极小种群野生植物白花兜兰的分布现状及生境研究

Research on the Distribution and Habitat of Plant Species with Extremely Small Populations,Paphiopedilum emersonii

关键词:  白花兜兰  极小种群  地理分布  生境  土壤营养

Key words:  Paphiopedilum emersonii  extremely small populations  geographical distribution  habitat  soil nutrition

摘要:

为有效保护极小种群野生植物白花兜兰Paphiopedilum emersonii，采用查阅资料、走访和实地调查相结合的方法，调查白花兜兰的地理分布、生境和资源现状，并对其分布区气候特征、土壤养分和植被等进行分析。结果表明，白花兜兰主要分布在广西河池市宜州区、环江县、罗城县、都安县和贵州荔波县的石灰岩山上，位于107°53'-108°35' E，23°56'-25°19' N，垂直分布高度为224-850 m，其中535-743 m较为常见。分布区气候温暖湿润，年均温为15.3-21.5℃，最高气温为40℃，最低气温为-10℃；年降水量为1 388.7-1 752.5 mm，多集中于4-8月，年均相对湿度为75%-83%。白花兜兰种群位于坡度大于30°山体的中上部，植株生长于荫蔽度大于60%的岩壁上，土壤稀少。种群受到不同程度的人为干扰，个体数量不足100丛，并以1-20丛居多；80%种群的植株年龄老化，属于衰退型种群。少数位于潮湿环境的种群生长有大量种子幼苗，具有一定自然更新能力。种群土壤主要为黑色石灰土，pH值为7.95-8.27，有机质、全氮、水解性氮和交换性钙含量丰富，其他元素含量较低。保护区内种群所在群落植被保存良好，保护区外原始植被破坏严重。群落植被由分布于49科80属的94个物种组成，且广西和贵州分布区的植被种类相似度极低。调查新发现白花兜兰野生种群6个，扩大了分布范围和资源数量。潮湿环境有利于白花兜兰种子自然萌发。本研究基本掌握了白花兜兰的地理分布、资源状况和主要生态特征，为其资源保护和引种栽培提供了科学依据。

Abstract:

In order to effectively protect the extremely small populations Paphiopedilum emersonii, the geographical distribution,habitat and resource status of P.emersonii were investigated by literature consulting,interview and field investigation.The climatic characteristics,soil nutrients and vegetation of its distribution area were analyzed.The results showed that P.emersonii mainly distributed in limestone mountains of Yizhou District,Huanjiang County，Luocheng County,Du'an County of Hechi City in Guangxi Province,Libo County in Guizhou Province.It was located in the region of 107°53' to 108°35' E and 23°56' to 25°19' N,with a vertical distribution height of 224-850 m,among which,the height of 535-743 m was more common.The distribution area was warm and humid with the annual average temperature of 15.3-21.5℃.The highest temperature and the lowest temperature were 40 and -10℃,respectively.The annual precipitation was 1 388.7-1 752.5 mm，mostly from April to August.The annual relative humidity was 75%-83%.The P.emersonii populations were located in the middle or upper part of the mountain with a slope greater than 30°.The plants grew on the rock wall with a shade degree greater than 60%,and the soil was scarce.The population was subjected to different degrees of human disturbance,and the number of individuals was less than 100 clusters,and the majority was 1-20 clusters.The plants of 80% population aged and belonged to the declining population.A few populations in the humid environment had a large number of seedlings and had a certain natural regeneration capacity.Population soil was mainly black calcareous soil with pH of 7.95-8.27.Its content of organic matter,total nitrogen,hydrolytic nitrogen and exchangeable calcium was rich,but the content of other elements was lower.The vegetation of the community in the reserve was well preserved,and the original vegetation outside the reserve was seriously damaged.The community vegetation consisted of 94 species distributed in 80 genera and 49 families,and the similarity of vegetation species among different distribution area of Guangxi and Guizhou was very low.Six new wild populations of P.emersonii were found in the survey,which expanded the distribution range and resource quantity.It was found that wet environment was beneficial to the natural germination of P.emersonii seeds.This research basically grasped the geographical distribution,resource status and main ecological characteristics of P.emersonii, which provided scientific basis for its resource protection and introduction and cultivation.