A near-natural vegetation landscape construction method of an urban wetland ecological island

Abstract

This invention relates to a method for constructing a near-natural vegetation landscape for urban wetland ecological islands. The city in question is located in the Yangtze River Delta region. The method includes the following steps: Step S1: Selecting several plant communities in the target area and its surrounding areas, and evaluating their naturalness using a modified AHP-entropy weight method, to obtain a reference native plant community suitable for constructing a near-natural vegetation landscape for the urban wetland ecological island; Step S2: Setting up several square sample grids within each reference native plant community, and identifying the climax pioneer species, successional sequence species, and successional climax species within each sample grid; Step S3: Using a heterospecific-heterogeneous diameter-class-simultaneous stratified mixed planting method, planting the climax pioneer species, successional sequence species, and successional climax species in the target area. This invention's vegetation landscape construction method is objective and scientific, has high ecological benefits, a rapid succession process, and low construction costs.

Description

Technical Field

[0001] This invention belongs to the field of ecological environment technology, and more specifically, relates to a method for constructing a near-natural vegetation landscape for urban wetland ecological islands. Background Technology

[0002] Urban wetlands, as an important component of urban ecosystems, play a vital role in maintaining biodiversity, regulating climate, and purifying water quality. Urban wetlands involve two interconnected ecological modules: wetlands and land. Overall, they possess an ecological succession series of aquatic plant communities, wetland plant communities, and terrestrial plant communities, resulting in a rich ecological landscape.

[0003] Currently, there is a lack of systematic research on the construction of urban wetland vegetation landscapes, and research on methods for constructing near-natural vegetation landscapes in urban wetland ecological islands is even scarcer. At present, ecological restoration of the terrestrial portion of urban wetlands mainly relies on engineering measures, and vegetation landscape creation often employs traditional landscaping and forestry afforestation methods, tending to imitate existing urban parks and green spaces. This has resulted in relatively fixed and monotonous "water forests" dominated by pond cypress and bald cypress, and / or open green spaces with more than 50% of their trees being introduced species. While this layout pattern can mitigate or reduce construction risks, it suffers from a drawback in the plant configuration process: insufficient consideration of the importance of native plants. Specifically, it lacks analysis comparing native plant communities and their compositional characteristics. This leads to irrationality in the ecological niche, successional status, and function of each plant in the existing layout pattern, unclear hierarchical planning of planting patterns (e.g., the absence of native shrub and herb layers), and inappropriate species matching. Consequently, the plant community under this layout pattern lacks self-renewal and self-sustaining capacity, resulting in insufficient biodiversity. In addition, the above layout pattern often uses artificially planted large-diameter seedlings (diameter at breast height of 15cm or more), which results in high procurement and maintenance costs.

[0004] Therefore, there is an urgent need to propose a method for constructing near-natural vegetation landscapes in urban wetland ecological islands. This would address the scarcity of research on such methods, the shortcomings of existing urban wetland land areas in plant configuration that do not adequately consider the importance of native plants, the irrationality in the ecological niche, successional status, and function of each plant species under the current layout pattern, the unclear hierarchical planning of planting patterns (e.g., the absence of native shrub and herb layers), and inappropriate species matching. These issues result in a lack of self-renewal and self-sustaining capacity of plant communities and insufficient biodiversity under this layout pattern. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the main objective of this invention is to propose a method for constructing near-natural vegetation landscapes in urban wetland ecological islands. This method aims to solve at least one of the following technical problems: the scarcity of research on methods for constructing near-natural vegetation landscapes in urban wetland ecological islands; insufficient consideration of the importance of native plants in the existing urban wetland terrestrial areas during plant configuration; irrational ecological niches, successional status, and functions of each plant configuration under the existing layout model; unclear hierarchical planning of planting patterns (e.g., the absence of native shrub and herb layers); and inappropriate species matching. These issues result in a lack of self-renewal and self-sustaining capacity of plant communities and insufficient biodiversity under the existing layout model.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This invention provides a method for constructing a near-natural vegetation landscape for urban wetland ecological islands, wherein the city is located in the Yangtze River Delta region, and the method includes the following steps:

[0008] Step S1: Select several plant communities in the target area for constructing near-natural vegetation landscape and its surrounding areas, and evaluate their naturalness using the improved AHP-entropy weight method to obtain a reference native plant community suitable for constructing near-natural vegetation landscape for urban wetland ecological islands.

