Abstract: The fresh mature seeds of three shrubs (Philadelphus incanus, Spiraea alpine and S. rosthornii) were collected from the eastern QinghaiTibet Plateau. After the seeds were stored at 5 ℃ for different time (0, 40, 80 and 160 d), they were used for germination under 5 ℃/25 ℃ and 12 h/12 h photoperiod in a growth incubator. In addition, the seeds naturally dehydrated at room temperature for 120 d were used for germination at 10 ℃/25 ℃ under five light conditions (white light, dark, red light, blue light, 12 h/12 h light/dark). Cold storage time had significant effects on the germination of the seeds of the three shrub species. Cold storage improved the germination ability of P. incanus and S. rosthornii, but reduced the germination ability of S. alpine. There were very significant differences in germination percentage among different light conditions for P. incanus seeds. The highest germination percentage and fastest germination rate were recorded under red light and 12 h/12 h light/dark, and the lowest germination percentage and slowest germination rate were found under dark and blue light. Seeds of S. rosthornii exhibited significant differences in germination percentage and germination rate among the different light conditions. The germination percentages under white light, red light, blue light, and 12 h/12 h light/dark were all more than 80%, and were significantly higher than that under dark. The germination rate was fastest under red light, and lowest under blue light. There were no significant differences in germination percentages among the different light conditions for S. alpine seeds. The germination percentages under all light conditions were more than 93%. But S. alpine seeds germinated fastest under red light and dark, while lowest under blue light. The results indicated that cold storage, as a dormancy breaking treatment, had different effects on seed germination for diversified species; however, as a trigger factor of germination, red light had consistent effects on seed germination among different species.

Key words: nature reserve, conservation efficiency, rapid assessment, landscape dynamic, Ar Horqin