我国濒危植物水仙花鸢尾所属群落特征与保护建议

Community Characteristics Associated with the Endangered Plant Iris narcissiflora and Conservation Implications

摘要:

水仙花鸢尾(Iris narcissiflora)是中国四川西部的特有物种，现有分布范围严重缩减，被列为国家Ⅱ级野生重点保护植物。当前对水仙花鸢尾种群现状及其生境特征的了解十分匮乏，不利于其濒危机制研究和保护措施制定。该研究对水仙花鸢尾目前的分布范围进行了详细踏查，调查野生种群状况及其生境，特别是所属群落特征。结果表明, 水仙花鸢尾分布于四川省甘孜州道孚县和康定市海拔3 779~4 100 m的高山灌丛或川西云杉(Picea likiangensis var. rubescens)林缘，各分布点种群规模小，仅含28~2100株；根据当前分布点的区域范围，依据IUCN受威胁物种评估标准B2ab(iii)将其重新评估为濒危(endangered, EN)；所属群落物种组成丰富，生活型以多年生草本植物为主，具较多温带成分；群落间物种组成相似性与地理距离呈显著的负相关；群落可划分为4种类型：川西云杉林缘和分别以毛蕊杜鹃(Rhododendron websterianum)、灰背杜鹃(R. hippo- phaeoides)、坡柳(Salix myrtillacea)为主要优势种的高山灌丛。水仙花鸢尾生境受修路、放牧影响，自然演替和全球气候变化也是潜在威胁。针对不同分布点的生境状况，提出设立保护小区，采取适当措施减轻川西云杉扩张和人为因素的影响，并建议开展迁地保护技术研究。

Abstract:

Iris narcissiflora is an endemic herb to western Sichuan Province, China, its current distribution range has been severely shrunk, and it was listed as a key national wild protected plant of grade II. However, the understanding of the population status and habitat characteristics of I. narcissiflora is very poor, which is not conducive to the study of its endangered mechanism and the formulation of conservation measures. The present distribution range of iris daffodil was investigated in detail to investigate the wild population status and habitat, especially the characteristics of the community. After extensive field surveys, I. narcissiflora was distributed in alpine shrubs or edge of spruce (Picea likiangensis var. rubescens) forests with the altitude of 3 779-4 100 m in Daofu County and Kangding City, Ganzi Prefecture, Sichuan Province, and the populations were small with 28 to 2 100 individuals. Based on current distribution, I. narcissiflora is reassessed as endangered (EN) according to the IUCN Threatened Species Assessment criteria B2ab(iii). The species composition of the community with I. narcissiflora was rich, the life type was mainly perennial herbs, with more temperate components. There was a significant negative correlation between species composition similarity and geographical distance between communities. A significantly negative relationship was observed between community similarity and geographic distance. The communities with I. narcissiflora could be divided into four types: spruce forest margin and alpine shrubs with Rhododendron websterianum, R. hippophaeoides and Salix myrtillacea as the dominant species, respectively. The habitat of I. narcissiflora was affected by road construction, grazing, natural succession and global climate change were also potential threats. According to the habitat conditions of different distribution sites, it was suggested to set up conservation areas, take appropriate measures to reduce the expansion of spruce in western Sichuan and the influence of human factors, and to carry out research on ex situ conservation technology.