Ancient and famous trees are living cultural relics and priceless treasures in China. All provinces and cities should organize special personnel to conduct detailed and systematic investigations to find out the situation of ancient tree resources in China. The investigation contents mainly include tree species, tree age, tree height, crown width, DBH, growth potential, pests and diseases, habitats, their ornamental and research functions, and conservation measures. At the same time, we should also collect historical and other information about ancient trees, such as poems, paintings, pictures, myths and legends about ancient trees. In a word, we should make concerted efforts with Qi Xin to gradually establish and improve the archives of ancient tree resources in China.

On the basis of investigation, China is usually divided into four grades according to the age of trees. Grade I: Old trees with a tree age of 1000 years or above, or famous trees with high scientific, historical and cultural values and strange postures; Grade ii: an ancient tree with a tree age of 600 ~ 1000 years, or a famous tree with important value; Grade III: ancient trees with a tree age of 300-599 years, or famous trees with certain value; Grade 4: old trees with age 100 ~ 299, or famous trees with preservation value.

For ancient and famous trees at all levels, permanent signs should be set up and numbered, and measures such as adding columns and strengthening protection and management should be taken. First-class ancient and famous trees should be included in special files, especially for special protection. If necessary, special funds should be allocated to assign special personnel to strengthen maintenance, and regular notification should be made. For ordinary growth, ornamental and research value is not great, according to the specific situation of the implementation of general maintenance management.

(2) General conservation and management measures for ancient and famous trees

1. Support and reinforcement

Because of the age, the trunk of ancient trees may be hollow, and the main branches often die, which leads to the imbalance of the crown and the easy inclination of the tree; Because of the aging of trees, branches are prone to droop and need other things to support them. For example, the pagoda tree in the Imperial Garden of the Forbidden City in Beijing and the Gu Song at the gate of the Imperial City are all supported by scaffolding with steel pipes. The lower end of steel pipe is reinforced with concrete foundation, and the cracked trunk is tied with flat steel, which has achieved good results.

2. Treatment of trunk wounds

For the wounds on branches caused by diseases, insects, freezing injury, sunburn or pruning, we should first scrape the periphery with a sharp knife to make the cortex edge arc, and then disinfect it with chemicals (2% ~ 5% copper sulfate solution, 0. 1% mercuric chloride solution, stone sulfur mixture stock solution, etc.). ). For the wound caused by pruning, flatten the wound and then apply protective agent. The selected protective agent should be easy to smear, good in adhesion, impervious to heat and water, non-corrosive to tree tissues, and have antiseptic and disinfection effects, such as lead oil and wax. A mixture of clay, fresh cow dung and a small amount of sulfur can also be used as a daubing agent in a large number of applications. If hormone application is more beneficial to wound healing, α -naphthylacetic acid ointment containing 0.0 1% ~ 0. 1% can be applied to the wound to promote wound healing.

Because the branches of the tree are cracked by the wind, they should be tied up with ropes at once, then disinfected and coated with protective agent. At present, some parks in Beijing are reinforced with iron hoops composed of two and a half circles. In order to prevent the bark from rubbing, they are padded with brown hemp and connected by bolts, which relax with the increase of trunk diameter. On the other hand (mainly used abroad), threaded iron bars or bolts are screwed into the trunk to play the role of connection and clamping.

Trees whose branches are chopped by lightning should be sawed off and coated with protective agent.

Repair the tree hole

Trees, especially ancient and famous trees, have long-term unhealed wounds due to various reasons. The xylem exposed for a long time was soaked in rain and gradually rotted, forming tree holes. In severe cases, the trunk is hollow and the bark is broken, which is generally called "broken belly". Because the xylem and pith of the trunk rot, the dredging tissue is destroyed, which affects the transportation and storage of water and nutrients, seriously weakens the tree potential, reduces the firmness and load capacity of branches, and shortens the life of trees. At the same time, it will affect the appearance and cause accidents, so it should be handled in time. First, the rotten part is completely removed, the necrotic tissue is scraped off, disinfected with drugs and coated with waterproof agent. Then according to the specific situation, take different methods to deal with it.

