【摘要】 <正> 一、前言桉树是属于桃金娘科(Myrtaceae)的常绿亚热带木本植物,其经济价值很高,生长异常迅速,为我国华南地区重要的造林树种之一。根据苏联试验的结果,桉树虽然可以用扦揷法来繁殖,但其揷穗的生根部分率很低(8%以下)。因此,桉树通常还是采用播种育苗进行造林。种子是育苗造林的基本材料,其品质的好坏是育苗造林的成败关键。因而在育苗造林之先,不仅需要研究种子的品质,而且需要改进和提高林木种子的品质,为培育良材而创造优越的条件。为此,我们对桉树的一切特征,及其与外界环境的关系进行了物候观测。更多还原

【Abstract】 This work was started in April,1954 and completed in July,1957. The characteristics of four species of eucalyptus and its ecological conditions are dis- cussed,and the observational methods and the phenomenal periods of phenology are par- ticularly emphasized.The phenomenal periods of phenology are divided into four major periods,namely:1.budding period:2.the ripening of buds 3.the bloomming period and 4.fruiting period.Eight minor periods are further divided such as:1.budding period 2.the formation of buds;3.the ripening of buds 4.the falling-off of opercule; 5.the withering of androecium;6.the withering of gynoecium 7.the formation of capsulo;8.period of capsule ripening.更多还原