A method for determining bamboo cultivation target by using canopy density of upper layer arbor vegetation type

Abstract

The embodiment of the present application provides a method for determining bamboo cultivation target by using the canopy density of upper arbor vegetation type, relates to the technical field of forestry, and evaluates the relevant indexes of the growth of square bamboo planted under different vegetation types in different site conditions, determines the square bamboo cultivation target under the corresponding forest category, forest type and origin of forest in different site conditions according to the evaluation result and the range of the upper arbor canopy that can be adjusted to according to the relevant felling technical regulations, and can also determine the square bamboo cultivation target according to the determined square bamboo cultivation target, and assist in screening the cultivation site by combining factors such as the forest category, forest type and origin, so as to provide a scientific basis for the development planning of bamboo industry.

Description

Technical Field

[0001] This invention relates to the field of forestry technology, and more specifically, to a method for determining bamboo forest cultivation targets using the canopy closure of upper-story tree vegetation types. Background Technology

[0002] The cultivation objectives of bamboo forests are diverse. Like arbor forests, bamboo forests offer ecological, economic, and environmental benefits. They can be managed as timber forests, economic forests, fuelwood forests (energy forests), as well as protective forests and special-purpose forests. The cultivation objectives of bamboo forests can be divided into three different categories: bamboo forests for shoots, bamboo forests for timber, and bamboo forests for both shoots and timber. In the current forestry development, especially against the backdrop of increasingly stringent farmland protection and vigorous promotion of understory economy to achieve high-quality forestry development, there is an urgent need to expand development space. With the development of the bamboo industry and the exploitation of understory resources, how to plan the development of the bamboo industry under the forest canopy, especially how to scientifically determine whether afforestation plots are for cultivating bamboo for shoots, timber, or dual-purpose bamboo, is of great significance for achieving scientific management and sustainable development.

[0003] Zhaotong has proposed a development goal of "two million mu" for bamboo industry, namely 1 million mu for *Phyllostachys edulis* and 1 million mu for *Phyllostachys edulis*. *Phyllostachys edulis* refers to all bamboo species in the *Phyllostachys edulis* group. The growth of both *Phyllostachys edulis* and *Phyllostachys edulis* requires the protection of upper-story trees, but neither the higher nor lower the canopy closure of these trees is always better; it is closely related to the cultivation goals. Different cultivation goals place different requirements on the canopy closure of the upper-story trees. Under basically the same site conditions, the canopy closure of the upper-story trees becomes the main factor affecting the economic goals of *Phyllostachys edulis* under the forest canopy. However, adjustments to the canopy closure of the upper-story trees are subject to restrictions from logging policies and logging technical regulations. Therefore, it is necessary to establish an effective method to help determine the cultivation goals of *Phyllostachys edulis* under the corresponding forest category, forest type, and origin under various site conditions; or to assist in the selection of cultivation sites based on the determined cultivation goals of *Phyllostachys edulis*, thereby providing a scientific basis for bamboo industry development planning. Summary of the Invention

[0004] The purpose of this invention is to provide a method for determining bamboo forest cultivation targets using the canopy closure of the upper tree vegetation type. This method is scientific, reasonable, and effective, and can provide reasonable bamboo forest cultivation target suggestions based on the canopy closure of the upper tree vegetation type, thus providing a scientific basis for bamboo industry development planning.

[0005] The embodiments of the present invention are implemented as follows:

[0006] A method for determining bamboo forest cultivation targets using the canopy closure of upper tree vegetation types, comprising:

[0007] Select plots of land with bamboo forests planted under the trees, divide the plots into several canopy closure levels according to the canopy closure of the upper trees, and randomly select multiple samples in the area corresponding to each canopy closure level.

[0008] The growth indicators of each sample were investigated, and the measurement results of the samples were analyzed by F-test and Q-test. Based on the analysis results, it was determined whether the area corresponding to each canopy closure level was suitable for bamboo forest planting.

