Leucaena leucocephala slope plant community restoration method

Abstract

The invention belongs to the technical field of vegetation restoration, and discloses a leucaena leucocephala slope plant community restoration method, which comprises the following steps: S1, introducing a fern spore source into a slope; s2, planting winter red seedlings among leucaena leucocephala plants; s3, planting callicarpa small arbors; and S4, carrying out tending treatment. According to the method, pteridium aquilinum, shrub and small arbor plant varieties which can survive in the leucaena leucocephala allelochemical soil structure are selected and are planted step by step, plant community composition is replaced, the continuity of the landscape can be guaranteed to the maximum extent, repeated rework of large-scale disassembly and large-scale construction is avoided, and the cost is reduced. The plant coverage rate of the repaired side slope is high, invasion of mikania micrantha is effectively resisted, the stability is high, and water and soil loss can be better avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of vegetation restoration, and in particular relates to a method for restoring a leucaena leucaena slope plant community. Background Art

[0002] Leucaena leucocephala is widely used in slope plant restoration in South China and Southwest my country. Although the slope site conditions are poor, Leucaena leucocephala has the characteristics of high growth rate, strong drought resistance, and resistance to barrenness, and can quickly form a forest and stabilize the slope in time. As a typical invasive alien plant, Leucaena leucocephala can release allelopathic substances into the soil through leaf leaching and volatilization, change the microhabitat conditions of understory plants, and inhibit the seed germination and seedling development of other species under the forest by promoting its own growth. After Leucaena leucocephala is established, it is often a single dominant pure forest. Few local plants settle and grow under the forest, resulting in low vegetation coverage on the ground surface under the forest, which seriously affects the species diversity of the community and also has a certain degree of impact on the soil and water conservation capacity of the slope. In addition, Leucaena leucocephala has a large number of seeds and grows rapidly. It can quickly spread and colonize around the slope, causing invasive damage to the local plant communities on the slope and the surrounding area. Therefore, the plant community on the slope of Leucaena leucocephala pure forest is in urgent need of restoration.

[0003] In the existing slope repair technology, some projects are equipped with a variety of plants such as Leucaena leucophylla, Cynodon dactylon, Croton rotundus and Medicago sativa to artificially create a stable plant community. However, under the poor site conditions of the slope, Leucaena leucophylla grows rapidly by virtue of its own advantages, and at the same time inhibits the normal growth of other surrounding plants through allelopathic effects, and eventually becomes a single Leucaena leucophylla pure forest. Patent CN202010195801.3 proposes to use Leucaena leucophylla as a pioneer plant to stabilize the slope, followed by mowing and inhibition treatment, and then replanting native seedlings such as Nephrolepis chinensis, Prunus armandii, and Chinese Worry-free Flower to achieve the repair effect. However, this technology has the following disadvantages: (1) There is a period of exposed loess after mowing, the landscape effect is poor, and mud landslides are prone to occur if it rains. (2) The technical requirements and difficulty coefficient are high, and the workload is large. Mowing and the inhibition treatment of applying herbicide slurry are both performed on the slope. In practical applications, it is difficult to achieve the purpose of completely inhibiting the survival of Leucaena leucophylla. (3) As the soil is affected by the fallen leaves and root allelopathic substances of Leucaena leucaena, the growth of native plants is poor and it is difficult to achieve the desired effect. (4) This technology is aimed at the slopes of park roads or highways in parks, botanical gardens and scenic spots, and its application scope is relatively small.

[0004] Therefore, how to increase the biodiversity and community-level complexity of the restored vegetation, improve the established Leucaena leucaena forests, and inhibit the "malignant" spread of Leucaena leucaena has become a key technical issue that needs to be urgently addressed in slope ecological restoration work. Summary of the invention

[0005] In view of the deficiencies of the prior art and actual needs, the present invention provides a method for restoring a leucaena slope plant community to solve the technical problems of using leucaena to repair slopes in the prior art, such as poor landscape, poor soil and water conservation, and narrow application range.

