A near-natural restoration and reconstruction method for declining Haloxylon ammodendron windbreak and sand-fixing forests

Abstract

This application discloses a method for near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests, belonging to the field of desert vegetation restoration. The method includes dividing the row-strip planting specifications of Haloxylon ammodendron windbreak and sand-fixing forests into mildly declining, moderately declining, and severely declining forest structures. When the forest is mildly declining, a first coppicing pattern with a coppicing intensity of 16% is used for rejuvenation in the first period. When the forest is moderately declining, a second coppicing pattern with a coppicing intensity of 25% is used for rejuvenation in the first period. When the forest is severely declining, Haloxylon ammodendron and Nitraria tangutorum are interplanted in the second period for replanting. This application provides diverse coppicing patterns with appropriate intensity and width, which is beneficial to the subsequent growth of Haloxylon ammodendron and enables near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests.

Description

Technical Field

[0001] This application relates to the field of desert vegetation restoration technology, and in particular to a near-natural restoration and reconstruction method for declining Haloxylon ammodendron windbreak and sand-fixing forests. Background Technology

[0002] Haloxylon ammodendron is an excellent tree species for windbreak and sand fixation in arid desert regions worldwide. It is mainly distributed in arid desert areas between 36° and 48° north latitude and 60° and 111° east longitude, and is currently a pioneer tree species for windbreak and sand fixation in my country. Haloxylon ammodendron windbreak and sand-fixing forests are an important component of the protective forests and ecological security barriers in northern sand control belts. Although large-scale artificial afforestation in recent years has increased the area of ​​artificial Haloxylon ammodendron forests in arid areas of western my country, due to climate change and human disturbance, large areas of these forests are currently showing a continuous decline. If effective restoration measures are not taken in time, this decline will continue to intensify, severely weakening the ecological service function of Haloxylon ammodendron windbreak and sand-fixing forests. Therefore, it is urgent to restore the declining Haloxylon ammodendron windbreak and sand-fixing forests.

[0003] Currently, the main restoration techniques for degraded Haloxylon ammodendron windbreak and sand-fixing forests are coppicing rejuvenation and replanting / remediation. One existing coppicing rejuvenation technique targets Haloxylon ammodendron with few new shoots and a tendency towards deterioration, and is carried out in early winter, from November to December. Coppicing is done in alternating sections, with a coppicing width of 20-30 meters, and the cut surfaces are covered with soil afterward. Another existing coppicing rejuvenation technique specifies a coppicing intensity of 100%, which is considered excessive. The existing replanting / remediation technique involves replanting Artemisia arenaria and Scutellaria barbata in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests.

[0004] Current techniques for rejuvenating Haloxylon ammodendron forests employ a single, excessively intensive coppicing method. Given the harsh natural conditions in the distribution areas of Haloxylon ammodendron windbreak and sand-fixing forests, these methods and intensities may cause irreversible damage to the trees, leading to death and stand decline. Haloxylon ammodendron windbreak and sand-fixing forests are typically planted in desert or arid regions to provide ecological protection against wind and sand. Excessive coppicing width weakens these benefits. Furthermore, existing replanting techniques do not adequately consider soil moisture capacity to support the increased stand density after replanting, and the selection of replanted tree species often fails to consider dominant species found in natural Haloxylon ammodendron forests. The selected mixed species also do not offer optimal windbreak and sand-fixing benefits. Summary of the Invention

[0005] This application provides a near-natural restoration and reconstruction method for declining Haloxylon ammodendron windbreak and sand-fixing forests. It can solve the problems of existing restoration techniques for declining Haloxylon ammodendron windbreak and sand-fixing forests, such as the single coppicing pattern, excessive coppicing intensity, excessive coppicing width, failure to adequately consider whether the soil moisture carrying capacity can support the stand density after replanting, and failure to select dominant tree species.

[0006] To achieve the above objectives, the technical solution of this invention is as follows:

[0007] This invention provides a method for near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests, including:

[0008] The row-and-strip planting specifications of Haloxylon ammodendron windbreak and sand-fixing forests are divided into mildly declining Haloxylon ammodendron windbreak and sand-fixing forests, moderately declining Haloxylon ammodendron windbreak and sand-fixing forests, and severely declining Haloxylon ammodendron windbreak and sand-fixing forests according to different forest stand structures.

[0009] When the Haloxylon ammodendron windbreak and sand-fixing forest is a slightly degraded Haloxylon ammodendron windbreak and sand-fixing forest, the first coppicing pattern is cyclically repeated in the first period to rejuvenate it with a coppicing intensity of 16%; when the Haloxylon ammodendron windbreak and sand-fixing forest is a moderately degraded Haloxylon ammodendron windbreak and sand-fixing forest, the second coppicing pattern is cyclically repeated in the first period to rejuvenate it with a coppicing intensity of 25%; when the Haloxylon ammodendron windbreak and sand-fixing forest is a severely degraded Haloxylon ammodendron windbreak and sand-fixing forest, it is replanted in the second period by intercropping Haloxylon ammodendron and Nitraria tangutorum.

[0010] In one possible implementation, the division of the row-strip planting pattern of Haloxylon ammodendron windbreak and sand-fixing forest into mildly declining, moderately declining, and severely declining Haloxylon ammodendron windbreak and sand-fixing forests according to different stand structures includes:

[0011] Haloxylon ammodendron windbreak and sand-fixing forests of the same age and with row and strip planting specifications are classified as follows: forests with a stand density of 280-400 trees / hectare, a mortality rate of 48%-68%, and a tree height of 130-160cm are classified as mildly declining Haloxylon ammodendron windbreak and sand-fixing forests; forests with a stand density of 220-280 trees / hectare, a mortality rate of 68%-72%, and a tree height of 110-130cm are classified as moderately declining Haloxylon ammodendron windbreak and sand-fixing forests; and forests with a stand density below 220 trees / hectare, a mortality rate above 72%, and a tree height below 110cm are classified as severely declining Haloxylon ammodendron windbreak and sand-fixing forests.

[0012] In one possible implementation, the first period is from November of the current year to March of the following year.

[0013] In one possible implementation, the first coppicing pattern is as follows: each planting strip contains two rows of planting, and every three consecutive planting strips form a group; in the first year, a planting strip is randomly selected from each group as the first coppicing strip, and the odd-numbered rows on the first side and the even-numbered rows on the second side of the first coppicing strip are coppiced at a predetermined stubble height, with the uncoppiced Haloxylon ammodendron being the first retained trees; in the fourth year, any one of the remaining two planting strips in each group is selected as the second coppicing strip, and the odd-numbered rows on the first side and the even-numbered rows on the second coppicing strip are coppiced at the predetermined stubble height, with the uncoppiced Haloxylon ammodendron being the first retained trees; in the fourth year, a planting strip is randomly selected from the remaining two planting strips in each group as the second coppicing strip, and the odd-numbered rows on the first side and the even-numbered rows on the second coppicing strip are coppiced at the predetermined stubble height, with the uncoppiced Haloxylon ammodendron being the first retained trees; In the seventh year, the remaining planting strip in each group becomes the third coppicing strip. The odd-numbered rows on the first side and the even-numbered rows on the second side of the third coppicing strip are coppiced at a predetermined stubble height. The remaining coppiced trees at the predetermined stubble height are the third retained trees. In the tenth year, the first retained trees in the first coppicing strip are coppiced at the predetermined stubble height. In the thirteenth year, the second retained trees in the second coppicing strip are coppiced at the predetermined stubble height. In the sixteenth year, the third retained trees in the third coppicing strip are coppiced at the predetermined stubble height. An eighteen-year coppicing cycle is completed.

[0014] And / or, the second coppicing pattern is as follows: each planting strip contains two rows of planting, and every two consecutive planting strips are grouped together; in the first year, a planting strip is randomly selected from each group as coppicing strip I, and the Haloxylon ammodendron on the odd-numbered first side and the even-numbered second side of the row of planting strip I are coppiced at a predetermined stubble height, and the uncoppiced Haloxylon ammodendron is retained as tree I; in the fourth year, the remaining planting strip in each group is coppicing strip II, and the Haloxylon ammodendron on the odd-numbered first side and the even-numbered second side of the row of planting strip II are coppiced at a predetermined stubble height, and the uncoppiced Haloxylon ammodendron is retained as tree II; in the seventh year, the retained trees I in coppicing strip I are coppiced at a predetermined stubble height; in the tenth year, the retained trees II in coppicing strip II are coppiced at a predetermined stubble height; a coppicing cycle is twelve years.

[0015] In one possible implementation, the predetermined stubble height is 50cm to 60cm.

[0016] In one possible implementation, the second period is late April each year.

[0017] In one possible implementation, the ratio of Haloxylon ammodendron and Nitraria tangutorum mixed replanting is Haloxylon ammodendron number: Nitraria tangutorum number = 3:1.

[0018] In one possible implementation, the mixed replanting and reseeding pattern of Haloxylon ammodendron and Nitraria tangutorum is as follows: the first Haloxylon ammodendron in the first row of every three existing rows is the target tree, and a cyclic replanting process is carried out based on the target tree; the cyclic replanting process is to replant 1 Haloxylon ammodendron every 2 holes in the longitudinal direction until 6 holes of Haloxylon ammodendron are replanted, and then replant 1 Nitraria tangutorum every 2 holes until 2 holes of Nitraria tangutorum are replanted.

[0019] In one possible implementation, pesticides are sprayed on Haloxylon ammodendron to suppress the hyacinth psyllid; and / or, adult Haloxylon ammodendron psyllids are attracted and killed with yellow sticky traps or fluorescent lamps; and / or, Haloxylon ammodendron branches and leaves are sprayed with bromocyanamide suspension, cyromazine and imidacloprid aqueous solution; and / or, natural enemies of the greater gerbil and their habitats are protected.

