A method for target tree management of mountainous Quercus acutissima and / or Quercus variabilis secondary forest

Abstract

This invention belongs to the field of forest cultivation technology, specifically relating to a method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis in mountainous areas. It includes: S1: selecting and marking target trees; S2: identifying and marking disturbance trees; S3: thinning and harvesting; S4: stand regeneration. The criteria for selecting target trees include: ① belonging to the target tree species: Quercus acutissima and / or Quercus variabilis; ② strong viability; ③ good timber quality; ④ no damage; ⑤ trees of seedling origin. Using this method can increase the forest stock volume per unit area by 20-40%, demonstrating significant potential for quality improvement and efficiency enhancement.

Description

Technical Field

[0001] This invention belongs to the field of forest cultivation technology, specifically relating to a method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis in mountainous areas. Background Technology

[0002] Both *Quercus variabilis* and *Quercus acutissima* are precious trees, listed in the latest revised edition of the *National Reserve Forest Tree Species Catalogue 2019* by the National Forestry and Grassland Administration in 2020, and classified as Class A precious and promoted tree species. Both *Quercus variabilis* and *Quercus acutissima* are native trees, widely distributed, and possess strong resilience, tolerating acid, alkali, and drought, and exhibiting strong adaptability to various soil types. In some mountainous areas, oak resources are mostly low-quality natural secondary forests, with a large proportion being sprouted forests. In Henan Province, natural oak forests account for 77.84% of the total area and 85.82% of the total oak arbor forest area and volume, respectively, with young and middle-aged forests accounting for 93.84% and 86.34% of the total area and volume, respectively. Summary of the Invention

[0003] This invention addresses the ecological problems of low growth and small stock volume in mountainous areas by providing a method for managing target trees in secondary forests of *Quercus acutissima* and / or *Quercus variabilis*. This method can increase forest stock volume per unit area by 20-40%, demonstrating significant potential for quality and efficiency improvement.

[0004] The technical solution of this invention is as follows:

[0005] A method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis in mountainous areas, comprising:

[0006] S1: Select the target tree and mark it; identify the interference tree and mark it;

[0007] S2: Tending and harvesting;

[0008] S3: Artificially promotes natural regeneration.

[0009] In S1 above, the criteria for selecting the target tree include:

[0010] ① Belongs to the target tree species; This invention selects Quercus acutissima and / or Quercus variabilis as the target tree species;

[0011] ② Strong vitality; large and dense crown: the crown accounts for 1 / 4 to 1 / 3 of the trunk height;

[0012] ③ Good quality timber; reflected in: A: straight trunk, or slightly curved; B: few branches: no more than three branches; C: no two branches within 5 meters of the main trunk.

[0013] ④ No damage (or at least no damage to the roots);

[0014] ⑤ Prioritize the selection of trees from seedlings, and in some cases, superior trees that have sprouted can be used as a supplement.

[0015] The target tree density is 120 trees / hm² 2 ~150 plants / hm 2 The target tree selection time is generally 15-40 years, with 15-25 years being the preferred time.

[0016] There are no restrictions on diameter at breast height (DBH) when selecting target trees; the height-to-diameter ratio (equal to total tree height ÷ DBH) should be kept between 70 and 100.

[0017] In S1 above, the interference tree is determined by selecting trees that affect the growth of the target tree's canopy, with the target tree as the center.

[0018] Timing of selecting interference trees: The interference trees are determined at the same time as the target tree is selected.

[0019] The above S2 includes:

[0020] Pruning of target trees: Remove dead branches and 1-2 whorls of live branches at the bottom of the crown. After pruning in the middle-aged forest stage, retain a crown length of no less than 1 / 2 of the tree height. Prune the branches as flat as possible, and the cut should not damage the phloem and xylem of the trunk.

[0021] Harvesting of disturbing trees: The direction in which trees fall should be strictly controlled during harvesting, and full consideration should be given to the protection of the target trees and naturally regenerating seedlings and saplings.

[0022] Felled timber disposal: For felled timber with larger diameter and higher economic value, it should be processed into lumber and stacked locally according to market demand. For felled timber with smaller diameter and logging residue with low economic value, usable timber should be transported away promptly after felling, and logging residue should be cleared away. It can be disposed of by transporting it out, spreading it flat in the forest, or piling it evenly in the forest at certain intervals. If conditions permit, it can be crushed and piled (buried) in fish-scale pits at the base of the target trees. For trees and logging residues infected with forestry quarantine pests and supplementary forestry quarantine pests, the entire tree should be removed from the forest stand and burned or buried deeply.

