Seed germinating characteristics of 54 gramineous species in the alpine meadow on the eastern Qinghai-Tibet plateau

The germination experiment was started on March 3,2004,and seeds were collected from July to October in 2003.We analyzed the percentage of germination,days to first germination,germination period and days to 50%germination.Among the 54 examined species,26 species exceeded 80%germination,11 species exceeded 60%–80%germination,8 exceeded 40%–0%,5 exceeded 20%–40%,and 4 showed less than 20%.A principalcomponent analysis revealed that the species were distributed along two statistically independent axes,the first primarily represented the germination rate and the second represented the time of germination process.Based on scores of germination characteristics,cluster analysis of the 54 gramineous species could be divided into 4 distinct groups:rapid,slow,intermediate germinating(germination percentage>50%),and low germinating(germination percentage<50%).The meaning of different groups to the vegetation regeneration was discussed.