(1) Open method

This method can be used for tree holes that are not too deep or too big. If the wound hole is not deep and there is no filler, it can be treated according to the above-mentioned wound treatment method. If the hole in the tree is very big, it gives people a strange tree feeling. You can use this method when you want to stay and watch. The method is to thoroughly remove the rotten xylem in the hole, scrape off the necrotic tissue at the edge of the hole until the new tissue is exposed, disinfect it with chemicals and apply protective agent. At the same time, change the shape of the hole to facilitate drainage, or insert a drainage pipe at the bottom of the tree hole. Check the waterproof layer and drainage regularly in the future, and brush the protective agent again every six months or so.

(2) Closed method

For narrow tree holes, the surface of the hole is covered with metal sheets, which are embedded in the tree after healing. You can also treat and disinfect the tree hole, nail slats on the surface of the hole, use putty and hemp knife ash (putty is made by mixing quicklime and cooked tung oil at the ratio of 1: 0.35) (you can also directly use putty for glass installation, commonly known as "putty"), and then apply white putty latex and pigment powder to increase the appearance. You can also press the lines similar to bark, or nail a layer of real bark on it.

(3) Filling method

The filler is preferably a mixture of cement and pebbles. If there is no cement, you can also use local materials. The filler must be compacted. In order to strengthen the connection between filler and xylem, several electroplating nails can be nailed in the hole, and a groove with a depth of about 4cm can be dug on both sides of the hole. The filler starts from the bottom and is separated by linoleum every 20 ~ 25 cm. The surface of each layer is slightly inclined outward to facilitate drainage. The edge of the filler should not exceed the xylem, so that the cambium can form callus on it. The outer layer is coated with lime, latex and colored powder, and the outermost layer is nailed with a layer of real bark to increase the appearance and realism.

4. Set lightning rod

According to the investigation, most ancient ginkgo biloba trees were struck by lightning, which seriously affected the growth of trees, and some even died shortly after being struck by lightning, and no remedial measures were taken. Therefore, tall ancient trees should be added with lightning rods. If you are struck by lightning, you should immediately scrape the wound flat, apply protective agent and block the tree hole.

5. Irrigation, scarification and fertilization

Irrigation in spring and summer is used to prevent drought, and irrigation in autumn and winter is used to prevent freezing. After irrigation, loosen the soil to keep the soil moisture and increase the permeability. There are many fertilization methods for ancient trees, such as digging ditches (depth 0.3m, width 0.7m, length 2m or depth 0.7m, width 1m, length 2m) on the protruding part of the crown, applying humus soil and thin manure, or applying chemical fertilizer, and some applying water chestnut or sesame sauce residue (oil cake) in the ditch.

Spray water on the tree

Due to the pollution of floating dust in urban air, ancient trees retain a lot of dust, which affects the ornamental effect and photosynthesis. Beihai Park and Zhongshan Park in Beijing are often cleaned by spraying water. This measure costs labor and water, and it is only used in key areas.

7. Plastic finishing

With less pruning, less short cutting, light cutting and thinning as the main principles, the original tree shape is basically maintained. When necessary, it should also be trimmed properly to facilitate ventilation and light transmission, reduce pests and diseases, and promote renewal and rejuvenation.

8. Control pests and diseases

Old trees are aging, easy to attract insects and cause diseases, and accelerate death. Beijing Tiantan Park has protected Cooper because of its efforts to prevent and control longicorn beetles. Their experience is: seize the opportunity to lay eggs from trees to bark around mid-March every year and spray 223 emulsion on Cooper, which workers call "tree sealing". Aphids and red spiders are prone to occur in May and need to be sprayed once to control them. Pay attention to the harm of trunk pests in July.

9. Set up fences, pile up soil and build platforms

For ancient trees in squares, sidewalks and places where tourists are easy to get close to, fences should be set up to protect them. The general fence should be 3 ~ 4m away from the trunk. If the density of people is high and the roots extend for a long time, the ground outside the fence should be paved with air. Pile up soil or build a platform on the basis of ancient tree trunks, which can protect and prevent waterlogging. Building a platform is particularly effective than piling up soil, and holes can be left at the edge of the platform for drainage.

10. Set up signs and billboards

Installation sign, indicating tree species, age, grade and number, and indicating the responsible unit for maintenance and management. The establishment of a publicity column should not only introduce the great significance and present situation of ancient and famous trees on the spot, but also pay attention to publicity and education to mobilize the masses to protect ancient and famous trees.

