Forest-water composite low-efficiency forest transformation method

Abstract

The invention discloses a forest-water composite low-efficiency forest reconstruction method, which is based on a forest-water collaborative reconstruction method of vertical gradient design-vegetation layered configuration-hydrological dynamic regulation and control, and constructs a low-efficiency forest reconstruction system of mutual assistance of forest water, diverse habitats and composite functions based on a natural succession law. The problems of unbalanced water regulation and control, single ecological structure and the like in traditional transformation are effectively solved, the forest land regulation and storage capacity, the biological diversity and the carbon sink water quality purification function are improved, and conversion from low-efficiency forests to a high-efficiency composite ecological system is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of forestry, and in particular to a method for transforming a low-efficiency forest with forest-water composite. Background Art

[0002] Low-efficiency forests refer to forest stands with low productivity and weak ecological functions due to unreasonable tree species configuration, unbalanced water regulation, and a single ecological structure. Currently, the transformation of low-efficiency forests faces the following key issues:

[0003] Fragmentation of the forest-water system: Traditional transformation focuses only on the forest itself, ignoring the synergistic effect of forest land and water systems. This leads to difficulty in draining water during the flood season (increasing the incidence of waterlogging by 30%-40%), insufficient water during the dry season (soil moisture content is 20%-30% lower than the optimum value), and restricted forest growth.

[0004] Unbalanced ecological structure: a high proportion of single tree species (often exceeding 70%), lack of vegetation in the terrestrial-aquatic transition zone, fragmented biological habitats (amphibians and bird populations decreased by 40%-50%), and the incidence of pests and diseases was 25%-35% higher than that in healthy forest stands.

[0005] Low functional efficiency: weak storage capacity (the flood storage efficiency of traditional forests is only 30%-40%), insufficient water purification (TN removal rate <20%), and carbon sequestration capacity is 20%-25% lower than that of complex ecosystems. Summary of the Invention

[0006] In view of this, the present invention provides a forest-water composite low-efficiency forest transformation method, which is suitable for the systematic ecological restoration and productivity improvement of various low-efficiency woodlands adjacent to water. The method is based on the forest-water coordinated transformation method of "vertical gradient design-vegetation stratification configuration-hydrological dynamic regulation", and constructs a low-efficiency forest transformation system of "forest-water mutual assistance, habitat diversity, and functional complexity" based on the law of natural succession. It effectively solves the problems of water regulation imbalance and single ecological structure in traditional transformation, improves the forest land regulation and storage capacity, biodiversity and carbon sink water purification function, and realizes the transformation of low-efficiency forests into high-efficiency composite ecosystems.

[0007] A method for transforming a low-efficiency forest with forest-water integration, comprising the following steps:

[0008] S1, diagnose the current status of the forest with low forest-water efficiency;

[0009] S2. Based on the current status of the forest-water composite low-efficiency forest, transform the adjacent waterfront land into a vertical gradient terrain consisting of low-bed terraces, middle-bed terraces, and high-bed terraces with different terrain slopes. The low-bed terraces retain their original natural slopes and their original hard revetments are removed and replaced with ecological revetments made of wooden piles, with the spaces between the piles filled with a mixture of humus and gravel.

[0010] S3, excavating an underground infiltration channel at a set depth underground in the vertical gradient terrain, and constructing a gravity overflow system on the ground of the vertical gradient terrain;

[0011] Constructing a three-dimensional drainage network on the high beach terrace of the vertical gradient terrain;

[0012] S4, reconstructing a multi-layered three-dimensional vegetation system on the vertical gradient terrain;

[0013] S5, constructing habitat creation facilities on the vertical gradient terrain;

[0014] S6, simulates high and low water levels to debug the three-dimensional drainage network and gravity overflow system to ensure stable drainage and water storage functions;

[0015] S7. Perform regular maintenance on the gravity overflow system, three-dimensional drainage network, multi-level three-dimensional vegetation system, and habitat creation facilities.

[0016] Preferably, the specific steps of constructing a gravity overflow system on the ground of the multi-level vertical gradient terrain in step S3 are:

[0017] Multi-level terraced detention ponds are excavated along the contour lines on the high beach terrace, with the upper and lower adjacent detention ponds separated by earth ridges;

[0018] A stepped ecological weir was arranged on the middle beach terrace, with a shallow pond-ridge composite terrain constructed between the upper and lower ecological weirs, and water level sensors buried at the edge of the shallow pond.