[0009] The beneficial effects of the embodiments of the present invention are:

[0010] This invention provides a method for determining bamboo forest cultivation targets using the canopy closure of upper-story tree vegetation types. It evaluates the growth of *Phyllostachys edulis* (square bamboo) planted under different site conditions and vegetation types. Based on the evaluation results, and considering the range of upper-story tree canopy closure allowed by relevant logging technical regulations for the corresponding forest category, forest origin, and forest species, the cultivation targets for *Phyllostachys edulis* under the corresponding forest category, species, and origin are determined for each site. Furthermore, the determined cultivation targets, combined with factors such as forest category, species, and origin, can assist in the selection of cultivation sites, thereby providing a scientific basis for bamboo industry development planning. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0012] The following is a detailed description of a method for determining bamboo forest cultivation targets using the canopy closure of upper-layer tree vegetation types, according to an embodiment of the present invention.

[0013] A method for determining bamboo forest cultivation targets using the canopy closure of upper tree vegetation types, comprising:

[0014] Select plots of land with bamboo forests planted under the trees, divide the plots into several canopy closure levels according to the canopy closure of the upper trees, and randomly select multiple samples in the area corresponding to each canopy closure level.

[0015] The growth indicators of each sample were investigated, and the measurement results of the samples were analyzed by F-test and Q-test. Based on the analysis results, it was determined whether the area corresponding to each canopy closure level was suitable for bamboo forest planting.

[0016] Furthermore, we selected sites with basically the same site conditions and similar types of upper tree vegetation for analysis; the tree vegetation types included at least one of coniferous forest, evergreen broad-leaved forest, mixed coniferous and broad-leaved forest, and deciduous broad-leaved forest.

[0017] Canopy closure is an important concept in forestry and ecology. It refers to the degree to which the canopy of trees in a forest covers the ground, or the ratio of the projected area of ​​the canopy layer to the forest floor area. It is a value from 0 to 1, where 0 represents no shading and 1 represents complete shading. When classifying canopy closure levels, the range 0 to 1 can be divided into several intervals as needed. For example, when dividing into 10 canopy closure levels, each interval of 0.1 canopy closure can be considered as one level; when dividing into 5 canopy closure levels, each interval of 0.2 canopy closure can be considered as one level; alternatively, it can be divided into 3 canopy closure levels, in which case each interval of 0.3 canopy closure is considered as one level, i.e., 0~0.3, 0.3~0.6, and 0.6~0.9. When the canopy closure is greater than 0.9, it is generally unsuitable for the growth of Phyllostachys edulis and can be disregarded.

[0018] Optionally, growth indicators include the number of shoots, the diameter at which shoots emerge, the number of bamboo plants, the height of bamboo, and the diameter at which bamboo emerges. Five or more clumps or at least three quadrats are randomly selected from each canopy closure level area.

[0019] Furthermore, for each growth index measurement results, an F-test analysis is first performed. If the F-test results show no significant difference, the growth index is determined to be optimal at each canopy closure level. If the F-test results show a significant difference, a Q-test analysis is then performed. The F-test analysis can be performed using software such as Excel or SPSS 17.0. The calculated F-value is compared with the F-critical value (usually F0.05). Data with an F-critical value greater than the F-critical value show a significant difference, while data with an F-critical value less than or equal to the F-critical value do not show a significant difference.

[0020] In the Q-test analysis, each growth index was analyzed separately. Within each growth index analysis, the regions corresponding to all N canopy closure levels were ranked according to their measurement results, and the determination was made according to the following rules:

[0021] S1. If there is no significant difference in the measurement results of N regions, the growth index is determined to be optimal under all canopy closure levels; if there is a significant difference in the measurement results of one of the regions, proceed to step S2 for determination.

[0022] S2. If there is no significant difference between the lowest region of the measurement results and region A of the remaining N-1 regions, the growth index is judged as unsuitable under the canopy closure level corresponding to the lowest region and region A; the remaining N-1-A regions are judged in step S3.

