Method for regulating structure of water conservation forest of drinking water source and improving function thereof

Abstract

This invention discloses a method for regulating the structure and enhancing the function of water conservation forests in drinking water source areas, comprising the following steps: (1) water source area survey; (2) site classification; (3) operational zoning; (4) afforestation regulation; (5) cultivation and tending of young trees; and (6) litter distribution. The technical method provided by this invention can, on the one hand, improve the forest ecosystem service benefits of water conservation forests in the short term, restoring high-quality forests with reasonable structure and vitality; on the other hand, through the scientific zoning, site-specific measures, and flexible operations of this invention, it can achieve tree species renewal and enhancement of conservation functions in water conservation forests, and is conducive to the stability of the structure, improvement of forest stand, and gradual beautification of the landscape of water conservation forests.

Description

Technical Field

[0001] This invention relates to the field of ecological environment protection and forest resource quality improvement engineering technology, specifically to methods for structural regulation and functional enhancement of water conservation forests in drinking water source areas. Background Technology

[0002] Currently, most of my country's existing drinking water source conservation forests were established in the 1970s and 80s. Forest planting designs have overemphasized annual timber volume growth and volume increase per unit area, neglecting the crucial water conservation and retention functions that significantly contribute to water source protection. These forests suffer from monotonous structures, inappropriate species configurations, low species richness, and overall low water conservation efficiency. Some ecologists have researched technologies to enhance the functions of water conservation forests and proposed constructive suggestions. For example, published patent documents CN201610999987.1, CN200810240189.6, CN202011287101.3, and CN201610399794.2 all discuss the transformation of water conservation forests. Although the water conservation forest improvement project proposed by these scholars incorporates the concepts of natural, ecological, and humanistic transformation to a certain extent, it is not yet very mature in terms of restoration engineering technologies such as plant selection, community construction, implementation steps, and community succession. It still remains at a simple, low-level design, such as plant replacement, terrain modification, and tending and regeneration. It has drawbacks such as inappropriate plant selection, insufficient system structure, neglect of biodiversity conservation, and unsatisfactory water source protection effects. It is difficult to realize the improvement of the ecological function of water conservation forests in water source protection. Summary of the Invention

[0003] Objective of the Invention: The technical problem this invention aims to solve is the serious inadequacy of existing technologies for the construction and functional enhancement of water conservation forests in drinking water source areas. This invention proposes a method for structural regulation and functional enhancement of water conservation forests. Based on theories of ecology, hydrology, soil science, and ecosystem structure, this method utilizes recent survey data on water conservation forest communities and integrates research findings on soil and water conservation, hydrology and ecology, litter retention, and practical techniques for transforming the forest landscape of water conservation forests. Through baseline surveys, scientific zoning, site-specific measures, and flexible operations, this method achieves a more efficient and effective transformation of water conservation forests under existing technological conditions, resulting in a dual improvement in both function and forest landscape.

[0004] To address the aforementioned technical problems, this invention discloses a method for regulating the structure and enhancing the function of water conservation forests in drinking water source areas, comprising the following steps: (1) Investigation of water source areas; (2) Site classification; (3) Work zone division; (4) Forest management and regulation; (5) Reclamation, pacification, and care for the young; (6) Distribution of litter.

[0005] In step (1), the purpose of the water source area survey is to comprehensively understand the status of the forest community and habitat characteristics of the water conservation forest. The forest community status includes forest structure, tree species composition, forest age, canopy closure, forest layer, young forest cover, litter thickness, leaf area index, as well as stand density, planting year, afforestation method, seedling source, and pest and disease status. The habitat characteristics include soil texture, soil thickness, soil fertility, soil pH, litter thickness, slope aspect, slope gradient, and slope position.

