香格里拉灌木、草本植物区系与垂直分布格局

草地作为全球生态系统功能服务最重要的组成部分,是农林牧业发展的基础,探究灌木、草本植物区系与地理分布特征对于揭示区域物种多样性和生物保护策略具有十分重要的意义。本研究通过野外样地调查和历史记录数据库,采用吴征镒植物区系分区方法,对香格里拉灌木和草本植物多样性、区系特点与垂直分布格局进行系统分析。结果表明：1)该区灌木、草本植物物种丰富,共有121科619属2 442种,其中草本植物占优,有94科514属2 048种。2)在科、属构成中,优势科属明显,单种科、寡种属比例高,占比分别为32.23%和51.05%,中国特有属极其丰富,共有28种。3)区系成分多样,含有13个科地理成分及15个属地理分布类型,科的区系分布类型以世界分布、泛热带分布和北温带分布为主,热带性与温带性分布的比值为1.29,热带分布型稍占优势;属的区系分布类型以北温带分布、东亚分布、泛热带分布为主,且热带性与温带性分布的比值为0.39,温带分布型占据主导地位。4)在垂直分布上,随着海拔的升高,热带区系成分占比逐渐降低、温带区系成分逐渐上升,物种丰富度呈先升后降的单峰分布格局,灌木、草本植物物种丰富度峰值位于2 600～2 900 m和3 200～3 500 m处,各海拔段草本物种数量均极显著高于灌木(P < 0.01)。本研究旨在展现“三江并流”世界自然遗产中心地带的植物多样性和同纬度地区植物分区特点,对当地灌木和草本植被生态修复物种选择和合理利用具有重要参考价值。

Shrub and herb flora and vertical distribution patterns in Shangri-La,China

As the most important components of global ecosystem functional services, grasslands are the basis for the development of agriculture, forestry, and animal husbandry; thus, a study of the characteristics of shrub and herb flora and geographical distribution is of great value, in particular to reveal regional species diversity and conservation strategies. In this study, the diversity, floristic characteristics, and vertical distribution patterns of shrubs and herbaceous (including graminoid) plants in Shangri-La were systematically analyzed with the use of field surveys and historical records database and applying the Wu Zhengyi flora zoning method. The results show that 1) the region is rich in shrub and herb (including graminoid) species, with 121 families, 619 genera and 2 442 species, and most of this richness can be attributed to herbs, with 94 families, 514 genera and 2 048 species. 2) In the composition of families and genera, the dominant families and genera were obvious, and the proportion of single species families and oligospecific genera was high, accounting for 32.23% and 51.05%, respectively, of the community composition. As well, the surveyed areas are extremely rich in endemic Chinese genera (28). 3) The regional components are diverse, containing 13 families and 15 genera of geographical distribution types. The distribution types of the family are mainly world distribution, pantropical distribution, and north temperate distribution. The ratio value of the tropical distribution and the temperate distribution is 1.29, which indicates that the tropical distribution type is slightly dominant. The distribution types of the genera are mainly north temperate distribution, East Asian distribution and pantropical distribution, and the ratio value of tropical distribution and the temperate distribution is 0.39, which indicates that the temperate distribution type is dominant. 4) In terms of vertical distribution, with the increase in elevation, the proportion of tropical zone components gradually decreases and temperate zone components gradually increase, and the species richness shows a single-peak distribution pattern of rising and then decreasing, with the peak of shrub and herb species richness located at 2 600 ~ 2 900 m and 3 200 ~ 3 500 m, respectively, and the number of herbaceous plants is more than that of shrubs in each altitude section (P < 0.01). With this study we have produced an altitudinal inventory of plant diversity and zone characteristics in the central area of the Three Parallel Rivers World Natural Heritage Site. This altitudinal inventory is expected to be a valuable reference for the selection and rational use of species for ecological restoration of regional shrublands and herbaceous vegetation.