(3) rejuvenation, conservation and management measures of ancient and famous trees

Ancient and famous trees are prone to aging and even death due to various reasons, such as tree decline, too dense soil, too small tree holes, too large surrounding pavement, deterioration of soil physical and chemical properties, man-made injuries, natural disasters and so on. Once you die, the loss is irreparable. Therefore, we should pay attention to the rescue measures such as rejuvenation of ancient and famous trees in order to help the weak become stronger and rejuvenate.

Beijing is a famous historical and cultural city with many ancient and famous trees. According to the research of Beijing Institute of Landscape Science, the basic reasons for the weak growth of ancient pine and cypress in Beijing parks and imperial homes are dense soil, malnutrition, poor ventilation and serious main pests and diseases. In view of the above reasons, they took the following main rejuvenation measures and received good results.

1. Buried strip method

It can be divided into radial trench buried strips and long trench buried strips.

In the former, 4 ~ 12 radial ditches are dug outside the crown projection, each ditch is about 120cm long, 40 ~ 70 cm wide and 80cm deep. First, loose soil with a thickness of 10cm is put in the ditch, then the branches cut from apples, begonia, Amorpha fruticosa, etc. are tied into bundles, and a layer is spread, each bundle is about 20cm in diameter, and a small amount of loose soil is sprinkled on it, and crushed sesame paste residue and urea are also applied. Apply 1kg sesame paste residue and 50g urea to each ditch. In order to supplement phosphate fertilizer, put a small amount of animal bones and shells and cover them with soil.

If the plant spacing is large, long trench burial can also be used. The ditch is 70 ~ 80cm wide, 80cm deep and 200cm long, and then the tree strips are buried in layers and covered with fertilizer.

2. Lay trapezoidal bricks and ground cover plants on the ground.

The lower layer is the same as the above embedding method. The ground is paved with special trapezoidal bricks with big top and small bottom, and there is no jointing between bricks, leaving ventilation. The lower layer is lined with lime mortar, and the ratio of lime, sand and sawdust is 1: 1: 0.5. At the same time, lawn or ground cover plants (such as white clover) can also be laid on the buried tree strips, and tourists are prohibited from stepping on the railings or laying cement bricks or iron mesh covers with holes or empty strips on them. This method has a good effect on rejuvenation of ancient trees.

Step 3 dig back into the spring ditch

The rejuvenation ditch is 80 ~ 100 cm deep and 80 ~ 100 cm wide, and its length and shape depend on the terrain. Some are straight grooves, others are semi-circular or u-shaped.

The contents of the ditch include: rejuvenation matrix, various tree strips and nutrient elements.

The rejuvenating matrix is composed of natural leaves of pine, oak and oak, mixed with 60% decomposed leaves and 40% semi-decomposed leaves, and added with a small amount of elements such as nitrogen, phosphorus, iron and manganese. This matrix is rich in various mineral elements, and its pH is below 7. 1 ~ 7.8. Rich in humic acid, humic acid and fulvic acid, it can promote the root growth of ancient trees. At the same time, organic matter decomposes year by year, forming aggregate structure with soil and granular colloid, thus improving soil physical properties, promoting microbial activities, and releasing various elements (such as Fe3+→Fe2+) fixed in soil year by year. The effective porosity of soil can be kept above 12% ~ 15% within 3 ~ 5 years after application.

Bury branches of various trees. Using Amorpha fruticosa, apple, poplar and other branches, cut into branches of about 40cm. Buried in the ditch, the tree branches form a big gap with the soil. From 1982, many years of experiments have proved that the roots of ancient trees can grow through branches, and the rejuvenation ditch can be paved with two layers of branches, each layer is 10cm.

Gain weight and improve nutrition. Iron is the main element, and a small amount of N and P elements are added. According to the length 1m and width of 0.8m, the dosage of ferrous sulfate (FeSO4 _ 4) is 0.1~ 0.2kg. In order to improve fertilizer efficiency, a small amount of sesame paste residue or horseshoe is generally mixed to form full fertilizer to better meet the needs of ancient trees.

The building location of Fuzhuanggou is outside the projection of the ancient tree crown, and it is vertically layered down from the surface. The surface layer is 10cm plain soil; The second layer is 20cm rejuvenation matrix; The third layer is10cm; Branchy; The fourth layer is 20cm rejuvenation matrix; The fifth layer is 10cm tree; The sixth layer is 20 cm thick coarse sand and ceramic particles.

