无柄小叶榕(Ficus concinna var. subsessilis)是分布在南亚热带最北缘的高大乔木,作为气候特征的指示植物在生态系统中扮演着关键角色,同时也是造林绿化的优良乡土树种。温州地区有其丰富的古树资源,但存在更新难、病腐严重、资源不断减少等生态退化现象。本文以100a以上的无柄小叶榕古树在温州的资源调查入手,运用主成分分析和非线性典型相关分析等方法定性定量评价现存古榕的资源状况,探讨影响古榕退化的原因;通过研究其种子发芽、种苗生长对生态因子的响应,揭示其生态响应机制,从而为有效保护遗传资源提供理论依据。本研究的主要结果如下:
1、古榕存在着更新不良、病腐严重、死亡率增大等严重的生长退化现象。通过主成分分析、单因素方差分析和非线性典型相关分析发现古榕分布的地理位置、古榕历史生长状况、土壤类型对温州古榕资源影响显著,土壤类型、土层厚度、立地条件和树龄等因子对现存古榕生长影响较大,生长在农村的古树生长势明显高于城市、生长在低山与水边的显著高于水泥封地的,300a以上树龄古榕生长状况较100a优。可见古榕退化主要原因是受环境和人为因素的影响。
2、无柄小叶榕种子在适宜...
【英文摘要】
Ficus concinna var. subsessilis is an arbor plant distributed in the northernmost south subtropic, which is a kind of excellent afforestation trees. This species is also an important indicator plant of climatic and play an important role in the ecosystem. In this study, we, firstly investigated the resources of the ancient ficus in Wenzhou, which were more than 100 years old. Then, the resource status and the main restricted factors of regeneration were evaluated In order to explore causes of ecologi...