[0020] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0021] The near-natural restoration and reconstruction method for declining Haloxylon ammodendron windbreak and sand-fixing forests provided in this invention, based on the stand structure of the Haloxylon ammodendron windbreak and sand-fixing forest, divides the row-and-strip planting specifications of Haloxylon ammodendron windbreak and sand-fixing forests into mildly declining, moderately declining, and severely declining Haloxylon ammodendron windbreak and sand-fixing forests according to different stand structures. Accurately classifying the degree of decline of the Haloxylon ammodendron windbreak and sand-fixing forest can provide a basis for precise restoration of declining stands, thereby improving the restoration effectiveness. When the Haloxylon ammodendron windbreak and sand-fixing forest is mildly declining, a first coppicing pattern with a coppicing intensity of 16% is used for rejuvenation in the first period. When the Haloxylon ammodendron windbreak and sand-fixing forest is moderately declining, a second coppicing pattern with a coppicing intensity of 25% is used for rejuvenation in the first period. When the Haloxylon ammodendron windbreak and sand-fixing forest is severely declining, a mixed planting of Haloxylon ammodendron and Nitraria tangutorum is used for replanting in the second period. The method in this application embodiment can classify existing Haloxylon ammodendron windbreak and sand-fixing forests according to different stand structures and degrees of decline, and then perform different coppicing patterns and intensities for rejuvenation or mixed planting based on these different degrees of decline. By applying corresponding coppicing intensities and patterns to Haloxylon ammodendron windbreak and sand-fixing forests with varying degrees of decline, the methods offer diverse coppicing patterns, appropriate intensities, and suitable widths, which are beneficial for the subsequent growth of Haloxylon ammodendron and enable near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests. For severely declining Haloxylon ammodendron windbreak and sand-fixing forests, mixed planting of Haloxylon ammodendron and Nitraria tangutorum can effectively utilize soil moisture carrying capacity to support the density of the replanted forest and select dominant tree species. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A flowchart illustrating the near-natural restoration and reconstruction method for declining Haloxylon ammodendron windbreak and sand-fixing forests provided in this application embodiment;

[0024] Figure 2 A schematic diagram of the first year of coppicing rejuvenation under a first coppicing pattern provided in an embodiment of this application;

[0025] Figure 3 A schematic diagram of the first year of coppicing rejuvenation under a second coppicing pattern provided in an embodiment of this application;

[0026] Figure 4 A schematic diagram illustrating a 3:1 ratio of mixed replanting of Haloxylon ammodendron and Nitraria tangutorum in a severely degraded Haloxylon ammodendron windbreak and sand-fixing forest, as provided in an embodiment of this application.

[0027] Figure 5 A schematic diagram of Embodiment 3 provided for the present application;

[0028] Figure 6 A schematic diagram of Embodiment 4 provided for the purposes of this application;

[0029] Figure 7 A schematic diagram of Embodiment 5 provided for the present application;

[0030] Figure 8 The actual working photos of the mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in the embodiments of this application, which was rejuvenated by the first coppicing mode with a coppicing intensity of 16% in the first year from November of the winter of the current year to March of the following spring.

[0031] Figure 9 The actual working photos of the moderately declining Haloxylon ammodendron windbreak and sand-fixing forest provided in the embodiments of this application, which were rejuvenated by the second coppicing mode in the first year with a coppicing intensity of 25% from November of the winter of the current year to March of the following spring;

[0032] Figure 10 Photographs of actual work on replanting of severely degraded Haloxylon ammodendron windbreak and sand-fixing forests with mixed Haloxylon ammodendron and Nitraria tangutorum in late April each year, as provided in the embodiments of this application.

[0033] Figure 11 Monthly growth of Haloxylon ammodendron after copulation rejuvenation with a copulation intensity of 16% for the mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in the embodiments of this application.

[0034] Figure 12 Monthly growth of Haloxylon ammodendron after copulation rejuvenation with a copulation intensity of 25% for the moderately degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in the embodiments of this application.

[0035] Figure 13 The monthly growth status of Haloxylon ammodendron and Nitraria tangutorum after replanting in a mixed cross of Haloxylon ammodendron number: Nitraria tangutorum number = 3:1 for the severely degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in the embodiments of this application;

[0036] Figure 14 A comparison of new shoot growth and crown growth of individual Haloxylon ammodendron plants with different coppicing intensities and no coppicing in a mildly declining Haloxylon ammodendron windbreak and sand-fixing forest provided in Embodiment 1 of this application;

[0037] Figure 15 A comparison of new shoot growth and crown growth in mildly degraded Haloxylon ammodendron windbreak and sand-fixing forests with different coppicing intensities and no coppicing treatment, provided in Embodiment 1 of this application;

[0038] Figure 16 This is a comparison chart of new shoot growth and crown growth of coppiced Haloxylon ammodendron individuals with different coppicing intensities and no coppicing in a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest provided in Example 2 of this application.

[0039] Figure 17 This is a comparison chart of new shoot growth and crown growth in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests with different coppicing intensities and no coppicing treatment, provided in Embodiment 2 of this application.

[0040] Figure 18 This is a comparison chart of the new shoot growth and crown growth of individual Haloxylon ammodendron individuals under 16% coppicing intensity in a mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in Example 3 of this application;

[0041] Figure 19 This is a comparison chart of new shoot growth and crown growth in a mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest with a 16% coppicing intensity, between different coppicing patterns and uncoppiced Haloxylon ammodendron forests under different coppicing treatments, as provided in Embodiment 3 of this application.

[0042] Figure 20 This is a comparison chart of the new shoot growth and crown growth of individual Haloxylon ammodendron individuals under 25% coppicing intensity in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests provided in Example 4 of this application;

[0043] Figure 21 This is a comparison chart of new shoot growth and crown growth in a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest with a 25% coppicing intensity and a Haloxylon ammodendron forest without coppicing, provided in Example 4 of this application.

[0044] Figure 22This is a comparison chart of vegetation coverage and density between different replanting patterns and unreplanted Haloxylon ammodendron forests in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests provided in Embodiment 5 of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0046] In the relevant descriptions of this embodiment, the terms "including," "containing," and "possessing" are all open terms and are generally understood to include but not be limited to; the term "at least one" is generally understood to mean one or more, where "multiple" refers to two or more; the term "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items, for example, "at least one of a, b, or c", or "at least one of a, b, and c", which can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple; the symbol "A / B" is used to describe the selection relationship of associated objects, generally indicating an "or" relationship.

[0047] In the following description of the embodiments, the terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0048] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within the scope of this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0049] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0050] This invention provides a method for near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests, comprising the following steps.

[0051] Step 1: The row-and-strip planting pattern of Haloxylon ammodendron windbreak and sand-fixing forests is divided into mildly declining, moderately declining, and severely declining forest structures according to different stand structures. By dividing the Haloxylon ammodendron windbreak and sand-fixing forests according to different stand structures, subsequent effective restoration and reconstruction can be carried out for forests with different degrees of decline.

[0052] Step 1 includes: classifying Haloxylon ammodendron windbreak and sand-fixing forests of the same age and planting specifications as follows: Forests with a stand density of 280-400 trees / ha, a mortality rate of 48%-68%, and a tree height of 130-160cm are classified as mildly declining Haloxylon ammodendron windbreak and sand-fixing forests; forests with a stand density of 220-280 trees / ha, a mortality rate of 68%-72%, and a tree height of 110-130cm are classified as moderately declining Haloxylon ammodendron windbreak and sand-fixing forests; and forests with a stand density below 220 trees / ha, a mortality rate above 72%, and a tree height below 110cm are classified as severely declining Haloxylon ammodendron windbreak and sand-fixing forests. Accurately classifying the degree of decline of Haloxylon ammodendron windbreak and sand-fixing forests provides a basis for precise restoration, thereby improving the restoration effectiveness.

[0053] Step 2: When the Haloxylon ammodendron windbreak and sand-fixing forest is a slightly degraded Haloxylon ammodendron windbreak and sand-fixing forest, in the first period, the first coppicing mode is used to rejuvenate it by coppicing with a coppicing intensity of 16%.

[0054] When the Haloxylon ammodendron windbreak and sand-fixing forest is a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest, in the first period, the second coppicing mode is used to carry out coppicing rejuvenation with a coppicing intensity of 25%.

[0055] The first period is from November of the current year to March of the following year, that is, before the saxaul sprouts in spring. Because the temperature is lower during this period, it inhibits plant transpiration and soil moisture evaporation, which can prevent excessive loss of plant water from the stubble after the saxaul is cut off, thus avoiding the death of the plant.

[0056] Furthermore, the first coppicing pattern is: each planting strip contains two rows of planting (e.g., Figure 2 As shown, the two columns of planting rows within the dashed box constitute one planting strip. Every three consecutive planting strips form a group. In the first year, one planting strip is randomly selected from each group as the first coppicing strip. The odd-numbered rows on the first side and the even-numbered rows on the second side of the first coppicing strip are coppiced at a predetermined stubble height (e.g., ...). Figure 2The orientation shown indicates that the first side is the left and the second side is the right. Of course, in practice, if the first side is the right, then the second side is the left. (The explanation for the first and second sides follows the same pattern here). Uncut saxaul trees are the first type of retained trees. Figure 2 The diagram shows that each planting strip includes two rows of planting. Every three consecutive planting strips form a group, and the third planting strip in each group is designated as the first coppicing strip. The *Haloxylon ammodendron* plants on the left side of the odd-numbered rows and the *Haloxylon ammodendron* plants on the right side of the even-numbered rows in the first coppicing strip are coppiced at a predetermined stubble height. That is, every four planting rows are coppiced, resulting in two coppiced rows (forming the first coppicing strip), with a staggered "Z" shape of alternating rows and plants within the first coppicing strip. In the fourth year, any one of the remaining two planting strips in each group is selected as the second coppicing strip. The *Haloxylon ammodendron* plants on the first side of the odd-numbered rows and the second side of the even-numbered rows in the second coppicing strip are coppiced at a predetermined stubble height. The uncoppiced *Haloxylon ammodendron* plants are designated as the second retained trees. In the seventh year, the remaining planting strip in each group is designated as the third coppicing strip. The *Haloxylon ammodendron* plants on the first side of the odd-numbered rows and the second side of the even-numbered rows in the third coppicing strip are coppiced at a predetermined stubble height. The uncoppiced *Haloxylon ammodendron* plants at the predetermined stubble height are designated as the third retained trees. In the tenth year, the first retained trees in the first coppicing zone are coppiced to the predetermined coppicing height. In the thirteenth year, the second retained trees in the second coppicing zone are coppiced to the predetermined coppicing height. In the sixteenth year, the third retained trees in the third coppicing zone are coppiced to the predetermined coppicing height. An eighteen-year coppicing cycle is completed.

