半干旱区河岸带灌木镰叶锦鸡儿种子萌发特征

Microhabitat Limitation Characteristics of Seed Germination of Caragana aurantiaca

通过室内模拟试验,探讨了土壤水分、凋落物覆盖和种子大小对镰叶锦鸡儿种子萌发的影响。镰叶锦鸡儿种子萌发主要受土壤含水量制约,在适宜的水分条件(8%含水量)下萌发迅速、整齐,发芽率达到80%~100%,而在低含水量(2%)时发芽率仅20%~40%;其次是凋落物,但凋落物的作用受土壤含水量的影响,在2%含水量条件下,凋落物具有明显的抑制作用,延长萌发天数,降低发芽率,但是在8%含水量下凋落物无明显作用;种子大小未明显影响发芽率。镰叶锦鸡儿具有一次、大量萌发的萌发对策,发芽率很高,在萌发阶段不存在限制种群更新问题,未来应从镰叶锦鸡儿种群种子散布以及微生境对幼苗存活影响等方面开展进一步研究。

The effects of soil moisture,litter cover and seed size on seed germination of Caragana aurantiaca were studied through manipulated simulation experiments.The seed germination of Caragana aurantiaca is mainly limited by soil water content.It germinates rapidly and neatly under appropriate water conditions(8%water content),and the germination rate reaches 80%-100%,while at low water content(2%),the germination rate is only 20%-40%;The second factor is litter,but the effect of litter is affected by soil water content.Under the condition of 2%water content,litter has obvious inhibitory effect,prolonging germination days and reducing germination rate,but litter has no obvious effect under 8%water content;Seed size did not significantly affect the germination rate.Caragana aurantiaca has the germination strategy of one-time and large-scale germination,and the germination rate is very high.There is no problem of limiting population regeneration in the germination stage.In the future,further research should be carried out from the aspects of seed dispersion of Caragana aurantiaca population and the impact of microhabitat on seedling survival.