[0006] In step (2), site classification involves dividing the water conservation forest land into site types based on site conditions. The site types are classified according to the method listed in Table 1, that is, using slope aspect as the primary indicator, soil thickness as the secondary indicator, and soil organic carbon mass fraction as the tertiary indicator to divide the site into 36 site types, which are then numbered sequentially. After the site classification is completed, a 20-24cm wide and 25-30cm deep isolation ditch is required between adjacent types on site. The site types are drawn on the map and clearly marked with signs on site.

[0007]

[0008] In step (3), the operation zoning is to divide the water conservation forest regulation area into several large operation areas. The zoning is based on the community habitat characteristics completed in the early stage, combined with tree species composition, forest age, canopy closure, forest layer, young forest cover, litter thickness, and leaf area index. Each large operation area is required to have relatively consistent site conditions. However, if the community parameters are significantly different within the same site type, it is further subdivided into several sub-operation areas. Each sub-operation area has relatively consistent community characteristics. Large operation areas and sub-operation areas can be concentrated in one area or distributed across different areas.

[0009] In step (4), the forest management refers to the implementation of corresponding management measures in different work areas according to the site conditions, so as to achieve the goal of adapting to local conditions and being targeted. The management measures include density adjustment, pure forest to mixed forest, steep forest to terrace, and removal of diseased and rotten trees. Density adjustment is to determine the number of thinning or replanting adjustments based on the number of trees per unit area of ​​the forest stand. The specific adjustment standard is based on the number of trees to be retained, namely 60-75 trees / mu for broad-leaved forest, 70-80 trees / mu for coniferous forest, 70-75 trees / mu for mixed coniferous and broad-leaved forest, and 180-220 trees / mu for bamboo forest. Pure forest to mixed forest means thinning and replanting when the tree species composition is a pure forest, on the premise of meeting the standard for the number of trees to be retained in the density adjustment. The following methods will be used for replanting: cutting coniferous trees to supplement broadleaf trees, or cutting broadleaf trees to supplement coniferous trees, or cutting bamboo to supplement different species, to ensure that the number of tree species in a single work area is greater than one. Replanting will follow these principles: existing sun-loving species will be replaced with shade-loving species, and vice versa; existing coniferous species will be replaced with broadleaf species, and vice versa; existing fast-growing species will be replaced with slow-growing species, and vice versa; existing evergreen species will be replaced with deciduous species, and vice versa; existing deep-rooted species will be replaced with shallow-rooted species, and vice versa, to achieve ecological overlap and complementary advantages and disadvantages; if the work area is a bamboo forest, different species of bamboo of the same genus will be planted.

[0010] In step (4), the steep-step transformation refers to the transformation of forest land when the slope of the site in the operation area is greater than 40 degrees. The transformation method is to excavate steep-steps in concentric circles parallel to the contour lines, and move the excavated soil from the transplanting area into the filling area. The excavation angle at the base of the excavation is controlled at 90-100°, and the slope length between the upper and lower steep-steps is controlled at 3-4m. Attention is paid to the backfilling of topsoil and humus. The topsoil and humus of the transplanting area cover the upper layer of the filling area, and the base of the transplanting area receives the topsoil and humus of the filling area above, ensuring that the humus in the surface soil of the forest land is not reduced, and enhancing the permeability, retention capacity and conservation capacity of the forest land soil.

[0011] In step (4), the removal of diseased and rotten wood involves moving trees, branches and roots that are affected by pests and diseases in the forest to outside the forest for treatment, thereby eliminating the source of infection.

[0012] In step (5), the "cultivation and tending" refers to the implementation of humus regulation, irrigation, and young forest tending measures after afforestation regulation in different work areas, in order to maintain the results of afforestation regulation. The humus regulation is to adjust the soil humus according to the habitat characteristics investigated in the early stage. If the surface coniferous litter accounts for the majority, then apply decomposed acidic organic fertilizer to promote the decomposition of litter, with a dosage not exceeding 15 kg per mu; if the surface broadleaf litter accounts for the majority, then apply decomposed neutral or slightly acidic organic fertilizer, with a dosage not exceeding 10 kg per mu; the irrigation refers to determining the water management measures for young forest land according to the soil moisture of the forest land. When the volumetric water content of the forest land is less than 25%, irrigation is carried out; the young forest tending is to carry out weeding and loosening of the soil within a radius of 1m of newly planted young trees 3 times each year during the growing season, with an interval of 2 months between each time.

