乌蒙山国家级自然保护区兰科植物多样性与分布格局研究

Diversity and distribution patterns of Orchidaceae in Wumeng Mountain National Nature Reserve

关键词:  兰科, 生物多样性, 物种组成, 海拔梯度, 濒危状况

Key words:  Orchidaceae, biodiversity, species composition, altitudinal gradient, conservation status

摘要:

兰科植物因包含众多珍稀濒危物种,其分布特征与生存状况一直是生物多样性保护研究的重点。为全面掌握滇东北乌蒙山国家级自然保护区兰科植物的物种多样性、分布格局及生存现状,该研究采用样方法对保护区内兰科植物进行了系统调查,并通过物种多样性指数分析及系统发育树构建,深入揭示该区域兰科植物的多样性特征。结果表明:(1)该保护区兰科植物以玉凤花属(Habenaria)、虾脊兰属(Calanthe)、舌唇兰属(Platanthera)为主要分布属,寡种属占比高达73%; 镰萼虾脊兰(Calanthe puberula)、羊耳蒜(Liparis campylostalix)、南川对叶兰(Neottia nanchuanica)、西南齿唇兰(Odontochilus elwesii)和光萼斑叶兰(Goodyera henryi)为优势物种。兰科植物的Margalef丰富度指数(D_MG)为4.035 6,Shannon-Wiener多样性指数(H')为2.622 8,Simpson优势度指数(λ)为0.113 6,这表示其存在中等多样性和低优势度。(2)就海拔分布而言,该保护区兰科植物主要分布在1 700～2 100 m的中高海拔段,亲缘关系较近的物种倾向于聚集在相近的海拔和生境中。(3)保护区内30%的兰科植物处于受威胁状态,尤其是具有重要的药用和观赏价值的种类,如峨眉金线兰(Anoectochilus emeiensis)、杜鹃兰(Cremastra appendiculata)、云南独蒜兰(Pleione yunnanensis)和春兰(Cymbidium goeringii)等,生存状况尤为堪忧。综上认为,保护区内兰科植物整体多样性不高、海拔分布不均衡,部分物种面临较高的生存风险。该研究为乌蒙山国家级自然保护区兰科植物多样性研究提供了重要的基础数据,其结果能够为后续兰科植物的系统保护和管理提供科学支撑。

Abstract:

Orchidaceae, encompassing numerous rare and endangered species, remains a focal group for biodiversity conservation research due to its distribution characteristics and survival status. To comprehensively master the species diversity, distribution patterns, and survival status of Orchidaceae in Wumeng Mountain National Nature Reserve of northeastern Yunnan Province, we systematically surveyed orchids using quadrat sampling and analyzed their diversity through diversity indices and phylogenetic reconstruction. It had deeply revealed the diversity characteristics of Orchidaceae in this region. The results were as follows:(1)The Orchidaceae flora was dominated by Habenaria, Calanthe, and Platanthera, with characteristic species including Calanthe puberula, Liparis campylostalix, Neottia nanchuanica, Odontochilus elwesii, and Goodyera henryi. Monotypic genera comprised 73% of the total. Diversity indices [Margalef's richness index(D_MG)=4.035 6, Shannon-Wiener diversity index(H')= 2.622 8, Simpson's dominance index(λ) = 0.113 6)] indicated moderate diversity and low dominance.(2)Species richness peaked at mid-high altitudes(1 700 - 2 100 m). Phylogenetically related species clustered at similar altitudes and habitats, suggesting strong habitat filtering.(3)Notably, 30% of species were threatened, particularly the taxa with medicinal and ornamental values such as Anoectochilus emeiensis, Cremastra appendiculata, Pleione yunnanensis, and Cymbidium goeringii and the survival status of these species were particularly worrying. In summary, the overall diversity of the Orchidaceae flora in this reserve is not high, and the distribution of species is uneven at different altitudes, and some species are facing high survival risks. The study provides critical baseline data for regional Orchidaceae diversity research and provide direct scientific support for the subsequent systematic protection and management of Orchidaceae.