[0019] Several overflow ditches are excavated on the ground of the low-lying terrace and a second gravel layer is laid in the ditches. Overflow weirs are set up on the water-adjacent embankments of the low-lying terrace and ecological gaps are reserved on the embankments.

[0020] Preferably, the shallow pond-ridge composite terrain includes multiple shallow ponds and ridges arranged between two adjacent shallow ponds.

[0021] Preferably, when constructing a shallow pond-ridge composite terrain, if the current status diagnosis result of the forest-water composite inefficient forest shows that its water quality index is greater than the set value, the total area of the shallow pond is designed to be 40%-50% of the overall area of the middle beach terrace, and an artificial aeration device is added to the shallow pond; if the current status diagnosis result of the forest-water composite inefficient forest shows that its water quality index is less than the set value, the total area of the shallow pond is designed to be 20%-30% of the overall area of the middle beach terrace.

[0022] Preferably, when the water level in the shallow pond is lower than the normal water level, the underground infiltration channel can be used to replenish water to the shallow pond.

[0023] Preferably, the specific steps of constructing a three-dimensional drainage network on the high beach terrace with vertical gradient terrain in step S3 are:

[0024] A plurality of shallow strip trenches with a first slope are excavated on the ground of the high beach terrace, and a first gravel layer is laid in the trenches;

[0025] Dig tree planting trenches on both sides of the shallow strip trench, bury branch pipes connected to the underground infiltration channel at the bottom of the tree planting trench and the shallow strip trench. In drought, the underground infiltration channel can be used to replenish water to the terrace soil through the branch pipes.

[0026] A drainage ditch connected to a strip-shaped shallow ditch is excavated on the ground of the high beach terrace.

[0027] Preferably, the specific steps of reconstructing a multi-layered three-dimensional vegetation system on the vertical gradient terrain in step S4 are:

[0028] Planting a vertical vegetation structure combining a multi-layer terrestrial plant system with a ground cover layer on the high beach terrace to form a high beach sparse forest terrace;

[0029] A vertical vegetation structure combining a multi-layered aquatic plant system and a moisture-resistant shrub layer is planted on the shallow pond-ridge composite terrain of the Zhongtan Terrace to form the Zhongtan Ecological Wetland.

[0030] Plant emergent plants along the direction of water flow on low-lying terraces.

[0031] Preferably, the multi-layer terrestrial plant system planted on the high beach terrace includes a tree layer, a shrub layer and a herb layer. The tree layer is planted along both sides of the strip-shaped shallow ditch, the shrub layer is located under the shade of the tree layer, and the herb layer is located below the shrub layer. The shrub layer is also planted on the earthen ridge between the upper and lower adjacent retention ponds.

[0032] Preferably, the multi-layer aquatic plant system planted in the shallow pond-ridge composite terrain of the Zhongtan Terrace includes a submerged plant layer, a floating leaf plant layer, an emergent plant layer and a shrub layer. The submerged plant layer is planted at the bottom of the shallow pond, a floating island is provided in the shallow pond, floating leaf plants are planted on the floating island, emergent plants are planted on the ridges and the edge of the shallow pond, the shrub layer is planted on the ridges, and a permeable geotextile is laid on the surface of the ridges.

[0033] Preferably, the specific steps of constructing the habitat creation facilities on the vertical gradient terrain in step S5 are:

[0034] In the bank transition zone of the high beach terrace, piles of fallen wood covered with mosses are set up, and wooden planks are built between the strip-shaped shallow grooves;

[0035] Artificial reefs were set up in the shallow ponds of the middle beach terrace, and wooden boardwalks were built between the shallow ponds;

[0036] Pile of fallen wood covered with mosses and artificial fish reefs are set up at the ecological gap of the embankment of the low-lying terrace, and wooden boardwalks are built between the overflow ditches.

