Abstract: After spring burning of sheepgrass steppe(Aneurolepidium chinense),the thousand seed weight of Stipa grandis, Serratura centauroides, Astragalus adsugens,Medicago ruthenia and Chenopodium glauca increased 2.7, 3.2, 8.2, 10.4 and 33.8% respectively in autumn havest.The seed germination rate from burned plots also increased 3.3, 39.6, 116.7, 133.3 and 275.0% for S.grandis, S.centauroides M.ruthenia,A.adsurgens, C.glauca respectively VS unburned plots.Heat treatment for 50℃ and four minites have most effects on seed germination from unburned plots.The response of seed germination from burned plots to dry heat treatement are obtuse.

Key words: Burning, Temperature, Seed germination rate, Grassland

摘要： 羊草草原火烧后,大针茅等五种植物当年生种子的千粒重平均增加11.7%,发芽率平均增加113.6%。实验室温度处理对种子的发芽有刺激作用,对采自未烧地种子的刺激作用更明显。随着处理温度的升高,种子的发芽率亦随之升高,以50℃、4分钟处理的发芽率最高,但随着处理温度的再升高,发芽率逐步降低。不同草种的种子对温度处理反应的敏感程度各异,灰绿藜受干热刺激最敏感,斜茎黄蓍等硬实种子对干热温度的刺激则反应迟钝。

关键词: 火烧, 干热作用, 种子发芽率, 草原