Change the soil

Ancient trees grow in a place for hundreds or even thousands of years, and the fertilizer content in the soil is limited, which often shows the symptoms of fertilizer deficiency; Coupled with manual trampling, poor ventilation and poor drainage are extremely unfavorable to root growth. Therefore, the aboveground parts of ancient trees are shrinking day by day. Starting from 1962, the garden department of the Forbidden City in Beijing began to use the method of changing soil to rescue ancient trees and rejuvenate them. For example, in 1962, there was a Gu Song outside Ningshou Gate of Yumen. Buds shrink and leaves turn yellow, as if they had been burned. The workers replaced the soil in the big taproot part within the projection range of the crown. When excavating, the excavation depth is 0.5m (the exposed roots are covered with soaked straw bags at any time), and the original old soil is mixed with sand, humus, feces, sawdust and a small amount of chemical fertilizer for filling. After half a year's soil replacement, this Gu Song plant has sprouted new buds, and the underground part has sprouted fibrous roots of 2-3 cm, finally coming back from the dead. After that, they changed several strains, and the effect was very good. For example, 1975, a dying Gu Song came back from the dead, and the tree was dug to 1.5m when changing soil, which exceeded the crown projection. At the same time, the drainage ditch with a depth of 4m is dug, the lower layer is filled with pebbles, the middle layer is filled with gravels and coarse sand, and the upper layer is filled with fine sand and garden soil, so that the drainage is smooth. At present, all the Gu Song in the Forbidden City, which has been reformed from native land to native land, have been rejuvenated, lush and full of vitality. This method is worth learning and popularizing.

5. Pest control

Diseases and insect pests are one of the main factors leading to the decline and death of ancient trees. The Beijing Institute of Landscape Science mainly used watering, burying and injecting methods in the prevention and control of major pests and diseases such as Gu Song, Cooper and Sophora japonica, and achieved good results.

(1) irrigation method

Based on the principle that the systemic agent is absorbed by the root system and transported to the whole tree to kill insects and mites, the problems of difficult spraying, multiple times, many days of killing, air pollution and so on caused by scattered, high and complex site conditions in the prevention and control of pests and diseases of ancient trees are solved.

Methods: Dig 3-5 arc ditches with a depth of 20cm, a width of 50cm and a length of 60cm in the root distribution area of the vertical projection edge of the crown, then pour the medicine into the ditches, and seal the soil after the liquid medicine permeates.

(2) Burying method

In order to achieve the purpose of killing insects, killing mites and maintaining the efficacy for a long time, the solid internal inhalation insecticide was used to bury the roots.

Methods: Similar to the irrigation method, solid particles were evenly scattered in the ditch, then covered with soil and poured with water.

(3) Injection method

This method can be used to solve the problems of ancient tree control that are difficult to be solved by other methods, such as complex surrounding environment, many obstacles, and difficulty in finding absorption root zone. This method is to inject the systemic insecticide and acaricide into the tree, and through the conductive tissue of the tree, the purpose of killing insects and acaricides for a long time can be achieved.

Methods: A hand drill (or electric drill) was used to drill different numbers of drug injection holes with a diameter of 0.6cm and a depth of 0.6cm in all directions at the base of the trunk, and then drugs were injected, and the holes were sealed with wet mud after injection.

6. Chemicals for thinning flowers and fruits

Thinning flowers and fruits can reduce the reproductive growth of ancient trees, expand vegetative growth, increase tree vigor and achieve the purpose of rejuvenation. The key to thinning flowers and fruits is thinning flowers, so it is best to spray chemical reagents in late autumn, winter or early spring. It is effective to spray 50 mg/L NAA and 3000 mg/L carbaryl or 200 mg/L gibberellin at the flowering stage of Sophora japonica. For Platycladus orientalis and Sabina vulgaris (or Sabina vulgaris), if sprayed in late autumn, 400mg/L NAA is better for Platycladus orientalis and 800mg/L NAA is better for Sabina vulgaris, but from the economic point of view, 200mg/L NAA is also very effective in inhibiting the production of male and female cones in the next year. If sprayed in spring, 800 ~ 1000 mg/L NAA, 800mg/L L2, 4-D and 400 ~ 600 mg/L IBA are suitable, and 400 ~ 1000 mg/L NAA is suitable for Pinus tabulaeformis.

7. Spraying or irrigating biological mixed preparation

According to the report of Lei Zengpu et al. (1995), the biological mixture ("5406" cytokinin, agroantibiotic 120, agrobacterium and biological nitrogen-fixing fertilizer) was mixed in1991-1999.