Chinese hippophae rhamnoides ecological forest grafting transformation method with banded function division

Abstract

The invention relates to the technical field of forest genetic breeding and ecological restoration, and particularly discloses a Chinese hippophae rhamnoides ecological forest grafting transformation method with banded functional partitions. The method aims at solving the problems that in existing sea-buckthorn ecological forest transformation, the target is not clear, the transformation efficiency is low, and the fruit yield is not obviously increased. The method comprises the core steps of scion collection and cold chain storage and transportation; a parallel belt-shaped functional unit composed of a grafting operation channel, a grafting operation area and a grafting reservation area is arranged along the forest belt; thinning male plants in the retention area according to a first'three-removal and three-retention 'principle, and regulating and controlling the sex and age structure of the forest stand; stumping the rootstocks in the working area, and determining interface branches according to a second'three-removing and three-reserving 'principle; grafting in a key phenological period; and post-grafting management is carried out. According to the method, through cooperation of space partition and structure regulation and control, the low-yield Chinese sea-buckthorn ecological forest is quickly and directionally transformed into the high-yield and stable-yield forest stand on the premise that the ecological system is not damaged, the fruit yield is remarkably increased, and the transformation efficiency is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of forest tree genetic breeding and forestry ecological engineering, and particularly relates to a method for grafting reconstruction of low-efficiency Hippophae rhamnoides subsp. sinensis ecological forest. BACKGROUND

[0002] Hippophae rhamnoides subsp. sinensis is a pioneer tree species for water and soil conservation and ecological construction, and has the characteristics of drought tolerance, poor soil tolerance and strong soil and water conservation capacity. In addition, the fruits are rich in vitamin C, and the leaves can be processed into tea, which has both ecological and economic value. However, a large number of existing Hippophae rhamnoides subsp. sinensis ecological forests are of seedling origin, and are naturally grown or extensively planted. The unbalanced ratio of female and male plants (insufficient pollen supply) results in low fruit yield, and the uneven density of the forest stand (part <150 plants / acre, part >300 plants / acre) affects the ecological protection function and picking efficiency, and affects the sustainable management of the forest stand and the income of the farmers.

[0003] Grafting technology is to graft the scion of a good variety onto an existing rootstock, which is an effective means to quickly improve low-efficiency forest stands and improve their economic value. However, existing Hippophae rhamnoides subsp. sinensis grafting technologies mainly focus on the grafting operation itself (such as wedge grafting and bud grafting), and lack systematic planning of the reconstruction object. In practice, the following technical bottlenecks are mainly faced: (1) the lack of sufficient and suitable pollen sources for the improved female plants, resulting in low fruit setting rate; (2) the wild rootstock has large differences in state, and the survival rate of grafting is unstable, with an average of less than 30%; (3) the work in the forest is not convenient, and the efficiency of large-scale reconstruction is low; (4) the management after grafting is extensive, and it is difficult to form a high-yield and stable forest stand structure.

[0004] Therefore, there is an urgent need for a grafting reconstruction method that can systematically solve the problems of pollination, rootstock, operation and management, in order to realize the efficient, standardized and large-scale improvement of Hippophae rhamnoides subsp. sinensis ecological forest. SUMMARY

[0005] The purpose of the present application is to provide a Hippophae rhamnoides subsp. sinensis ecological forest grafting reconstruction method with functional zoning, in order to overcome the shortcomings of the prior art. Through innovative spatial layout and refined process management, the reconstructed forest stand has both ecological function and high economic output.

[0006] In order to achieve the above purpose, the following technical scheme is adopted in the present application:

[0007] A Hippophae rhamnoides subsp. sinensis ecological forest grafting reconstruction method with functional zoning, comprising the following steps:

[0008] 1. Scion collection and processing: 15-20 days before bud sprouting, collect healthy 1-year-old branches with diameter ≥0.8 cm from the female plants of the approved variety, and cut them into 7.0-9.0 cm long sections with full buds. Then, perform wax sealing treatment by dipping the upper end of the scion into food-grade paraffin at 100-120°C for 1.0-1.5 seconds to form a uniform wax film. After cooling, reseal the cracks. Store the treated scions in double-layer PE fresh-keeping bags in a cold storage at 2-8°C for ≤90 days. During transportation, place the scions in foam boxes lined with ice bags, and stack them in ≤5 layers. If the transportation time exceeds 24 hours, use a refrigerated truck with a constant temperature of 3-6°C, and avoid violent shaking.

