Expansion-controllable treatment method for oligodendrocalamus affinis

Abstract

The invention relates to the technical field of forest management, and discloses a management method capable of controlling expansion of oligodendrocalamus affinis. Comprising the following steps that S1, felling is conducted from the beginning of autumn to white dew, and nutrition supply of overground parts to bamboo rhizomes is cut off; s2, the cutting residues are subjected to strip-shaped composting, and nutrient returning is achieved; s3, carrying out hole reclamation and soil preparation from March to April in the next year, complementarily planting indigenous tree species, interplanting soybeans or peanuts in gaps, and carrying out knife smoothing in September; s4, cleaning redundant saplings and miscellaneous irrigation, and determining a target tree; s5, soil loosening, weeding and covering are conducted on the 1-5-year-old target trees, and fertilization is conducted according to needs. By means of the method, the expansion control rate of the oligostachys affinis can reach 100%, the under-forest renewal rate is increased by 20% or above, a reference method and basis are provided for effectively inhibiting disordered expansion of the oligostachys affinis, and remarkable ecological and economic benefits are achieved.

Description

Technical Field

[0001] This invention relates to the field of forest management technology, specifically to a controllable management technology for the expansion of bamboo with few spikelets and rough flowers. Background Technology

[0002] Rough-flowered bamboo with few spikelets ( Oligostachyum scabriflorum Distributed in Jiangxi, Guangdong, Hunan, and Fujian provinces, *Phyllostachys pubescens* is the most widely distributed and common species in the genus. This species has rapidly expanded due to its inherent advantages such as rapid growth, high reproductive capacity, variable phenotype, and synergistic behavior. Through competitive mechanisms including shading, mechanical damage, litter suppression, nutrient competition, and allelopathy, it displaces other plants and continuously invades neighboring plant communities, affecting community composition, biodiversity, soil properties, ecological processes, and functions to varying degrees. Therefore, effectively curbing the disorderly expansion of *Phyllostachys pubescens* is a core challenge currently faced.

[0003] Taking Daping State-owned Forest Farm in Rucheng County as an example, the total area of ​​the forest farm is 13,951.43 hectares. Among the 3,962 sub-compartments, 369 sub-compartments have varying degrees of expansion of scattered mixed bamboo. These scattered mixed bamboos are mainly *Phyllostachys edulis*, and the expansion area of ​​scattered mixed bamboos in 2020 reached 1,615.63 hectares, accounting for 11.58% of the total area of ​​the forest farm. In May 2025, a field survey conducted at Daping State-owned Forest Farm in Rucheng County (the experimental base of Central South University of Forestry and Technology in Zhongshan Village) showed that the average DBH of *Phyllostachys edulis* in the eight newly established standard plots was 3.3 cm, the average height was 5.52 m, and the plant density reached as high as 18,250 plants per hectare. -1 Among them, the number of new bamboo plants in 2025 reached 5050 per hectare. -1 However, other coniferous and broad-leaved tree species with a DBH of 1 cm or more only numbered 4,200 trees per hectare. -1 These scattered, miscellaneous bamboo species, primarily *Phyllostachys pubescens*, currently have low utilization value and severely hinder the natural regeneration of natural forests, resulting in low stand quality and difficulty in effectively realizing the functions of the forest ecosystem, particularly impacting biodiversity. However, if they are harvested incorrectly or at inappropriate times, underground rhizomes will sprout new shoots the following year, making it difficult to limit their expansion and impact on natural forests.

[0004] Early research primarily focused on the impacts of bamboo expansion at the community scale, such as its effects on species composition, biodiversity, and stand structure. Given the series of ecological problems caused by the disorderly expansion of bamboo, Wang Xiuyun et al. proposed using sesame extract to irrigate bamboo seedlings to regulate their growth; Cai Liang et al. proposed preliminary control strategies such as ditch digging and irrigation based on the growth status analysis of bamboo rhizomes; and others have proposed the use of bamboo herbicides. However, with the continuous rise in labor costs, the above methods all face significant limitations in practical application. Therefore, developing a novel and efficient research method for inhibiting bamboo expansion is particularly urgent. Summary of the Invention

[0005] The purpose of this invention is to provide a controllable method for the expansion of Phyllostachys edulis. By accurately controlling the timing of logging and adopting reasonable logging, forest clearing, replanting, and thinning of young forests, the expansion can be curbed from the root and the rapid growth of target trees can be promoted to restore the mixed coniferous and broad-leaved forest. This provides a reference method and basis for effectively suppressing the disorderly expansion of Phyllostachys edulis.

