中文摘要：

四川黄龙沟森林和钙化滩流地两种生境中分布着大量的少花鹤顶兰,而且生长在这两种生境中的少花鹤顶兰有性繁殖成功存在着差异,目前尚不清楚这种差异是否是由生境差异所致,及其影响有性繁殖成功的机制。通过对黄龙沟少花鹤顶兰两种生境主要环境因子的调查和两种生境中的花部特征和传粉情况的测量,结果表明森林生境中林木盖度、土壤厚度、土壤含水量、土壤有机质、土壤全氮以及空气相对湿度比钙化滩流地中的高,而灌木盖度、草本盖度、苔藓盖度、空气温度、相对光照强度、土壤温度、全钙以及pH则是钙化滩流地中更高。而两种生境中少花鹤顶兰的形态特征和有性繁殖成功之间也存在明显的差异。在森林生境中的个体与钙化滩流地中的个体相比,最大叶长和最大叶宽更大,花朵数更多,距长也更长,单花和花序寿命更长。但花粉移走率和结实率却是钙化滩流地中的更高。两种生境中温度和光照的差异可能是导致两种生境中少花鹤顶兰花粉移走率和结实率差异的重要原因。

英文摘要：

There are thousands of Phaius delavayi individuals,which mainly distributed in two different habitats,.i e.travertine areas and the remained forests,in Huanglong Valley,Sichuan,and the individual pollination successes were different between these two habitats.However,little is know about the causes and mechanisms leading to the differences.The differences of the microenvironmental conditions,morphological traits,male and female reproductive success of P.delavayi in two habitats were measured.The results showed that the microenvironmental conditions were found to be quite different between these two habitats,tree cover,soil depth,soil moisture,soil organic matter,total nitrogen,and relative air humidity were higher in forest areas,on the contrary,shrub cover,herb cover,moss cover,air temperature,relative light intensity,soil temperature,total calcium,and pH were higher in travertine areas.The results also showed that floral traits and reproductive success of P.delavayi had significant differences between these two habitats.The individuals in travertine areas had larger length and width of the largest leaf,more numbers of flowers within inflorescence,larger length of spur,and longer life span of both single flower and inflorescence than those in forest areas.However,both male and female reproductive successes were lower in travertine areas than those of that in forest areas.We supposed that the differences of temperature and light between two habitats may play important roles in leading to the differences of pollinia removal and nature fruit set of P.delavayi in the studied area.