[0013] In step (6), the litter distribution refers to the quantitative spreading of litter during the young forest tending period based on the surface litter condition, so as to evenly cover the forest land with litter, reduce surface runoff and water loss, and enhance water conservation and regulation capacity. The quantitative spreading of litter is carried out based on the annual accumulated litter quantity in the forest land to reduce surface gaps and enhance litter retention capacity. The regulation principle is based on the annual average thickness of the forest land litter in the work area as the base, and the distribution quantity satisfies the following formula: M = X ± Y, In the formula, Y is the thickness of the litter that needs to be quantitatively spread, X is the thickness of the litter as determined by the on-site survey, and M is the annual average thickness.

[0014] Beneficial Effects: This invention addresses the severe deficiencies in current technologies for the construction and functional enhancement of water conservation forests in my country, proposing a method for structural regulation and functional enhancement of water conservation forests in drinking water source areas. This method is developed based on theories of ecology, hydrology, soil science, and ecosystem structure, utilizing data from recent water conservation forest community surveys and integrating previous research findings on soil and water conservation, hydrological ecology, litter retention, and forest stand transformation in water conservation areas. From the perspective of implementation results, this invention overcomes the shortcomings of existing afforestation techniques, such as arbitrary plant regeneration, simplistic transformation methods, neglect of terrain modification, and improper litter treatment. It grasps the key to limiting the function of water conservation forests in drinking water source areas, and focuses on core elements such as operational zoning, structural regulation, maintenance and management, and litter retention to carry out internal quality transformation and refined management of water conservation forest ecosystems. On the one hand, it can improve the forest regulation function of water conservation forests in the short term and restore high-quality forests with reasonable structure and vitality. On the other hand, through scientific zoning, site-specific measures, and flexible operations, it can achieve tree species renewal, structural stability, improved forest stand, and gradually beautiful landscape in water conservation forests, which is in line with the goals and directions of my country's "Guidelines for Ecological Protection and Restoration Projects of Mountains, Rivers, Forests, Fields, Lakes and Grasslands (Trial)" (Ministry of Natural Resources, Ministry of Finance, and Ministry of Ecology and Environment, 2020). Attached Figure Description

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0016] Figure 1 Technical flowchart for implementation; Figure 2 Side view of steep-step relocation implementation in afforestation regulation; Figure 3 A top-down view of steep-step relocation in afforestation regulation.

[0017] In the diagram, A represents the higher elevation of the work area (mountain top), a represents the horizontal line of the steep step, 1 represents the soil relocation area, 1′ represents the topsoil and humus of the soil relocation area, 2 represents the fill area, 2′ represents the topsoil and humus of the fill area, n represents the excavation angle of the soil relocation area, and L represents the slope length between the upper and lower steep steps. Detailed Implementation

[0018] The present invention can be better understood from the following embodiments. The descriptions of the embodiments are for illustrative purposes only and should not, and will not, limit the invention as described in detail in the claims. Example

[0019] From September 2022 to October 2023, an experiment on the structural regulation and functional enhancement of water conservation forests in the upstream area of ​​Tianmu Lake Wetland Park in Liyang City, Jiangsu Province (Tianmu Lake Town, Liyang City, Jiangsu Province) was carried out. The implementation process is as follows: (1) Water source area survey: From September to October 2022, a systematic survey was conducted in the implementation area to comprehensively understand the status of the forest community and habitat characteristics of the water conservation forest. The forest community status survey mainly included forest structure, tree species composition, forest age, canopy closure, forest layer, young forest cover, litter thickness, leaf area index, as well as stand density, planting year, afforestation method, seedling source, and pest and disease status indicators. The habitat characteristics survey included soil texture, soil thickness, soil fertility, soil pH, litter thickness, slope aspect, slope gradient, and slope position. All survey results were uniformly registered and recorded.