[0037] The beneficial effects of the present invention are:

[0038] 1. The three-level terrace forest-water complex ecosystem transformed by the present invention realizes the natural regulation and infiltration of water through the elevation difference of high, middle and low beaches, breaking through the transformation limitations of traditional low-efficiency forests in a single plane, reducing the risk of forest waterlogging, and constructing a multi-layer vegetation system from emergent plants to terrestrial trees on the high, middle and low beach terraces, forming a complete ecological chain, improving biodiversity and ecological functions, and constructing a "structurally stable, functionally complex and self-sustaining" forest-water complex system, providing a replicable technical paradigm for the transformation of low-efficiency forests in different regions across the country.

[0039] 2. This invention utilizes the three-element control mechanism of "elevation difference drive - vegetation damping - soil infiltration" to form a gravity overflow system through a 0.5-1.0m terrace elevation difference. Compared with traditional electric gate storage and regulation, the energy consumption is reduced by 100%. Combined with gravel layer infiltration and plant root blockage, it realizes hydrological and ecological regulation without electricity dependence. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 It is a schematic diagram of the three-level terrace forest-water complex ecosystem after transformation according to the present invention.

[0042] The meanings of the numbers in the figure are:

[0043] 1 is a low beach terrace, 2 is a middle beach terrace, 3 is a high beach terrace, 4 is an underground infiltration channel, 5 is a retention pond, 6 is an ecological weir, 7 is an overflow ditch, 8 is the second gravel layer, 9 is an overflow weir, 10 is a shallow pond, 11 is a drainage ditch, 12 is the first gravel layer, 13 is a branch pipe of the infiltration channel, 14 is an artificial fish reef, and 15 is a pile of fallen trees. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the present invention more clearly apparent, the present invention is described below using specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0045] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0046] It should be understood that although the terms first, second, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be understood to indicate or imply relative importance. These terms are only used to distinguish information of the same type from each other. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information without departing from the scope of this disclosure. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining."

[0047] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0048] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0049] In order to better understand the technical solution of the present invention, the present invention is described in detail below with reference to the accompanying drawings.

[0050] The present invention provides a method for transforming a low-efficiency forest with forest-water composite, which specifically comprises the following steps:

[0051] S1. Diagnose the current status of the forest-water inefficient forest, including the normal water level, topography, soil moisture content, groundwater level, vegetation composition, water quality, etc. of the forest-water inefficient forest.

[0052] When detecting the normal water level of the forest-water composite low-efficiency forest, a level with an accuracy error of ±1 cm is used to measure the average water level line of the water body over many years (based on the long-term observation data of the local hydrological station), and concrete benchmark piles (diameter 10 cm, depth 1.5 m) are buried on the embankment of the water body. The normal water level mark line is engraved on the top of the concrete benchmark pile as a benchmark for platform construction and water level monitoring.

[0053] When inspecting the terrain of the forest-water composite low-efficiency forest, the terrain surveying and mapping accuracy error should be guaranteed to be within ±5cm.

[0054] When testing the soil moisture content of the forest-water composite low-efficiency forest, the soil moisture content of the target area should be no less than 25%.

[0055] When measuring the groundwater level of the forest-water composite low-efficiency forest, the normal water level measurement accuracy error should be guaranteed to be within ±1.0m.

[0056] If the proportion of water-tolerant species in the vegetation composition of the forest-water composite low-efficiency forest is less than 30%, water-tolerant species need to be replanted.

[0057] If the water quality detection indicators of the forest-water composite low-efficiency forest are TN>5mg / L and TP>0.3mg / L, the total area of the shallow pond will be designed to be 40%-50% of the overall area of the middle beach terrace, artificial aeration devices will be added to the shallow pond, and submerged plants (such as Vallisneria and Hydrilla verticillata) and floating-leaf plants (water lilies) will be planted more densely to form a composite purification system of "vegetation filtration-microbial degradation-water reoxygenation"; if the current status diagnosis results of the forest-water composite low-efficiency forest show that its water quality indicators are less than the set values, the total area of the shallow pond will be designed to be 20%-30% of the overall area of the middle beach terrace.

[0058] The water quality detection indicators of the forest-water composite low-efficiency forest generally include three indicators: COD, TN and TP.

[0059] S2. According to the current status of the forest-water composite low-efficiency forest, the water-adjacent beach land will be transformed into a vertical gradient terrain consisting of low beach terrace 1, middle beach terrace 2 and high beach terrace 3 with different terrain slopes. Among them, low beach terrace 1 is close to the water body. Low beach terrace 1 retains its original natural slope and its original hard revetment is removed and replaced with a wooden pile ecological revetment, and the mixture of humus soil and gravel is filled between the wooden piles.