[0009] Step S2: Set up several square sample grids in each native plant community of the reference system, and mark the species, diameter at breast height and coordinate position information of woody plants with a height of more than 1.5m in each sample grid. Based on the marked information, divide the apical pioneer species, succession sequence species and succession apex species in each sample grid.

[0010] Step S3: Using a mixed planting method of different species, different diameter at breast height, and simultaneous layered intercropping, plant the climax pioneer species, succession sequence species, and succession climax species in the target area of ​​the near-natural vegetation landscape construction. Before planting, the succession sequence species and succession climax species are dipped in a mud slurry made of root-promoting microbial agent and water.

[0011] Preferably, in step S1, 10-15 plant communities are selected in the target area for constructing near-natural vegetation landscape and its surrounding area.

[0012] Preferably, in step S2, 3-5 square sample grids are set in each native plant community of the reference system, and the side length of the square sample grid is not less than 10m.

[0013] Preferably, in step S2, the climax pioneer species, successional sequence species, and successional climax species are classified according to the frequency curve of thorax diameter class. The frequency curve of thorax diameter class of the climax pioneer species is unimodal, and the unimodal corresponds to the small thorax diameter class. The frequency curve of thorax diameter class of the successional sequence species is a discontinuous plurality of unimodal, and the plurality of unimodal are concentrated in the medium thorax diameter class. The frequency curve of thorax diameter class of the successional climax species is a continuous distribution in an inverted J-shape, showing a large peak in the small thorax diameter class and a small peak in the large thorax diameter class. The horizontal axis of the frequency curve of thorax diameter class is the thorax diameter, and the horizontal axis is in units of 5 cm.

[0014] Preferably, in step S2, the small chest diameter range is less than 5cm, the medium chest diameter range is less than 5cm-20cm, and the large chest diameter range is greater than 20cm.

[0015] Preferably, in step S2, the apex pioneer species is selected from at least two of the following: Celtis sinensis, Quercus acutissima, Liquidambar formosana, Ziziphus jujuba, Pistacia chinensis, Koelreuteria paniculata, Pterocarya stenoptera, Rhizoma et Rhizoma serrata, Celtis sinensis, Acer triangularis, Ulmus parvifolia, Acer palmatum, Pyrus pyrifolia, Melia azedarach, Dalbergia odorifera, and Morus alba.

[0016] Preferably, in step S2, the succession sequence species are selected from at least three of the following: *Phoebe zhennan*, *Phoebe bournei*, *Symplocos pubescens*, *Cinnamomum camphora*, *Cinnamomum camphora*, *Elaeocarpus decipiens*, *Ilex cornuta*, *Ligustrum lucidum*, *Myrica rubra*, *Cinnamomum camphora*, *Photinia serratifolia*, *Loropetalum chinense*, *Bauhinia purpurea*, *Prunus salicina*, and *Lonicera japonica*.

[0017] Preferably, in step S2, the climax species of succession is selected from at least three of the following: Quercus glauca, Castanopsis chinensis, Quercus microcarpa, Cinnamomum camphora, Castanopsis sclerophylla, Castanopsis sclerophylla, Ficus microcarpa var. sclerophylla, Camellia sinensis, Camellia japonica, Gardenia jasminoides, Stachys chinensis, Ilex cornuta, Elaeagnus pungens, and Osmanthus fragrans.

[0018] Preferably, in step S3, the climax pioneer species are randomly planted at a density of 1 to 1.5 plants per square meter, with 1 to 3 species, a diameter at breast height of 3 to 5 cm, and a height of 2 to 4 m, forming a shade layer on the upper part of the community; the successional sequence species are densely planted in clusters at a density of 2 to 3 plants per square meter, with 3 to 5 species and a height of 1 to 1.5 m; the successional climax species are densely planted in clusters at a density of 2 to 3 plants per square meter, with 3 to 5 species and a height of 0.5 to 1 m, forming a shade-tolerant layer of the community.

