种子萌发时间格局对科尔沁沙地榆树幼苗生长的影响

The effect of germination time pattern on the Ulmus pumila seedlings recruitment

选择榆树种子与科尔沁沙地典型一年生草本植物狗尾草种子作为对象,研究榆树种子和狗尾草种子萌发的时间格局下,榆树幼苗的生物量、地上高度、根系长度、叶片数目的变化。结果表明:狗尾草种子先萌发的情况下,榆树幼苗生物量显著减少,而且地上高度明显增加。与狗尾草种子同时种植以及先于狗尾草种子种植的情况下,榆树幼苗生长状况差异不显著。因此,为促进榆树的更新,在榆树落种期结束后、大部分榆树种子萌发前,可以适度地进行放牧活动,通过抑制其他草本植物的生长,为榆树更新创造条件。

To investigate whether the growth of Ulmus pumila seedlings was influenced by different germination order, we selected Setaria viridis as disturbing species. It was found that biomass decreased and length of stem increased for the Ulmus pumila seedlings when Setaria viridis seeds sowed firstly. However, there was no significant difference in other treatments （ p 〉 0.05 ）. Therefore, it was suggested that to promote the recruitment of Ulmus pumila, proper grazing is necessary. Furthermore, the time to grazing is vital and best time is the period between the end of seeds fallen and the beginning of seeds germination.