浙江天童7种优势乔木的种子形态特征和萌发特性

Seed Morphologic Traits and Germination Characteristics of Seven Dominant Tree Species in Tiantong,Zhejiang Province

以浙江天童地区雷公鹅耳枥等7种常见优势乔木种子为材料,对其形态特征和近自然条件下的萌发特性进行了研究.结果表明,种子体积最大的是长叶石栎(6 370.54mm3),最小的为雷公鹅耳枥(17.72mm3);千粒重最大的是长叶石栎(3 580.868g),最小的为木荷(5.148g);含水量最高的是长叶石栎(43.72%),最低的为西川朴(11.78%).在光/暗期温度25℃/15℃,光照强度1 402lx(14h/d)条件下,种子萌发率木荷、云山青冈较高,分别达55.5%和56.5%,栲树、西川朴和长叶石栎较低,分别为20%、10.5%和6%,雷公鹅耳枥和南酸枣没有萌发;开始萌发时间木荷最早(6d),云山青冈最迟(35d),萌发持续时间西川朴、木荷和云山青冈均超过50d,并依次延长;木荷和云山青冈的种子萌发格局为缓萌型,而栲树、西川朴、长叶石栎、雷公鹅耳枥和南酸枣为低萌型.天童地区7种常见优势乔木采取了不同的萌发策略来适应当地外界环境,可能是其成为不同微地形中优势种的重要因素.

Seed morphologic traits and germination characteristics under simulated local natural forest cano py condition in laboratory of 7 dominant tree species, which are commonly seen in Tiantong, Zhejiang Province, have been studied. Seed size of Cyclobalanopsis nubium （6 370.54 mm3） is the largest, while that of Carpinus viminea （17.72 mm3） the smallest. Cyclobalanopsis nubiurn also has the largest seed mass （3 580. 868 g/1 000 seeds）, while that of Schima superba, the smallest （5. 148 g/1 000 seeds）. The seed water content of Cyclobalanopsis nubiurn （43.72 %） is the largest, while that of Celtis vandervoetiana the smallest （11. 78%）. Seed germination rate of Schima superba is 55.50%, and Cyclobalanopsis nubium , 56. 50%. Castano nation rates of 6.00%, 10. psis fargesii , Celtis vandervoetiana and Lithocarpus harlandii have low germi 50% and 20.00%, respectively; Carpinusviminea and Choerospondiasa3ilia ris have no germination. Shima superba has the earliest germination which was 6 d, and Cyclobalanopsis nubium the latest which is 35 d. Germination time lasted from Celtis vandervoetiana, Shima superba to Cyclobalanopsis nubiurn, all more than 50 d. Germination pattern of Schima superba and Cyclobanopsis nubiurn is slow, while Castanopsis fargesii , Celtis vandervoetiana , Lithocarpus harlandii , Carpinus viminea and Choerospondias aziliaris low. 7 common dominant tree species adopted different germination strategies to be fit for the varied environment, which may be one of the factors determining their dominance in the mirco-landforms.