1 Preparation before moving?

1? 1 concept differentiation

At present, there are several definitions of transplanting big trees, which are not very uniform. The author thinks that transplanting big trees should be different from planting big seedlings. The so-called "big tree transplantation" refers to the process of transplanting trees with DBH size that have been planted in the original destination to a new destination, that is, the change of destination; And "big seedling afforestation" refers to the process of afforestation with big seedlings, which is the first time to reach the destination for afforestation. Although there is no strict division between "big trees" and "big seedlings" here, big trees were cultivated as forest trees before, and their human controllability is reduced; However, the big seedlings are raised as seedlings, which has high manual controllability. Therefore, it is more difficult to transplant trees. ?

1? 2 Fully demonstrate

There are many restrictive factors related to tree transplantation, which must be fully demonstrated and carefully planned before transplantation. According to the principle of suitable site and suitable tree and habitat similarity, select native tree species with vigorous growth as far as possible, and control the habitat difference within the suitable range of tree species. On-the-spot investigation was conducted on the proposed tree species, varieties and specifications, and comprehensive demonstration was made on the cost accounting, the difficulty of soil ball handling, excavation and transportation conditions, and the probability of ensuring survival after transplantation, so as to be foolproof. For the selected trees, they should be numbered in sequence, filed by hanging cards and calibrated in the north-south direction. Demonstration and tree selection should be completed 2 ~ 3 growth periods in advance. ?

1? 3 transplant period

Transplanting of big trees is usually carried out in the period of slow sap flow, which can reduce the evaporation of water in trees and improve the survival rate. The best transplanting period of most broad-leaved trees is early spring or late autumn after defoliation and before soil freezing, and the aboveground parts of trees are dormant, so transplanting with soil balls and increasing pruning are beneficial to improve the survival rate; If transplanting is needed in midsummer, due to the large transpiration of trees, transplanting is not easy to survive, and measures such as increasing soil balls, strengthening pruning, shading and moisturizing must be taken. ?

1? Pre-shift treatment of 4 shifts

In order to ensure the survival of the big tree, the root cutting and crown cutting of the target tree must be done well before transplantation. Roots are usually pre-treated by root cutting and root girdling to promote the growth of fibrous roots of trees. That is, 1/3 ~ 1/2 of the root is cut off every year before transplantation, and the whole process takes 2 ~ 3 years. In 1 year, the roots of the tree were cut off on opposite sides. According to the planned seedling digging form (square lump or round lump) and specifications, dig trenches vertically downwards until there are no big roots. When the fine roots meet, they are cut off. The stout roots are annularly peeled so that they can still absorb nutrients, and the adjacent two sides are cut off in the same way every other year. Within the specified time, the sooner the root is cut off, the better, but it can't be scattered. If you need to cut off a tree, generally choose 3 ~ 5 main branches at 2 ~ 3 m from the trunk, and cut them off at 50 ~ 60 cm away from the trunk. Immediately, treat the wound with plant ash, and wrap the fracture with plastic film to reduce water evaporation and prevent bacterial infection. The remaining lateral branches were sawed off in the bud, and the wound was also bandaged with plant ash. ?

1? Step 5 dig holes for disinfection

One week before transplanting, a tree hole should be dug in the newly planted field according to the transplanting plan. The diameter of the hole should be 40 ~ 60 cm larger than the planned diameter of the soil ball of the transplanted tree, and the depth should exceed the height of the soil ball 15 ~ 20 cm. When digging a pit, the topsoil and subsoil should be spread separately to dry, and the unearthed stones, bricks and other impurities should be cleaned up. When the excavated soil has poor ventilation and permeability and poor water and fertilizer conservation ability, it should be considered to mix the soil with sediment or use all the good soil from other places. At the same time, new tree holes and transplanted soil should be disinfected and destroyed. ?

1? 6 Other jobs

In addition to the above points, technical training should be given to relevant personnel before transplantation to clarify the division of labor and responsibilities; Determine transportation routes and equipment (cars, cranes), and prepare necessary tools and materials, such as shovels, pillars, mulch, plant ash, water sources and watering facilities, and bundled packaging materials. Do a good job in transportation and quarantine certificates and other procedures. ?

2 dig seeds?