[0057] Of course, in a forest of Haloxylon ammodendron for windbreak and sand fixation, each group generally adopts the same first coppicing pattern.

[0058] And / or, Figure 3 As shown, the second coppicing pattern is as follows: each planting strip contains two rows of planting, and every two consecutive planting strips form a group. In the first year, a planting strip is randomly selected from each group as coppicing strip I. The *Haloxylon ammodendron* plants on the first side of the odd-numbered rows and the *Haloxylon ammodendron* plants on the second side of the even-numbered rows in coppicing strip I are coppiced according to a predetermined stubble height (e.g., ...). Figure 3 The orientation shown indicates that the first side is the left and the second side is the right. Of course, in practice, if the first side is the right, then the second side is the left. (The explanation for the first and second sides follows the same pattern here). Uncut saxaul is considered retained wood (I). Figure 3As shown, each planting strip consists of two rows of planting. Every two consecutive planting strips form a group, and the second planting strip in each group is designated as coppicing strip I. The *Haloxylon ammodendron* plants on the left side of the odd-numbered rows and the *Haloxylon ammodendron* plants on the right side of the even-numbered rows in coppicing strip I are coppiced at a predetermined stubble height. That is, every two rows of planting are coppiced, resulting in two rows of planting (coppicing strip I). In coppicing strip I, the coppicing is done in a zigzag pattern, alternating rows and plants. In the fourth year, the remaining planting strip in each group is coppicing strip II. The *Haloxylon ammodendron* plants on the first side of the odd-numbered rows and the second side of the even-numbered rows in coppicing strip II are coppiced at a predetermined stubble height. The uncoppiced *Haloxylon ammodendron* plants are retained as retained trees II. In the seventh year, retained trees I in coppicing strip I are coppiced at the predetermined stubble height. In the tenth year, retained trees II in coppicing strip II are coppiced at the predetermined stubble height. A coppicing cycle is twelve years.

[0059] Of course, in a forest of Haloxylon ammodendron for windbreak and sand fixation, each group generally adopts the same second coppicing pattern.

[0060] The appropriate coppicing intensity in the embodiments of this application will not damage the stand structure stability of the Haloxylon ammodendron windbreak and sand-fixing forest. At the same time, the "Z" shaped coppicing pattern can improve the stand structure of the Haloxylon ammodendron windbreak and sand-fixing forest and enhance its windbreak and sand-fixing ecological benefits.

[0061] The predetermined stubble height is 50cm~60cm, which can promote the growth of later shoots of Haloxylon ammodendron, balance transpiration water consumption with the growth needs of Haloxylon ammodendron, prevent excessive pruning leading to the death of Haloxylon ammodendron, and improve the convenience of actual operation. Moreover, the area where Haloxylon ammodendron plays a role in windbreak and sand fixation is mainly 0cm~60cm from the ground surface, and this predetermined stubble height can also enhance the ecological function of Haloxylon ammodendron in windbreak and sand fixation.

[0062] like Figure 8 The actual working photos show the mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in this application embodiment, which underwent coppicing rejuvenation in the first year with a coppicing intensity of 16% through the first coppicing mode from November of the current year to March of the following year. Figure 9 The actual working photos show the moderately declining Haloxylon ammodendron windbreak and sand-fixing forest provided in this application embodiment, which underwent a second coppicing model for the first year of rejuvenation with a coppicing intensity of 25% from November of the current year to March of the following year. Figure 11 The monthly growth status of Haloxylon ammodendron after coppicing at a strength of 16% in the mildly degenerated Haloxylon ammodendron windbreak and sand-fixing forest provided in this application embodiment. Figure 12 The figure shows the monthly growth of Haloxylon ammodendron after coppicing at a intensity of 25% in the moderately declining Haloxylon ammodendron windbreak and sand-fixing forest provided in this application embodiment. As can be seen from the figure, the Haloxylon ammodendron in the restored Haloxylon ammodendron windbreak and sand-fixing forest is growing well, thanks to the near-natural restoration and reconstruction method of the declining Haloxylon ammodendron windbreak and sand-fixing forest in this application embodiment.

[0063] When the Haloxylon ammodendron windbreak and sand-fixing forest is severely degraded, it can be replanted by intercropping Haloxylon ammodendron and Nitraria tangutorum in the second period.

[0064] In desert Haloxylon ammodendron forests, the dominant companion species are Nitraria tangutorum and Salix babylonica, but the importance of Salix babylonica in the species composition of natural Haloxylon ammodendron forests is lower than that of Nitraria tangutorum. Furthermore, studies on soil moisture utilization by Salix babylonica revealed that it primarily utilizes soil moisture from deeper layers (70cm-160cm), while Haloxylon ammodendron mainly utilizes soil moisture from deeper layers (60cm-120cm). Therefore, Salix babylonica and Haloxylon ammodendron may compete for soil moisture utilization. Moreover, with increasing wind speed, the sand-blocking efficiency of different shrubs varies, with Haloxylon ammodendron and Nitraria tangutorum exhibiting significantly higher sand-blocking efficiency than sand-fixing plants such as Calligonum mongolicum.

[0065] In summary, considering the importance of the species composition of *Nitraria tangutorum* and *Symplocos rubrum* in natural *Haloxylon ammodendron* forests, the soil moisture utilization strategies of *Haloxylon ammodendron*, *Nitraria tangutorum*, and *Symplocos rubrum*, and the comprehensive performance of each species in windbreak and sand-fixing benefits, *Nitraria tangutorum* was ultimately determined to be the optimal mixed-species species for deteriorating *Haloxylon ammodendron* windbreak and sand-fixing forests. Mixing with *Nitraria tangutorum* can not only increase the species richness and stability of the stand structure of deteriorating *Haloxylon ammodendron* windbreak and sand-fixing forests, but also leverage its highly efficient sand-blocking effect, thereby enhancing the windbreak and sand-fixing ecological service function of these forests. *Nitraria tangutorum* is a dominant companion species in natural *Haloxylon ammodendron* forests, and its windbreak and sand-fixing benefits are the best among companion species suitable for mixed-species planting in *Haloxylon ammodendron* windbreak and sand-fixing forests. The current mixed-planting density is within the vegetation carrying capacity of arid desert areas; therefore, this technique can ensure the survival rate of plants after mixed-planting and increase the species richness of *Haloxylon ammodendron* windbreak and sand-fixing forests, thereby enhancing their windbreak and sand-fixing ecological function.

[0066] The second planting period is late April each year. During this period, the climate conditions in the areas where the Haloxylon ammodendron windbreak and sand-fixing forests are distributed are suitable. As spring temperatures rise, the soil in these areas gradually thaws, and soil moisture and temperature are ideal for planting Haloxylon ammodendron and Nitraria tangutorum. Planting Haloxylon ammodendron and Nitraria tangutorum in April allows full utilization of the long growing season from spring to autumn, giving the plants sufficient time for photosynthesis, nutrient accumulation, and growth. Planting Haloxylon ammodendron and Nitraria tangutorum in winter or early spring may result in severe cold weather, causing frost damage or hindered growth. At the same time, the areas where the Haloxylon ammodendron windbreak and sand-fixing forests are distributed experience strong winds and sandstorms, making the ecological environment fragile. Planting psammophytes such as Haloxylon ammodendron and Nitraria tangutorum can enhance the windbreak and sand-fixing ecological function of the Haloxylon ammodendron windbreak and sand-fixing forests, thereby improving the ecological environment. Therefore, late April is the best time to replant Haloxylon ammodendron and Nitraria tangutorum, which is beneficial for plant growth and ecological environment restoration.

[0067] The ratio of Haloxylon ammodendron and Nitraria tangutorum for replanting is 3:1 (Haloxylon ammodendron number: Nitraria tangutorum number).

[0068] like Figure 4As shown, the replanting method for mixed planting of Haloxylon ammodendron and Nitraria tangutorum is as follows: The first Haloxylon ammodendron tree in the first row of every three existing rows is the target tree, and a cyclical replanting process is implemented based on this target tree. The cyclical replanting process involves planting one Haloxylon ammodendron tree every two holes longitudinally until six holes are planted. Then, one Nitraria tangutorum tree is planted every two holes until two holes are planted. That is, the planting density for mixed planting of Haloxylon ammodendron and Nitraria tangutorum is 6 holes / acre for Haloxylon ammodendron and 2 holes / acre for Nitraria tangutorum. After mixed planting, the overall ratio of Nitraria tangutorum to Haloxylon ammodendron in the forest land is 6:4, and the total forest land density is 23-27 holes / acre. The spacing between the plants and rows for both Haloxylon ammodendron and Nitraria tangutorum is 9m × 9m, arranged in a triangular pattern. During replanting, the seedlings are straightened, compacted, and lightly covered with loose soil, following the "lift, tamp, and mound" method, ensuring the seedlings are upright and the roots are sparse. The watering density is approximately 10-15 kg / hole.

[0069] like Figure 10 The actual working photos of the mixed replanting of Haloxylon ammodendron and Nitraria tangutorum in late April each year for the severely degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in the embodiments of this application are shown. Figure 13 The monthly growth status of Haloxylon ammodendron in the mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in this application embodiment after coppicing rejuvenation with a coppicing intensity of 16%. As shown in the figure, after replanting and re-establishing the severely degraded Haloxylon ammodendron windbreak and sand-fixing forest with mixed planting of Haloxylon ammodendron and Nitraria tangutorum, both Haloxylon ammodendron and Nitraria tangutorum grow well.