[0006] To achieve the above objectives, the present invention provides a method for controlling the expansion of bamboo with few spikelets and rough flowers, comprising the following steps: S1. Determine the timing for controllable harvesting of the expanded Bambusa gracilistylus; S2. Cleanup of logging residues; S3. Land preparation, replanting and restoration; S4. Young forest tending, thinning, and target tree identification; S5. Fertilize the target tree.

[0007] Furthermore, in S1, the accurate control of the harvesting time for *Phyllostachys edulis* (a type of bamboo) is based on the 24 solar terms and the life rhythm of *Phyllostachys edulis*, as well as the energy accumulation pattern of *Phyllostachys edulis* rhizomes in nurturing bamboo shoots. During the expansion, energy storage, and shoot formation stages of the underground rhizomes, the nutrient supply from the above-ground parts to the rhizomes is reduced in advance, removing the foundation for shoot germination from the underground rhizomes and inhibiting their expansion capacity. Therefore, the optimal harvesting time for controlling expansion is determined: harvesting should begin around the beginning of autumn and be completed before the White Dew solar term. Harvesting too early allows for the survival of dormant buds in the rhizomes; harvesting too late allows *Phyllostachys edulis* to begin accumulating energy for shoot formation after the White Dew solar term, triggering the shoot formation mechanism. Therefore, under normal site and climatic conditions, the harvesting and clearing of *Phyllostachys edulis* should be completed before the White Dew solar term. If the felling of *Phyllostachys edulis* cannot be completed before the White Dew solar term, a small number of new shoots will appear on the felled areas, temporarily failing to meet the requirements for controllable expansion. In this case, further clearing can be carried out around the Autumn Equinox of the following year to completely control the expansion of *Phyllostachys edulis*. Therefore, in principle, when clearing the above-ground parts, it is required to completely remove all above-ground parts of *Phyllostachys edulis*. If not completely removed, as long as there are bamboo culms providing energy, it will be difficult to achieve the controllable goal. Therefore, it is necessary to further block the lateral expansion path of the unfelled *Phyllostachys edulis* rhizomes through physical or ecological control measures to prevent the re-germination and spread of any remaining rhizome segments.

[0008] Furthermore, in S2, the strip composting technology for logging residues aims to scientifically treat bamboo stalks, leaves, and other residues generated during logging. This strip composting method avoids excessive competition for understory resources during decomposition, while simultaneously creating a suitable microenvironment for subsequent natural forest vegetation restoration. During composting, a large amount of nutrients are promptly returned to the forest land, which is beneficial for understory regeneration and relatively saves on fertilization costs.

[0009] Furthermore, in S3, pit clearing and land preparation are carried out in March to April of the first year after logging, and native tree species suitable for the local habitat are replanted; soybeans or peanuts are intercropped in areas with larger gaps in the forest, and the trees are cut and smoothed in September of the same year.

[0010] Furthermore, in S4, because the rapidly expanding *Phyllostachys edulis* species were removed, and understory debris was cleared, seed germination conditions improved, leading to a significant increase in the number of naturally regenerating tree species, shrubs, and weeds. Regular tending and management of the replanted saplings, including weeding, loosening the soil, and water and fertilizer regulation, were implemented to ensure the saplings' growth advantages and accelerate the stand reconstruction process.

[0011] Furthermore, in S5, during the period of 1 year ≤ tree age ≤ 5 years, with the target tree as the center, loosen the soil to a depth of 5-10 cm within a radius of 50-100 cm, loosening the soil once a year; remove weeds and shrubs once; and cover the loosened soil around the base of each tree with branches pruned from weeds and shrubs.

[0012] Furthermore, in S5, the fertilizer application rate for the target tree species is 100 catties of compound fertilizer per mu, wherein the N:P:K ratio in the compound fertilizer is 1:1:1.

[0013] The advantages and positive effects of the method for controlling the spread of Phyllostachys edulis with few spikelets described in this invention are as follows: 1. This invention employs techniques such as accurately controlling the timing of harvesting Phyllostachys edulis, scientifically handling harvesting residues, timely replanting and restoration, thinning and tending of young forests, and fertilizing target trees to effectively control the disorderly expansion of gramineous bamboo plants and restore damaged natural forests.

[0014] 2. By adopting the management method of the present invention, the expansion control rate of Phyllostachys edulis with few spikelets reaches 100%, and the understory regeneration rate is increased by more than 20%, with significant effects and economic benefits higher than those of ordinary natural forest management techniques.

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is a graph showing the growth process and non-structural carbon content of *Phyllostachys edulis*, a plant of the present invention. In the graph, NSC represents non-structural carbon content. Detailed Implementation

[0017] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. Experimental instruments, equipment, and reagents in the following embodiments that do not specify their sources are all commercially available materials.