[0006] To achieve the above-mentioned purpose, the present invention provides a method for restoring the Leucaena leucaena slope plant community. The restoration method comprises the following steps:

[0007] S1: introduction of ferns into the slope;

[0008] S2: Plant winter red seedlings between Leucaena leucaena plants;

[0009] S3: Plant small trees of the genus Callicarpa.

[0010] Furthermore, the operation of introducing ferns into the slope in step S1 is carried out from May to September, and the ferns are planted next to the Leucaena leucaena plants at a planting density of 5-10 plants / 100 square meters, and watered once on the day of planting.

[0011] Furthermore, the fern plant is a mature individual of one or more of Pteris cretica, Pteris fasciata and Pteris fasciata.

[0012] Furthermore, the operation of planting winter red seedlings between Leucaena leucaena plants in step S2 is carried out from October to January of the following year.

[0013] Further, the specification of the winter red seedlings is 10-30 cm in height, and the planting density is 3-5 plants / 10 square meters. After planting, water once every 15 days for 3 consecutive times, and no watering is required in case of rain.

[0014] Furthermore, the planting of Callicarpa spp. small trees in step S3 is carried out from February to May of the following year, with a plant height of 50-80 cm and a planting density of 10-30 plants / 100 square meters. Watering is performed once every half month after planting for 2 consecutive times.

[0015] Furthermore, the Callicarpa spp. small tree is one or more of Callicarpa macrophylla, Callicarpa oleracea and Callicarpa nudiflora.

[0016] Furthermore, the step S3 also includes cutting down the Leucaena leucaena 1-3 cm above the ground to expose ferns and winter holly.

[0017] Furthermore, the method further comprises:

[0018] S4: Perform nurturing treatment.

[0019] Furthermore, the nurturing is carried out 6 months and 1 year after planting the Callicarpa spp.

[0020] Furthermore, the 6-month care after planting Callicarpa spp. small trees includes applying compound fertilizer, removing climbing invasive plants such as Mikania micrantha and Ipomoea aurea, and eradicating new shoots of Leucaena leucaena.

[0021] Furthermore, the compound fertilizer is NPK=15-15-15, that is, a compound fertilizer with a nitrogen content of 15%, a phosphorus content of 15%, and a potassium content of 15%.

[0022] Furthermore, the care one year after planting Callicarpa ovata small trees includes cutting the Callicarpa ovata 1.5-2 meters above the ground to promote the growth of side branches; and removing the sporadic sprouts from the cut ends of Mikania micrantha and Leucaena leucophylla.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention provides a method for restoring a leucaena leucaena slope plant community, which can respectively plant ferns, shrubs and small trees in a step-by-step manner, change the community composition, ensure the continuity of the landscape, avoid large-scale demolition and repeated rework, and can protect the stability of the slope and avoid soil erosion.

[0025] (2) High plant survival rate. Select plant species that can survive in the soil structure of Leucaena leucaena allelopathic substances to improve the survival rate of seedlings.

[0026] (3) Good economic efficiency. Planting a small amount of ferns mainly relies on the ferns' own survival strategies and wind power to complete the spore spread and the expansion of ferns, reducing manpower and financial resources.

[0027] (4) Small impact on the ecological environment. No herbicides or other chemical agents are used to avoid changing the soil structure and microhabitat.

[0028] (5) Enrich the plant species on the slopes. Form a composite vegetation of small trees, shrubs, and ferns to improve the biodiversity and stability of the slope community.

[0029] (6) Effectively prevent and control invasive plants. The native plant Callicarpa gracilis was used as the plant for slope restoration. Its leaf litter has an inhibitory effect on the seed germination, stem rooting, and vegetative growth of Mikania micrantha, thus avoiding the risk of invasion by Mikania micrantha.

