中文摘要：

本文通过对黄河源区退化高寒草甸48种常见植物种子的萌发特性研究,比较了不同功能群植物萌发行为的异质性,旨在揭示不同植物萌发对策的生态适应机制。结果显示;萌发率超过80%的植物有17种,小于20%的有14种,1种植物未萌发;萌发速率在l以下的有15种,大于10的有21种;萌发起始时间小于5 d的有12种,大于15 d的有5种;有6种植物的萌发持续15 d以上,30种植物的萌发在10 d内结束。种子萌发速率与种子大小呈显著负相关（P〈0.05）,小种子物种有更高萌发率（P=0.085）和更早萌发起始时间（P=0.093）的趋势。48种植物的萌发划分为爆发型、过渡型、缓萌型和低萌型等4种类型,其中禾本科植物以爆发型为主,莎草科则是低萌型和缓萌型占优势,杂类草在几种萌发类型中均有分布,说明不同功能群植物在生存风险分摊上的异质性策略。

英文摘要：

In order to reveal seed germination countermeasures and its ecological significance of species,seed germination characteristics（germination percentage,germination rate,and germination period） of 48 common plant species of degraded alpine meadow in the Headwater area of Yellow River were studied.The main results were that the seed germination percentages of all tested species displayed a bimodal distribution except for one species that could not germinate.The seed germination percentages of 17 species were more than 80%,and that of 14 species was less than 20%.The germination rates of 15 species were less than 1,while the germination rates of 21 species were more than 10.The starting time of germination was less than 5 days for 12 species,while 5 species failed to germinate over 15 days.The germination period was more than 15 days for 6 species,while 30 species had a germination period of less than 10 days.Seed germination rate increased with the increase of seed size（P〈0.05）.Both germination percentage（P =0.085） and starting time of germination（P=0.093） had a weak positive relationship with seed size.However,no correlation was observed between germination period and seed size.Principal component analysis and clustering analysis divided 48 species into four germination patterns：rapid,intermediate,slow and low germination.The experiment showed that different plant functional groups of the alpine meadow were heterogeneous in their germination strategies.The gramineous species had a higher proportion of rapid germination pattern,whereas sedge species had a higher proportion of slow and low germination patterns.These results showed that the plants of different functional groups had the heterogeneity strategy of survival risk.