[0019] Preferably, in step S3, the root-promoting microbial agent is selected from at least two of the following: Frankiaspp., Bacillus megaterium, Bacillus velezensis, Paenibacillus polymyxa, Bacillus thuringiensis, Paenibacillus polymyxa, Bacillus megaterium, Bacillus subtilis, Glomus intraradices, and Laccaria bicolor.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] This invention proposes a method for constructing near-natural vegetation landscapes in urban wetland ecological islands, filling a research gap in this field. It fully considers the importance of native plants in the plant configuration of the terrestrial portion of urban wetlands. By employing an improved AHP-entropy weight method for naturalness evaluation, a reference native plant community suitable for constructing a near-natural vegetation landscape for urban wetland ecological islands is obtained. Within each reference native plant community, several square sample areas are set up, and the height exceeding the specified limit within each sample area is marked. Based on the information of woody plants exceeding 1.5m in height, their diameter at breast height (DBH), and their coordinate positions within the sample grid, the climax pioneer species, successional sequence species, and climax species within each sample grid are identified. A mixed planting method of heterospecies-heterosperm diameter-simultaneous stratified intercropping is employed, planting the climax pioneer species, successional sequence species, and climax species in the target area of ​​the near-natural vegetation landscape construction, artificially promoting the plant community succession process. This layout pattern enhances the self-renewal and self-sustaining capacity of the plant community, resulting in higher biodiversity. Attached Figure Description

[0022] Figure 1 The relevant steps of a method for constructing a near-natural vegetation landscape in an urban wetland ecological island according to this application are shown.

[0023] Figure 2 This illustrates the effect of creating a near-natural vegetation landscape on the Cherry River Ecological Island in Embodiment 1 of this application;

[0024] Figure 3 The illustration shows the effect of creating a near-natural vegetation landscape on the Wenzhou Sanyang Wetland Ecological Island in Embodiment 2 of this application. Detailed Implementation

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0026] See Figure 1 This invention provides a method for constructing a near-natural vegetation landscape for urban wetland ecological islands, wherein the city is located in the Yangtze River Delta region, and the construction method includes the following steps:

[0027] Step S1: Select several plant communities in the target area for constructing near-natural vegetation landscape and its surrounding areas, and evaluate their naturalness using the improved AHP-entropy weight method to obtain a reference native plant community suitable for constructing near-natural vegetation landscape for urban wetland ecological islands.

[0028] Step S2: Set up several square sample grids in each native plant community of the reference system, and mark the species, diameter at breast height, and coordinate position information of woody plants with a height of more than 1.5m in each sample grid. Based on the marked information, divide the climax pioneer species, successional species, and climax species in each sample grid.

[0029] Step S3: Using a mixed planting method of different species, different diameter at breast height, and simultaneous layered intercropping, plant the climax pioneer species, succession sequence species, and succession climax species in the target area of ​​the near-natural vegetation landscape construction. Before planting, the succession sequence species and succession climax species are dipped in a mud slurry made of root-promoting microbial agent and water.

[0030] It should be noted that in step S1, the improved AHP-entropy weight method combines the 1-9 scale method and e 0 / 4 ~e 8 / 4A combined scaling and entropy weighting method was used to construct an evaluation system for naturally assessing plant community activity, quantifying naturalness using combined weight values. This system encompasses four aspects: plant community species composition, community structural characteristics, plant community vitality, and disturbance level, all of which can be objectively quantified through measurement. Specifically, plant community species composition includes richness index, evergreen-to-fallen ratio, and natural composition coefficient; community structural characteristics include tree density, tree diameter dispersion, and average diameter at breast height (DBH); plant community vitality includes the number of naturally regenerated seedlings, canopy closure of the tree layer, canopy closure of the shrub layer, and community stability; and disturbance level includes the proportion of invasive plants and the degree of anthropogenic interference. Actual survey measurements were used for evaluation, calculating the naturalness value of each indicator. Each indicator was standardized, converted to data within the [0,1] interval, and a cumulative score was calculated, followed by further standardization. The grading system is divided into four levels: I, II, III, and IV. Level I is defined as 75% or higher, Level II as 50% or higher, Level III as 25% or higher, and the rest as Level IV.