[0023] No tending or felling measures are taken for auxiliary trees and other trees.

[0024] The above S3 includes:

[0025] (1) Preparatory measures include selecting a good year for acorn production. In spring, check if the oak trees have a large number of inflorescences. In summer, check again to see if the acorns are well developed and whether they have been damaged by late frost or drought.

[0026] (2) Once a bumper acorn harvest is confirmed, artificial methods to promote natural regeneration will be implemented, as follows:

[0027] ① Before the oak seeds fall in autumn, lightly harrow the land to create shallow horizontal ditches or embankments to help the seeds germinate.

[0028] ②Piling up dead branches and fallen leaves in rows can reduce rodent damage;

[0029] ③ In the second spring, check the germination status to ensure there are enough seedlings;

[0030] ④ In the autumn of the second year, remove the weeds that crowd the seedlings. It is also necessary to thin them out in the southeast and southwest directions of the mother tree to give the seedlings more space and more sunlight.

[0031] In the process of managing the aforementioned target trees, it is also necessary to protect wild animals and wild plants.

[0032] The forest stand after the management of the target trees should meet the following requirements:

[0033] (1) The canopy closure of the forest stand is not less than 0.6;

[0034] (2) In areas affected by wind and snow damage, or when the disturbing trees are felled for the first time, the canopy closure shall not decrease by more than 0.2;

[0035] (3) The number of target trees does not decrease;

[0036] (4) The average diameter at breast height (DBH) of the stand shall not be lower than the average DBH before logging;

[0037] (5) The trees are evenly distributed and do not create gaps or open spaces in the forest. For natural forests, if gaps or open spaces appear, they should be replanted.

[0038] Definitions:

[0039] Forest stock volume: The total volume of various living trees existing in a certain area of ​​forest.

[0040] Secondary forests: Forests formed on secondary bare land after primary forests have been disturbed; they can be understood as a degradation of the primary forest ecosystem.

[0041] The beneficial effects of this invention are as follows:

[0042] This invention emphasizes utilizing the combined forces of natural and human management, adapting to nature, and combining natural possibilities with human needs to achieve maximum management effectiveness. Utilizing individual differences in nature makes it possible to select target trees. If succession relies solely on natural forces, the selected trees may be the most vigorous but not necessarily the best in quality, thus failing to meet human needs. Human selection, however, ensures that the trees of the highest quality, vigorous growth, and highest value are chosen as target trees for management. Target trees are climax species in forest ecosystem succession and trees with superior genetic material. This means that the forest ecosystem has a foundation for continuous quality improvement and provides high-quality acorn seed sources for natural regeneration. Furthermore, human intervention to promote natural regeneration facilitates positive forest succession, resulting in continuous forest cover and promoting the formation of mixed-age forests.

[0043] This invention emphasizes full-cycle management. 120-150 target trees are selected per hectare, and only disturbing trees that negatively impact the growth of the target trees are felled. The entire management process and measures revolve around these target trees. Furthermore, since target trees can only be harvested and utilized once they reach the desired diameter, the forest ecosystem possesses a foundation for long-term dynamic stability. By selectively felling individual target trees to maintain the overall forest framework, and by implementing artificial measures to promote natural regeneration before the final felling of the target trees, new generations are formed, preventing bare soil and resulting in better soil and water conservation and biodiversity protection.

[0044] This invention emphasizes the economic input and output. Target tree management focuses solely on the target tree, allowing it to develop a free canopy and receive ample sunlight to grow into large-diameter logs. Pruning further ensures the trunk develops into knot-free, high-quality timber, resulting in extremely high value per tree. While technically complex, target tree management has lower unit input costs. Traditional forest management focuses on the entire stand, leading to higher unit input costs; it achieves intermediate profits by felling understory trees, but the stands mostly produce small- to medium-diameter timber, resulting in high yields but low economic value. Attached Figure Description

[0045] Figure 1 Distribution map of 10 target trees. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0047] Example 1

[0048] A method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis in mountainous areas, comprising the following:

[0049] 1. Select the target tree

[0050] (1) Selection method

[0051] ① "Look from two distances": check if the trunk is straight and if the crown is compact and round.

[0052] ② "Three close inspections": check whether the trees are seedlings, whether their growth is vigorous, and whether there is any mechanical damage or pests.