[0019] Unless otherwise defined or stated, all technical and scientific terms used in this invention have the same meaning as those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein can be applied to the methods of this invention. It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0020] In the following examples, the soil in fertile areas has a total nitrogen content greater than 2.0 g / kg, a total phosphorus content greater than 1.0 g / kg, and a total potassium content greater than 25 g / kg; the soil in infertile areas has a total nitrogen content less than 1.0 g / kg, a total phosphorus content less than 0.6 g / kg, and a total potassium content less than 15 g / kg.

[0021] Example 1 A method for controlling the expansion of bamboo with few spikelets and rough flowers includes the following steps: S1. Determination of the controllable harvesting period for the expansion of *Phyllostachys edulis*.

[0022] Starting in December 2023, four components of *Phyllostachys pubescens* were collected approximately every one and a half months: the stump, rhizome, stump root, and rhizome root. The variation of non-structural carbon (NSC) in the underground part of *Phyllostachys pubescens* was measured in detail over a growth cycle. Three replicates were set up, and the measurement was carried out for one year, with a total of 96 samples. Figure 1 The diagram shows the growth process and non-structural carbon content of *Phyllostachys edulis*. The experimental results are shown in Table 1. The results indicate that around the beginning of spring each year, as bamboo shoots sprout, there is a significant output of underground non-structural carbon from bamboo culms and rhizomes, decreasing from 30.1% NSC to a minimum of around 8.5% around the beginning of autumn. During this stage, the main task is cultivating new bamboo, which consumes a large amount of energy. Essentially all the energy generated by photosynthesis within the bamboo forest is used for the production and maturation of new bamboo.

[0023] Starting from the beginning of autumn, newly synthesized energy begins to be supplied to the underground parts of bamboo, such as the rhizomes and culms, initiating the growth of a new generation of bamboo shoots. From the autumnal equinox, the NSC content in the underground parts begins to rise, and photosynthetic energy begins to accumulate underground in large quantities. The rhizomes trigger the mechanism for the growth of a new generation of bamboo shoots starting from the beginning of the Autumnal Equinox each year. The underground NSC content gradually increases until the large-scale germination of winter and spring bamboo shoots. Analysis shows that the main component of non-structural carbon in the underground parts of *Phyllostachys edulis* is starch, accounting for 73% of the NSC, while fructose and sucrose account for 11% and 13%, respectively.

[0024] Based on the seasonal variation patterns of NSC, the expansion of Phyllostachys edulis can be determined by the harvesting period from the beginning of autumn to before the White Dew solar term each year, that is, from about August 8 to September 10 each year. The specific time should be determined based on the local weather and site conditions of the forest stand.

[0025] Table 1. Seasonal variation of non-structural carbon content in the underground part of *Phyllostachys edulis*.

[0026] Note: The data in the table are mean ± standard deviation.

[0027] Experimental results conducted in 2023 at Daping State-owned Forest Farm, Rucheng County, Hunan Province, showed that logging before the beginning of autumn (especially before July) and logging after September 10th resulted in a certain number of new bamboo shoots sprouting from the logged areas in the spring of 2024. The experimental results are shown in Table 2. Table 2. Number of new bamboo shoots following the harvest of *Phyllostachys pubescens* at different harvesting times.

[0028] As shown in Table 2, the controllable harvesting period for the expansion of Phyllostachys edulis is from August 15 to September 10. Harvesting too early or too late cannot effectively stop the expansion of Phyllostachys edulis. Of course, if the harvesting time is not right, the new bamboo the following year, whether in terms of diameter at breast height or tree height, will be significantly lower than that of the control group. This indicates that after harvesting, Phyllostachys edulis lacks the energy supply from the mother bamboo. Although the mechanism for nurturing new bamboo is still there, the growth of new bamboo is significantly lower than that of the new bamboo in the control group.

[0029] S2. Cleanup of logging residues; After logging, the bamboo can be classified and disposed of according to the current status of processing and utilization of rough-flowered bamboo in the local area. Since the processing and utilization of rough-flowered bamboo in Daping State-owned Forest Farm is not very optimistic at present, the price is low and the transportation cost is high. Therefore, a large amount of logging residue is centrally processed. On the one hand, this saves labor costs, and on the other hand, the method of strip composting can promote fertilization and maintain regeneration.