[0070] Step 3: Spray Haloxylon ammodendron with pesticides to suppress Haloxylon ammodendron; and / or, use yellow sticky traps or fluorescent lamps to trap adult Haloxylon ammodendron; and / or, spray Haloxylon ammodendron branches and leaves with bromocyanamide suspension, cyromazine and imidacloprid aqueous solution; and / or, protect natural enemies of the greater gerbil and their habitats.

[0071] Specifically, the saxaul psyllid often lays its eggs in the soil. Covering the stubble with soil after coppicing may pose a risk of infestation. Spraying saxaul psyllid-inhibiting pesticides such as triadimefon, 12% abamectin, and chlorfenapyr can chemically control this major pest in saxaul windbreak and sand-fixing forests. Yellow sticky traps or fluorescent lamps can also be used to attract and kill adult saxaul psyllids, thus controlling the pest.

[0072] The Cistanche borer flies bore into the roots of Cistanche deserticola, creating tunnels that eventually reach the plant, causing it to rot and decay. This also damages the roots of Haloxylon ammodendron. Spraying the branches and leaves of Haloxylon ammodendron with a 1000-fold dilution of 19% cypermethrin suspension, a 3000-5000-fold dilution of 75% cyromazine, and a 1000-2000-fold dilution of 20% imidacloprid aqueous solution can effectively control the Cistanche borer flies, one of the main pests in Haloxylon ammodendron windbreak and sand-fixing forests, and suppress their growth.

[0073] The greater gerbil is a naturally distributed rodent species in certain areas of Haloxylon ammodendron windbreak and sand-fixing forests, mainly found in Haloxylon ammodendron and Nitraria tangutorum desert shrublands. It primarily damages desert vegetation by digging burrows and gnawing on branches, leading to vegetation death and desertification. Protecting the greater gerbil's natural enemies and their habitats is crucial. For example, artificially setting up perches, nests, and bird boxes at the edges of desert forests and near agricultural areas can optimize the habitat, breeding environment, and predation conditions for the greater gerbil's natural enemies, thus enabling biological control of this major pest in Haloxylon ammodendron windbreak and sand-fixing forests.

[0074] Through the above-mentioned chemical pesticide and biological control measures, pests, diseases, and rodents in the Haloxylon ammodendron windbreak and sand-fixing forest can be reduced, the health of the forest stand can be improved, and a more stable growth and development environment can be provided for Haloxylon ammodendron.

[0075] The near-natural restoration and reconstruction method for declining Haloxylon ammodendron windbreak and sand-fixing forests provided in this invention, based on the stand structure of the Haloxylon ammodendron windbreak and sand-fixing forest, divides the row-and-strip planting specifications of Haloxylon ammodendron windbreak and sand-fixing forests into mildly declining, moderately declining, and severely declining Haloxylon ammodendron windbreak and sand-fixing forests according to different stand structures. Accurately classifying the degree of decline of the Haloxylon ammodendron windbreak and sand-fixing forest can provide a basis for precise restoration of declining stands, thereby improving the restoration effectiveness. When the Haloxylon ammodendron windbreak and sand-fixing forest is mildly declining, a first coppicing pattern with a coppicing intensity of 16% is used for rejuvenation in the first period. When the Haloxylon ammodendron windbreak and sand-fixing forest is moderately declining, a second coppicing pattern with a coppicing intensity of 25% is used for rejuvenation in the first period. When the Haloxylon ammodendron windbreak and sand-fixing forest is severely declining, a mixed planting of Haloxylon ammodendron and Nitraria tangutorum is used for replanting in the second period. The method in this application embodiment can classify existing Haloxylon ammodendron windbreak and sand-fixing forests according to different stand structures and degrees of decline, and then perform different coppicing patterns and intensities for rejuvenation or mixed planting based on these different degrees of decline. By applying corresponding coppicing intensities and patterns to Haloxylon ammodendron windbreak and sand-fixing forests with varying degrees of decline, the methods offer diverse coppicing patterns, appropriate intensities, and suitable widths, which are beneficial for the subsequent growth of Haloxylon ammodendron and enable near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests. For severely declining Haloxylon ammodendron windbreak and sand-fixing forests, mixed planting of Haloxylon ammodendron and Nitraria tangutorum can effectively utilize soil moisture carrying capacity to support the density of the replanted forest and select dominant tree species.

[0076] The method described in this application is mainly used to improve the restoration of degraded Haloxylon ammodendron windbreak and sand-fixing forests, enhance their ecological benefits in windbreak and sand fixation, and provide technical support for precise restoration of forest health. It provides a basis for improving Haloxylon ammodendron plantation afforestation methods, can supplement forest management techniques, and can also promote the vigorous development of the Haloxylon ammodendron-Cistanche deserticola industry.

[0077] To ensure that the above-described implementation details and operations of this application can be clearly understood by those skilled in the art, and to highlight the significant advancements of the near-natural restoration and reconstruction method for declining Haloxylon ammodendron windbreak and sand-fixing forests in the embodiments of this application, the above technical solutions are illustrated below through multiple embodiments.

[0078] Example 1

[0079] Two experimental plots, 100m×75m and 70m×75m in size, were established in a mildly declining Haloxylon ammodendron windbreak and sand-fixing forest. From November of the first year to March of the following year, coppicing rejuvenation experiments were conducted with coppicing intensities of 16% and 25%, respectively, using the first coppicing model (simulating only the first year). Uncoppiced and coppiced Haloxylon ammodendron were selected as the subjects of measurement. Both were managed with the same care measures. The new shoot growth and crown growth of coppiced and retained Haloxylon ammodendron trees were measured three months after coppicing. Based on the coppicing intensity, the new shoot growth and crown growth of individual coppiced Haloxylon ammodendron trees and the Haloxylon ammodendron forest (coppiced trees + retained trees) under each coppicing intensity were calculated. The measurement results were analyzed and processed as follows: Figure 14 ~and Figure 15 As shown.

[0080] Figure 14 This is a comparison chart of the new shoot growth and crown growth of individual Haloxylon ammodendron plants with different coppicing intensities and no coppicing treatment in a mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in Embodiment 1 of this application. Figure 14 The left and middle figures show the new shoot growth of individual Haloxylon ammodendron plants with different coppicing intensities and without coppicing in a mildly declining Haloxylon ammodendron windbreak and sand-fixing forest. Figure 14 The right-middle figure shows the crown growth of individual Haloxylon ammodendron individuals with different coppicing intensities and without coppicing in a mildly declining Haloxylon ammodendron windbreak and sand-fixing forest. Figure 14 In the text, different lowercase letters a and b indicate that the markers are slightly degraded at the P < 0.05 level. The differences in the amount of new shoot growth and crown growth of individual Haloxylon ammodendron under different coppicing intensities in the Haloxylon ammodendron windbreak and sand-fixing forest were significant.

[0081] Depend on Figure 14 As shown in the left figure, in a mildly declining *Haloxylon ammodendron* windbreak and sand-fixing forest, the new shoot growth of *Haloxylon ammodendron* individuals under the 16% coppicing intensity treatment was higher than that under the 25% coppicing intensity treatment, and significantly higher than that under the uncoppiced treatment (CK). Figure 14 As shown in the right figure, the crown growth of individual Haloxylon ammodendron under the 16% coppicing intensity treatment was higher than that under the 25% coppicing intensity treatment, and significantly higher than that under the uncoppiced treatment (CK).

[0082] Figure 15 This is a comparison chart of new shoot growth and crown growth in mildly degraded Haloxylon ammodendron windbreak and sand-fixing forests with different coppicing intensities and without coppicing, provided in Embodiment 1 of this application. Figure 15The left and middle figures show the new shoot growth of Haloxylon ammodendron forests with different coppicing intensities and those without coppicing in mildly declining Haloxylon ammodendron windbreak and sand-fixing forests. Figure 15 The right-middle figure shows the crown growth of Haloxylon ammodendron forests with different coppicing intensities and those without coppicing in mildly degraded Haloxylon ammodendron windbreak and sand-fixing forests. Figure 15 In the text, different lowercase letters a and b indicate that the markers are slightly degraded at the P < 0.05 level. The differences in shoot growth and crown growth of Haloxylon ammodendron forest under different coppicing intensities were significant.

[0083] Depend on Figure 15 As shown in the left figure, in a mildly declining *Haloxylon ammodendron* windbreak and sand-fixing forest, the new shoot growth of the *Haloxylon ammodendron* forest treated with 16% coppicing intensity was higher than that treated with 25% coppicing intensity, and significantly higher than that of the uncoppiced treatment (CK). Figure 15 As shown in the right figure, the canopy growth of Haloxylon ammodendron under the 16% coppicing intensity treatment was higher than that under the 25% coppicing intensity treatment, and significantly higher than that under the uncoppiced treatment (CK).

[0084] To determine the optimal coppicing intensity in mildly declining Haloxylon ammodendron windbreak and sand-fixing forests, the increases in the growth of individual Haloxylon ammodendron plants and the growth of new shoots and crown width of Haloxylon ammodendron forests under different coppicing intensity treatments and without coppicing were compared (Tables 1-2).

[0085] Table 1. Increase in new shoot and crown growth of coppiced *Haloxylon ammodendron* individuals under different coppicing intensities in mildly degraded *Haloxylon ammodendron* windbreak and sand-fixing forests.

[0086]

[0087] In Table 1, lowercase letter 'a' indicates that the difference in the increase of new shoot growth and crown growth of individual Haloxylon ammodendron under different coppicing intensities was not significant at the P < 0.05 level; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0088] As can be seen from Table 1, in the mildly declining Haloxylon ammodendron windbreak and sand-fixing forest, the increase in the growth of new shoots and crown width of individual Haloxylon ammodendron under the 16% coppicing intensity treatment was higher than that under the 25% coppicing intensity treatment.

[0089] Table 2. Increase in new shoot and crown growth of *Haloxylon ammodendron* forests under different coppicing intensities in mildly degraded windbreak and sand-fixing forests.

