Abstract: A field observation was conducted to study the seed germination characteristics and their correlations with seed sizes of 31 common weeds in the families Gramineae, Compositae, and Boraginaceae in eastern Qinghai-Tibet Plateau, aimed to provide theoretical bases for local weed control. It was found that the seed germination had four patterns, i.e., rapid, intermediate, slow, and low, with the proportions being 25.8%, 32.3%, 32.3%, and 9.7%, respectively. The peak germination percentage had a significant negative correlation with seed size, while the peak germination time was in adverse. Both the germination percentage and the germination index had a weak negative correlation with seed size, the starting time of germination was weakly positively correlated to seed size, and no correlation was observed between germination duration and seed size.

Key words: Biomass, Turnover value, Land remained bare