[0030] (7) Strong applicability. The repair method of the present invention has a wide range of applications, and can be applied not only to park road slopes or highway slopes in parks, botanical gardens, and scenic spots, but also to other types of slopes, such as mountain collapse slopes, open-pit mine slopes, dam slopes, and building slopes. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0032] Figure 1 It is a pure forest of Leucaena leucaena on the road slope of Shenzhen Xiaping Environmental Park;

[0033] Figure 2 It is a pure forest of Leucaena leucaena on the slope of the highway;

[0034] Figure 3 It is a small amount of black fern growing under the pure forest of Leucaena leucaena.

[0035] Figure 4 This is the GC-MS spectrum of the ethanol extract of fresh leaves of Callicarpa nudiflora;

[0036] Figure 5 The road slope condition of Shenzhen Xiaping Environmental Park after restoration in Example 1 of the present invention;

[0037] Figure 6 This is the highway slope condition after repair in Example 2 of the present invention. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments and drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The present invention is specifically introduced below in conjunction with the specific embodiments.

[0039] Plant allelopathy is the release of allelopathic substances produced by plants into the environment during their growth process, which has a direct or indirect impact on other plants around them. Allelopathy, as a way for plants to exchange information with each other, is a common phenomenon in ecosystems. Almost all plants can produce substances with allelopathic effects and have varying degrees of impact on other species. Through allelopathy, plants can improve their competitiveness against other individuals in ecological elements such as sunlight, water, nutrients and space. This interaction is an important survival strategy adopted by plants in the long-term evolution process.

[0040] Seed germination and seedling settlement growth are important stages in the life history of plants. They are also the stages when plants are most sensitive to external environmental conditions. Therefore, they are also the stages when plants are most susceptible to allelopathic effects. Studies have found that Leucaena leucophylla has an allelopathic inhibitory effect on the seed germination and seedling survival of companion species. By producing allelopathic substances, it inhibits seed germination and seedling growth, thereby inhibiting the settlement of other plants. This is one of the important reasons why other species find it difficult to settle under Leucaena leucophylla forests. In pure Leucaena leucophylla slope forests, when the concentration of allelopathic substances released into the soil reaches the effective action threshold, the seed germination, seedling settlement growth, organ development and other growth and development stages of other companion plants under the forest, as well as photosynthetic physiology and other functions will be inhibited to varying degrees. This inhibitory effect has a concentration effect. The higher the concentration, the stronger the inhibitory effect.

[0041] Therefore, after the slopes restored with Leucaena leucophylla are forested, the allelopathic effect of the pure Leucaena leucophylla forest will affect the settlement and succession of other local species, resulting in reduced species diversity, lack of surface vegetation layer, and low soil and water conservation capacity of the community. Figure 1-Figure 2 The figure shows the road slopes and highway slopes of Shenzhen Xiaping Environmental Park that were restored using Leucaena leucaena. It can be seen that after the Leucaena leucaena forest formed, there were almost no other native species underneath, which to some extent affected the ecological protection effect after the slope restoration.

[0042] In response to the allelopathic effect of pure Leucaena leucaena forest and the resulting problems such as low species diversity and simple structure of the community, the inventors screened out species with strong adaptability to the allelopathic effect of Leucaena leucaena after conducting a large number of field surveys, and planted them at intervals between Leucaena leucaena plants, increasing the chances of local shrubs and herbaceous plants settling in the community, thereby increasing the species diversity of the slope, improving the structure of the community, and enhancing the stability of the slope ecosystem.

[0043] The embodiment of the present invention provides a method for restoring acacia leucaena slope plant community. The restoration method comprises the following steps:

[0044] S1: introduction of a source of fern spores into the slope;

[0045] S2: Plant winter red seedlings between Leucaena leucaena plants;

[0046] S3: Plant small trees of the genus Callicarpa.

