1 method to improve the survival rate of big tree transplantation
(1) takes root. During the dormant period or relatively slow growth period before tree transplantation, circle the tree according to the radius of 3~5 times of the trunk DBH, dig a ditch with a width of 30~40 cm and a depth of 50~70 cm along the circle, cut it off with a hand saw or a chainsaw when encountering thick lateral roots, keep the incision flat and prevent rot, then fill it with loose and fertile soil, step on it every 20~30 cm, and water it after filling.
(2) pruning. After root cutting, prune branches and leaves according to the proportion of root cutting to the whole root. For tree species whose wounds are difficult to heal and can't form callus in time, artificial forced leaf thinning (leaf picking) should be changed. Pruning branches should be thick rather than thin. Pruning procedures are generally: diseases and insect pests, overgrowth, overlapping branches, abnormal branches, weak branches, over-dense branches and central trunk branches (this pruning is mainly used for bare root transplantation). Note that the incision should be hidden and smooth, vertical to the ground as far as possible, and the large incision should be sealed with wax or asphalt to prevent water rot.
(3) Tie the branches. In order to facilitate transportation and transplantation, the trees should be tied with branches before transportation. Trees with short branches and loose crowns are surrounded by ropes to tighten the crowns; For trees branching from the base, such as pine and cypress, tie one end of the straw rope to the base of the trunk, and tie the tree around with the straw rope from bottom to top; Trees that are easy to break, such as black pine, are fixed between branches and trunks with wooden sticks to form mutual support, which can prevent branches from breaking.
(4) All-in. The part of the trunk below the ground 1~2 m should be wrapped with soft materials such as straw rope with a thickness of 5~ 10 cm.
2 Management after transplantation
(1) Watering once after transplanting, the second time after 2-3 days in sunny days, and the third time after 1. The watering interval can be appropriately extended. Precious and particularly humid trees, such as Cinnamomum camphora, can be moisturized by spraying water on the crown to avoid getting wet in the surface soil. Pay attention to the rain for several days, and cover the surface with rain to prevent root rot caused by long-term immersion in water.
(2) Fix tall trees, such as poplars, and immediately support them with pillars after planting. Generally, three pillars are erected, the fulcrum is not less than 2/5 of the height of the tree, and the included angle between the pillars and the ground is not more than 60.
(3) Shade-loving tree species, such as spruce and torreya grandis, should be provided with a sunshade net if the sunlight is too strong after transplantation to prevent the sun from burning and losing too much water.
(4) For tree species with blue bark or many lenticels, such as Pinus armandii, the trunk and the main branches near the trunk should be tightly wrapped with straw ropes to reduce water evaporation and prevent sunburn and freezing injury.
(5) Leave the bud, raise the bud position as much as possible, and leave the bud in the higher part of the branch. If the bud position is high, the water potential will be strong, which will transport water and nutrients to a higher place and drive the whole plant to grow.