[0020] (2) Site Classification: Based on site conditions, the water conservation forest was classified into 36 site types according to the method listed in Table 1, namely, using slope aspect as the primary indicator, soil thickness as the secondary indicator, and soil organic carbon mass fraction as the tertiary indicator. These site types were numbered sequentially. After classification, isolation ditches with a width of 20-24cm and a depth of 25-30cm were set up between adjacent site types and marked with signs. All site types were mapped.

[0021]

[0022] (3) Operational zoning: After the site type classification was completed, the operation zoning was carried out, and 36 large operation areas were divided. The zoning was based on the community habitat characteristics, combined with tree species composition, forest age, canopy closure, forest layer, young forest cover, litter thickness, and leaf area index. Each large operation area has relatively consistent site conditions. However, if the tree species composition, forest age, canopy closure, forest layer, young forest cover, and leaf area index are significantly different within the same site type, it is further subdivided into several sub-operation areas. Each sub-operation area has relatively consistent community characteristics. (4) Forest management: Different management measures were implemented in different work areas according to the site conditions. These measures included density adjustment, conversion of pure forests to mixed forests, conversion of steep slopes to terraces, and removal of diseased and rotten trees. Density adjustment was based on the principle of retaining the number of trees: 60 trees / mu for broad-leaved forests, 70 trees / mu for coniferous forests, 75 trees / mu for mixed coniferous and broad-leaved forests, and 180 trees / mu for bamboo forests. The process of converting pure forests to mixed forests involves thinning and replanting when the tree species composition is a single forest. Under the premise of meeting the density adjustment and retention standards, thinning and replanting are carried out to ensure that the number of tree species in a single operation area is greater than 1. The replanting principle is as follows: replace pine forests with Celtis sinensis, replace pure Celtis sinensis forests with bald cypress, replace Chinese fir forests with Zelkova serrata, replace paper mulberry forests with Alnus davidii, replace black locust forests with Sapium sebiferum, and replace holly forests with maple. At the same time, it takes into account the high degree of integration of shade-loving and sun-loving tree species, fast-growing and slow-growing tree species, evergreen and deciduous tree species, and deep-rooted and shallow-rooted tree species to facilitate ecological overlap and complementary advantages and disadvantages.

[0023] Meanwhile, steep slopes exceeding 40 degrees were converted into terraces in the forest areas, with the conversion method involving digging and supplementing steep terraces in concentric circles parallel to the contour lines. Figure 2 , Figure 3 During the renovation, excavated soil from relocation area 1 is moved into fill area 2. The excavation angle n at the base of the excavation is controlled at 90-100°, and the slope length L between the upper and lower steep steps is controlled at 3-4 m. Attention is paid to the backfilling of topsoil and humus 1′. The topsoil and humus 1′ of the relocation area cover the upper layer 2′ of the fill area. The base of the relocation area receives the topsoil and humus 2” of the fill area above, ensuring that the humus in the forest surface soil is not reduced and enhancing the permeability, retention capacity and nutrient conservation of the forest soil.

[0024] At the same time, in each work area, trees, branches and roots that are affected by pests and diseases are moved outside the forest for crushing and burying to remove the source of infection and effectively reduce the spread of pests and diseases.

[0025] Forest management and sapling tending: After afforestation and regulation in different work areas, humus regulation, irrigation, and sapling tending measures were implemented. Humus regulation involved adjusting soil humus according to the habitat characteristics identified in the preliminary survey. Since field surveys showed that surface needle litter accounted for over 85%, Biom acidic organic fertilizer was applied to the forest land at a rate of 15 kg per acre to promote litter decomposition. Water management measures for saplings were determined based on soil moisture conditions. Irrigation was implemented when the soil volumetric moisture content fell below 25%, with four irrigations per year. During the growing season each year, weeding and loosening of the soil within a 1-meter radius of newly planted saplings were carried out three times, with each application spaced two months apart.

