Abstract: This paper discusses the prevention and transplantation of tree cortex injury.

Keywords: classification reason? Injury prevention, transplantation and repair

Garden trees are important greening elements in the process of urban landscaping. In landscape architecture, the quality of trees directly affects the success or failure of landscape effect. In the actual construction of landscaping, the damage of tree cortex is very common. How to prevent tree cortex from being damaged, repair damaged cortex and transplant bark are important measures to improve the quality of plant landscape and improve the artistic effect of landscape.

First, the classification and causes of tree cortex injury

1. Mechanical damage: The main ways of mechanical damage to the cortex of greening trees are careless digging, loading and unloading, transportation and planting, resulting in accidental injuries such as scratches, bumps and abrasions on the cortex of trees after planting. It causes a small area of tree cortex damage or peeling, but there is also a large area of bark peeling.

2. Sunburn: After trees are planted, root damage will greatly affect the absorption of water. If you don't take effective sunscreen and moisturizing measures in time. One side of the trunk is exposed to high temperature sun, and the cortex is dehydrated and dried, resulting in burns on the upper and lower parts of the trunk or the entire trunk (mostly on the southwest side of the trunk).

3. Frozen laceration: Before winter comes after planting trees. Can't take effective anti-freezing and warm-keeping measures for trees in time. The increase of temperature difference between day and night and between north and south of the tree leads to different internal tension of the trunk, which leads to frost crack and frostbite of the local cortex of the trunk.

Second, prevent tree cortex damage.

It is generally believed that the cortex of trees is irrelevant, but in fact the bark is damaged or peeled off. It can block phloem, cambium and conduits near cambium, and weaken the supply of water and nutrients absorbed by roots and the downward transportation and storage of assimilates. At the same time, it is easy to be infected by fungi and bacteria and invaded by insects. Causing decay of xylem and pith line. Therefore, how to prevent bark damage is a very important link in tree transplantation construction.

1. Before digging the tree, tightly surround the tree with straw rope to protect the bark from being injured by tools for digging the tree.

2. Before loading and unloading trees, soft objects such as waste tires and straw rolls should be buckled on the rails, especially on the rear rails, and then lightly unloaded in sequence. If you are loading a big tree, you should also put a woven bag filled with soil at the branch of the trunk or behind the carriage to prevent the bark from being scratched by the tailgate of the carriage. When loading and unloading, the rope buckle should be lined with hemp and wood to prevent the rope from hurting the bark. When unloading the car, the mud balls and treetops of the whole tree should be hoisted or lifted at the same time, and then the car should be unloaded smoothly, instead of unloading the mud balls or tree crowns first. So as not to be barked in the corner of the carriage.

3. Wrap the straw rope around the trunk immediately after planting trees or check the wrapped straw rope before digging trees, and repair the fallen straw rope. To keep the bark surface moist. Prevent high temperature sunburn of tree cortex.

4. Before winter comes, paint the trunk white to reflect the local sunshine, reduce the temperature difference of trees and prevent the bark from freezing and cracking.

Third, repair and transplantation of damaged cortex.

1. Tool preparation: wood saw, pruning shears, big grafting knife, woodworking chisel, carving knife, wire brush, brush, sprayer, etc.

2. Material preparation: bark with the same age as the damaged bark (the age of the peeled tree shall not exceed 10 year), antibacterial drugs such as shellac and carbendazim, stainless needles, steel mesh, cement, gravel, plastic film, adhesive tape, hemp chips, straw rope and cardboard.

3. Repair the original skin of damaged bark: newly damaged bark. First clean the wound and spray antibacterial drugs for sterilization, then reset the fallen bark piece by piece and fix it with stainless nails, and then spray antibacterial drugs such as carbendazim. Apply shellac to the wrapped joint and tighten it layer by layer with plastic diaphragm from bottom to top. Each layer is pressed by one third of the width of the plastic diaphragm.

4. Transplant and repair of damaged bark: Generally, when sap begins to flow out in spring, the rotting and bacterial-infected bark at the damaged part should be clearly marked first, and the cutting line of bark transplantation should be drawn at 1cm outside the contour line of damaged bark, and the shape of transplanted bark should be unfolded on the trunk with white paper with an area larger than that of transplanted bark. Stick white paper on a thick paper board, and cut out the template for transplanting bark according to the shape lines spread on the paper. The paper template is fixed on the trunk epidermis with adhesive tape, and the outer line is aligned with the cutting line of transplanted bark. Disinfect the cortex and cutting tools, and cut the bark along the periphery of the paper template with a grafting knife, slightly reaching the xylem. When cutting bark, the blade is slightly inclined around to form an inclined incision, which is convenient for interface healing. Remove the paper template and remove the bark at the cutting line. Spray antibacterial drugs after taking out. Then the paper model is fixed on the waste trunk of healthy cortex prepared in advance with adhesive tape. After sterilization, cut along the periphery of the template with a knife and reach the xylem. When lifting the knife, the blade body is slightly inclined around, and the angle is the same as when cutting the transplanted bark. Then gently peel off the bark from top to bottom with a grafting knife, and transplant the bark to the damaged trunk immediately after peeling off the bark. Align the seams and fix them with stainless steel nails. Spray antibacterial drugs. Coat the joints with shellac. Then wrap it with plastic film tape from bottom to top. Half the bandwidth of each laminated plastics film. First, tape the top. In order to prevent bacteria from invading again and affect the healing and survival of cortex. Straw rope or hemp rope is the same as above.

5. Repair the cortex of rotten trees in trunk xylem: Most of the damaged trees in trunk xylem are bark damage or long-term damage and fall off. When eggs or germs invade the wound for a long time, the xylem in the damaged part of the cortex rots. First of all, the rotten part should be completely eradicated with a woodworking chisel, and then the rotten wood layer should be finely repaired with carving. And carefully check the wormholes and eggs. Clean the surface layer with a wire brush, and then disinfect it with potassium permanganate solution or carbonic acid. Cut a piece of steel wire mesh slightly smaller than the area of rotten wood layer, and fix the steel wire mesh on the cleaned rotten wood layer with stainless nails. It is required that the mesh surface should be lower than the surface of the wooden part 10 mm. If the net thickness exceeds 30 mm, it should be filled with 1: 35 concrete. After watering and curing the next day, apply 1: 2.5 cement mortar in layers. Every time the thickness is not more than 10 mm, the surface of plastering layer should be flush with the surface of wood layer. After painting for 24 hours, apply shellac to the joints, wrap straw ropes around them, and water them for maintenance. After a growth cycle of trees. When the cortex and cement layer of the tree are completely occluded. Then the cortex was repaired by grafting bark damaged by cortex. Different, such trees are generally older. The age of transplanted bark should be controlled within 10 year. The trees in Yingluonian are vigorous, easy to peel off the cortex, and the survival rate of bark transplantation is high.

Fourth, the conclusion.

Through 10 years of cortical repair and transplantation, and after repeated repair and transplantation experience. The success rate of repairing damaged cortex of trees reached 95%. The success rate of bark transplantation repair reached. 90%。 The tree with the largest DBH after successful bark transplantation is Du Ying, which is 18 cm. Bark wound is 102 cm long and 14 cm wide, and it has been injured for two years. The transplant time is March 28th. The weather is fine, and the age of the transplanted bark is 10 years old. DBH 12cm, Shangzhi was injured by Typhoon K the year before last. Bark transplantation was carried out according to the above bark transplantation repair technology. One month after transplantation, it was found that the transplanted bark had healed and survived. Remove all bandages at the end of the year. The transplanted bark is no different from the original bark. The next spring, the bark grew normally.

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