[0009] 2. Functional zoning in strips: Continuously arrange basic units along the natural direction of the forest belt. Each unit contains three parallel functional zones in strips. The central zone is a grafting operation path with a width of 1.0-2.0 m, and its two sides are grafting operation zones with a width of 0.5-1.0 m. The outer side of the operation zones is a grafting reservation zone with a width of 2.5-3.0 m. Remove all Hippophae rhamnoides plants in the operation path, control the stump height to be <5.0 cm, and immediately apply tung oil or a special wood wound protection paint on the cut surface to seal the wound, prevent bacterial infection, and prevent water loss.

[0010] 3. Directional thinning in reservation zones: In the grafting reservation zone, perform directional thinning on male plants according to the first "three remove and three retain" principle to form a target stand structure with excellent female plants as the main body and a certain number of healthy male plants. The first "three remove and three retain" principle is as follows: remove male plants with a diameter at breast height (DBH) >5.0 cm, retain male plants with a DBH ≤4.0 cm, remove male plants with a tree age >15 years, retain healthy male plants with a tree age of 5-10 years, remove male plants with a curved main stem, and retain male plants with an upright main stem. For retained plants with a height >3.0 m, remove the crossing branches and overlapping branches within the canopy, and retract the main branches to 2.0-2.5 m to ensure ventilation, light penetration, and pollen dispersion.

[0011] 4. Rootstock treatment and interface branch determination in operation zones: 10 days before grafting, top the plants in the operation zones to a stubble height of 0.8-1.0 m, and make the cut surface smooth without tearing. Remove all branches below the grafting interface, leaving a stubble height ≤1 cm with a smooth cut. Follow the second "three remove and three retain" principle to select interface branches: remove thick branches with a base diameter >3.5 cm, old branches with a tree age >10 years, and curved branches with an angle <45° to the main stem; retain vertical and upright branches with a base diameter of 2.5-4.0 cm and a tree age of 3-5 years; retain 1 main branch for single-head grafting and 2-3 evenly distributed main branches for multi-head grafting.

[0012] 5. Timely grafting: the bud of the spring stock sprouts, and the operation area is dynamically adjusted according to the measured air temperature. When the diameter of the stock grafting interface is less than or equal to 4.0 cm, single bud grafting is adopted, and when the diameter of the stock grafting interface is greater than 4.0 cm, double bud or triple bud grafting is adopted. The edge of the stock grafting interface is beveled, the angle of the beveled surface is 15-20°, and the length of the beveled surface is 1 / 6-1 / 4 of the cross-sectional circumference, and the beveled surface is smooth without tearing. The longitudinal skin is carved along the edge of the stock grafting interface, the length of the carved opening is 2.5-3.0 cm, and the depth reaches the xylem by 0.2-0.3 cm. One carved opening is provided for single bud grafting, and 2-3 carved openings are uniformly provided according to the direction for multi-bud grafting. The two sides of the lower end of the scion morphology are cut into asymmetric double wedge surfaces, the length of the long cut surface is 3.0-4.0 cm, and 3-4 complete bud bodies are reserved, the length of the short cut surface is 1.5-2.0 cm, and the angle between the long cut surface and the short cut surface is 15-20°, and the two sides of the scion are lightly cut to the fresh phloem with a light yellow color. The scion is connected to the stock, and it is ensured that the cambium of the scion and the cambium of the stock are aligned on at least one side and the contact width is greater than or equal to 2 mm. The special grafting film is used for closed packaging, the stock grafting interface area is covered first, and then the spiral packaging is performed from 1.0-2.0 cm below the carved opening, the scion bud is exposed by 0.3-0.5 cm, the top end is reserved by 0.5-1.0 cm for moisture retention, and a gradient packaging structure of loose top and tight bottom is formed.

[0013] 6. Post-grafting management: the first shoot removal is carried out 30-40 days after grafting, and then the shoot removal is carried out every 30-40 days, the base sprouts of the stock are completely removed, and it is ensured that there is no competing branch within 20 cm below the top end of the scion. The non-survival grafting interface is supplemented with pre-stored scions.

[0014] The beneficial effects of the present application are that through the "strip-shaped functional partition" configuration, a plurality of key problems in ecological forest reconstruction are simultaneously solved: the strip-shaped reserved area provides a stable and efficient pollen source, improves pollination, the directional thinning optimizes the light and space in the forest, promotes the growth of female plants, and at the same time, the overall optimization of the forest structure also improves the stability and protection function of the ecological forest. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 Schematic diagram of the partition layout of the Chinese Hippophae rhamnoides ecological forest "grafting operation road-grafting reserved area-grafting operation area"

[0016] 1-grafting operation road (width 1.0-2.0 m); 2-grafting operation area (width 0.5-1.0 m); 3-grafting reserved area (width 2.5-3.0 m); 4-reserved area plants (diameter ≤4.0 cm, height 2.0-2.5 m); 5-operation area to be grafted stock (stump height 0.8-1.0 m). DETAILED DESCRIPTION