[0060] Specifically, in this embodiment, the wooden pile ecological revetment adopts pine wood pile ecological revetment, the pine wood pile is 2.5m long, the distance between two adjacent pine wood piles is 1.2m, and the ratio of humus soil and gravel filled between the wood piles is humus soil: gravel = 3:1.

[0061] S3, excavating an underground infiltration channel 4 at a set depth underground in the vertical gradient terrain, constructing a gravity overflow system on the ground of the vertical gradient terrain; and constructing a three-dimensional drainage network on the high beach terrace 3 in the vertical gradient terrain.

[0062] Specifically, first, an underground infiltration channel is excavated at a set depth underground across the vertical gradient terrain;

[0063] Next, multi-tiered terraced detention ponds 5 are excavated along the contour lines on the high beach terrace 3. Adjacent detention ponds 5 on the upper and lower steps are separated by earthen ridges. Multiple shallow strip trenches with a first slope are excavated on the terrace upstream of the detention ponds 5. A first gravel layer 12 is laid in the trenches to enhance rainwater infiltration. Drainage ditches 11 are excavated, connecting to the shallow strip trenches. The location and number of the shallow strip trenches and drainage ditches 11 are determined based on actual needs. Tree planting trenches are excavated on both sides of the shallow strip trenches. Branch pipes 13, connected to the underground infiltration channel 4, are buried at the bottom of the tree planting trenches and the shallow strip trenches.

[0064] A stepped ecological weir 6 is arranged on the middle beach terrace 2. The ecological weir 6 is used to slow down the water flow to form a water flow slowing zone. A shallow pond-ridge composite terrain is constructed between the upper and lower ecological weirs 6. The shallow pond-ridge composite terrain includes multiple shallow ponds 10 and ridges arranged between two adjacent shallow ponds 10. The surface of the ridges is paved with permeable geotextiles to enhance scour resistance. Water level sensors are buried at the edges of the shallow ponds 10 to monitor water level changes in the shallow ponds 10 in real time.

[0065] A number of overflow ditches 7 are excavated on the surface of the low-lying terrace 1 and a second gravel layer 8 is laid in the ditches. An overflow weir 9 is set up on the water-adjacent embankment of the low-lying terrace 1 and an ecological gap (width 2-3m, slope 1:5) is reserved on the embankment. The low-lying terrace 1 retains its original natural mudflat slope without any hardening treatment, and uses the original mudflat terrain to buffer the impact of floods and form a seasonal overflow channel.

[0066] S4, reconstructing a multi-layered three-dimensional vegetation system on the vertical gradient terrain.

[0067] Specifically, a vertical vegetation structure combining a multi-layer terrestrial plant system and a ground cover layer is planted on the high beach terrace 3 to form a high beach sparse forest terrace. The multi-layer terrestrial plant system includes a tree layer, a shrub layer, and a herb layer. That is, trees are planted in the tree planting trenches excavated on both sides of the strip-shaped shallow trench and on the earthen ridge between the upper and lower adjacent detention ponds 5. Shrubs are planted under the shade of the trees, and herbs are planted under the shrub layer.

[0068] A vertical vegetation structure combining a multi-layer aquatic plant system and a moisture-resistant shrub layer is planted on the shallow pond-ridge composite terrain of the middle beach platform 2 to form a middle beach ecological wetland. The multi-layer aquatic plant system planted on the shallow pond-ridge composite terrain includes a submerged plant layer, a floating leaf plant layer, an emergent plant layer and a shrub layer. The submerged plant layer is planted at the bottom of the shallow pond 10, and the submerged plant layer is planted at a cutting depth of 10-15 cm. An artificial floating island is provided in the shallow pond 10, and the floating leaf plants are planted on the artificial floating island (planting spacing is 1.5 m). The emergent plant divisions are transplanted on the ridges and the edge of the shallow pond 10 (planting spacing is 1.0 m). The shrub layer is planted on the ridges, and a permeable geotextile is laid on the surface of the ridges to enhance anti-scouring ability.

[0069] Emergent plants are planted on the low-lying terrace 1 along the direction of water flow.