[0030] S3. Land preparation, replanting and restoration; In the first year after harvesting *Phyllostachys edulis*, when there are few mother trees and large gaps in the forest, pit planting and land preparation should be carried out. From March to April, native tree species should be selected for replanting and reforestation. When the gaps are large, soybeans or peanuts can be interplanted. In September of the same year, thinning should be carried out; young forest tending work should be carried out. S4. Young forest tending, thinning, and target tree identification; After the removal of the rough-flowered bamboo with few spikelets, a large number of seeds germinated in the forest. Combined with the replanting of other tree species, the number of saplings regenerating in the forest floor was too large. It was necessary to promptly remove the excess saplings and identify the target trees.

[0031] S5. Fertilize the target tree; During the period from 1 year to 5 years of tree age, in the process of tending young forests, loosen the soil to a depth of 5 to 10 cm within a radius of 50 to 100 cm around the target tree, once a year; remove weeds and shrubs once; cover the soil around the base of each tree with branches pruned from weeds and shrubs; and apply an appropriate amount of growth promoter once.

[0032] Example 2 A method for controlling the expansion of bamboo with few spikelets and rough flowers includes the following steps: The steps for S1 and S2 are the same as in Example 1.

[0033] S3. Land preparation, replanting and natural forest regeneration effects; A replicated block experiment was used to set up 5 groups of bamboo forests with few spikelets and rough flowers during the controlled harvesting period, before the start of the controlled harvesting period (before July), after the controlled harvesting period (after September 10), and without harvesting (control group). For the forest stand regeneration survey, 5m quadrats were used, with at least three replicates within each block. The forest stand regeneration results for four different treatments are shown in Table 3.

[0034] Table 3 Results of natural forest regeneration in the replicated experimental area

[0035] Table 3 shows that the bamboo regeneration rate was 0 during controlled harvesting, indicating that no new bamboo was produced in the second year within the sample plot. This demonstrates that the correctly selected harvesting time effectively suppressed the regeneration of *Phyllostachys edulis*. The shrub regeneration rate showed little difference among the groups. The herbaceous regeneration rate and the natural regeneration rate of saplings both showed the following order: harvesting after September 10th > controlled harvesting > harvesting before the beginning of autumn > control. This indicates that after harvesting *Phyllostachys edulis*, the upper layer space and nutrient resources of the stand were released and absorbed by the herbaceous and sapling layers, significantly increasing the regeneration rate. Steps S4 and S5 are the same as in Example 1.

[0036] Therefore, this invention provides a controllable method for the expansion of Phyllostachys edulis. By accurately controlling the timing of logging and adopting reasonable logging, forest clearing, replanting, and thinning of young forests, its expansion is curbed at the source, and the rapid growth of target trees is promoted to restore the mixed coniferous and broad-leaved forest. This provides a reference method and basis for effectively suppressing the disorderly expansion of Phyllostachys edulis, with significant ecological benefits and broad application prospects.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for controlling the expansion of bamboo with few spikelets and rough flowers, characterized in that, Includes the following steps: S1. Determine the timing for controllable harvesting of the expanded Bambusa gracilistylus; S2. Cleanup of logging residues; S3. Land preparation, replanting and restoration; S4. Young forest tending, thinning, and target tree identification; S5. Fertilize the target tree.

2. The treatment method according to claim 1, characterized in that, In S1, based on the twenty-four solar terms and the life rhythm of Phyllostachys edulis, as well as the energy accumulation pattern of Phyllostachys edulis rhizomes in the development of bamboo shoots, the timing for controllable harvesting of Phyllostachys edulis expansion was determined: harvesting should begin around the beginning of autumn and be completed before the White Dew solar term.

3. The treatment method according to claim 2, characterized in that, If the harvesting cannot be completed before the White Dew solar term, the newly sprouted bamboo shoots will be replenished and cleaned up during the Autumn Equinox of the following year.

4. The treatment method according to claim 1, characterized in that, In S2, logging residues are cleaned up using a strip composting method to promote nutrient return and suppress weed growth.

5. The treatment method according to claim 1, characterized in that, In S3, pit clearing and land preparation are carried out in March and April of the first year after logging, and native tree species suitable for the local habitat are replanted; soybeans or peanuts are intercropped in areas with larger gaps in the forest, and the trees are cut and smoothed in September of the same year.

6. The treatment method according to claim 1, characterized in that, In S5, during the period of 1 year ≤ tree age ≤ 5 years, take the target tree as the center and loosen the soil to a depth of 5-10 cm within a radius of 50-100 cm, loosening the soil once a year; remove weeds and shrubs once a year; cover the soil around the base of each tree with branches pruned from weeds and shrubs after loosening the soil.

7. The treatment method according to claim 1, characterized in that, In S5, growth promoters or NPK compound fertilizers are applied according to site conditions; the fertilizer application rate for the target tree species is 100 catties of compound fertilizer per mu, wherein the N:P:K ratio in the compound fertilizer is 1:1:1.

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