[0031] Preferably, in step S1, 10-15 plant communities are selected in the target area for constructing near-natural vegetation landscape and its surrounding area.

[0032] Preferably, in step S2, 3 to 5 square sample grids are set in each native plant community of the reference system, and the side length of the square sample grid is not less than 10m.

[0033] Preferably, in step S2, the climax pioneer species, successional sequence species, and successional climax species are classified according to the diameter-at-breast-width (DBH) frequency curve. The DBH frequency curve of the climax pioneer species is unimodal, with only a few large-diameter individuals (over 20cm) and deciduous broad-leaved trees with a lifespan of over 100 years, lacking subsequent regeneration individuals of small diameter (0-5cm), and the population shows a declining trend. The DBH frequency curve of the successional sequence species is discontinuous, with a large number of individuals, and the population structure shows several unimodal peaks, with a large number of small-diameter subsequent regeneration individuals, and the population shows a significant growth trend. The DBH frequency curve of the successional climax species is continuously distributed in an inverted J-shape, showing a large peak in the small-diameter category and a small peak in the large-diameter category, and the population is a mature and stable type. The horizontal axis of the DBH frequency curve is the diameter at breast height (DBH), and the horizontal axis is in units of 5cm.

[0034] It should be noted that in step S2, the population diameter at breast height (DBH) frequency distribution method can clearly reflect the age distribution and ecological niche of woody plant populations at different successional stages, thereby effectively identifying the ecological role and successional stage of each woody plant species in the community. Compared with other methods, DBH frequency distribution provides more intuitive quantitative structural information, accurately identifying the rapid growth characteristics of pioneer species, the continuous regeneration trend of successional sequence species, and the stable characteristics of climax species. Furthermore, this method relies entirely on field-measured survey data, reducing the influence of subjective evaluation and judgment, and enhancing its scientific rigor and accuracy.

[0035] Preferably, in step S2, the apex pioneer species is selected from at least two of the following: Celtis sinensis, Quercus acutissima, Liquidambar formosana, Ziziphus jujuba, Pistacia chinensis, Koelreuteria paniculata, Pterocarya stenoptera, Rhizoma et Rhizoma serrata, Celtis sinensis, Acer triangularis, Ulmus parvifolia, Acer palmatum, Pyrus pyrifolia, Melia azedarach, Dalbergia odorifera, and Morus alba.

[0036] Preferably, in step S2, the succession sequence species are selected from at least three of the following: *Phoebe zhennan*, *Phoebe bournei*, *Symplocos pubescens*, *Cinnamomum camphora*, *Cinnamomum camphora*, *Elaeocarpus decipiens*, *Ilex cornuta*, *Ligustrum lucidum*, *Myrica rubra*, *Cinnamomum camphora*, *Photinia serratifolia*, *Loropetalum chinense*, *Bauhinia purpurea*, *Prunus salicina*, and *Lonicera japonica*.

[0037] Preferably, in step S2, the climax species of succession is selected from at least two of the following: Quercus glauca, Castanopsis chinensis, Quercus microcarpa, Cinnamomum camphora, Castanopsis sclerophylla, Castanopsis sclerophylla, Ficus microcarpa sessileus, Camellia sinensis, Camellia japonica, Gardenia jasminoides, Stachys chinensis, Ilex cornuta, Elaeagnus pungens, and Osmanthus fragrans.

[0038] Preferably, in step S3, the climax pioneer species are randomly planted at a density of 1 to 1.5 plants per square meter, with 1 to 3 species, a diameter at breast height of 3 to 5 cm, and a height of 2 to 4 m, forming a shade layer on the upper part of the community; the successional sequence species are densely planted in clusters at a density of 2 to 3 plants per square meter, with 3 to 5 species and a height of 1 to 1.5 m; the successional climax species are densely planted in clusters at a density of 2 to 3 plants per square meter, with 3 to 5 species and a height of 0.5 to 1 m, forming a shade-tolerant layer of the community.