[0090]

[0091] In Table 2, different lowercase letters a and b indicate that the difference in the increase of new shoot growth and crown growth of Haloxylon ammodendron forest under different coppicing intensities is significant at the P<0.05 level; the values ​​are expressed as mean ± standard error (Mean±SE).

[0092] As can be seen from Table 2, in the mildly declining Haloxylon ammodendron windbreak and sand-fixing forest, the increase in new shoot growth and crown growth under the 16% coppicing intensity treatment was significantly higher than that under the 25% coppicing intensity treatment.

[0093] To further clarify the optimal coppicing intensity in mildly degraded Haloxylon ammodendron windbreak and sand-fixing forests, the reduction in the decline index of Haloxylon ammodendron forests under different coppicing intensity treatments and without coppicing treatment was compared (Table 3).

[0094] Table 3. Reduction in the decline index of *Haloxylon ammodendron* forests under different coppicing intensities in mildly declining windbreak and sand-fixing forests.

[0095]

[0096] In Table 3, lowercase letter 'a' indicates that the difference in the reduction of the decline index among different coppicing intensities of Haloxylon ammodendron windbreak and sand-fixing forests was not significant at the P < 0.05 level; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0097] According to the classification of the degree of decline in the Haloxylon ammodendron windbreak and sand-fixing forest decline evaluation index system, the degree of decline increases with the increase of the decline index. As shown in Table 3, the reduction in the decline index of Haloxylon ammodendron forest under the 16% coppicing intensity treatment is higher than that under the 25% coppicing intensity treatment.

[0098] In summary, under the 16% coppicing intensity treatment in mildly declining Haloxylon ammodendron windbreak and sand-fixing forests, the increases in the growth of individual coppiced Haloxylon ammodendron plants and new shoots and crown growth, as well as the decrease in the decline index of the Haloxylon ammodendron forest, were all higher than those under the 25% coppicing intensity treatment. Therefore, the optimal coppicing intensity for mildly declining Haloxylon ammodendron windbreak and sand-fixing forests should be 16%.

[0099] Example 2

[0100] Figure 16 This is a comparison chart of the new shoot growth and crown growth of coppiced Haloxylon ammodendron individuals with different coppicing intensities and without coppicing in a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest, as provided in Example 2 of this application. Figure 16 The left and middle figures show the new shoot growth of individual Haloxylon ammodendron plants with different coppicing intensities and without coppicing in a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest. Figure 16 The right-middle figure shows the crown growth of individual Haloxylon ammodendron plants with different coppicing intensities and those without coppicing in a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest. Figure 16 In the text, different lowercase letters a, b, and c indicate that the differences in the amount of new shoot growth and crown growth of individual Haloxylon ammodendron plants under different coppicing intensities are significant at the P < 0.05 level in Haloxylon ammodendron windbreak and sand-fixing forests with moderate decline.

[0101] Depend on Figure 16As shown in the left figure, in a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest, the new shoot growth of individual Haloxylon ammodendron plants under the 25% coppicing intensity treatment was significantly higher than that under the 16% coppicing intensity treatment and the uncoppiced treatment (CK). Figure 16 As shown in the right figure, the crown growth of individual Haloxylon ammodendron under the 25% coppicing intensity treatment was higher than that under the 16% coppicing intensity treatment, and significantly higher than that under the uncoppiced treatment (CK).

[0102] Figure 17 This is a comparison chart of new shoot growth and crown growth in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests with different coppicing intensities and without coppicing, provided in Example 2 of this application. Figure 17 The left and middle figures show the new shoot growth of Haloxylon ammodendron forests with different coppicing intensities and those without coppicing in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests. Figure 17 The right-middle figure shows the crown growth of Haloxylon ammodendron forests with different coppicing intensities and those without coppicing in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests. Figure 17 In the text, different lowercase letters a, b, and c indicate that the differences in shoot growth and crown growth of Haloxylon ammodendron forest under different coppicing intensities are significant at the P < 0.05 level in moderately deteriorated Haloxylon ammodendron windbreak and sand-fixing forests.

[0103] Depend on Figure 17 As shown in the left figure, in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests, the new shoot growth of Haloxylon ammodendron forests under the 25% coppicing intensity treatment was significantly higher than that under the 16% coppicing intensity treatment and the uncoppiced treatment (CK). Figure 17 As shown in the right figure, the canopy growth of Haloxylon ammodendron under the 25% coppicing intensity treatment was significantly higher than that under the 16% coppicing intensity treatment and the no-coppicing treatment (CK).

[0104] To determine the optimal coppicing intensity in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests, the increases in the growth of coppiced Haloxylon ammodendron individuals and the growth of new shoots and crown width of Haloxylon ammodendron forests were compared between different coppicing intensity treatments and the uncoppiced treatment (Tables 4-5).

[0105] Table 4. Increase in new shoot and crown growth of coppiced *Haloxylon ammodendron* individuals under different coppicing intensities in moderately degraded *Haloxylon ammodendron* windbreak and sand-fixing forests.

[0106]

[0107] In Table 4, different lowercase letters a and b indicate that at the P < 0.05 level, the differences in the increase of new shoot growth and crown growth of individual Haloxylon ammodendron under different coppicing intensities in the moderately declining Haloxylon ammodendron windbreak and sand-fixing forest are significant; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0108] As shown in Table 4, in the moderately declining Haloxylon ammodendron windbreak and sand-fixing forest, the increase in new shoot growth of individual Haloxylon ammodendron under the 25% coppicing intensity treatment was significantly higher than that under the 16% coppicing intensity treatment; the increase in crown growth of individual Haloxylon ammodendron under the 25% coppicing intensity treatment was higher than that under the 16% coppicing intensity treatment.

[0109] Table 5. Increase in new shoot and crown growth of moderately degraded Haloxylon ammodendron windbreak and sand-fixing forests under different coppicing intensities.

[0110]

[0111] In Table 5, different lowercase letters a and b indicate that at the P < 0.05 level, the differences in the increase of new shoot growth and crown growth of Haloxylon ammodendron forest under different coppicing intensities in moderately deteriorated Haloxylon ammodendron windbreak and sand-fixing forest are significant; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0112] As can be seen from Table 5, in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests, the increase in new shoot growth and crown growth under the 25% coppicing intensity treatment was significantly higher than that under the 16% coppicing intensity treatment.

[0113] To further clarify the optimal coppicing intensity in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests, the reduction in the decline index of Haloxylon ammodendron forests under different coppicing intensity treatments and without coppicing treatment was compared (Table 6).

[0114] Table 6. Reduction of Decline Index of Haloxylon ammodendron Forest under Different Coppicing Intensities in Moderately Declining Haloxylon ammodendron Windbreak and Sand-Fixing Forest

[0115]

[0116] In Table 6, different lowercase letters a and b indicate that the difference in the reduction of the decline index of Haloxylon ammodendron forest under different coppicing intensities is significant at the P<0.05 level in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0117] According to the evaluation index system for the decline of Haloxylon ammodendron windbreak and sand-fixing forests, the degree of decline increases with the increase of the decline index. As shown in Table 6, the reduction in the decline index of Haloxylon ammodendron forests under the 25% coppicing intensity treatment is significantly higher than that under the 16% coppicing intensity treatment.

[0118] In summary, under the 25% coppicing intensity treatment in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests, the increases in the growth of coppiced Haloxylon ammodendron individuals and new shoots and crown growth, as well as the decrease in the decline index of the Haloxylon ammodendron forest, were all higher than those under the 16% coppicing intensity treatment. Therefore, the optimal coppicing intensity for moderately declining Haloxylon ammodendron windbreak and sand-fixing forests should be 25%.

[0119] The extent of compensatory growth after damage to the above-ground parts of a plant is related to the degree of damage. In Examples 1 and 2, coppiced plants exhibited high compensatory growth capacity and typical acquisition strategies in the early stages of recovery. Coppiced plants allocated more biomass and resources to the growth of above-ground tissues such as branches and leaves. Therefore, after coppicing, the height and crown width of *Haloxylon ammodendron* significantly increased, promoting clump growth, increasing the number of branches, and enhancing the length and amount of new branches. On the other hand, increased coppicing intensity reduces water consumption by older branches, while increasing the amount of water available per unit area for sprouting new branches, thus promoting the growth and development of new branches. Therefore, in this application, as the degree of decline of the *Haloxylon ammodendron* windbreak and sand-fixing forest increases, the coppicing intensity also increases. Implementing coppicing rejuvenation technology on *Haloxylon ammodendron* windbreak and sand-fixing forests can reduce transpiration water consumption, alleviate excessive water consumption in the forest, and promote recovery growth, thereby enhancing the windbreak and sand-fixing capacity of *Haloxylon ammodendron*.

[0120] Example 3

[0121] For mildly declining Haloxylon ammodendron windbreak and sand-fixing forests, rejuvenation was achieved by coppicing at an intensity of 16% from November of the current year to March of the following year using coppicing patterns A, B, and C (simulating only the first year) to obtain the optimal coppicing pattern. For example... Figure 5 As shown.

[0122] Coppicing Pattern A: Each planting zone contains two planting rows. The third planting zone out of every three consecutive planting zones is designated as the coppicing zone. The odd-numbered rows of Haloxylon ammodendron in the coppicing zone are coppiced according to a predetermined stubble height. That is, every four planting rows are coppiced, and two planting rows are coppiced (forming the coppicing zone). Within the coppicing zone, coppicing is done every other row.

[0123] Coppicing Pattern B: Each planting zone contains two planting rows. The third planting zone out of every three consecutive planting zones is designated as the coppicing zone. The entire row of Haloxylon ammodendron on the right side of the coppicing zone is coppiced according to the predetermined stubble height. That is, every 5 planting rows, 1 planting row is coppiced.

[0124] Coppicing Pattern C: Each planting strip contains two rows of planting. The third planting strip out of every three consecutive planting strips is designated as the coppicing strip. The *Haloxylon ammodendron* plants on the left side of the odd-numbered rows and on the right side of the even-numbered rows in the coppicing strip are coppiced according to a predetermined stubble height. That is, every four planting rows are coppiced, and two planting rows are coppiced (forming the coppicing strip). Within the coppicing strip, coppicing is done in a staggered "Z" shape, alternating between every other row and every other plant.

