凤尾蕨科三种濒危植物:种群现状与保护建议

Three endangered Pteridaceae species in China:Current population and conservation suggestion

凤尾蕨科是中国蕨类植物物种多样性排名第四的大科,其中涵盖地生、岩生、水生等多种生态类型的18个濒危物种。考察具有不同生态类型和适应性的濒危物种的种群现状、比较生态适应特征,并模拟其潜在分布区格局,可以为凤尾蕨科濒危物种的保护提供参考。本研究实地考察了荷叶铁线蕨(Adiantum nelumboiddes)、中国蕨(Aleuritopteris grevilleoides)和粗梗水蕨(Ceratopteris pteridoides)3种濒危凤尾蕨科植物在中国大陆的野生种群的地理分布与规模;分析了影响其生存的关键气候因子;并通过MaxEnt模型模拟在当前气候情景下的潜在分布格局。结果表明:荷叶铁线蕨仅分布于长江三峡库区重庆忠县至万州的狭长区域,对温度变化范围较敏感,野外种群规模仅有500余株,人为干扰严重,亟待保护;中国蕨适应冬季温暖、年降水量较少的环境,主要分布于云南省北部楚雄州大姚县与昆明市禄劝县等地,模型模拟发现同为金沙江流域的元谋县、永仁县、永胜县等地是中国蕨的高度适生区,可能存在尚未发现的野生居群;粗梗水蕨广泛分布于长江中下游湿地以及山东微山湖芦苇荡,种群规模相对较大。基于以上结果,我们对这3种凤尾蕨科植物的保护工作提出了建议。

Pteridaceae is the fourth fern family in China with respect to species richness,which contains 18 threatened species with various ecotypes including terrestrial,lithophytic and aquatic.Understanding the status of endangered Pteridaceae species with different ecotypes can provide useful information for the conservation of the endangered fern species.We investigated the location and size of natural populations of three endangered Pteridaceae species on the Chinese mainland:Adiantum nelumboiddes and Aleuritopteris grevilleoides,both terrestrial or lithophytic,and aquatic Ceratopteris pteridoides.We compared their climatic adaptability with 19 bioclimatic factors from WorldClim and found their dominant climatic factors.We simulated their potential distribution patterns using MaxEnt model under current climate scenario.Ad.nelumboiddes,is sensitive to the temperature annual range(bio7)and confined in the canyon of the Yangtze River from Zhongxian County to Wanzhou District of Chongqing City.Its natural population size is extremely small,with a total of about 500 individuals.Since it has high medical and economic values,the natural population has been under the pressure of serious human disturbance.Al.grevilleoides prefers warm winter(bio11)and low annual precipitation(bio12)and is found in Dayao County of Chuxiong Autonomous Prefecture and Luquan County of Kunming City in the north of Yunnan Province.The model simulation showed that Yuanmou,Yongren and Yongsheng in Yunnan Province which belonged to the dry-warm valleys of the Jinsha River basin,were highly suitable areas for Al.grevilleoides.Population size of C.pteridoides was much larger than other two species,which is widely distributed in the shallow wetlands of the middle and lower reaches of the Yangtze River as well as the in the reed marsh at the lakeshore of Weishan Lake in Shandong Province.We proposed suggestions for the conservation of these three species.