[0039] It should be noted that a mixed planting method involving different species, different diameters, and simultaneous stratification is employed to achieve rapid restoration of near-natural zonal vegetation. Simultaneously, the main zonal vegetation species with different successional sequences, age structures, and diameter classes are constructed into near-natural plant communities, achieving a near-natural vegetation landscape of upper deciduous and lower evergreen layers in the urban wetland ecological islands of the Yangtze River Delta. The tree species and specifications used are designed for efficient seedling planting and rapid post-planting recovery. The constructed community structure is well-developed, resulting in high seedling survival rates, good community stability, and strong aesthetic appeal. This is a highly effective method for constructing near-natural urban wetland ecological island landscapes. Compared to traditional afforestation methods that create forest communities with limited tree species, monotonous layering, and poor stability, this invention utilizes only seedlings and saplings of native tree species that have already been developed to a certain scale. This results in a high survival rate and significant recovery capacity within the first year. It leverages the 3-5 year window of recovery period provided by larger seedlings (diameter at breast height 10cm or more) to achieve vegetation recovery capacity and degree comparable to the landscape effect of large-scale seedlings. After 10-15 years, the vegetation recovery effect of the urban wetland ecological islands created by this invention is comparable to that of large-scale seedling afforestation, with a similar or even shorter total recovery time.

[0040] Preferably, in step S3, the root-promoting microbial agent is selected from at least two of the following: Frankiaspp., Bacillus megaterium, Bacillus velezensis, Paenibacillus polymyxa, Bacillus thuringiensis, Paenibacillus polymyxa, Bacillus megaterium, Bacillus subtilis, Glomus intraradices, and Laccaria bicolor.

[0041] It should be noted that the microorganisms used in the vegetation restoration process play a crucial role in improving soil conditions, promoting plant growth, and balancing the ecosystem. Radial rhizobia improve nitrogen supply in poor soils by fixing nitrogen and forming symbiotic relationships with the roots of non-leguminous plants. Bacillus megaterium and Bacillus phosphate-solubilizing bacteria enhance soil phosphorus availability and promote plant growth through phosphorus solubilization. Marine Bacillus has disease-resistant properties, helping plants enhance their disease resistance and adaptability. Bacillus thuringiensis acts as a biocontrol agent, reducing the use of chemical pesticides by controlling pests. Collagenous Bacillus not only fixes nitrogen and solubilizes phosphorus but also secretes bioactive substances, enhancing plant stress resistance. Bacillus subtilis promotes plant growth by inhibiting pathogens and secreting plant hormones. Arbuscular mycorrhizal fungi, such as *Armillaria mellea*, form symbiotic relationships with plant roots, improving the absorption of water and phosphorus and enhancing stress resistance; while *Armillaria mellea* forms a symbiotic relationship with trees, improving nutrient absorption and enhancing drought and disease resistance. The application of these microorganisms not only improves soil fertility and plant growth rate, but also helps to establish a more stable plant-microbe ecosystem, providing a solid foundation for long-term vegetation restoration.

[0042] Example 1

[0043] Near-natural vegetation landscape construction of Cherry River Ecological Island in Minhang District, Shanghai

[0044] The Cherry River Ecological Island in Minhang District, Shanghai, is located within the Minhang Campus of East China Normal University. It is bounded by the intersection of Xinglin East Road, Xinglin West Road, and the Buyun Bridge section of the Cherry River, comprising a triangular area of ​​8847 square meters and a long, narrow island of 3534 square meters. During the near-natural vegetation reconstruction, ten typical plant community quadrats were selected from the preserved natural vegetation of Dajinshan Island and Sheshan Remnant Hills near Shanghai. Two quadrats were selected on the Cherry River Ecological Island as controls. The improved AHP-entropy weighted naturalness evaluation method of this patent was used to comprehensively evaluate the naturalness of the selected plant communities. The levels were divided into four categories: I, II, III, and IV, based on percentage. If scores were consistent, the closer the evaluation content was to the upper or lower position, the higher level was selected. Branches greater than or equal to 75% were classified as Level I, greater than or equal to 50% as Level II, greater than or equal to 25% as Level III, and the rest as Level IV. The results are shown in Table 1.