[0023] S3. In the remaining N-1-A regions, if there is no significant difference between the highest region and the other B regions in the measurement results, then the growth index is determined to be most suitable under the canopy closure level corresponding to the highest region and the B regions; the remaining N-1-AB regions are determined to be suitable.

[0024] In the Q test described above, to determine whether there is a significant difference between two regions, the absolute value of the difference between the data in the two regions is compared with the Q critical value. If the absolute value of the difference is greater than the Q critical value, it indicates that there is a significant difference between the data in the two regions; otherwise, there is no significant difference.

[0025] Optionally, the analysis results of each growth index in the area corresponding to each canopy closure level are quantified and summed. The results are then determined as follows: the most suitable is scored as 1 point, suitable as 0.5 points, and unsuitable as 0 points. The summed score P is used to determine whether the canopy closure level is suitable for bamboo forest growth.

[0026] When determining whether the canopy closure level is suitable for bamboo growth using the summation score P, the calculated summation score P is compared with the theoretical maximum value P of the summation score P. max Compare. When P ≥ 0.8 * P max When the value is 0.8 * P, it is considered optimal; when the value is 0.8 * P, it is considered optimal. max >P≥0.6*P max When P < 0.6 * P, it is considered appropriate; when P < 0.6 * P max At that time, it was deemed inappropriate.

[0027] Furthermore, when the bamboo forest is used for both bamboo shoots and timber, the number of bamboo shoots, the diameter of the bamboo shoots, the number of bamboo plants, the height of the bamboo plants, and the diameter of the bamboo plants are all factors that need to be considered. Therefore, the analysis and judgment are based on the summation score P of the five growth indicators: the number of bamboo shoots, the diameter of the bamboo shoots, the number of bamboo plants, the height of the bamboo plants, and the diameter of the bamboo plants.

[0028] When the bamboo forest is used for timber, the number of bamboos, bamboo height, and bamboo diameter are the main influencing factors. In this case, the summation fraction P1 of the three growth indicators of bamboo number, bamboo height, and bamboo diameter can be used instead of P for analysis and judgment.

[0029] When the bamboo forest is used for bamboo shoots, the number of bamboo shoots and the diameter of the bamboo shoots are the main influencing factors. In this case, the sum of the two growth indicators, the number of bamboo shoots and the diameter of the bamboo shoots, P2, can be used instead of P for analysis and judgment.

[0030] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0031] Example 1

[0032] This embodiment provides a method for determining bamboo forest cultivation targets using the canopy closure of the upper tree vegetation type. The method was developed in 2024 at the Erxi Shuifu Tongluoba Bamboo Industry Professional Cooperative in Taiping Town, Shuifu City, Zhaotong City, to evaluate the growth of Phyllostachys edulis under the upper tree forest. This evaluation provides a basis for determining cultivation targets for planting Phyllostachys edulis in the Shuifu area under the same site conditions. The upper tree vegetation type is a natural evergreen and deciduous mixed coniferous and broad-leaved forest. The specific steps include:

[0033] 1) The upper canopy trees were divided into five canopy closure levels (0~0.2, 0.2~0.4, 0.4~0.6, 0.6~0.8, and 0.8~1, respectively). Ten clumps of Phyllostachys edulis were randomly selected from each canopy closure level. The number of shoots, the diameter at ground level of the shoots, the number of bamboo stalks, their height, and their diameter at ground level were investigated for each sample. The samples within the five canopy closure levels were respectively classified into five sample groups: A, B, C, D, and E. The measured canopy closures of each group were as follows: A = 0.13; B = 0.26; C = 0.42; D = 0.7; and E = 0.92.

[0034] 2) Data on bamboo shoot diameter, bamboo diameter, number of shoots, number of bamboo plants, and bamboo height were collected for all samples. SPSS 17.0 software was used to process the data. For the 5 sample groups, totaling 50 samples, the corresponding critical F-value was F0.05(4,45) = 2.575. Calculations showed that the F-values ​​for bamboo shoot diameter, bamboo diameter, number of shoots, number of bamboo plants, and bamboo height were all greater than 2.575, indicating that canopy closure significantly affects these parameters.