[0125] Each treatment pattern consisted of three experimental plots, with two replicates and one control group. Each treatment area was 30m × 15m, i.e., 4 rows and 6 columns of *Haloxylon ammodendron*, with each control group spaced approximately 5m apart. Uncut and coppiced *Haloxylon ammodendron* were selected as the subjects of measurement. Both were managed under the same care. The shoot growth and crown growth of coppiced and retained *Haloxylon ammodendron* trees were measured three months after coppicing. Based on the coppicing intensity, the shoot growth and crown growth of individual coppiced *Haloxylon ammodendron* trees and the *Haloxylon ammodendron* forest (coppiced trees + retained trees) under each coppicing intensity were calculated. The results were analyzed and processed as follows. Figures 18-19 As shown.

[0126] Figure 18 This is a comparison chart of the new shoot growth and crown growth of individual Haloxylon ammodendron plants under different coppicing patterns and uncoppiced Haloxylon ammodendron plants in a mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest provided in Example 3 of this application, at a coppicing intensity of 16%. Figure 18 The left figure shows the new shoot growth of individual Haloxylon ammodendron plants with 16% coppicing intensity and those without coppicing in a mildly declining Haloxylon ammodendron windbreak and sand-fixing forest. Figure 18 The right-middle figure shows the crown growth of individual Haloxylon ammodendron individuals with 16% coppicing intensity and those without coppicing in a mildly declining Haloxylon ammodendron windbreak and sand-fixing forest.

[0127] Figure 18 In the text, different lowercase letters a and b indicate that at the P < 0.05 level, the differences in new shoot growth and crown growth of individual coppiced Haloxylon ammodendron under the 16% coppicing pattern are significant.

[0128] From the above Figure 18 It can be seen that in the mildly declining Haloxylon ammodendron windbreak and sand-fixing forest, the new shoot growth and crown growth of the cut Haloxylon ammodendron under the cut mode C treatment at 16% cut intensity were higher than those under the cut mode A and cut mode B, and significantly higher than those under the uncut treatment (CK).

[0129] Figure 19 This is a comparison chart of new shoot growth and crown growth in a mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest with a 16% coppicing intensity, as provided in Example 3 of this application, between various coppicing patterns and uncoppiced Haloxylon ammodendron forests. Figure 19 The left figure shows the new shoot growth of a mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest with 16% coppicing intensity and an uncoppiced Haloxylon ammodendron forest. Figure 19 The right-middle figure shows the crown growth of a mildly degraded Haloxylon ammodendron windbreak and sand-fixing forest with a 16% coppicing intensity and an uncoppiced Haloxylon ammodendron forest.

[0130] Figure 19 In the text, different lowercase letters a, b, and ab indicate that the differences in shoot growth and crown growth in Haloxylon ammodendron forests under the 16% coppicing pattern are significant at the P < 0.05 level.

[0131] From the above Figure 19It can be seen that in the mildly declining Haloxylon ammodendron windbreak and sand-fixing forest, the new shoot growth and crown growth of Haloxylon ammodendron forest under the coppicing mode C treatment at 16% coppicing intensity were higher than those under coppicing mode A and coppicing mode B, and significantly higher than those under the uncoppiced treatment (CK).

[0132] To determine the optimal coppicing pattern under 16% coppicing intensity, the increases in new shoot growth and crown growth of individual Haloxylon ammodendron and Haloxylon ammodendron forests under different coppicing pattern treatments and no coppicing treatments were compared (Tables 7-8).

[0133] Table 7. Increase in new shoot and crown growth of *Haloxylon ammodendron* individuals under different coppicing patterns at 16% coppicing intensity.

[0134]

[0135] In Table 7, lowercase letter 'a' indicates that the difference in the increase of new shoot growth and crown growth of individual Haloxylon ammodendron under different coppicing patterns at 16% coppicing intensity at the P<0.05 level is not significant; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0136] As can be seen from Table 7, under a 16% coppicing intensity in the mildly degenerated Haloxylon ammodendron windbreak and sand-fixing forest, the increase in the growth of new shoots and crown width of coppiced Haloxylon ammodendron individuals in coppicing mode C was higher than that in coppicing mode A and coppicing mode B.

[0137] Table 8. Increase in new shoot and crown growth of Haloxylon ammodendron forests under different coppicing patterns at 16% coppicing intensity.

[0138]

[0139] In Table 8, different lowercase letters a and b indicate that the differences in the increment of new shoot growth and crown growth of Haloxylon ammodendron forest under different coppicing patterns at 16% coppicing intensity at the P<0.05 level are significant; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0140] As can be seen from Table 8, under a 16% coppicing intensity, the increase in new shoot growth of the Haloxylon ammodendron forest treated by coppicing mode C was higher than that of coppicing mode A and coppicing mode B; the increase in crown growth of the Haloxylon ammodendron forest treated by coppicing mode C was higher than that of coppicing mode A, and significantly higher than that of coppicing mode B.

[0141] To further clarify the optimal coppicing pattern for mildly degraded Haloxylon ammodendron windbreak and sand-fixing forests at a coppicing intensity of 16%, the reduction in the deterioration index of Haloxylon ammodendron forests under different coppicing pattern treatments and the uncoppiced treatment at a coppicing intensity of 16% was compared (Table 9).

[0142] Table 9. Reduction of Decline Index of Haloxylon ammodendron forests under different coppicing patterns at 16% coppicing intensity.

[0143]

[0144] In Table 9, the lowercase letter 'a' indicates that the difference in the reduction of the Haloxylon ammodendron decline index among different coppicing patterns at a coppicing intensity of 16% at the P < 0.05 level is not significant; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0145] As can be seen from Table 9, the reduction in the decline index of Haloxylon ammodendron forest under the coppicing pattern C treatment was greater than that under the coppicing patterns A and B.

[0146] In summary, under a 16% coppicing intensity in mildly degraded Haloxylon ammodendron windbreak and sand-fixing forests, the increase in new shoot growth and crown growth of coppiced Haloxylon ammodendron individuals and forests, as well as the decrease in the forest degradation index, were all higher under coppicing mode C than under coppicing mode A and coppicing mode B. Therefore, the most suitable coppicing mode at a 16% coppicing intensity should be coppicing mode C, which is the first coppicing mode in the embodiments of this application.

[0147] Example 4

[0148] For moderately declining Haloxylon ammodendron windbreak and sand-fixing forests, rejuvenation was achieved by coppicing at an intensity of 25% from November of the current year to March of the following year using coppicing patterns D, E, and F (simulating only the first year) to obtain the optimal coppicing pattern. Figure 6 As shown.

[0149] Coppicing Pattern D: Each planting zone contains two planting rows. The second planting zone in every two consecutive planting zones is designated as the coppicing zone. The odd-numbered rows of Haloxylon ammodendron in the coppicing zone are coppiced according to a predetermined stubble height. That is, every two planting rows are coppiced, forming a coppicing zone, and the coppicing is done every other row.

[0150] Coppicing Pattern E: Each planting zone contains two planting rows. The second planting zone out of every two consecutive planting zones is designated as the coppicing zone. The entire row of Haloxylon ammodendron on the right side of the coppicing zone is coppiced according to the predetermined stubble height. That is, every three planting rows are coppiced, and one planting row is coppiced.

[0151] Coppicing Pattern F: Each planting zone consists of two planting rows. The second planting zone in every two consecutive planting zones is designated as the coppicing zone. The *Haloxylon ammodendron* plants on the left side of the odd-numbered rows and the *Haloxylon ammodendron* plants on the right side of the even-numbered rows in the coppicing zone are coppiced at a predetermined stubble height. That is, every two planting rows are coppiced, forming two coppiced rows (the coppicing zone). Within the coppicing zone, the coppicing is done in a staggered "Z" shape, alternating between every other row and every other plant.

[0152] Each treatment pattern consisted of three experimental plots, with two replicates and one control group. Each treatment area was 20m × 15m, i.e., four rows and four columns of *Haloxylon ammodendron*, with each control group spaced approximately 5m apart. Both uncut and coppiced *Haloxylon ammodendron* were selected as the subjects of measurement. All were managed under the same care measures. The shoot growth and crown growth of both coppiced and retained *Haloxylon ammodendron* trees were measured three months after coppicing. Based on the coppicing intensity, the shoot growth and crown growth of individual coppiced *Haloxylon ammodendron* trees and the *Haloxylon ammodendron* forest (coppiced trees + retained trees) at each coppicing intensity were calculated. The results were analyzed and processed as follows. Figures 20-21 As shown.

[0153] Figure 20 This is a comparison chart of the new shoot growth and crown growth of individual Haloxylon ammodendron plants under various coppicing patterns and uncoppiced Haloxylon ammodendron plants in a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest provided in Example 4 of this application. Figure 20 The left figure shows the new shoot growth of individual Haloxylon ammodendron plants with 25% coppicing intensity and those without coppicing in a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest. Figure 20 The right-middle figure shows the crown growth of individual Haloxylon ammodendron individuals with 25% coppicing intensity and those without coppicing in a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest.

[0154] Figure 20 In the text, different lowercase letters a, b, c, and ab indicate that at the P < 0.05 level, under 25% coppicing intensity, the differences in new shoot growth and crown growth of coppiced Haloxylon ammodendron individuals under different coppicing patterns are significant.

[0155] From the above Figure 20 It can be seen that in the moderately declining Haloxylon ammodendron windbreak and sand-fixing forest, the new shoot growth of Haloxylon ammodendron individuals treated with coppicing mode F at 25% coppicing intensity was higher than that of coppicing mode D, and significantly higher than that of uncoppiced treatment (CK) and coppicing mode E. The crown growth of Haloxylon ammodendron individuals treated with coppicing mode F at 25% coppicing intensity was higher than that of coppicing mode D and coppicing mode E, and significantly higher than that of uncoppiced treatment (CK).