[0045] Table 1. Naturalness Evaluation Results of Typical Plant Communities in and Around Cherry River Eco-Island

[0046]

[0047]

[0048] In plots 1, 6, 7, and 8, the population diameter-level frequency distribution method of this patent was used to select climax pioneer species, successional sequence species, and successional climax species. The results are shown in Table 2.

[0049] Table 2. Recommended Species for Near-Natural Community Restoration on Cherry River Eco-Island

[0050] Top-level adaptability Recommended species Pioneer species of succession Liquidambar formosana, Chinaberry, Goldenrain tree, Celtis sinensis, Coral hackberry Succession sequence Red nan, Zhoushan new wood ginger, ligustrum lucidum, cassia wood, mosquito mother tree Climax of succession Oak, small-leaved oak, camphor, holly, oleaster

[0051] Plots 11 and 12 were restored using the heterogeneous-diameter-class-synchronous stratified mixed planting method of this patent. The natural plant community multi-layered structure was constructed as follows: The upper layer consisted of randomly planted saplings of the aforementioned five deciduous broad-leaved tree species at a density of 1-1.5 trees per square meter to form a shade-providing layer. The saplings had a diameter at breast height (DBH) of 2-3 cm and a height of 1.5-3 m. The lower layer consisted of randomly mixed and densely planted five successional sequence species and climax species at a density of 2-3 trees per square meter to form a shade-tolerant plant layer. The saplings had a height of 0.5-1.5 m. After planting, the plants were thoroughly watered. The soil surface was covered with crop straw or other organic mulch from green plants and appropriately reinforced to prevent soil drying and weed growth. After three years of growth, once the lower-layer tree species of the community had reached a certain scale, the succession pioneer species and succession sequence species were appropriately thinned out, and the density of the main tree species was adjusted to reduce the competitive pressure between different layers of the plant community and within the same layer.

[0052] Results of this embodiment: Two, ten, and fifteen years after completion, the naturalness evaluation index of the sample plot was re-evaluated with reference to the initial evaluation of typical plant communities in this embodiment. The results are shown in Table 3.

[0053] Table 3. Evaluation results of the naturalness of plant communities at different restoration stages on Cherry River Eco-Island

[0054]

[0055] Ecological aspects: See Figure 2After two years of restoration, the rating of plot 11 improved from IV to III, and the near-natural evaluation value of the plant community in plot 12 also improved. In both plots, the pioneer deciduous trees showed rapid growth, reaching a maximum height of over 5 meters, while the maximum height of evergreen broad-leaved trees was around 3 meters. The relative height growth of the main target tree species was over 45%. The canopy closure reached 70%, indicating that the forest was essentially closed. After 15 years of growth, the rating of plot 11 has been upgraded from II to III, and plot 12 has also been upgraded to III. The height of deciduous trees in the plots can reach 12-15m, and the diameter at breast height ranges from 20-35cm. Among the succession sequence species and climax species, the height of evergreen trees reaches more than 10m and the diameter at breast height reaches 15-25cm, making it a lush and healthy ecological island. It has attracted more than 90 species of birds to settle and rest here. The stability of the plant community has been greatly improved, shortening the succession time from secondary bare land to evergreen deciduous broad-leaved forest from at least 50 years to about 15 years, which greatly shortens the vegetation succession process.

[0056] Economically, cost accounting shows that the total cost of planting trees and maintaining them for two years under this invention is 200,000 yuan per hectare. In comparison, the cost of afforestation in similar green areas in Shanghai is 520,000 yuan per hectare. Therefore, the cost of this invention is only about 40% of that of conventional afforestation. Thus, the construction cost of the near-natural plant landscape construction method for ecological islands using this invention is significantly reduced.

[0057] Example 2

[0058] Near-natural vegetation landscape construction of Wenzhou Sanyang Wetland Ecological Island

[0059] Sanyang Wetland Park is located in central Wenzhou, bordered by Ouhai Avenue to the north, Nantang Avenue to the west, Zhongxing Avenue to the east, and faces Daluo Mountain across the expressway to the south. Fourteen typical forest belts within the park were selected for a comprehensive evaluation of their naturalness using the improved AHP-entropy weight naturalness evaluation method of this patent. The naturalness was assessed based on percentage levels, resulting in four levels: I, II, III, and IV. If scores were consistent, the closer the evaluation content was to the upper or lower position, the higher level was selected. Branches greater than or equal to 75% were classified as Level I, greater than or equal to 50% as Level II, greater than or equal to 25% as Level III, and the remainder as Level IV. The results are shown in Table 4.