2? 1 mining

When transplanting big trees, it is necessary to ensure that there are enough soil balls and keep as many roots and rhizosphere original soil as possible, so as to facilitate the trees to take root. During excavation, the diameter of the soil ball is 6 ~ 8 times that of the trunk DBH, with the tree pocket as the center, and the excavation is carried out from the outside to the inside. Pay attention to the dumping direction. If necessary, it can be lifted by bracket or crane until the big and small roots are completely cut off. ?

2? 2 packaging

Packaging materials and methods should be considered comprehensively according to the size of trees and soil balls, soil compactness of soil balls, transportation distance and so on. Generally, the diameter of trees is less than 15 cm, and the excavated soil balls are round dense soil, which can be packed with cattail, woven bags, straw ropes, etc. For trees with large diameter, the earth balls dug out are large and square, so they should be packed in existing wooden boxes. Trees that need to be hoisted at a long distance should be packed in wooden boxes to ensure the integrity of soil balls. At the same time, the trunk should be wrapped with straw rope to prevent damage to the bark during shipment and reduce water evaporation. ?

2? 3 leave

The transportation of big trees is one of the important links of transplantation. Generally, the crane or pulley is used for hoisting, and the automobile transportation is completed. This link must be commanded by engineers and technicians, and pay attention to the reinforcement, binding position and balance of soil balls. When hoisting trees, the crown should face the rear of the car, and the root clods should be close to the cab. The trunk is wrapped with soft materials and placed on the wooden frame, tied tightly with soft ropes, and the crown is properly wrapped with soft ropes. The clods are padded with boards, and then the clods are clamped with boards, or tied tightly on both sides of the carriage with ropes. When hoisting in inappropriate seasons, we should also pay attention to shading, hydrating and moisturizing to reduce the evaporation of water from trees. ?

2? 4 Colonization

These trees must be planted as soon as possible after they arrive. When planting, according to the construction requirements, the trees are gently hung obliquely in the planting holes, and the ropes tied around the crown are removed, so that the crown stands upright. Carefully inspect the tree shape and environment, move and adjust the crown orientation, try to conform to the original orientation and ensure the appropriate planting depth. Then, remove the rope wrapped around the soil ball (fragile soft bags such as grass pieces cannot be removed to prevent the soil ball from scattering) and tamp it in layers. Do a good job of stopping water trees and fully watering them.

3 maintenance management?

3? 1 Support and fixation

After transplanting, the tree must be fixed to prevent the crown from skewing, and fixing the root system is beneficial to the root growth. Generally, the three-column support method is adopted to support the tree firmly and ensure the stability of the tree. Usually 1~2 years later can be removed. ?

3? 2 Water and fertilizer management

The first few months after transplanting big trees are the key period of water and fertilizer management. If the roots are short of water and the bark cracks, it will lead to the death of trees; Too much watering, poor soil permeability, difficulty breathing and root rot can also lead to tree death. Therefore, the period of watering, the amount of watering and the number of watering are very important for the survival of trees, depending on the specific situation. Generally, when the soil is dry, the newly planted tree holes should be watered before planting, and then the cushion soil and soil balls should be watered together after transplanting. The next watering time depends on the soil moisture, grasp the principle of seeing dry and seeing wet, and then pour thoroughly. In the hot summer, we should also pay attention to sun protection, irrigate roots and spray dry leaves in time. When there is too much rain, we should also pay attention to flood drainage and flood control; In winter, measures such as preventing cold and keeping warm should be strengthened.

Transplanting of big trees is harmful, and fertilization cannot be applied 1 year after planting. According to the growth of trees in early spring and autumn of the following year, farmyard manure or foliar fertilizer should be applied for 2-3 times to improve the nutritional level of trees and promote their health, but it should be used with caution to prevent excessive fertilization from damaging the roots. ?

3? 3 pruning and shaping

After transplanting big trees, many broad-leaved tree species will be covered with new buds and sprout branches. The growth of these shoots is positively correlated with the growth and germination of underground roots. Don't rush to wipe the buds and trim them, and then trim and shape them step by step after making sure that the tree has fully recovered its growth function. ?

3? 4 pest control

Trees transplanted by sawing have many wounds, tender buds and leaves, weak resistance, and are prone to pests and diseases. So we should strengthen prevention. The newly grown branches and leaves are easy to cause aphid damage, and can be mixed with pesticides such as carbendazim or Tobuzin and diluted to 0? Spraying 0.83% solution for control.