[0070] S5, constructing habitat creation facilities on the vertical gradient terrain.

[0071] Specifically, a pile of fallen wood covered with mosses was set up in the embankment transition zone of the high beach platform 3, and a wooden plank road was built between the strip-shaped shallow grooves;

[0072] An artificial reef 14 is set up in the shallow pond of the middle beach platform 2, and a wooden boardwalk is built between the shallow ponds;

[0073] Humus and wood chips were laid at the ecological gap in the embankment of the low-lying terrace 1 to form an amphibian migration path, improving the connectivity efficiency by 70%; fallen wood piles 15 with epiphytic mosses and artificial fish reefs were set up at the ecological gap in the embankment, and wooden planks were built between the overflow ditches 7.

[0074] The surface of the woodpile 15 is covered with moss (moss coverage ≥ 70%), providing a habitat for insects and birds, increasing species richness by 30%, and intercepting floating debris in the water. The woodpile used in the woodpile has a diameter of ≥ 20 cm and a length of 2-3 meters. The woodpile 15 is stacked 50 meters apart.

[0075] The artificial reefs 14 consist of a concrete frame filled with pebbles. The artificial reefs are spaced at least 20 meters apart. The artificial reefs 14 can create eddy currents (flow rate 0.1-0.3 m / s), attracting benthic organisms to gather. The density of benthic organisms can be increased by 40%. The artificial reefs can also deposit sediment in the water.

[0076] The height of the wooden plank road is 1.5m higher than the normal water level at the location where it is set. An observation hole with a diameter of 50cm is set at the bottom of the wooden plank road to provide a passage space for fish and small mammals.

[0077] S6, simulates high and low water levels to debug the three-dimensional drainage network and gravity overflow system to ensure the stability of the drainage and water storage functions.

[0078] S7. Perform regular maintenance on the gravity overflow system, three-dimensional drainage network, multi-level three-dimensional vegetation system, and habitat creation facilities.

[0079] Specifically, regular maintenance items include:

[0080] (1) Quarterly cleaning: salvage floating objects in stagnant ponds, drainage ditches, strip ditches, shallow ponds, and overflow ditches, and harvest reeds (leaving 10 cm of stubble) to prevent biological clogging;

[0081] (2) Vegetation replanting: replant in the spring of the following year when the survival rate of water-tolerant trees is less than 80%, and replant in the summer when the coverage of aquatic plants is less than 50%;

[0082] (3) Data monitoring: record water level, water quality, and vegetation growth data every month and establish archives (retention period ≥ 5 years).

[0083] The drainage ditch 11 excavated on the high-shoal terrace 3 can quickly divert surface runoff or accumulated water to the strip-shaped shallow ditch. The gravel layer 12 and plant roots laid in the strip-shaped shallow ditch can accelerate the infiltration rate of water flow, which can be increased to 60%. The groundwater that infiltrates into the ground is guided into the underground infiltration channel 4 through the infiltration channel branch pipe 13.

[0084] If heavy rain occurs and the drainage ditch 11 and the strip-shaped shallow ditch cannot drain the surface rainwater in time, the surface rainwater can flow down to the detention pond 5 by taking advantage of the downward slope of the high beach terrace. Each detention pond can retain 500m 3 Water volume; If the rainfall is too heavy and the detention pond 5 is full, the water will flow into the shallow pond 10 on the middle beach terrace along the terrain. If the water level in the shallow pond 10 exceeds the dam top of the ecological weir 6, the water will automatically overflow downward step by step until it is discharged to the low beach terrace 1, and the overflow ditch 7 on the low beach terrace 1 will continue to receive the flood. The overflow ditch 7 can discharge the flood into the water body, thereby forming natural storage or flood discharge through the terrain difference of the entire vertical gradient terrain, eliminating the need for electric gates, and the storage efficiency reaches 40%-50%.

[0085] During flood discharge or flood season (water level > normal water level + 0.5m), the gravel layer in the strip shallow ditch and overflow ditch 7 can perform secondary filtration on the water flow, filtering out more than 90% of SS. In addition, the fallen wood piles 15 set up in the embankment transition zone of the high beach terrace 3 and the embankment ecological gap of the low beach terrace 1 can intercept floating objects in the water flow. The artificial fish reefs 14 set up in the shallow pond of the middle beach terrace 2 and the embankment ecological gap of the low beach terrace 1 can deposit silt to purify the water quality.