[0047] The main purpose of step S1 is to introduce spore sources for fern reproduction into the pure forest of Leucaena leucophylla, and to reduce the labor costs of watering and digging for planting as much as possible. The inventor found through field investigation that the soil on the slope of the pure forest of Leucaena leucophylla was very dry and barren, with bare loess under the forest, and only a small amount of black hair fern, centipede pteris, and line feather pteris were distributed, and no other species (such as Figure 3As shown in the figure, only a small amount of black hair ferns exist under the pure forest of Leucaena leucaena. Ferns can survive normally and produce spores when there is water, and can quickly produce spores for propagation when there is a lack of water, meeting the need to introduce a source of fern spores. Therefore, the inventor believes that these three ferns have good drought resistance and can survive in the soil after the allelopathic effect of Leucaena leucaena.

[0048] Specifically, the operation of introducing the fern spore source into the slope in step S1 is carried out from May to September, and the fern is planted next to the Leucaena leucaena plants at a planting density of 5-10 plants / 100 square meters, and watered once on the day of planting.

[0049] Specifically, the fern plant is a mature individual of one or more of Pteris cretica, Pteris cretica, and Pteris cretica.

[0050] The inventors found that the winter red can not only survive and grow in the soil after the allelopathic effect of Leucaena leucaena, but also survive and grow slowly under hidden conditions; it grows rapidly when there is sufficient sunlight, has a large number of flowers and can attract bees, insects and birds, and has good landscape and ecological effects; the branches are soft, and after the branch height reaches 1.5 meters, it droops naturally, and has the advantage of good coverage, which is suitable for restoring the community diversity of pure Leucaena leucaena forests.

[0051] Specifically, the operation of planting winter red seedlings between Leucaena leucaena plants in step S2 is carried out from October to January of the following year.

[0052] Specifically, the specification of the winter red seedlings is 10-30 cm in height, and the planting density is 3-5 plants / 10 square meters. After planting, water once every 15 days for 3 consecutive times, and no watering is required in case of rain.

[0053] In order to reduce the impact on the local ecology, the inventors selected a type of local native plant: Callicarpa, as the tree for restoring the pure forest of Leucaena leucophylla. Callicarpa plants grow rapidly and can gain an advantage in the competition with Leucaena leucophylla sprouts. Some studies have shown that the leaves of Callicarpa plants are rich in ingredients such as luteolin, luteolin, and verbascoside, which can effectively resist the influence of Leucaena leucophylla allelopathic substances; at the same time, these ingredients can also inhibit the growth of roots and leaves of Mikania micrantha and the germination of seeds, making it difficult for invasive plants such as Mikania micrantha to invade the Callicarpa community. The inventors used the existing general extraction method and referred to the literature method (Pan Zhenghong, Huang Sisi, Huang Sheng, et al. Study on the antioxidant activity of Callicarpa nudiflora extract and its main components [J]. Guangxi Plants, 2016, 36(09): 1107-1111.) to process the samples: 5 kg of fresh leaves of Callicarpa nudiflora were cut into pieces and extracted with 95% ethanol under heating and reflux. The extract was filtered and concentrated under reduced pressure to 100 ml of concentrate. Wuhan Maiwei Metabolic Biotechnology Co., Ltd. was commissioned to use Shimadzu conventional gas chromatography-mass spectrometry (GCMS-QP2010 Plus) to perform extensive targeted metabolome analysis on the samples based on gas chromatography-mass spectrometry (GC-MS) technology. The GC-MS spectrum obtained in the experiment is shown in the figure. Figure 4 For specific metabolite identification and analysis methods, please refer to the company's instruction manual. Figure 4 It can be seen that the leaves of Callicarpa nudiflora are rich in compounds such as luteolin (peak 24), luteolin glycoside (peak 15), and verbascoside (peak 10), indicating that Callicarpa nudiflora has the ability to survive under Leucaena leucaena forests and prevent other invasive species.

[0054] Specifically, the planting of Callicarpa spp. small trees in step S3 is carried out from February to May of the following year, with a plant height of 50-80 cm and a planting density of 10-30 plants / 100 square meters. Watering is performed once every half month after planting for 2 consecutive times.

[0055] Specifically, the Callicarpa spp. small tree is one or more of Callicarpa macrophylla, Callicarpa oleracea and Callicarpa nudiflora.