[0035] 3) The data were further subjected to a Q-test, and the results are shown in Tables 1-5. In the tables, The average value of data from a certain location. ~ The values ​​are the average values ​​of the data from plots A to E, respectively. "*" indicates that the data has significant differences.

[0036] Table 1. Results of the Q test for bamboo shoot diameter.

[0037]

[0038] Table 2. Results of Q-test on the number of bamboo shoots sprouted

[0039]

[0040] Table 3. Results of the Q test for bamboo diameter at ground level

[0041]

[0042] Table 4. Results of the Q test for bamboo height

[0043]

[0044] Table 5. Results of Q-test on the number of bamboo plants

[0045]

[0046] Based on the data in Tables 1-5, determine the suitability of each growth indicator in this region. Taking Table 1 as an example, the determination is made according to the following rules:

[0047] S1. Significant differences were found among the measurement results of the five regions, so step S2 was performed to determine the outcome.

[0048] S2. The lowest region (region E) of the measurement results showed no significant difference from any of the other four regions (0 regions). - As can be seen from the data, the growth index of bamboo shoot diameter is determined to be unsuitable in the lowest region (E region); the remaining 4 regions are judged by step S3.

[0049] S3. In the remaining 4 regions, the region with the highest measurement results (region B) does not show a significant difference from the other 3 regions (as can be seen from the data in row B). Therefore, the growth index is determined to be most suitable in the region with the highest measurement results (region B) and the corresponding canopy closure level of the other 3 regions; no region is determined to be suitable.

[0050] The data processing for Tables 2 through 5 follows the same principle.

[0051] 4) The analysis results of each growth index in the area corresponding to each canopy closure level were quantified. The results were determined as follows: the most suitable was scored as 1 point, the suitable as 0.5 points, and the unsuitable as 0 points. The sum of the scores P, P1, and P2 was used to determine whether the canopy closure level was suitable for bamboo forest growth. The results are shown in Table 6.

[0052] Table 6. Bamboo Growth Factors and Cultivation Target Type Scoring Table

[0053]

[0054] 5) Compare the calculated summation fraction P with the theoretical maximum value P of the summation fraction P. max Compare. When P ≥ 0.8 * P max When the value is 0.8 * P, it is considered optimal; when the value is 0.8 * P, it is considered optimal. max >P≥0.6*P max When P < 0.6 * P, it is considered appropriate; when P < 0.6 * P max If the condition is not met, it is deemed inappropriate. The results are shown in Table 7.

[0055] Table 7. Evaluation Results of Bamboo Growth Factors and Cultivation Target Types

[0056]

[0057] Table 7 shows that the suitable canopy closure range for planting under *Phyllostachys pubescens* forests is 0.1–0.8, the optimal canopy closure range for cultivating bamboo for shoots is 0.1–0.4, and the optimal canopy closure range for cultivating bamboo for both timber and shoots is 0.2–0.8. The evaluation results of this case are only applicable to the same site type and vegetation type. Under this premise, *Phyllostachys pubescens* can be planned for planting within a canopy closure range of 0.1–0.8. If the planned plot (compartment) is an artificial commercial forest, it can be planned for cultivating bamboo for shoots; if the planned plot (compartment) is a natural commercial forest, it can be planned for cultivating bamboo for both timber and shoots; if the planned plot (compartment) is a public welfare forest (protective forest within a public welfare forest), it can be planned for cultivating bamboo for shoots. Developing the bamboo industry in special-purpose forests is not recommended.