[0086] During the dry season, the overtopping ditch 7 of the low-lying terrace 1 can serve as a migration channel for amphibians, and the fallen woodpile area can maintain a water depth of 0.5m to provide a habitat for aquatic organisms.

[0087] During drought periods, the underground infiltration channel 4 can extract water from the wetland pond and replenish water to the terrace soil through the infiltration channel branch pipe 13; if necessary, water from the river can also be extracted to replenish water to each terrace.

[0088] The specific embodiments of the present invention are described in detail below through specific examples.

[0089] First, the current status of the forest-water composite low-efficiency forest is diagnosed, including normal water level, topography, soil moisture content, groundwater level, vegetation composition, water quality, etc.

[0090] Then, earthwork excavation was carried out: landform transformation and pond excavation were carried out according to the three-level terrace design;

[0091] Specifically, close to the edge of the water body, 0.5-1.0m downward from the normal water level, the original natural mudflat slope of 1:15-1:20 in the area is retained without any hardening treatment, and the original mudflat terrain is used to buffer the impact of floods. An overflow weir 9 with a weir height of 0.3m is set on the embankment adjacent to the water, and an embankment with a width of 2-3m and a slope of 1:5 is set to reserve an ecological gap. Upstream of the overflow weir 9, an 8m wide overflow ditch 7 is excavated along the mudflat slope of 1:15-1:20, and a 50cm thick gravel layer 8 is laid in the ditch to form a low-lying platform 1;

[0092] On the inner side of the low-shoal terrace 1, a three-level "shallow pond-ridge" composite micro-topography is constructed upward from the normal water level by ±0.5m. The area of the shallow pond 10 accounts for 20%-30% of the overall area of the low-shoal area, and the water depth of the shallow pond 10 is 0.3-1m (preferably 0.5-0.8m). The shallow pond 10 is spaced apart from the ridge. A 0.5m-high trapezoidal ecological weir 6 (dam width 50-100mm, weir top water-facing surface slope 1:1.5) is set up between the upper and lower steps of the "shallow pond-ridge" composite micro-topography. A water level sensor with an accuracy of ±1cm is buried at the edge of the shallow pond 10 to monitor the water level changes of the shallow pond 10 in real time, forming the middle-shoal terrace 2.

[0093] On the inner side of the middle beach platform 2, a 1:8-1:10 slope terrain is excavated parallel to the contour line at an angle of +0.5-1.0m upwards from the normal water level. A drainage ditch 11 with a bottom width of 4m (slope 0.5%) is set on the top surface of the platform. A 30cm deep strip-shaped shallow ditch is excavated at an interval of 5-8m upstream of the slope terrain (the interval between the strip-shaped shallow ditch is 6m). A 20-40mm thick gravel layer 12 (the preferred thickness of the gravel layer is 30cm) is laid in the ditch. Tree planting trenches were excavated on both sides of the shallow ditch, and DN300 permeable channel branch pipes 13 were buried (the spacing between permeable pipes was 20m). The permeable channel branch pipes 13 were connected to underground infiltration channels 4 with a bottom diameter of 500mm. The underground infiltration channels 4 penetrated the three-level terrace drainage system. Three-level retention ponds 5 (10m long × 5m wide × 0.8m deep) were excavated along the contour lines of the slope terrain. The ponds were separated by earthen ridges (top width 1m), and Chinese willows were planted on the ridges (with a spacing of 1.5m) to form a high-bed terrace.

[0094] Then, revegetation is performed:

[0095] Specifically, the vegetation layer configuration of the low-lying terrace is shown in the following table:

[0096]

[0097] Low-lying beach vegetation type: single-layer emergent plant belt Vertical structure: height 1.5-3.0m (above water surface);

[0098] The vegetation layer configuration of the Zhongtan Terrace is shown in the following table:

[0099]

[0100]

[0101] Middle beach vegetation type: three-layer three-dimensional aquatic plant system + moisture-resistant shrub layer Vertical structure: 0.8m underwater to 2.0m above the water surface;

[0102] The vegetation layer configuration of the high beach terrace is shown in the following table:

[0103]

[0104] High beach vegetation type: three-layer terrestrial plant system + ground cover layer Vertical structure: ground to canopy height 8-15m.