[0053] ③ "Four Priorities": Prioritize native tree species, prioritize precious tree species, prioritize broad-leaved tree species in coniferous-dominated stands, and prioritize target tree species with a small proportion in mixed forests. Based on the purpose of this invention, *Quercus acutissima* and *Quercus variabilis* were selected as the target tree species.

[0054] (2) Selection requirements

[0055] Follow the criteria of the target tree.

[0056] ① Belongs to the target tree species; namely, Quercus acutissima and / or Quercus variabilis.

[0057] ② Strong vitality; large and dense crown: the crown accounts for 1 / 4 to 1 / 3 of the trunk height;

[0058] ③ The quality of the timber is good; this is reflected in: A: the trunk is straight or slightly curved, B: there are few branches, C: there are no two branches within 5 meters of the main trunk.

[0059] ④ No damage (or at least no damage to the roots);

[0060] ⑤ Prioritize trees of seedling origin; in exceptional cases, superior trees sprouted from seed may be used as a supplement. Superior trees (also known as "excellent individual trees," "positive trees," or "plus trees") refer to individual trees that exhibit exceptionally outstanding performance in terms of growth, trunk shape, wood quality, stress resistance, and fruit production within the same type of natural or planted forest under the same site conditions and of similar age.

[0061] In addition, when selecting target trees, it is important to note that: it is not necessary to arrange the target trees in rows, but to distribute them evenly; in some cases, two or three trees can be placed together, but the outer canopy should be spread out.

[0062] The forest trees are classified as follows:

[0063] A: Target trees: These are trees selected based on forest management planning objectives that support the dominant functions of the forest (such as timber production, ecosystem services, and biodiversity conservation).

[0064] B: Auxiliary trees: also known as "ecological target trees", are trees that help improve forest biodiversity, protect rare and endangered species, improve forest spatial structure, and protect and improve soil.

[0065] C: Interference trees: Trees that directly and adversely affect the canopy growth of the target tree and need to be harvested in the near future.

[0066] D: Other trees: Trees in the forest stand other than target trees, auxiliary trees, and disturbance trees.

[0067] (3) Target tree density

[0068] The method for determining the spacing of target oak trees is as follows: multiply the target diameter at breast height (DBH) by a factor of 25. For example, if the target DBH is 60cm, then multiplying 60cm by 25 gives a distance of 15m between target oak trees. However, the distance between target trees cannot be determined mechanically. In reality, if two or three trees are close together, all are performing well, and there are no suitable trees nearby, they can be preserved as a group.

[0069] The target tree density is 120 trees / hm². 2 ~150 plants / hm 2 .

[0070] (4) Time for selecting the target tree

[0071] Generally, it is between 15 and 40 years, with 15 to 25 years being the preferred time.

[0072] There are no restrictions on diameter at breast height (DBH) when selecting target trees; the height-to-diameter ratio (equal to total tree height ÷ DBH) should be kept between 70 and 100.

[0073] 2. Determine the interference tree

[0074] (1) Determine the time

[0075] At the same time, select the target tree and determine the interference tree.

[0076] (2) Determine the requirements

[0077] Identifying interfering trees is a dynamic process. Trees that do not currently affect the canopy growth of the target tree may become so in a few years, at which point they should be removed. However, retaining the understory, including shrubs, is beneficial and harmless; other trees below the target tree canopy (some are shade trees to prevent the main trunk from growing dense branches, and some are unrelated trees) can be retained as long as they do not affect the canopy of the target tree.

[0078] 3. Mark

[0079] (1) Target tree labeling

[0080] After selecting the target tree, temporarily mark it by binding it with brightly colored straps at breast height. Once the target tree passes inspection, remove the temporary markers and replace them with permanent markers using paint or other brightly colored, durable materials. The markers should be in a circular pattern and visible from all directions.

[0081] (2) Interference tree tagging

[0082] After identifying the interfering tree, use brightly colored straps that are clearly distinguishable from the target tree's markings to tie the tree at breast height as a temporary marker.

[0083] After the disturbance trees pass inspection, the temporary markers are retrieved, and a mark 40cm-60cm long, 5cm-7cm wide, and deep to the xylem is made on the trunk diameter at breast height with a knife. Marks are also made on the rootstock.

[0084] 4. Tending and felling

[0085] Determine which timber to retain and which to harvest:

[0086] Trees to be retained: target trees, auxiliary trees, and other trees; trees to be harvested: interference trees;

[0087] The following are the tending measures for the target trees that need to be preserved:

[0088] Pruning of target trees: Remove dead branches and 1-2 whorls of live branches at the bottom of the crown. After pruning in the middle-aged forest stage, retain a crown length of no less than 1 / 2 of the tree height. Prune the branches as flat as possible, and the cut should not damage the phloem and xylem of the trunk.

