Seed Germination Characteristics of 48 Common Plant Species of Degraded Alpine Meadow in Yellow River Headwater Area

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(P0.05).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.