[0058] Example 2

[0059] This embodiment provides a method for determining bamboo forest cultivation targets using the canopy closure of upper-story tree vegetation types. The research site is located in Village Group 19, Erxi Village, Taiping Town, Shuifu City. Erxi Village is situated in the southwest of Shuifu City, bordering Yanjing Village to the east, Fuxing Village to the south, Banli Township of Suijiang County to the west, and Yanjin County to the north. It stretches 10.3 km north-south and 6.8 km east-west, with a total land area of ​​65.5 km². 2 The area has a subtropical climate with an average annual rainfall of over 1200 mm, limited sunshine, and predominantly purple soil with some yellow soil. The upper canopy consists of wild hickory and birch. The experimental site is at an altitude of 1375–1385 m. The *Phyllostachys edulis* var. *jinfoshanensis* was planted in the winter of 2018, and the survey was conducted in March 2021. The specific steps include:

[0060] 1) Select Phyllostachys japonica with canopy closure of 0.3, 0.6 and 0.9 in the upper tree layer within the afforestation plot, set up a 30×30m plot, and randomly select 5 clumps of Phyllostachys japonica in the plot.

[0061] 2) Data on bamboo shoot diameter, bamboo diameter, number of shoots, number of bamboo plants, and bamboo height were collected for all samples. SPSS 17.0 software was used to perform F-test analysis on the data. For the three sample groups, totaling 15 samples, the corresponding critical F-value was F0.05(2, 12) = 3.89. The calculated F-values ​​for bamboo shoot diameter, bamboo diameter, number of shoots, number of bamboo plants, and bamboo height were all less than 2.575, indicating that canopy closure had no significant effect on these parameters, and a Q-test was not performed.

[0062] The evaluation results of this embodiment are only applicable to the same site type and vegetation type as in this case. Under this premise, since canopy closure has no significant impact on bamboo shoot diameter, bamboo diameter, number of shoots, number of bamboo plants, and bamboo height, "square bamboo" can be planned for planting when the canopy closure is between 0.1 and 0.9. Whether it is a commercial forest or a protective forest in a public welfare forest, bamboo forests for shoots, bamboo forests for both shoots and timber, or bamboo forests for timber can be planned for cultivation. However, although the impact on bamboo forest growth is not significant when the canopy closure is 0.9, due to logging restrictions, bamboo forests are generally not allowed to be planned for development in special purpose forests without approval.

[0063] Example 3

[0064] This embodiment provides a method for determining bamboo forest cultivation targets using the canopy closure of upper-story tree vegetation. The survey site for this method is located in Wugu Village, Weixin County, with a forest area of ​​2,580.56 hm². 2 Of which, the area of ​​arbor forest is 1445.78 hm². 2 Forest land accounts for 56.02% of the total forest area; shrubland accounts for 847.12 hm². 2 This accounts for 32.83%. The average altitude of the area is 1,420m, and it has a subtropical monsoon climate with four distinct seasons. The entire village has 605 hectares of Phyllostachys edulis planted under the forest canopy. 2 The survey plots were Chinese fir forests with varying canopy closures, all with a soil layer thickness of 30–40 cm, yellow soil, northwest-facing slopes, and elevations ranging from 1427 to 1516 m. The specific steps included:

[0065] 1) Select five different canopy closures of Chinese fir forests: 0.5, 0.6, 0.7, 0.8, and 0.9, labeled A, B, C, D, and E respectively. Set up sample plots under each type of canopy closure. In each sample plot, randomly sample five clumps of Phyllostachys edulis. Measure the diameter at ground and height of each Phyllostachys edulis clump according to age. For newly sprouted bamboo shoots, only investigate the number of shoots and measure the diameter at ground of each shoot.

[0066] 2) Data on bamboo shoot diameter, bamboo diameter, number of shoots, number of bamboo plants, and bamboo height were collected for all samples. SPSS 17.0 software was used to process the data. For the 5 sample groups, totaling 50 samples, the corresponding critical F-value was F0.05(4,45) = 2.575. Calculations showed that the F-values ​​for bamboo shoot diameter, bamboo diameter, number of shoots, number of bamboo plants, and bamboo height were all greater than 2.575, indicating that canopy closure significantly affects these parameters.