[0156] Figure 21 This is a comparison chart of new shoot growth and crown growth in moderately degraded Haloxylon ammodendron windbreak and sand-fixing forests under 25% coppicing intensity, as provided in Example 4 of this application, between various coppicing patterns and uncoppiced Haloxylon ammodendron forests. Figure 21 The left figure shows the new shoot growth of a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest with 25% coppicing intensity and without coppicing treatment. Figure 21 The right-middle figure shows the crown growth of a moderately declining Haloxylon ammodendron windbreak and sand-fixing forest with 25% coppicing intensity and an uncoppiced Haloxylon ammodendron forest. Figure 21 In the figure, different lowercase letters a and b indicate that the differences in shoot growth and crown growth of Haloxylon ammodendron forests under different coppicing patterns at 25% coppicing intensity at the P<0.05 level are significant.

[0157] From the above Figure 21 It can be seen that in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests, the new shoot growth of Haloxylon ammodendron forests under the coppicing mode F treatment with 25% coppicing intensity is higher than that of coppicing mode D and coppicing mode E, and is significantly higher than that of the uncoppiced treatment (CK). The crown growth of Haloxylon ammodendron forests under the coppicing mode F treatment with 25% coppicing intensity is higher than that of coppicing mode D and coppicing mode E, and is significantly higher than that of the uncoppiced treatment (CK).

[0158] To determine the optimal coppicing pattern under 25% coppicing intensity, the increases in the growth of individual Haloxylon ammodendron individuals and the growth of new shoots and crown width of Haloxylon ammodendron forests under different coppicing pattern treatments and no coppicing treatments were compared (Tables 10-11).

[0159] Table 10. Increase in new shoot and crown growth of *Haloxylon ammodendron* individuals under different coppicing patterns at 25% coppicing intensity.

[0160]

[0161] In Table 10, different lowercase letters a and b indicate that the differences in the changes in the amount of new shoot growth and crown growth of individual Haloxylon ammodendron under different coppicing patterns at 25% coppicing intensity at the P<0.05 level are significant; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0162] As can be seen from Table 10, under a coppicing intensity of 25%, the increase in new shoot growth of coppiced Haloxylon ammodendron individuals treated with coppicing mode F was higher than that of coppicing mode D, and significantly higher than that of coppicing mode E; the increase in crown growth of coppiced Haloxylon ammodendron individuals treated with coppicing mode F was higher than that of coppicing mode D and coppicing mode E.

[0163] Table 11. Increase in new shoot and crown growth of Haloxylon ammodendron forests under different coppicing patterns at 25% coppicing intensity.

[0164]

[0165] In Table 11, different lowercase letters a and b indicate that the differences in the increment of new shoot growth and crown growth of Haloxylon ammodendron forest under different coppicing patterns at 25% coppicing intensity at the P<0.05 level are significant; the values ​​are expressed as mean ± standard error (Mean±SE).

[0166] As can be seen from Table 11, under the coppicing intensity of 25%, the increase in new shoot growth of Haloxylon ammodendron forest under coppicing mode F treatment was higher than that under coppicing mode D, and significantly higher than that under coppicing mode E; the increase in canopy growth of Haloxylon ammodendron forest under coppicing mode F treatment was higher than that under coppicing mode D and coppicing mode E.

[0167] To further clarify the optimal coppicing pattern under 25% coppicing intensity, the reduction in the decline index of Haloxylon ammodendron forests under different coppicing pattern treatments and the uncoppiced treatment under 25% coppicing intensity was compared (Table 12).

[0168] Table 12. Reduction in the decline index of Haloxylon ammodendron forests under different coppicing patterns at a 25% coppicing intensity.

[0169]

[0170] In Table 12, the lowercase letter 'a' indicates that the difference in the reduction of the decline index of Haloxylon ammodendron forest under different coppicing intensities at a P < 0.05 level is not significant; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0171] As can be seen from Table 12, the reduction in the decline index of Haloxylon ammodendron forest under the coppicing pattern F treatment was greater than that under the coppicing patterns D and E.

[0172] In summary, under a 25% coppicing intensity in moderately declining Haloxylon ammodendron windbreak and sand-fixing forests, the increase in new shoot growth, crown growth, and reduction in the decline index of coppiced Haloxylon ammodendron individuals and forests under coppicing mode F treatment were all higher than those under coppicing modes D and E. Therefore, the optimal coppicing mode under a 25% coppicing intensity should be coppicing mode F, which is the second coppicing mode in the embodiments of this application.

[0173] For Examples 3 and 4, coppicing patterns C and F were the optimal coppicing patterns under the two coppicing intensities because the stand structure configuration under coppicing patterns C and F is closer to a "triangular" configuration. The "triangular" configuration helps form complex airflow channels, increases airflow energy consumption, and makes the airflow distribution in the Haloxylon ammodendron windbreak and sand-fixing forest more uniform. This configuration can reduce wind speed and wind damage, providing a more stable environment for Haloxylon ammodendron growth. Furthermore, the "triangular" configuration of the Haloxylon ammodendron windbreak and sand-fixing forest can provide some shade, reducing the area of ​​direct sunlight on the ground, thereby lowering surface temperature and reducing soil moisture evaporation. Simultaneously, the more uniform airflow distribution in the Haloxylon ammodendron forest helps form weak updrafts, increasing soil moisture and providing more favorable water conditions for Haloxylon ammodendron growth. The "triangular" configuration can also improve the soil environment of the Haloxylon ammodendron windbreak and sand-fixing forest, improving soil fertility and aeration, which helps the Haloxylon ammodendron roots better absorb nutrients and water from the soil, thereby promoting the growth and development of Haloxylon ammodendron. Therefore, under different coppicing intensities, coppicing patterns C and F, which are close to the "triangular configuration", are the optimal coppicing patterns for Haloxylon ammodendron windbreak and sand-fixing forests.

[0174] Example 5

[0175] An experiment was conducted in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests to determine the optimal planting ratio of Haloxylon ammodendron and Nitraria tangutorum. Based on the forest soil moisture carrying capacity and stand species composition, three planting patterns (A, B, and C) for mixed Haloxylon ammodendron and Nitraria tangutorum were designed. Figure 7 As shown.

[0176] Replanting Mode A:

[0177] Haloxylon ammodendron:Nelumbo nucifera = 1:1

[0178] The first tree in the first row of every three existing rows of Haloxylon ammodendron is the target tree. The A-cycle replanting process is carried out based on the target tree. The A-cycle replanting process is to replant one Haloxylon ammodendron every two holes in the longitudinal direction until two Haloxylon ammodendron holes are replanted. Then, one Nitraria tangutorum is replanted every two holes until two Nitraria tangutorum holes are replanted.

[0179] Replanting Mode B:

[0180] Haloxylon ammodendron:Nelumbo nucifera = 2:1

[0181] The first tree in the first row of every three existing Haloxylon ammodendrons is the target tree. A B-cycle replanting process is carried out based on the target tree. The B-cycle replanting process is to replant one Haloxylon ammodendron every two holes in the longitudinal direction until four holes are replanted. Then, one Nitraria tangutorum is replanted every two holes until two Nitraria tangutorum are replanted.

[0182] Replanting Mode C:

[0183] Haloxylon ammodendron:Nelumbo nucifera = 3:1

[0184] The first tree in the first row of every three existing rows of Haloxylon ammodendron is the target tree. A C-cycle replanting process is then implemented based on the target tree. The C-cycle replanting process involves planting one Haloxylon ammodendron every two holes longitudinally until six holes are planted. Then, one Nitraria tangutorum is planted every two holes until two Nitraria tangutorum holes are planted. (That is, the replanting pattern of the method in the embodiments of this application).

[0185] Each treatment area was 18m × 72m, with 8 plants planted in each hole, arranged in two rows. Two replicates and one control group were set up for each treatment. Both unreplanted and replanted Haloxylon ammodendron were selected as the measurement subjects. The same management measures were applied to both. Stand vegetation cover and stand density were measured 3 months after replanting. The results were analyzed as follows. Figure 22 As shown:

[0186] Figure 22 This is a comparison diagram of vegetation cover and density between different replanting patterns and unreplanted Haloxylon ammodendron forests in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests provided in Embodiment 5 of this application. Figure 22 The left figure shows the vegetation cover under different replanting patterns in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests. Figure 22 The right figure shows the density under different replanting patterns in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests.

[0187] Figure 22 In the figure, different lowercase letters a and b indicate that the vegetation coverage and density of Haloxylon ammodendron forest under different replanting patterns are significantly different at the P < 0.05 level.

[0188] Depend on Figure 22 It can be seen that in the severely degraded Haloxylon ammodendron windbreak and sand-fixing forest, the vegetation coverage of Haloxylon ammodendron forest under the replanting mode C treatment is higher than that under the replanting mode B treatment, and is significantly higher than that under the replanting mode A treatment and the no-replanting treatment (CK); the density of Haloxylon ammodendron forest under the replanting mode C treatment is higher than that under the replanting mode A treatment and the replanting mode B treatment, and is significantly higher than that under the no-replanting treatment.

[0189] To determine the optimal replanting pattern for severely degraded Haloxylon ammodendron windbreak and sand-fixing forests, the increase in vegetation cover and density of Haloxylon ammodendron forests with different replanting patterns and no replanting was compared (Table 13).

[0190] Table 13. Increase in vegetation cover and density of severely degraded Haloxylon ammodendron windbreak and sand-fixing forests under different replanting patterns.

[0191]

[0192] In Table 13, different lowercase letters a, b, and c indicate that the difference in the increase of vegetation cover and density of Haloxylon ammodendron forest under different replanting patterns in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests is significant at the P < 0.05 level; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0193] As can be seen from Table 13, the increase in vegetation coverage and density of Haloxylon ammodendron forest under replanting mode C in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests was significantly higher than that under replanting mode A and replanting mode B.

[0194] From the perspective of the increase in vegetation cover and density of Haloxylon ammodendron forests under different replanting treatments and without replanting, replanting mode C is the optimal replanting mode for severely degraded Haloxylon ammodendron windbreak and sand-fixing forests. The reduction in the Haloxylon ammodendron forest decline index between different replanting treatments and without replanting in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests will be compared (Table 14) to enhance the accuracy of the existing results.