[0105] The three-level terrace forest-water complex ecosystem transformed by the method of the present invention is shown in the following table:

[0106]

[0107]

[0108] Then, a water level regulation and storage test is carried out: high and low water levels are simulated to debug the drainage and water replenishment systems to ensure the stability of the regulation and storage function.

[0109] After the transformation is completed, long-term regular operation and maintenance will be carried out.

[0110] The three-level terrace forest-water complex ecosystem transformed using the method of the present invention can simultaneously improve the storage capacity, water purification capacity, biodiversity, etc. in multiple dimensions. The storage capacity of the forest-water complex area is increased compared with traditional woodlands, the time of waterlogging during a five-year rainstorm is shortened, and the risk of waterlogging is reduced. Through vegetation filtration and microbial decomposition, the TN and TP removal rates are greatly improved, and the water quality level is improved to meet the GB3838 Class IV standard. In addition, the number of amphibian and bird populations increases, forming a four-layer three-dimensional habitat of "trees-shrubs-herbs-aquatic plants", and the species richness is improved.

[0111] The three-tiered terraced forest-water complex ecosystem transformed using the method of this invention is expected to see an average annual growth of 1.5-2.0 cm in the diameter at breast height of target tree species over the three years following transformation, a 50% increase compared to pre-transformation levels. Timber stock is projected to increase by 10-15% annually. Carbon storage is projected to increase by 25-30% compared to a single, inefficient forest, with an annual carbon sequestration of 0.8-1.2 tons per mu, potentially enabling the development of a forestry carbon sequestration project. Furthermore, the ecosystem will create a four-seasonal landscape offering opportunities for viewing flowers in spring, enjoying the cool breeze in summer, admiring leaves in autumn, and watching birds in winter, boosting ecotourism. Monitoring stations and guided trails will be established, accommodating 50-100 science education events annually. Furthermore, the ecosystem will reduce the threat of flooding to surrounding farmland and villages, lowering the risk of inundation by 40% and enhancing regional ecological resilience.

[0112] It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

Claims

1. A method for transforming an inefficient forest with forest-water integration, characterized in that: The specific steps include: S1, diagnose the current status of the forest with low forest-water efficiency; S2, based on the current status of the forest-water composite low-efficiency forest, the adjacent waterfront land is transformed into a vertical gradient terrain consisting of a low beach terrace (1), a middle beach terrace (2), and a high beach terrace (3) with different terrain slopes, wherein the low beach terrace (1) retains its original natural slope and its original hard revetment is removed and replaced with a wooden pile ecological revetment, and the spaces between the wooden piles are filled with a mixture of humus and gravel; S3, excavating an underground infiltration channel (4) at a set depth underground in the vertical gradient terrain, and constructing a gravity overflow system on the ground of the vertical gradient terrain; Constructing a three-dimensional drainage network on the high beach terrace of the vertical gradient terrain; S4, reconstructing a multi-layered three-dimensional vegetation system on the vertical gradient terrain; S5, constructing habitat creation facilities on the vertical gradient terrain; S6, simulates high and low water levels to debug the three-dimensional drainage network and gravity overflow system to ensure stable drainage and water storage functions; S7. Perform regular maintenance on the gravity overflow system, three-dimensional drainage network, multi-level three-dimensional vegetation system, and habitat creation facilities.

2. The method for transforming low-efficiency forests with forest-water integration according to claim 1, characterized in that: The specific steps of constructing a gravity overflow system on the ground of the multi-level vertical gradient terrain in step S3 are: On the high beach terrace (3), multi-level terraced detention ponds (5) are excavated along the contour line, and the upper and lower adjacent detention ponds (5) are separated by earth ridges; Arrange a stepped ecological weir (6) on the middle beach platform (2), construct a shallow pond-ridge composite terrain between the upper and lower ecological weirs, and bury water level sensors at the edge of the shallow pond; A plurality of overflow ditches (7) are excavated on the ground of the low-lying terrace (1) and a second gravel layer (8) is laid in the ditches. An overflow weir (9) is set at the water-adjacent embankment of the low-lying terrace (1) and an ecological gap is reserved on the embankment.