[0060] Table 4. Evaluation results of plant communities of different vegetation types in Sanyang Wetland

[0061]

[0062]

[0063] The results of selecting climax pioneer species, successional sequence species and successional climax species in plots 1, 2, 3, 7, 8 and 10 using the population diameter-level frequency distribution method of this patent are shown in Table 5.

[0064] Table 5. Recommended Zonal Species of Near-Natural Community in Sanyang Wetland

[0065] Top-level adaptability Recommended species Pioneer species of succession Sour jujube, hackberry, goldenrain tree, sweetgum, Chinese pistache Succession sequence Waxberry, Monkey Delight, Cinnamon Tree, Elaeocarpus decipiens, Photinia, Bauhinia purpurea, Loropetalum chinense, Honeysuckle, and Prunus sasanqua Climax of succession Castanopsis sclerophylla, Cinnamomum camphora, Quercus glauca, Ficus microcarpa var. sessileus, Elaeagnus pungens, Camellia japonica, Gardenia jasminoides

[0066] Ecological aspects: Plots 4, 5, 6, 9, 11, 12, 13, and 14 were restored using the heterospecies-differentiated-diameter-level stratified mixed planting method of this patent. Construction of a multi-layered natural plant community structure: Native trees were planted as the dominant species, with different tree heights and species in the tree layer. Three successor pioneer species were randomly planted at a density of 1-1.5 trees per square meter, with the pioneer species being *Koelreuteria paniculata*, *Liquidambar formosana*, and *Celtis sinensis*. At a density of 2-3 trees per square meter, densely planted successor sequence species and climax species, including *Quercus glauca*, *Castanopsis fargesii*, *Ligustrum lucidum*, *Lonicera japonica*, *Jasminum nudiflorum*, and *Loropetalum chinense*, were randomly mixed to form a shade-tolerant layer in the lower part of the community, constructing a heterospecies-differentiated-diameter-level stratified mixed planting structure, promoting community succession while increasing seasonal phenological layers. The expected plant landscape effect after 15 years is as follows: Figure 3 As shown, a heterogeneous-diameter-level multilayered structure is formed by the mixing of evergreen and deciduous plants.

[0067] Economically, after constructing a near-natural vegetation landscape in the Sanyang Wetland Park using this patent, cost accounting shows that the total cost of tree planting and two-year maintenance over the two-year period is 160,000 yuan per hectare. In comparison, the cost of afforestation for similar green areas in Wenzhou is 400,000 yuan per hectare. Therefore, the cost of this invention is only 40% of that of conventional greening. Thus, the near-natural plant landscape construction method of this invention significantly reduces construction costs.

