四川格西沟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 Pattern of Orchids in Gexigou National Nature Reserve,Sichuan,China

为了解四川格西沟国家级自然保护区兰科植物多样性与分布特征,于2020和2021年采用样线样方结合法,在保护区内进行系统性调查,共设置了17条总长95 km的样线,涵盖保护区各功能区、生境类型以及海拔范围。结果表明:(1)保护区内调查到兰科植物20属34种。其中珍稀濒危物种有10种,包括5种国家二级保护野生种类;四川省新记录种2种[褐花羊耳蒜(Liparisbrunnea)、齿突羊耳蒜(L.rostrata)];生活型以地生兰为主,属的地理成分以北温带分布占绝对优势。(2)34种兰科植物共调查到6703株,分布于290个点位,以二叶盔花兰(Galearis spathulata)数量最多,大花鸟巢兰(Neottia megalochila)最少,火烧兰(Epipactis helleborine)分布点位最多。紫点杓兰(Cypripedium guttatum)植株高度与海拨呈极显著负相关性,其余种类在同物候期的种间高度变化轻微。(3)保护区3100~3300 m内的兰科植物种属数最多,其次是2900~3100 m区间,3900~4100 m内的兰科植物数量最多。(4)头蕊兰(Cephalanthera longifolia)数量与坡度因子呈显著的中度正相关,二叶盔花兰数量与海拔呈显著的强正相关,叉唇角盘兰(Herminium lanceum)数量与植被呈显著的强正相关,角盘兰属(Herminium)数量与海拨呈显著的中度负相关。综上,在四川省内,格西沟自然保护区的兰科植物资源相对丰富,分布格局符合“中间高度膨胀型”,大部分种类的数量与环境因子不显著相关,与历史上对该保护区的调查相比,本次调查到的兰科植物种属数量大幅增加,但有3种国家重点保护且观赏价值高的杓兰属植物未调查到,1种杓兰属植物在调查期间种群数量下降。因此,对保护区的兰科植物保护、宣传、执法等刻不容缓。

In order to understand the diversity and distribution characteristics of orchids in Gexigou National Nature Reserve in Sichuan province,a systematic survey was conducted using the line transect combined with sample sampling method from 2020 to 2021.A total length of 95 km including 17 lines were set up,covering various function,habitat and elevation of the reserve.34 species of Orchidaceae in 20 genera were investigated.Among them,10 were rare and endangered species,five were wild species under second-class national protection;and two(Liparis brunnea and L.rostrate)were new record species in Sichuan province.Most of them were mainly in terrestrial orchid of life type and absolutely dominant in north temperate zone of geographical.A total of 6703 orchids of 34 species were investigated and distributed in 290 sites.Galearis spathulata and Neottia megalochila were the most and least abundant species respectively,and Epipactis helleborine was the most widely-distributed.Among them,the height of Cypripedium guttatum showed a significant negative correlation with elevation,while there was a slightly correlation in other species.Most of Orchidaceae genera were distributed in 3100-3300 m,followed by 2900-3100 m,while the maximum number of individuals were distributed in 3900-4100 m.The number of Cephalanthera longifolia was positively correlated with slope significantly,the number of Galearis spathulata was positively correlated with elevation significantly,the number of Herminium lanceum was positively correlated with vegetation significantly,the number of whole genus of Herminium was positively correlated with elevation moderately.In general,the orchid resources in Gexigou Nature Reserve are relatively rich,and more distribute in the middle elevation.The number of some species is significantly correlated with environmental factors.Compared with the previous investigations in this reserve,the number of orchid species is significantly increased.However,three national protected species of Cypripedium with high ornamental value were not found,and the population of one species of Cypripedium decreased.Therefore,it is urgent to protect,publicize and enforce the law on orchids in the reserve.