[0089] For retained trees—auxiliary trees and other trees:

[0090] No tending or felling measures are taken for auxiliary trees and other trees.

[0091] The following measures are taken to remove the interfering trees in this example:

[0092] Harvesting of interfering trees:

[0093] During felling, the direction of tree fall should be strictly controlled, and full consideration should be given to the protection of the target tree and naturally regenerating seedlings and saplings. Markings of the rootstock should be retained during felling.

[0094] The following measures should be taken for felled trees:

[0095] For felled timber with a large diameter and high economic value, it should be processed locally and hauled away according to market demand. For felled timber with a small diameter and logging residues with low economic value, the following requirements should be met:

[0096] After logging, usable timber should be transported away in a timely manner, and logging residues should be cleared away. They can be transported out, laid flat in the forest, or piled evenly in the forest at certain intervals. If conditions permit, they can be crushed and piled (buried) in fish-scale pits at the base of the target trees.

[0097] For trees and logging residues infected with forestry quarantine pests and supplementary forestry quarantine pests, the entire tree should be removed from the forest stand and burned or buried deeply in a centralized manner.

[0098] Forest stands managed with target trees should meet the following requirements:

[0099] (1) The canopy closure of the forest stand is not less than 0.6;

[0100] (2) In areas prone to wind and snow damage, or when the disturbing trees are felled for the first time, the canopy closure shall not decrease by more than 0.2;

[0101] (3) The number of target trees does not decrease;

[0102] (4) The average diameter at breast height (DBH) of the stand shall not be lower than the average DBH before logging;

[0103] (5) The trees are evenly distributed and do not create gaps or open spaces in the forest. For natural forests, if gaps or open spaces appear, they should be replanted.

[0104] 5. Biodiversity conservation

[0105] (1) Wildlife protection

[0106] The following measures should be taken to protect wild animals during forest tending activities:

[0107] ① Trees with bird nests in their canopies, regardless of species, should be retained as auxiliary trees;

[0108] ② Trees with animal nests or hiding places on their trunks should be retained as auxiliary trees;

[0109] ③ Protect wildlife habitats and animal corridors. Caretaker operation design should consider the sequence of operations and the continuity and isolation of work areas to provide hiding places for wildlife during operations.

[0110] (2) Wild plant protection

[0111] The following measures should be taken to protect wild plants during forest tending activities:

[0112] ① Tree species that are under national or local key protection, or that are listed in the list of rare and endangered plants, should be marked as auxiliary trees or target trees for preservation;

[0113] ②Preserve plant species that are under national or local key protection;

[0114] ③ Plants that retain ornamental, edible, and medicinal value;

[0115] ④ Retain trees that have little utilization value but do not affect the stand's sanitary conditions and the growth of target trees;

[0116] ⑤ Preserve ancient and famous trees.

[0117] (3) Other protective measures

[0118] In forest tending activities, the following measures should also be taken to protect biodiversity:

[0119] ① Protect forest edges. The area within 5m to 8m of the forest stand extending from the roadside into the forest stand, adjacent to villages or along roads with frequent human activity, is considered the forest edge. In principle, forest edges should not be tended and should be allowed to grow naturally.

[0120] ② During forest tending operations, necessary measures should be taken to protect the target tree species and seedlings and saplings of precious tree species in the forest understory;

[0121] ③Retain appropriate understory trees. Understory shrubs that do not affect the operation or the growth of seedlings and saplings of the target tree species shall not be felled (cut off).

[0122] ④ Combustible materials should be removed in conjunction with weeding, pruning and other tending measures.

[0123] 6. Artificially promoting natural regeneration

[0124] (1) Preparatory measures include selecting a good year for acorn production. In spring, check if the oak trees have a large number of inflorescences. In summer, check again to see if the acorns are well developed and whether they have been damaged by late frost or drought.

[0125] (2) Once a bumper acorn harvest is confirmed, artificial methods to promote natural regeneration will be implemented, as follows:

[0126] ① Before the oak seeds fall in autumn, lightly harrow the land to create shallow horizontal ditches or embankments to help the seeds germinate.