[0056] Specifically, the step S3 further comprises cutting down the Leucaena leucaena 1-3 cm above the ground to expose ferns and winter lilies.

[0057] Specifically, the method further includes:

[0058] S4: Perform nurturing treatment.

[0059] Specifically, the nurturing is carried out 6 months and 1 year after planting the Callicarpa spp.

[0060] Specifically, the 6 months of nurturing after planting small trees of the genus Callicarpa include applying compound fertilizers, removing climbing invasive plants such as Mikania micrantha and Ipomoea aurea, and eradicating new shoots of Leucaena leucaena.

[0061] Specifically, the compound fertilizer is NPK=15-15-15, that is, a compound fertilizer with a nitrogen content of 15%, a phosphorus content of 15%, and a potassium content of 15%.

[0062] Specifically, the care one year after planting the Callicarpa small trees includes cutting the trunk of the Callicarpa small trees 1.5-2 meters above the ground to promote the growth of their side branches; and removing the sporadic sprouts from the cut ends of Mikania micrantha and Leucaena leucophylla.

[0063] The following is explained in conjunction with specific embodiments:

[0064] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified, and the techniques not described in detail are all performed according to standard methods well known to those skilled in the art.

[0065] Example 1 Plant community restoration of the Leucaena leucaena slope in Shenzhen Xiaping Environmental Park

[0066] This embodiment provides a method for restoring the plant community of a leucaena leucaena slope on a park road. The method for restoring the plant community of a leucaena leucaena slope comprises the following steps:

[0067] S1: Introducing a source of fern spores into the slope

[0068] In August 2022, in the slope Leucaena forest ( Figure 1 ) were introduced into the soil, and mature individuals of Pteris cretica and Pteris fasciata were planted next to the Leucaena leucaena plants. The planting density of Pteris cretica was 3 plants / 100 square meters, and the planting density of Pteris cretica was 3 plants / 100 square meters. Watering was done once on the day of planting.

[0069] S2: Planting winter red seedlings between Leucaena leucaena plants

[0070] In December, plant 10-30cm tall winter red seedlings between Leucaena plants, with a planting density of 3-5 plants / 10 square meters. Water once every 15 days after planting, for 3 consecutive times, and no watering is required if it rains.

[0071] S3: Planting Callicarpa spp.

[0072] In April of the following year, cut the leucaena off the ground 1-3cm, exposing the ferns and winter red, and plant the 50-80cm tall Callicarpa macrophylla and Callicarpa nudiflora, with a planting density of 5 plants / 100 square meters and 15 plants / 100 square meters respectively. Water once every half month after planting for 2 consecutive times.

[0073] S4: Nurturing treatment

[0074] In October of the following year, compound fertilizer (NPK=15-15-15, with 15% nitrogen, 15% phosphorus and 15% potassium) was applied to the restored forest to remove climbing invasive plants such as Mikania micrantha and Ipomoea aurea, and to wipe out new shoots of Leucaena leucaena.

[0075] In April of the following year, the stems of small Callicarpa trees should be cut back 1.5-2 meters from the ground to promote the growth of side branches; the sporadic sprouts from the cut ends of Mikania micrantha and Leucaena leucaena should be removed.

[0076] Repair effect

[0077] like Figure 5 As shown, the Leucaena leucaena slope restored by the method described in the present invention has a surface vegetation coverage of 100% and significantly improved species diversity.

[0078] Example 2 Plant community restoration of Leucaena leucaena slope on highway

[0079] This embodiment provides a method for restoring the plant community of a leucaena leucaena slope on a park road. The method for restoring the plant community of a leucaena leucaena slope comprises the following steps:

[0080] S1: Introducing a source of fern spores into the slope

[0081] In August 2022, in the slope Leucaena forest ( Figure 2 ) were introduced into the soil, and mature individuals of Pteris cretica and Pteris fasciata were planted next to the Leucaena leucaena plants. The planting density of Pteris cretica was 3 plants / 100 square meters, and the planting density of Pteris cretica was 3 plants / 100 square meters. Watering was done once on the day of planting.

