凋落物及播种时间对高山栲和滇青冈种子萌发的影响

Effects of Forest Litter and Sowing Time on Seed Germination of Castanopsis delavayi and Cyclobalanopsis glaucoides

高山栲(Castanopsis delavayi)和滇青冈(Cyclobalanopsis glaucoides)种子播种后,分别覆盖约2 cm厚的高山栲、滇青冈、元江栲(Castanopsis orthacantha)和云南油杉(Keteleeria evelyniana)枯枝落叶,以覆盖红壤为对照,研究了森林凋落物及播种时间对半湿润常绿阔叶林建群种高山栲和滇青冈种子萌发的影响。结果表明:不同森林凋落物对高山栲和滇青冈种子萌发率的影响趋势一致,其中对照处理的红壤最高(29.1%和66.9%),其次是云南油杉枯枝落叶(28.2%和57.1%)、高山栲枯枝落叶(25.1%和53.3%)和滇青冈枯枝落叶(20.7%和51.6%),最低的是元江栲枯枝落叶(18.7%和44.0%)。播种时间对高山栲和滇青冈种子萌发率的影响差异极显著,其中12月份播种的种子萌发率最高,分别为58.0%和68.7%;随着播种时间的后移,其萌发率逐渐降低。高山栲种子在次年5月中旬开始萌发,休眠期为6个月,而滇青冈种子的休眠期约5个月,于次年4月中旬开始萌发;两种植物的萌发期大致在6个月左右,且萌发高峰期基本一致,即出现在次年6月份。

A study was conducted to discuss the effects of forest litter and sowing time on seed germination of the constructive species,Castanopsis delavayi and Cyclobalanopsis glaucoides,in semi-humid broad-leaved forests.The seeds of C.delavayi and C.glaucoides sown on the soil surface were covered with red soil or litter of C.delavayi,C.glaucoides,Keteleeria evelyniana,and C.orthacantha,respectively.Results show that the changes in germination rate of the two species under the five different treatments were in the same order.The germination rate for the red soil were the highest（29.1% for C.delavayi,66.9% for C.glaucoides）,followed by the litter of K.evelyniana（28.2% and 57.1%）,the litter of C.delavayi（25.1% and 53.3%）,the litter of C.glaucoides（20.7% and 51.6%）,and the litter of C.orthacantha（18.7% and 44.0%）.The sowing time strongly affected the germination rates of C.delavayi and C.glaucoides seeds.The germination rates of the seeds sown in December were the highest（58.0% for C.delavayi and 68.7% for C.glaucoides）,then the germination rate gradually decreased with the prolonging of sowing time.The dormant period of C.delavayi seeds was about 6 months and began to germinate in mid-May for the coming year,while that for C.glaucoides seeds was about 5 months and began to germinate in mid-April for the coming year.The germination periods of the two species were about 6 months,with the highest germination rates occurred in June for the coming year.