[0026] Litter distribution: Based on the annual accumulated litter survey data, quantitative control and distribution of litter are carried out to ensure even litter coverage, reduce surface runoff and water loss, and enhance water conservation capacity. The control principle is based on the annual average litter thickness surveyed within the work area as a baseline, and the distribution quantity satisfies the following formula: M = X ± Y, In the formula, Y is the thickness of the litter that needs to be quantitatively spread, X is the thickness of the litter as determined by the on-site survey, and M is the annual average thickness.

[0027] Implementation Results: An effectiveness survey was conducted in the implementation area starting in October 2024. The replanted trees grew vigorously and recovered well, with a significant increase in species diversity. Simpson's Diversity Index increased by 30%, and the forest stand approached perfection. Forest litter was evenly distributed with an average thickness of 4.4 cm, and the effective water retention capacity exceeded 26 t·hm². -2 This effectively reduces soil erosion, ensures clear water, stable reservoir capacity, and meets water quality standards, resulting in significant potential economic benefits.

[0028] This invention provides a method for regulating the structure and enhancing the function of water conservation forests in drinking water source areas. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A method for regulating the structure and improving the function of a drinking water source forest, characterized in that, Includes the following steps: (1) Water source area survey: to fully understand the status of the forest community and habitat characteristics of the water conservation forest; (2) Site classification: Based on the site conditions, the water conservation forest is classified into different site types. A 20-24cm wide and 25-30cm deep isolation ditch is set between adjacent types. The site types are drawn on the map and marked on site. (3) Operational zoning: After site type classification is completed, operational zoning is carried out to divide the site into several large operational zones. The zoning is based on community habitat characteristics and community characteristic parameters. Each large operational zone has relatively consistent site conditions, but if the community characteristic parameters within the same site type are significantly different, it is further subdivided into several sub-operational zones. Each sub-operational zone has relatively consistent community characteristics. Large operational zones and sub-operational zones can be concentrated in one area or distributed across different areas. The community characteristic parameters include tree species composition, forest age, canopy closure, forest layer, young forest cover, litter thickness, and leaf area index. (4) Forest management and control: Different management and control measures are implemented in different work areas according to the site conditions, so as to be tailored to local conditions and targeted. The management and control measures include density adjustment, pure to mixed forest, steep to terraced forest, and removal of diseased and rotten trees. (5) Reclamation and tending of young trees: After the afforestation regulation in different operation areas, humus regulation, irrigation and water replenishment and young forest tending measures are implemented; (6) Litter distribution: During the tending period of young forests, litter is spread in a quantitative manner according to the litter condition on the ground to ensure that the litter is evenly covered in the forest land, reduce surface runoff and water loss, and enhance the water conservation and regulation capacity.

2. The method according to claim 1, wherein, In step (1), the forest community status includes forest structure, tree species composition, forest age, canopy closure, forest layer, young forest cover, litter thickness, leaf area index, as well as stand density, planting year, afforestation method, seedling source, and pest and disease status; the habitat characteristics include soil texture, soil thickness, soil fertility, soil pH, litter thickness, slope aspect, slope, and slope position.

3. The method according to claim 1, wherein, In step (2), the site type is divided according to the method listed in Table 1, that is, the slope aspect is used as the primary indicator, the soil thickness as the secondary indicator, and the soil organic carbon mass fraction as the tertiary indicator to divide the site into 36 site types, which are numbered sequentially; wherein, the slope aspect includes south slope, north slope, west slope and east slope. 。 4. The method according to claim 1, wherein, In step (4), the density adjustment refers to determining the number of thinning or replanting adjustments based on the number of trees per unit area of ​​the forest stand. The specific adjustment standard is based on the number of trees to be retained, namely 60-75 trees / mu for broad-leaved forests, 70-80 trees / mu for coniferous forests, 70-75 trees / mu for mixed coniferous and broad-leaved forests, and 180-220 trees / mu for bamboo forests.

