。总体上,西藏特有种子植物的空间分布格局极不均匀,喜马拉雅东南麓是丰富度最高的区域。西藏特有种子植物的海拔分布范围宽泛,集中分布在3000~4500 m,特有种丰富度在海拔梯度上呈单峰分布格局。本研究结果可为将来确定西藏植物多样性保护优先次序、红色名录制定及自然保护体系的建设提供参考。

Based on the list of endemic seed plants of Tibet,combined with the natural geographic distribution of species,the composition characteristics of family,genus,and species diversity,species life-form diversity,vertical altitude and county-scale distribution patterns,and floristic properties at the genus level were analyzed,with endemic species hotspots also identified.Results showed 1079 species of endemic seed plants in Tibet,belonging to 89 families and 297 genera,with high specificity.Among the identified plants,19 families contained more than 20 species,and Asteraceae contained the most endemic species.In total,24 genera contained more than 10 species,with Delphinium and Berberis identified as the most endemic genera.Perennial herbs accounted for the highest proportion(66.4%)among endemic plants.In terms of floristic composition,temperate genera were dominant(61.6%).Medog County contained the largest number of endemic species(271 species).In general,the distribution pattern of endemic seed plants in Tibet was extremely uneven,with the southeast Himalayas showing the highest richness.The endemic seed plants also exhibited an extremely wide altitudinal range,showing a single-peak species-richness distribution pattern along the altitudinal gradient,concentrated at 3000–4500 m.The results of this study provide basic plant data to support the prioritization of plant diversity conservation in Tibet,the establishment of a red list,and the construction of a natural protection system in the future.