[0017] Example 1: Qian-gou village, Shenzhong township, Huangyuan county (gentle slope land)

[0018] Forest background: The original forest density is high (320-350 plants / acre), the ratio of male and female plants is close to 7:3, and the yield is small. The understory is insufficient, natural regeneration is poor, and the ecological function is degenerative. DETAILED DESCRIPTION

[0020] 1. Scion preparation: In March 2025, collect 1-year-old vegetative branches from the female plants of the approved variety 'Yu Lu' that are growing healthily, with plump buds, and a diameter of 0.8-1.0 cm. After strict selection, the scions are treated with wax sealing, with the wax temperature controlled at 110±5℃, and then stored in a 4℃ refrigerator for use.

[0021] 2. Zonal design: Based on the forest direction, determine the basic unit, with a central grafting operation path 1.5m wide for personnel access and material transportation; on both sides, set up a grafting operation area 0.8m wide as the core transformation area; and on the outermost side, set up a grafting reservation area 3.0m wide as a permanent pollen source and ecological barrier. Use a chainsaw to completely remove all shrubs and sea buckthorn plants in the operation path, with the stump height strictly controlled at <5cm, and immediately apply a special wound protector.

[0022] 3. Directional thinning in the reservation area: Apply the first "three-removal and three-retention" principle for thinning in the reservation area. Focus on removing king male plants with a diameter >5.0cm, old individuals with a tree age >15 years, and deformed plants with a trunk curvature >15°. After thinning, the reservation area density is reduced from about 300 plants / acre to about 220 plants / acre, and all retained are high-quality male plants with a diameter ≤4.0cm and a tree age of 5-10 years.

[0023] 4. Rootstock treatment in the operation area: All target rootstocks in the operation area are uniformly pruned, with a stubble height of 0.9m and smooth cuts without splitting. Remove all branches within 20cm below the cut. Then, based on the second "three-removal and three-retention" principle, select 2-3 straight branches that grow healthily and are evenly distributed from multiple branches after pruning as grafting branches.

[0024] 5. Grafting operation: In late April to early May 2025 (before the bud of the rootstock swells and the leaves appear), use the modified cut grafting method for grafting. According to the diameter of the grafting branch, choose single, double, or triple grafting. Ensure that the scion and the rootstock cambium are aligned on at least one side and tightly fit, and use elastic grafting film for full-closed packaging.

[0025] 6. Post-grafting management: Conduct the first comprehensive weeding in late June 2025, and then conduct weeding every 30-40 days until autumn. In late June, supplement grafting for non-survival points.

[0026] After investigation in July 2026, the average grafting survival rate of this area reached 85.2%. After the transformation, the forest showed a clear zonal structure, and the growth space of the grafted female plants in the operation area was sufficient. The light transmittance in the forest increased by more than 50%. The young male plants in the reserved area were vigorous, and the pollen supply was expected to be sufficient. The overall forest health and expected economic output capacity were significantly improved.

[0027] Example 2: Shenzhong Village, Shenzhong Township, Huangyuan County (gully area - over-dense declining low-efficiency forest)

[0028] Location and forest background: A gully area in Shenzhong Village, Shenzhong Township, due to excessive natural sprouting in the early stage, the forest density is extremely large (average > 350 plants / acre), and the trees are in fierce competition. The number of male plants is dominant, but most of them are weak "old trees". DETAILED DESCRIPTION

[0030] 1. Scion preparation: Same as Example 1, using 'Yu Lu' scion.

[0031] 2. Zonal partitioning and cleaning: Considering the terrain and initial density, the operation path width is set to 1.2m to facilitate operation. The operation area is 0.7m wide, and the reserved area is 2.8m wide. One of the focuses of this operation is to thoroughly clean the existing dead and severely diseased trees in the operation path and the forest.

[0032] 3. Heavy thinning in the reserved area: In this area, the thinning intensity is large. Strictly implement the principle of "removing large (diameter > 5cm), old (age > 15 years), and weak (poor growth)", significantly reducing the canopy density of the reserved area. After thinning, the density is reduced to about 200 plants / acre, greatly improving the ventilation and light transmittance conditions of the entire forest.

[0033] 4. Strong pruning of rootstock: For some severely aged rootstocks, the height of the stubble is reduced to 0.8m to stimulate the germination of new branches. Due to the release of space, each plant is reserved 1-3 uniform and strong branches as the grafting branch.

[0034] 5. Grafting: Grafting was completed in the middle and late May of 2025. Due to the relatively thick diameter of some rootstocks, double scion grafting was used for branches with a diameter of >4.0cm. Due to the large original density of the forest and the strong sprouting ability of the rootstock, the focus of the operation was on the removal of the sprouts.