[0127] ②Piling up dead branches and fallen leaves in rows can reduce rodent damage;

[0128] ③ In the second spring, check the germination status to ensure there are enough seedlings;

[0129] ④ In the autumn of the second year, remove the weeds that crowd the seedlings. It is also necessary to thin them out in the southeast and southwest directions of the mother tree to give the seedlings more space and more sunlight.

[0130] Example 2, Application Example

[0131] The following forest compartments (13 sub-compartments) of the Nanshan State-owned Forest Farm in Jiyuan City were selected. The forest is a cork oak forest, naturally formed, 30 years old, with a canopy closure of 0.8, an average diameter at breast height (DBH) of 15.0 cm, an average tree height of 13.0 m, 1125 trees per hectare, a stock volume of 95.03 cubic meters per hectare, and shrub cover of 70%. Target tree management methods will be adopted, as follows:

[0132] 1. Select the target tree

[0133] (1) Selection method

[0134] ① Check if the trunk is straight and if the crown is compact and round.

[0135] ② Check whether the trees are seedlings, whether their growth is vigorous, and whether there is any mechanical damage or pests and diseases.

[0136] ③ Select *Quercus variabilis* as the target tree species.

[0137] (2) Selection requirements

[0138] Follow the criteria of the target tree.

[0139] ① It belongs to the target tree species, *Quercus variabilis*;

[0140] ② Strong vitality; large and dense crown, accounting for 1 / 4 to 1 / 3 of the trunk height;

[0141] ③ Good quality timber; reflected in: A: straight trunk, or slightly curved; B: few branches: no more than three branches; C: no two branches within 5 meters of the main trunk.

[0142] ④ No damage (or at least no damage to the roots);

[0143] ⑤ Prioritize the selection of seedling-originating trees. In this embodiment, there are many seedling-originating trees in the small plot, so there is no need to select superior sprouting trees to supplement them.

[0144] In addition, when selecting target trees, it is important to note that: it is not necessary to arrange the target trees in rows, but to distribute them evenly; in some cases, two or three trees can be placed together, but the outer canopy should be spread out.

[0145] The classification of trees is the same as in Example 1.

[0146] (3) Target tree density

[0147] The difference from Example 1 is that the target diameter at breast height (DBH) of this stand is 50 cm. Therefore, 50 cm multiplied by 25 equals a distance of 12.5 m between the target trees, Quercus variabilis.

[0148] The target tree density for this stand is 150 trees / hm². 2 .

[0149] (4) Time for selecting the target tree

[0150] The stand is 30 years old, which meets the requirements. The stand's height-to-diameter ratio (equal to total tree height ÷ diameter at breast height) is between 80 and 90.

[0151] 2. Determine the interference tree

[0152] (1) Determine the time

[0153] At the same time, select the target tree and determine the interference tree.

[0154] (2) Determine the requirements

[0155] Same as Example 1.

[0156] 3. Mark

[0157] (1) Target tree labeling

[0158] After selecting the target tree, use bright green ribbons to temporarily mark it at breast height. Once the target tree passes inspection, remove the temporary markers and use red paint to create a permanent mark. The marker should be a ring shape, visible from all directions.

[0159] (2) Interference tree tagging

[0160] Once the disturbing tree is identified, use bright yellow ribbons to tie the tree at breast height as a temporary marker.

[0161] After the disturbance trees pass inspection, the temporary markers are retrieved, and a mark 40cm-60cm long, 5cm-7cm wide, and deep to the xylem is made on the trunk diameter at breast height with a knife. Marks are also made on the rootstock.

[0162] 4. Tending and felling

[0163] Determine which timber to retain and which to harvest:

[0164] Trees to be retained: target trees, auxiliary trees, and other trees; trees to be harvested: interference trees;

[0165] The nurturing measures for the target trees are the same as in Example 1.

[0166] The measures for retaining the wood—auxiliary trees and other trees are the same as in Example 1.

[0167] The following measures are taken to remove the interfering trees in this example:

[0168] Harvesting of interfering trees: Same as in Example 1.

[0169] The following measures should be taken for felled trees:

[0170] For felled timber with a large diameter and high economic value, it should be processed locally and hauled away according to market demand. For felled timber with a small diameter and logging residues with low economic value, the following requirements should be met:

[0171] After logging, usable timber should be transported away promptly, and logging residues should be cleared and piled evenly in the forest at certain intervals.