[0067] 3) The data were further subjected to a Q-test, and the results are shown in Tables 8-12. In the tables, The average value of data from a certain location. ~ The average values ​​of the data from plots A to E are given. "*" indicates that the data has significant differences.

[0068] Table 8. Results of the Q test for bamboo shoot diameter.

[0069]

[0070] Table 9. Results of Q-test on the number of bamboo shoots sprouted

[0071]

[0072] Table 10. Results of the Q test for bamboo diameter at ground level

[0073]

[0074] Table 11. Results of the Q test for bamboo height

[0075]

[0076] Table 12. Results of Q-test on the number of bamboo plants

[0077]

[0078] Based on the data in Tables 8-12, determine the suitability of each growth indicator in this region. Taking Table 8 as an example, the determination is made according to the following rules:

[0079] S1. Significant differences exist among the measurement results of the 5 regions; proceed to step S2 for determination.

[0080] S2. The lowest region (region E) of the measurement results showed no significant difference from any of the other four regions (0 regions). - As can be seen from the data, the growth index of bamboo shoot diameter is determined to be unsuitable in the lowest region (E region); the remaining 4 regions are judged by step S3.

[0081] S3. In the remaining 4 regions, there is no significant difference between the region with the highest measurement results (region A) and the other 2 regions (regions B and C) (as can be seen from the data in row A). Therefore, the growth index is determined to be most suitable under the canopy closure level corresponding to the highest region (region A) and the 2 regions (regions B and C); the remaining 1 region (region D) is determined to be suitable.

[0082] The data processing for Tables 9 to 12 follows the same principle.

[0083] 4) The analysis results of each growth index in the area corresponding to each canopy closure level were quantified. The results were determined as follows: the most suitable was scored as 1 point, the suitable as 0.5 points, and the unsuitable as 0 points. The sum of the scores P, P1, and P2 was used to determine whether the canopy closure level was suitable for bamboo forest growth. The results are shown in Table 13.

[0084] Table 13. Bamboo Growth Factors and Cultivation Target Type Scoring Table

[0085]

[0086] 5) Compare the calculated summation fraction P with the theoretical maximum value P of the summation fraction P. max Compare. When P ≥ 0.8 * P max When the value is 0.8 * P, it is considered optimal; when the value is 0.8 * P, it is considered optimal. max >P≥0.6*P max When P < 0.6 * P, it is considered appropriate; when P < 0.6 * P max If the condition is not met, it is deemed inappropriate. The results are shown in Table 14.

[0087] Table 14. Evaluation Results of Bamboo Growth Factors and Cultivation Target Types

[0088]

[0089] As shown in Table 7, planting *Phyllostachys jinfoshanensis* under *Cunninghamia lanceolata* forests with an upper canopy closure of 0.5-0.6 is suitable for managing *Phyllostachys lanceolata* forests for shoots, timber, and dual-purpose (shoot and timber). At a canopy closure of 0.5, it is most suitable for managing bamboo forests for shoots, timber, or dual-purpose (shoot and timber). At a canopy closure of 0.6, it is most suitable for managing bamboo forests for shoots and dual-purpose (shoot and timber). Canopy closures of 0.7-0.9 are not suitable for managing bamboo forests of any purpose. *Cunninghamia lanceolata* is an evergreen species. Under suitable site conditions for planting *Phyllostachys lanceolata*, when planting under evergreen forests, the cultivation goals of *Phyllostachys lanceolata* can be planned based on the requirements of logging policies and corresponding logging technical regulations regarding forest category or species and origin, combined with the above assessment results.