[0082] S2: Planting winter red seedlings between Leucaena leucaena plants

[0083] In December, plant 10-30cm tall winter red seedlings between Leucaena plants, with a planting density of 3-5 plants / 10 square meters. Water once every 15 days after planting, for 3 consecutive times, and no watering is required if it rains.

[0084] S3: Planting Callicarpa spp.

[0085] In April of the following year, cut the leucaena off the ground 1-3cm, exposing the ferns and winter red, and plant the 50-80cm tall Callicarpa macrophylla and Callicarpa nudiflora, with a planting density of 5 plants / 100 square meters and 15 plants / 100 square meters respectively. Water once every half month after planting for 2 consecutive times.

[0086] S4: Nurturing treatment

[0087] In October of the following year, compound fertilizer (NPK=15-15-15, with 15% nitrogen, 15% phosphorus and 15% potassium) was applied to the restored forest to remove climbing invasive plants such as Mikania micrantha and Ipomoea aurea, and to wipe out new shoots of Leucaena leucaena.

[0088] In April of the following year, the stems of small Callicarpa trees should be cut back 1.5-2 meters from the ground to promote the growth of their side branches; the sporadic sprouts from the cut ends of Mikania micrantha and Leucaena leucaena should be removed.

[0089] Repair effect

[0090] like Figure 6 As shown, the Leucaena leucaena slope restored by the method described in the present invention has a surface vegetation coverage of 100% and significantly improved species diversity.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for restoring a Leucaena leucaena slope plant community, comprising: S1: introduction of ferns into the slope; S2: Plant winter red seedlings between Leucaena leucaena plants; S3: Planting small trees of the genus Callicarpa.

2. The repair method according to claim 1, characterized in that: The operation of introducing ferns into the slope in step S1 is carried out from May to September. The ferns are planted next to the Leucaena leucaena plants at a planting density of 5-10 plants / 100 square meters, and watering is performed once on the day of planting.

3. The repair method according to claim 1 or 2, characterized in that: The fern plant is one or more mature individuals of Pteris cretica, Pteris spheniscus and Pteris spheniscus.

4. The repair method according to claim 1, characterized in that: The operation of planting winter red seedlings between Leucaena leucaena plants in step S2 is carried out from October to January of the following year.

5. The repair method according to claim 1 or 4, characterized in that: The specifications of the winter red seedlings are plant height 10-30cm, and the planting density is 3-5 plants / 10 square meters; after planting, water them once every 15 days for 3 consecutive times, and no watering is required in case of rain.

6. The repair method according to claim 1, characterized in that: The planting of Callicarpa small trees in step S3 is carried out from February to May of the following year, the height of the Callicarpa small trees is 50-80 cm, and the planting density is 10-30 trees / 100 square meters; after planting, watering is carried out once every half month for 2 consecutive times.

7. The repair method according to claim 1 or 6, characterized in that: The Callicarpa spp. small tree is one or more of Callicarpa macrophylla, Callicarpa oleracea and Callicarpa nudiflora.

8. The repair method according to claim 1 or 6, characterized in that: The step S3 also includes cutting down the Leucaena leucaena 1-3 cm above the ground to expose ferns and winter lilies.

9. The repair method according to claim 1, characterized in that: The method further comprises S4: performing a tending treatment.

10. The repair method according to claim 9, characterized in that: The nurturing is carried out 6 months and 1 year after the planting of the Callicarpa spp. The nurturing treatment includes applying compound fertilizer, removing climbing invasive plants such as Mikania micrantha and Ipomoea aurea, and eradicating new shoots of Leucaena leucaena; Alternatively, cut back the stems of Callicarpa spp. small trees 1.5-2 meters above the ground to promote the growth of their side branches; and remove the sporadic sprouts from the cut ends of Mikania micrantha and Leucaena leucophylla.

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