[0068] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for constructing a near-natural vegetation landscape for urban wetland ecological islands, characterized in that, The city in question is a city in the Yangtze River Delta region, and the construction method includes the following steps: Step S1: Select several plant communities in the target area for constructing near-natural vegetation landscape and its surrounding areas, and evaluate their naturalness using the improved AHP-entropy weight method to obtain a reference native plant community suitable for constructing near-natural vegetation landscape for urban wetland ecological islands. Step S2: Set up several square sample grids in each native plant community of the reference system, and mark the species, diameter at breast height and coordinate position information of woody plants with a height of more than 1.5m in each sample grid. Based on the marked information, divide the apical pioneer species, succession sequence species and succession apex species in each sample grid. Step S3: Using a mixed planting method of different species, different diameter at breast height, and simultaneous layered intercropping, plant the apex pioneer species, succession sequence species, and succession apex species in the target area of ​​the near-natural vegetation landscape construction. Before planting, the succession sequence species and succession apex species are dipped in a mud slurry made of root-promoting microbial agent and water. In step S2, the climax pioneer species, successional sequence species, and successional climax species are classified according to the frequency curve of diameter at breast height (DBH). The DBH frequency curve of the climax pioneer species is unimodal, corresponding to the small DBH class. The DBH frequency curve of the successional sequence species is a discontinuous series of unimodal peaks, concentrated in the medium DBH class. The DBH frequency curve of the successional climax species is a continuous inverted J-shaped distribution, exhibiting a large peak in the small DBH class and a small peak in the large DBH class. The horizontal axis of the DBH frequency curve represents the diameter at breast height (DBH), with 5 cm as a unit. The small chest diameter range is less than 5cm, the medium chest diameter range is less than 5cm-20cm, and the large chest diameter range is greater than 20cm. In step S3, the climax pioneer species are randomly planted at a density of 1 to 1.5 trees per square meter, with 1 to 3 species, a diameter at breast height of 3 to 5 cm, and a height of 2 to 4 m, forming a shade layer on the upper part of the community; the successional sequence species are densely planted in clusters at a density of 2 to 3 trees per square meter, with 3 to 5 species and a height of 1 to 1.5 m; the successional climax species are densely planted in clusters at a density of 2 to 3 trees per square meter, with 3 to 5 species and a height of 0.5 to 1 m, forming a shade-tolerant layer of the community. In step S3, the root-promoting microbial agent is selected from Rhizobium radialis (Radiata rhizobium). Frankia spp.), Bacillus megaterium ( Bacillus megaterium ), Bacillus subtilis ( Bacillus velezensis ), gelatinous spore-forming bacteria ( Paenibacillus polymyxa ), Bacillus thuringiensis ( Bacillus thuringiensis ), gelatinous spore-forming bacteria ( Paenibacillus polymyxa ), Bacillus phosphate-solubilizing Bacillus megaterium Bacillus subtilis ( Bacillus subtilis ), globosum ( Glomus intraradices ) and Armillaria mellea ( Laccaria bicolor At least two of them.

2. The method for constructing a near-natural vegetation landscape for an urban wetland ecological island according to claim 1, characterized in that, In step S1, 10-15 plant communities are selected in the target area for constructing near-natural vegetation landscape and its surrounding areas.

3. The method for constructing a near-natural vegetation landscape for an urban wetland ecological island according to claim 1, characterized in that, In step S2, 3-5 square sample grids are set in each reference system native plant community, and the side length of the square sample grid is not less than 10m.

4. The method for constructing a near-natural vegetation landscape for an urban wetland ecological island according to claim 1, characterized in that, In step S2, the apex pioneer species is selected from at least two of the following: Celtis sinensis, Quercus acutissima, Liquidambar formosana, Ziziphus jujuba, Pistacia chinensis, Koelreuteria paniculata, Pterocarya stenoptera, Rhizoma et Rhizoma serrata, Celtis sinensis, Acer triangularis, Ulmus parvifolia, Acer palmatum, Pyrus pyrifolia, Melia azedarach, Dalbergia odorifera, and Morus alba.

5. The method for constructing a near-natural vegetation landscape for an urban wetland ecological island according to claim 1, characterized in that, In step S2, the succession sequence species are selected from at least three of the following: *Phoebe zhennan*, *Phoebe bournei*, *Symplocos pubescens*, *Cinnamomum camphora*, *Homalomena occulta*, *Elaeocarpus decipiens*, *Ilex cornuta*, *Ligustrum lucidum*, *Myrica rubra*, *Cinnamomum camphora*, *Photinia serratifolia*, *Loropetalum chinense*, *Bauhinia purpurea*, *Prunus salicina*, and *Lonicera japonica*.

6. The method for constructing a near-natural vegetation landscape for an urban wetland ecological island according to claim 1, characterized in that, In step S2, the climax species of succession is selected from at least two of the following: Quercus glauca, Castanopsis chinensis, Quercus microcarpa, Cinnamomum camphora, Castanopsis sclerophylla, Castanopsis sclerophylla, Ficus microcarpa sessileus, Camellia sinensis, Camellia japonica, Gardenia jasminoides, Staphylococcus aureus, Ilex cornuta, Elaeagnus pungens, and Osmanthus fragrans.

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