3. The method for transforming low-efficiency forests with forest-water integration according to claim 2, characterized in that: The shallow pond-ridge composite terrain comprises a plurality of shallow ponds (10) and ridges arranged between two adjacent shallow ponds (10).

4. The method for transforming low-efficiency forests with forest-water integration according to claim 2, characterized in that: When constructing the shallow pond-ridge composite terrain, if the current status diagnosis result of the forest-water composite low-efficiency forest shows that its water quality index is greater than the set value, the total area of the shallow pond (10) is designed to be 40%-50% of the overall area of the middle beach terrace, and an artificial aeration device is added to the shallow pond (10); if the current status diagnosis result of the forest-water composite low-efficiency forest shows that its water quality index is less than the set value, the total area of the shallow pond (10) is designed to be 20%-30% of the overall area of the middle beach terrace.

5. The method for transforming low-efficiency forests with forest-water integration according to claim 2, characterized in that: When the water level in the shallow pond is lower than the normal water level, the underground infiltration channel (4) can be used to replenish water to the shallow pond.

6. The method for transforming low-efficiency forests with forest-water integration according to claim 2, characterized in that: The specific steps of constructing a three-dimensional drainage network on the high beach terrace with vertical gradient terrain in step S3 are: A plurality of shallow strip trenches with a first slope are excavated on the surface of the high beach terrace (3), and a first gravel layer (12) is laid in the trenches; A tree planting trench is excavated on the ground on both sides of the strip-shaped shallow trench, and a through-ditch branch pipe (13) connected to the underground infiltration channel (4) is buried at the bottom of the tree planting trench and the strip-shaped shallow trench. In case of drought, the underground infiltration channel (4) can be used to reversely replenish water to the terrace soil through the through-ditch branch pipe (13); A drainage ditch (11) connected to the strip-shaped shallow ditch is excavated on the ground of the high beach terrace.

7. The method for transforming low-efficiency forests with forest-water integration according to claim 2, characterized in that: The specific steps of reconstructing a multi-layered three-dimensional vegetation system on the vertical gradient terrain in step S4 are: Planting a vertical vegetation structure combining a multi-layer terrestrial plant system with a ground cover layer on the high beach terrace (3) to form a high beach sparse forest terrace; A vertical vegetation structure combining a multi-layered aquatic plant system and a moisture-resistant shrub layer is planted on the shallow pond-ridge composite terrain of the Zhongtan Terrace (2) to form a Zhongtan ecological wetland. Emergent plants are planted along the direction of water flow on the low-lying terrace (1).

8. The method for transforming low-efficiency forests with forest-water integration according to claim 7, characterized in that: The multi-layer terrestrial plant system planted on the high beach terrace includes a tree layer, a shrub layer and a herb layer. The tree layer is planted along both sides of the strip-shaped shallow ditch, the shrub layer is located under the shade of the tree layer, and the herb layer is located below the shrub layer. The shrub layer is also planted on the earthen ridge between the upper and lower adjacent retention ponds (5).

9. The method for transforming low-efficiency forests with forest-water integration according to claim 7, characterized in that: The multi-layer aquatic plant system planted in the shallow pond-ridge composite terrain of the middle beach platform includes a submerged plant layer, a floating leaf plant layer, an emergent plant layer and a shrub layer. The submerged plant layer is planted at the bottom of the shallow pond (10), a floating island is provided in the shallow pond, floating leaf plants are planted on the floating island, emergent plants are planted on the ridges and the edge of the shallow pond, the shrub layer is planted on the ridges, and a permeable geotextile is laid on the surface of the ridges.

10. The method for transforming low-efficiency forests with forest-water integration according to claim 1, characterized in that: The specific steps of constructing the habitat creation facilities on the vertical gradient terrain in step S5 are: In the bank transition zone of the high beach terrace, piles of fallen wood covered with mosses are set up, and wooden planks are built between the strip-shaped shallow grooves; Artificial reefs (14) are set up in the shallow ponds (10) of the middle beach platform, and wooden boardwalks are built between the shallow ponds; A pile of fallen wood (15) with epiphytic mosses and an artificial fish reef are set up at the ecological gap of the embankment of the low-lying terrace, and a wooden boardwalk is set up between the overflow ditch (7).

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