[0035] 6. Post-grafting management: The first comprehensive removal of sprouts was carried out on June 30, 2025, and a total of 3 times of concentrated removal of sprouts were carried out.

[0036] The average grafting survival rate of this area was 80.3%. After the transformation, the forest density was effectively controlled, the individual growth space of the trees was released, the selected male plants in the reserved area recovered their growth, the understory vegetation began to recover, and the soil and water conservation function was significantly enhanced.

[0037] Example 3: Dashangan village, Shenzhong Township, Huangyuan County (high-altitude mountainous area)

[0038] Site and stand background: Dashangan village, Shenzhong Township, is at a high altitude of about 2800-3000 meters, with uneven forest stand and generally dwarfed and weakly growing plants. Due to environmental stress, it is difficult to distinguish between female and male plants, and the pollination conditions are poor, with almost no yield. DETAILED DESCRIPTION

[0040] 1. Scion preparation: same as Example 1, using 'Yu Lu' scions.

[0041] 2. Zonal adaptation to terrain: the zones are set according to the mountain terrain, and the working path is appropriately widened to 2.0 m for convenience in steep slope operations. The working area is 0.5 m wide, and the reserved area is 2.5 m wide.

[0042] 3. Precision thinning in reserved area: during thinning, focus on retaining young, straight individuals with strong adaptability, and removing obviously degraded, curved plants to enhance the stress resistance of the reserved area population.

[0043] 4. Rootstock treatment and grafting: carried out in late May to early June 2025. Most plants have small growth, and single-head single-scion grafting is mainly used.

[0044] 5. Post-grafting management: the risk of late frost is high in high-altitude areas, so the weather is closely monitored, and no special intervention is performed. The first weed removal is in early July.

[0045] The average survival rate of grafting in this area is 79.2%. This proves the applicability of the method of the present application in high-altitude and poor site conditions. The excellent variety 'Yu Lu' is successfully introduced, and a stable stand system is initially established through the zonal structure, laying a foundation for the subsequent recovery of ecological and economic benefits.

Claims

1. A method for grafting and transforming Chinese sea buckthorn ecological forests in a strip-shaped functional zoning pattern, characterized in that, Includes the following steps: (1) Scion collection and treatment: One-year-old healthy branches of female plants of superior Chinese sea buckthorn species are collected as scions, and after being sealed with wax, they are stored and transported in a cold chain at 2-8℃. (2) Strip functional zoning: Based on the natural direction of the forest belt, basic units are continuously configured along the forest belt. Each unit includes 3 parallel strip functional zones. The center is a grafting operation road with a width of 1.0m to 2.0m, and the two sides are grafting operation areas with a width of 0.5m to 1.0m. The outer side of the grafting operation area is a grafting retention area with a width of 2.5m to 3.0m. (3) Targeted thinning in the reserve area: In the grafting reserve area, male trees are selectively thinned according to the first "three removals and three retentions" principle in order to form a target forest stand structure with excellent female trees as the main body and a suitable number of male trees retained. (4) Treatment of rootstocks and determination of grafting branches in the work area: Within 10 days before grafting, all rootstocks in the grafting work area shall be coppiced to a height of 0.8m to 1.0m, and all branches below the cut shall be removed. If two or more branches remain after coppicing, one to three evenly distributed strong main branches shall be selected as grafting grafting branches in accordance with the second "three removals and three retentions" principle. (5) Timely grafting: During the critical window period from the sprouting of rootstock buds to the leaf unfolding, the scion obtained in step (1) is grafted onto the rootstock treated in step (4) using the branch grafting method. (6) Post-grafting management: Remove the first sprouts 30 to 40 days after grafting, and promptly regraft any plants that have not survived.

2. The method according to claim 1, characterized in that: In step (2), all existing plants in the grafting operation path need to be cut down to ensure passage. The grafting operation area is a concentrated area for grafting and modification. The grafting retention area is the core area for pollen supply and fruit production.

3. The method according to claim 1, characterized in that, In step (3), the first "three removals and three retentions" principle applies to male plants, specifically: remove male plants with a diameter at breast height (DBH) > 5.0 cm and retain male plants with a DBH ≤ 4.0 cm; remove male plants with an age > 15 years and retain healthy male plants aged 5-10 years; remove male plants with a bent trunk and retain upright male plants.

4. The method according to claim 1, characterized in that, In step (4), the second "three removals and three retentions" principle is as follows: remove branches with a base diameter > 3.5 cm and retain branches with a base diameter of 2.5-4.0 cm; remove branches with an age > 10 years and retain branches that are 3-5 years old; remove curved branches with an angle < 45° with the main trunk and retain upright branches.

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