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同的杨树品种对环境条件的适应性和变化幅度也各不相同,有的品种适应性强,有的品种适应性差。总之,杨树是喜水、喜肥喜光、喜通气的树木。林龄不超过4年,2～3年为宜,苗木规格要达到优质壮苗标准。掘苗时,水平根幅不小于40厘米,垂直根长不小于30厘米,最好现掘苗,现造林,要避免长途运输。大苗造林,苗木侧枝保留太多,虽然营养贮备丰富,能促进光合作用和有机务的积累,但耗水量大,成活率低。如果侧枝紧贴树干全部剪掉、不留茬,由于伤口面积增大,与伤口相连的主干部位枯干,树皮颜色变暗,造成苗木严重失水,导致生理干旱,也会影响造林成活率和生长量。有的地方,用大苗成片造林,采取截头,虽然成活率高,但影响干形,降低了木材等级。
The same poplar varieties of environmental conditions and the extent of the changes are also different, and some species adaptability, and some varieties of poor adaptability. In short, poplar is hi water, like hi light, hi ventilation trees. Forest age no more than 4 years, 2 to 3 years is appropriate, seedling specifications to achieve high quality seedlings standards. Digging seedlings, the horizontal root width of not less than 40 cm, vertical root length of not less than 30 cm, it is best to dig seedlings, now afforestation, to avoid long-distance transport. Large seedlings afforestation, seedling side branches to retain too much, although rich nutrient reserves, can promote photosynthesis and organic accumulation, but the water consumption, low survival rate. If the side branches cling to the trunk all cut, not stubble, due to the wound area increases, the wound connected to the main parts withered, bark color dark, resulting in serious water loss seedlings, leading to physiological drought, will also affect the survival rate of afforestation and Growth volume. In some places, planting large trees into pieces and taking truncated trunks, although the survival rate is high, it affects the dryness and reduces the timber grade.