所谓林木良种,一是要具有速生、丰产、优质的遗传特性;二是种子发育健全、纯净、饱满、发芽率高、生活力强、无病虫害。壮苗是指苗茎粗壮、根系发达、生根力强的苗木。在相同的气候、土壤条件和相同的经营措施下,采用良种壮苗造林成活率高,林木生长快,材质好,抗病虫能力强。多年来,用劣种弱苗造林教训很深,不仅成活率低,而且大都长成“小老树”。近两年来,在自留山、责任山上造林,不顾品种及苗木质量的现象更为突出,既造成了经济损失,又影响了绿化速度。 The so-called forest seed, one is to have fast-growing, high yield, high-quality genetic characteristics; second seed development sound, pure, full, high germination rate, strong vitality, no pests. Strong seedling refers to seedling sturdy roots and developed rooting strong seedlings. Under the same climate, soil conditions and the same management measures, the adoption of seedling seedlings afforestation survival rate, forest fast growth, good material, pest resistance. Over the years, with poor seedlings planting afforestation lesson, not only low survival rate, but most grow into “little old tree.” In the past two years, the phenomenon of afforestation in responsible hills, regardless of species and nursery stock quality, has become more prominent in the self-retaining hill, which has not only caused economic losses but also affected the rate of afforestation.