【摘要】 对内蒙古额济纳绿洲胡杨种群的苗库状况、种子雨、种子生活力以及环境因子对种子萌发的影响进行了研究,结果表明:胡杨萌生苗占更新苗的绝大多数;胡杨能够产生出大量的有生活力的种子,胡杨种子散播时间在种群内部存在异质性;在恶劣的自然条件下,胡杨种子在落种后生活力迅速降低,(6-40)d后绝大部分种子(95%)会丧失活力。种子萌发试验表明:表土层含水量低、含盐量高、生化他感作用是胡杨种子萌发的限制性因子。由于胡杨种子属于短命种子,在其短暂的活力期内没有适宜的环境条件使之萌发,从而造成种子萌发失败。缺水所导致的种子安全萌发生境的缺失是额济纳胡杨的有性繁殖失败的首要原因。更多还原

【Abstract】 Seed ram, seed longevity and effects of environment factors that affect seed germination for the Populus euphratica seedling bank are investigated. A sexual reproduction is absolutely predominant as the means of reproduction of P. euphratica. The maternal trees can produce a large quantity of seed with vigor; there was heterogeneity in seed rain time in the P. euphratica meta-population. The seed vigor reduced rapidly under normal circumstances, almost all the seeds lost vigor in (6-40) days. Germination experiments showed that low moisture, high salt content and allelopathy chemicals had negative effect on the seed germination. For the ephemeral seeds, there were no favorable condition for germinate during their short lives. The lack of a safe germinant environment is the primary cause for the failure of P. euphratica sexual reproduction.更多还原