[0090] In summary, this invention provides a method for determining bamboo forest cultivation targets using the canopy closure of upper-story tree vegetation types. It evaluates the growth of *Phyllostachys edulis* (square bamboo) planted under different site conditions and vegetation types. Based on the evaluation results, and considering the range of upper-story tree canopy closure allowed by relevant logging technical regulations for the corresponding forest category, forest origin, and forest species, the cultivation targets for *Phyllostachys edulis* under the corresponding forest category, species, and origin are determined for each site. Furthermore, the determined cultivation targets for *Phyllostachys edulis*, combined with factors such as forest category, species, and origin, can assist in the selection of cultivation sites, thereby providing a scientific basis for bamboo industry development planning.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining bamboo forest cultivation targets using the canopy closure of upper-story tree vegetation types, characterized in that, include: Select plots of land with bamboo forests planted under the trees, divide the plots into several canopy closure levels according to the canopy closure of the upper trees, and randomly select multiple samples in the area corresponding to each canopy closure level. The growth indicators of each sample were investigated, and the measurement results of the samples were analyzed by F-test and Q-test. Based on the analysis results, it was determined whether the area corresponding to each canopy closure level was suitable for bamboo forest planting. In the Q-test analysis, each growth index is analyzed separately; in the analysis of each growth index, all N regions corresponding to the canopy closure levels are sorted according to the measurement results, and the judgment is made according to the following rules: S1. If there is no significant difference in the measurement results of N regions, the growth index is determined to be the most suitable under all the canopy closure levels; if there is a significant difference in the measurement results of one of the regions, then proceed to step S2 for determination. S2. If there is no significant difference between the lowest region of the measurement results and A regions among the remaining N-1 regions, then the growth index is determined to be unsuitable under the canopy closure level corresponding to the lowest region and A regions; the remaining N-1-A regions are then determined in step S3. S3. In the remaining N-1-A regions, if there is no significant difference between the highest region and the other B regions in the measurement results, then the growth index is determined to be most suitable under the canopy closure level corresponding to the highest region and the B regions; the remaining N-1-AB regions are determined to be suitable. The analysis results of each growth index in the area corresponding to each canopy closure level are quantified and summed. The results are determined as follows: most suitable is scored as 1 point, suitable is scored as 0.5 points, and unsuitable is scored as 0 points. The summation score P is used to determine whether the canopy closure level is suitable for bamboo forest growth. When P ≥ 0.8 * P max When the value is 0.8 * P, it is considered optimal; when the value is 0.8 * P, it is considered optimal. max >P≥0.6*P max When P < 0.6 * P, it is considered appropriate; when P < 0.6 * P max When, it is deemed inappropriate; among them, P max To find the theoretical maximum value of the sum fraction P.

2. The method according to claim 1, characterized in that, The site was selected for analysis based on plots with basically the same site conditions and the same type of upper tree vegetation; the tree vegetation type includes at least one of coniferous forest, evergreen broad-leaved forest, mixed coniferous and broad-leaved forest and deciduous broad-leaved forest.

3. The method according to claim 1, characterized in that, The growth indicators include the number of bamboo shoots, the diameter of the bamboo shoot, the number of bamboo plants, the height of the bamboo, and the diameter of the bamboo.

4. The method according to claim 3, characterized in that, For the measurement results of each growth index, the F test is first used for analysis. If there is no significant difference in the F test results, the growth index is determined to be the most suitable at each canopy closure level. If there is a significant difference in the F test results, the Q test is then performed.

5. The method according to claim 4, characterized in that, When the bamboo forest is used for both bamboo shoots and timber, the analysis and judgment are based on the summation score P of five growth indicators: the number of bamboo shoots, the diameter of bamboo shoots, the number of bamboo plants, the height of bamboo, and the diameter of bamboo.

6. The method according to claim 5, characterized in that, When the purpose of the bamboo forest is for timber, the summation fraction P1 of the three growth indicators—bamboo quantity, bamboo height, and bamboo diameter—is used instead of P for analysis and judgment.

7. The method according to claim 6, characterized in that, When the purpose of the bamboo forest is for bamboo shoots, the sum of the two growth indicators, the number of bamboo shoots and the diameter of the bamboo shoots, is used as the basis for analysis and judgment, replacing P.

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