[0195] Table 14. Reduction in Decline Index of Severely Degraded Haloxylon ammodendron Windbreak and Sand-Fixing Forests under Different Replanting Patterns

[0196]

[0197] In Table 14, the lowercase letter 'a' indicates that the difference in the reduction of the decline index of Haloxylon ammodendron forest under different replanting patterns in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests is not significant at the P < 0.05 level; the values ​​are expressed as mean ± standard error (Mean ± SE).

[0198] As can be seen from Table 14, the reduction in the decline index of Haloxylon ammodendron forest under replanting mode C was higher than that under replanting modes A and B.

[0199] In summary, under replanting pattern C in severely degraded Haloxylon ammodendron windbreak and sand-fixing forests, the increase in vegetation cover and density, as well as the decrease in the decline index, were all higher than those under replanting patterns A and B. Therefore, the most suitable replanting pattern for severely degraded Haloxylon ammodendron windbreak and sand-fixing forests is replanting pattern C, i.e., Haloxylon ammodendron number: Nitraria tangutorum number = 3:1.

[0200] In severely degraded Haloxylon ammodendron windbreak and sand-fixing forests, human disturbance such as grazing has led to initial planting densities exceeding the soil moisture carrying capacity of the forest vegetation, resulting in large-scale plant death, sparse existing Haloxylon ammodendrons, and disrupted stand structure. Consequently, the windbreak and sand-fixing ecological function of these forests has significantly declined. Therefore, this application's embodiment selects Nitraria tangutorum, a dominant associated species in natural Haloxylon ammodendron forests, for mixed planting and replanting.

[0201] In the replanting experiment of severely degraded Haloxylon ammodendron windbreak and sand-fixing forests, the replanting effect of replanting mode C was better than other modes because: First, the replanting ratio of replanting mode C is closer to the ratio of Haloxylon ammodendron and Nitraria tangutorum in natural Haloxylon ammodendron forests. The spatial distribution of Haloxylon ammodendron and Nitraria tangutorum populations generally shows obvious mosaicism, and the optimal distribution ratio of Haloxylon ammodendron and Nitraria tangutorum is 3:1.

[0202] Secondly, for severely degraded Haloxylon ammodendron windbreak and sand-fixing forests, water balance can be achieved when the Haloxylon ammodendron density is 125 trees / ha and the rainfall is greater than 140 mm. Under all three replanting models, the plant density in the forest land was 123 trees / ha, and the average annual rainfall in the experimental area was 212.3 mm. Therefore, the plant density under all three replanting models was within the soil moisture carrying capacity of the forest land. However, under the mixed planting ratio of replanting model C, the spatial distribution of Haloxylon ammodendron and Nitraria tangutorum was closer to the spatial distribution of Haloxylon ammodendron and Nitraria tangutorum in natural Haloxylon ammodendron forests. The spatial distribution of Nitraria tangutorum populations is mainly centered on the mother plant. In mixed Haloxylon ammodendron and Nitraria tangutorum forests, Nitraria tangutorum forms relatively independent communities or patches, interspersed and mosaicked with Haloxylon ammodendron communities.

[0203] Therefore, under the mixed planting ratio of replanting pattern C, the spatial distribution of the forest stand formed after the mixed planting of Haloxylon ammodendron and Nitraria tangutorum is closer to the spatial distribution characteristics of the two species in natural mixed Haloxylon ammodendron and Nitraria tangutorum forests. This reduces the interspecific competition between Haloxylon ammodendron and Nitraria tangutorum on a small scale, which is conducive to the growth and development of the replanted seedlings. Therefore, with the same management measures, the plant growth in mixed planting pattern C will be better than that in replanting patterns A and B.

[0204] Based on the soil moisture carrying capacity of Haloxylon ammodendron windbreak and sand-fixing forests, and referring to the stand spatial structure and species composition of natural Haloxylon ammodendron forests, this application has developed new methods for coppicing rejuvenation and mixed planting of Nitraria tangutorum. The research focuses on aspects such as the selection of coppicing intensity, coppicing pattern, coppicing time, stubble height, the ratio of Haloxylon ammodendron and Nitraria tangutorum mixed planting in Haloxylon ammodendron windbreak and sand-fixing forests, and pest and disease control. This aims to achieve precise restoration, enhance the ecological benefits of Haloxylon ammodendron windbreak and sand-fixing forests, improve water deficit in Haloxylon ammodendron windbreak and sand-fixing forest land, promote the sustainable development of Haloxylon ammodendron windbreak and sand-fixing forests, and thus enhance their windbreak and sand-fixing ecological functions.

[0205] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0206] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A method for near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests, characterized in that, include: The row-and-strip planting pattern of Haloxylon ammodendron windbreak and sand-fixing forests is divided into mildly declining, moderately declining, and severely declining Haloxylon ammodendron windbreak and sand-fixing forests according to different stand structures. This includes: Haloxylon ammodendron windbreak and sand-fixing forests of the same age planted in row-and-strip patterns, with stand densities of 280-400 trees / hectare, mortality rates of 48%-68%, and tree heights of 130-160 cm. The term "mildly declining Haloxylon ammodendron windbreak and sand-fixing forest" refers to the following: Haloxylon ammodendron windbreak and sand-fixing forests with a stand density of 220-280 trees / hectare, a mortality rate of 68%-72%, and a tree height of 110-130cm are classified as "moderately declining Haloxylon ammodendron windbreak and sand-fixing forests"; Haloxylon ammodendron windbreak and sand-fixing forests with a stand density below 220 trees / hectare, a mortality rate above 72%, and a tree height below 110cm are classified as "severely declining Haloxylon ammodendron windbreak and sand-fixing forests". When the Haloxylon ammodendron windbreak and sand-fixing forest is a slightly degraded Haloxylon ammodendron windbreak and sand-fixing forest, the first coppicing pattern is cyclically repeated in the first period to rejuvenate it with a coppicing intensity of 16%; when the Haloxylon ammodendron windbreak and sand-fixing forest is a moderately degraded Haloxylon ammodendron windbreak and sand-fixing forest, the second coppicing pattern is cyclically repeated in the first period to rejuvenate it with a coppicing intensity of 25%; when the Haloxylon ammodendron windbreak and sand-fixing forest is a severely degraded Haloxylon ammodendron windbreak and sand-fixing forest, it is replanted in the second period by intercropping Haloxylon ammodendron and Nitraria tangutorum, with the intercropping ratio of Haloxylon ammodendron number: Nitraria tangutorum number = 3:1; The first coppicing pattern is as follows: each planting strip contains two rows of planting, and every three consecutive planting strips form a group; in the first year, a planting strip is randomly selected from each group as the first coppicing strip, and the odd-numbered rows on the first side and the even-numbered rows on the second side of the first coppicing strip are coppiced at a predetermined stubble height, with the uncoppiced Haloxylon ammodendron being the first retained trees; in the fourth year, any one of the remaining two planting strips in each group is selected as the second coppicing strip, and the odd-numbered rows on the first side and the even-numbered rows on the second coppicing strip are coppiced at the predetermined stubble height, with the uncoppiced Haloxylon ammodendron being the second retained trees; In the seventh year, the remaining planting strip in each group is designated as the third coppicing strip. The odd-numbered rows on the first side and the even-numbered rows on the second side of the third coppicing strip are coppiced at a predetermined stubble height. The remaining coppiced trees at the predetermined stubble height are designated as the third retained trees. In the tenth year, the first retained trees in the first coppicing strip are coppiced at the predetermined stubble height. In the thirteenth year, the second retained trees in the second coppicing strip are coppiced at the predetermined stubble height. In the sixteenth year, the third retained trees in the third coppicing strip are coppiced at the predetermined stubble height. An eighteen-year coppicing cycle is observed. And / or, the second coppicing pattern is as follows: each planting strip contains two rows of planting, and every two consecutive planting strips are grouped together; in the first year, a planting strip is randomly selected from each group as coppicing strip I, and the Haloxylon ammodendron on the odd-numbered first side and the even-numbered second side of the row of planting strip I are coppiced at a predetermined stubble height, and the uncoppiced Haloxylon ammodendron is retained as tree I; in the fourth year, the remaining planting strip in each group is coppicing strip II, and the Haloxylon ammodendron on the odd-numbered first side and the even-numbered second side of the row of planting strip II are coppiced at a predetermined stubble height, and the uncoppiced Haloxylon ammodendron is retained as tree II; in the seventh year, the retained trees I in coppicing strip I are coppiced at a predetermined stubble height; in the tenth year, the retained trees II in coppicing strip II are coppiced at a predetermined stubble height; a coppicing cycle is twelve years.

2. The method for near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests according to claim 1, characterized in that, The first period is from November of the current year to March of the following year.

3. The method for near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests according to claim 1, characterized in that, The predetermined stubble height is 50cm~60cm.

4. The method for near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests according to claim 1, characterized in that, The second period is late April each year.

5. The method for near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests according to claim 1, characterized in that, The replanting pattern for mixed planting of Haloxylon ammodendron and Nitraria tangutorum is as follows: the first Haloxylon ammodendron in the first row of every three existing rows is the target tree, and a cyclic replanting process is carried out based on the target tree; the cyclic replanting process is to replant 1 Haloxylon ammodendron every 2 holes in the longitudinal direction until 6 holes of Haloxylon ammodendron are replanted, and then replant 1 Nitraria tangutorum every 2 holes until 2 holes of Nitraria tangutorum are replanted.

6. The method for near-natural restoration and reconstruction of declining Haloxylon ammodendron windbreak and sand-fixing forests according to claim 1, characterized in that, Spraying Haloxylon ammodendron with pesticides that suppress the psyllid; and / or using yellow sticky traps or fluorescent lamps to kill adult psyllids; and / or spraying Haloxylon ammodendron branches and leaves with bromocyanamide suspension, cyromazine, and imidacloprid aqueous solution; and / or protecting natural enemies of the greater gerbil and their habitats.

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