5. The method for regulating the structure and enhancing the function of water conservation forests in drinking water source areas according to claim 1, characterized in that, In step (4), when the tree species composition is a simple forest, thinning and replanting are carried out. Under the premise of meeting the density adjustment and retention of the number of trees, coniferous trees are cut down to replace broad-leaved trees, or broad-leaved trees are cut down to replace coniferous trees, or broad-leaved trees are cut down to replace broad-leaved trees, or bamboo is cut down to replace different species, so that the number of tree species in a single operation area is greater than 1. The replanting follows the following principles: existing positive tree species are replaced with negative tree species, existing negative tree species are replaced with positive tree species; existing coniferous tree species are replaced with broad-leaved tree species, existing broad-leaved tree species are replaced with coniferous tree species; existing fast-growing tree species are replaced with slow-growing tree species, existing slow-growing tree species are replaced with fast-growing tree species; existing evergreen tree species are replaced with deciduous tree species, existing deciduous tree species are replaced with evergreen tree species; existing deep-rooted tree species are replaced with shallow-rooted tree species, existing shallow-rooted tree species are replaced with deep-rooted tree species, so as to achieve ecological overlap and complementary advantages and disadvantages; if the operation area is a bamboo forest, then different species of bamboo of the same genus are added.

6. The method for regulating the structure and enhancing the function of water conservation forests in drinking water source areas according to claim 1, characterized in that, In step (4), the steep step transformation refers to the transformation of forest land when the slope of the site in the operation area is greater than 40 degrees. The transformation method is to excavate steep steps in concentric circles parallel to the contour lines. The excavated soil area (1) is moved into the filling area (2). The excavation angle at the base of the excavation is controlled at 90-100°. The slope length between the upper and lower steep steps is controlled at 3-4m. Attention is paid to the backfilling of topsoil and humus (1′). The topsoil and humus (1′) of the excavation area cover the upper layer (2′) of the filling area. The base of the excavation area receives the topsoil and humus (2") of the filling area above, ensuring that the humus in the surface soil of the forest land is not reduced, and enhancing the permeability, retention capacity and conservation capacity of the forest land soil.

7. The method for regulating the structure and enhancing the function of water conservation forests in drinking water source areas according to claim 1, characterized in that, In step (4), the removal of diseased and rotten wood means moving the trees, branches and roots that are affected by pests and diseases in the forest to outside the forest for treatment, thereby eliminating the source of infection.

8. The method for regulating the structure and enhancing the function of water conservation forests in drinking water source areas according to claim 1, characterized in that, In step (5), the humus regulation refers to adjusting the soil humus according to the habitat characteristics investigated in the early stage. If the surface is dominated by coniferous litter, apply more well-rotted acidic organic fertilizer to promote the decomposition of litter, with a dosage not exceeding 15 kg per mu. If the surface is dominated by broadleaf litter, apply more well-rotted neutral or slightly acidic organic fertilizer, with a dosage not exceeding 10 kg per mu. The irrigation and water replenishment refers to determining the water management measures for the young forest land according to the soil moisture condition. When the volumetric water content of the forest land soil is less than 25%, irrigation and water replenishment operations are carried out. The young forest tending refers to weeding and loosening the soil within a radius of 1m of the newly planted young trees 3 times each year during the growing season, with an interval of 2 months between each time.

9. The method for regulating the structure and enhancing the function of water conservation forests in drinking water source areas according to claim 1, characterized in that, In step (6), the quantitative spreading of litter refers to the allocation of litter based on the amount of litter accumulated in the forest land each year, in order to reduce surface blanks and enhance the litter retention capacity. The control principle is based on the annual average thickness of litter in the forest land survey within the operation area as the base, and the allocation quantity satisfies the following formula: M = X ± Y, In the formula, Y is the thickness of the litter that needs to be quantitatively spread, X is the thickness of the litter as determined by the on-site survey, and M is the annual average thickness.

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