[0172] Forest stands managed with target trees should meet the following requirements:

[0173] (1) The canopy closure of the forest stand is 0.65, and not less than 0.6;

[0174] (2) In areas prone to wind and snow damage, or when the disturbing trees are felled for the first time, the canopy closure shall not decrease by more than 0.2;

[0175] (3) The number of target trees has not decreased;

[0176] (4) The average diameter at breast height (DBH) of the stand is 15.2 cm, which is not lower than the average DBH before logging;

[0177] (5) The trees are evenly distributed and there are no gaps or open spaces in the forest.

[0178] Figure 1The distribution map of 10 target trees is provided. The target trees selected in the sample plot are generally above the average diameter at breast height of the stand, of seedling origin, with strong vitality, straight trunk, full crown and healthy trees. They are determined at 10 trees per acre, which is relatively even. At the same time, the trees that affect the growth of the target trees are identified and felled.

[0179] 5. Biodiversity conservation

[0180] Same as Example 1.

[0181] 6. Artificially promoting natural regeneration

[0182] Same as Example 1.

[0183] 7. Small class monitoring

[0184] Long-term monitoring plots were set up in the target tree management plots, and control plots were also set up in the adjacent plots where target tree management was not carried out. Surveys were conducted in the first and third years, respectively.

[0185] Results of the first year's survey: The volume per hectare of the target tree management plot was 95.03 cubic meters, while the volume per hectare of the control plot was 94.18 cubic meters.

[0186] The results of the third year's survey showed that the volume of the target tree plot was 125.23 cubic meters per hectare, while the volume of the control plot was 103.74 cubic meters per hectare.

[0187] Calculations showed that the target tree plots increased the volume per hectare by 31.78%, while the control plots increased by 10.15%, resulting in a 21.63% increase in volume per hectare compared to the control plots. Moreover, the target trees generally achieved their best results in the fifth year after implementation.

[0188] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis in mountainous areas, characterized in that, include: S1: Select the target tree and mark it; identify the interference tree and mark it; S2: Tending and harvesting; S3: Artificially promotes natural regeneration.

2. The method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis according to claim 1, characterized in that, In S1, the criteria for selecting the target tree include: ① Target tree species: Quercus acutissima and / or Quercus variabilis; ② Strong vitality: The canopy accounts for 1 / 4 to 1 / 3 of the trunk height; ③ Good quality timber: A: Straight trunk; B: No more than three branches; C: No two branches within 5 meters of the main trunk; ④ No damage; ⑤ Select trees that originated from seed.

3. The method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis according to claim 1, characterized in that, In S1, the target tree density is 120 trees / hm². 2 ~150 plants / hm 2 The target tree should be selected between 15 and 40 years old, and its height-to-diameter ratio should be maintained between 70 and 100.

4. The method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis according to claim 1, characterized in that, In S1, the interference tree is determined by selecting trees that affect the growth of the target tree's canopy, with the target tree as the center.

5. The method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis according to claim 1, characterized in that, In S1, the timing of selecting the interference tree is as follows: the interference tree is determined at the same time as the target tree is selected.

6. The method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis according to claim 1, characterized in that, S2 includes: (1) Pruning of target trees: Remove dead branches and 1-2 rounds of live branches at the bottom of the crown. After pruning in the middle-aged forest stage, retain a crown length of not less than 1 / 2 of the tree height. Prune the branches flat and the cut should not damage the phloem and xylem of the trunk. (2) Interference with tree felling; (3) No tending and felling measures shall be taken for auxiliary trees and other trees.

7. The method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis according to claim 1, characterized in that, In S3, a bumper year for acorn production is selected for artificial promotion of natural regeneration.

8. The method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis according to claim 7, characterized in that, The artificial promotion of natural regeneration includes: ① Harrow the land before the oak seeds fall in autumn; ② Gather the dead branches and fallen leaves into rows and pile them up; ③ Check the germination in the second spring to ensure there are enough seedlings; ④ In the autumn of the second year, remove the weeds that are crowding out the seedlings and thin them out in the southeast and southwest directions of the mother tree.

9. The method for managing target trees in secondary forests of Quercus acutissima and / or Quercus variabilis according to claim 1, characterized in that, The forest stand after the target tree management must meet the following requirements: (1) The canopy closure of the forest stand is not less than 0.6; (2) In areas affected by wind and snow damage, or when the disturbing trees are felled for the first time, the canopy closure shall not decrease by more than 0.2; (3) The number of target trees does not decrease; (4) The average diameter at breast height (DBH) of the stand shall not be lower than the average DBH before logging; (5) The trees are evenly distributed and do not create gaps or open spaces in the forest.

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