CN114375750A

CN114375750A - Rapid construction method of coastal windproof sand-fixing salt-tolerant landscape community

Info

Publication number: CN114375750A
Application number: CN202111623877.2A
Authority: CN
Inventors: 董运常; 江良为; 罗伟聪; 刘贵才
Original assignee: Huayuan Landscape Architecture Co ltd
Current assignee: Huayuan Landscape Architecture Co ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2022-04-22
Anticipated expiration: 2041-12-28
Also published as: CN114375750B

Abstract

The invention discloses a rapid construction method of a coastal windproof, sand-fixing and salt-tolerant landscape community, belonging to the technical field of ecological restoration. The method for quickly constructing the coastal windproof sand-fixing salt-tolerant landscape community comprises the following steps: site investigation; dividing a field; soil improvement; screening salt-tolerant plants; rapidly building a salt-tolerant landscape community; tending and managing. The screened salt-tolerant plants have various shapes, rich flower leaves and high ornamental value, and the plants with different salt-tolerant grades are subjected to echelon configuration of forest belts with different functions and three-dimensional matching of arbor-shrub grasses, so that the aims of wind prevention, sand fixation and salt resistance can be effectively fulfilled, and a good ecological landscape effect can be quickly formed; the construction method is simple, convenient and practical, the tending management is simple, the coastal vegetation communities with stable structures and rich biodiversity can be formed after 2-year maintenance, the durable repair and soil improvement of the coastal saline-alkali soil can be realized, and the method is suitable for being popularized in the Yangtze delta of Zhujiang and even coastal areas of south China.

Description

Rapid construction method of coastal windproof sand-fixing salt-tolerant landscape community

Technical Field

The invention relates to the technical field of ecological restoration, in particular to a rapid construction method of a coastal windproof, sand-fixing and salt-tolerant landscape community.

Background

The main causes of the formation of coastal saline-alkali soil are seawater influence, soil transpiration, reclamation of land reclamation projects, forest cutting and lake enclosing salt production, and the coastal saline-alkali soil is mainly characterized in that the soil has high salt content and underground water level and the natural soil desalting rate is low; the fresh water resources are lacked, the daily variation and the seasonal variation of hydrology exist, the diversity and the quantitative property of vegetation varieties are poor, and the native tree species and the saline-alkali tolerant tree species grow slowly and cannot rapidly form forests; the ecological environment is easily affected by typhoon, sea tide, salt dust and salt fog. There are many well-established improvements, mainly including physical, biological, chemical and comprehensive improvements. The physical improvement measures adopt a physical method which is easy to implement and simple in conditions to improve the soil and reduce the salt content of the soil, thereby meeting the growth requirements of plants. The chemical improvement measures reduce the alkalinity and salinity of the soil by spraying chemical improvement agents in the saline-alkali soil. The existing coastal wasteland is mostly treated by physical measures and chemical measures and then planted with plants, but the coastal wasteland has weak environmental adaptability compared with the original plants in the coastal region, the plants are easier to have plant diseases and insect pests in the saline-alkali environment, in addition, the management and maintenance costs of new plant invasion, watering, fertilization and the like caused by foreign soil are higher, and the improved soil fertility is not lasting. The ecological restoration of the coastal saline-alkali soil not only improves the ecological environment of coastal areas, enriches the local greening landscape pattern, provides a new habitat for biological diversity, but also can better solve the problems in environmental development and economic development of the coastal areas, and provides a wide space for realizing virtuous circle and sustainable development of society, economy and ecology.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a rapid construction method of a coastal wind-prevention, sand-fixation and salt-tolerance landscape community.

In order to achieve the purpose, the invention adopts the technical scheme that: a method for quickly constructing a coastal windproof sand-fixing salt-tolerant landscape community comprises the following steps:

(1) site investigation: each 667m of the land is saline-alkali land in the coastal area²Dividing the soil into a planting cell, and measuring the soil EC value of the planting cell;

(2) dividing a field: arranging a grass irrigation sand fixation belt, a tree irrigation windproof belt and an ecological landscape belt from near to far from a seashore line respectively, and arranging plant fences among different forest belts;

(3) soil improvement: ploughing and alkaline-earth improving the field soil;

(4) screening salt-tolerant plants: carrying out primary screening on plants according to the growth indexes, the wind prevention indexes, the sand fixation indexes, the ornamental indexes and literature records of the plants in the coastal areas, and carrying out a potted salt stress test on the primary screened plants;

(5) and (3) rapidly constructing a salt-tolerant landscape community: constructing a tree and shrub windproof belt, a hedgerow, an ecological landscape belt and a shrub and grass sand-fixing belt in sequence;

(6) tending management: tending management comprises water management, fertilization management, salinity management and replanting management.

The invention adopts the conventional soil EC instrument to measure the soil EC value of each cell, has simple and convenient instrument operation, can quickly and accurately grasp the integral salt-containing condition of the site, quickly improves alkaline earth on the basis, has strong pertinence and simple and convenient method, and is suitable for large-scale construction of salt-tolerant landscape communities of the saline-alkali site.

According to the invention, three forest belts with wind prevention, sand fixation, salt resistance and landscape functions are reasonably arranged according to the climate, hydrological characteristics and distance from a seashore line of a coastal saline-alkali site, and different forest belts are three-dimensionally configured according to height and distance, so that the stability and biological diversity of a community are effectively considered, and the stable performance of the formation effect of the community and the ecological landscape function is facilitated.

In the tending management of the landscape community, water is managed by manually watering for 1-3 times at the initial stage of field planting of various nursery stocks according to the drought condition of soil; in rainy season, natural rainfall irrigation is adopted, and water supplement is not needed in other periods; in the fertilization management, in order to improve the adaptability of the primary-planted nursery stocks to saline-alkali soil and promote vigorous growth of plants, 0.01% brassin and 1.0% compound fertilizer aqueous solution are irrigated to the roots of trees and shrubs of each plant (bush) for 1-3 times, the concentration of the shrubs and herbaceous plants is halved, and the fertilizer is sprayed to the leaf surfaces for 1-3 times; the salinity management is that arbors and shrubs planted on an ecological landscape zone and an arbor and shrub windproof zone are covered with a layer of pine scales with the thickness of 2-4 cm within the range of 1m or 1m multiplied by 1m of root radius. The loose scales covered on the roots and stones filled in the drainage ditches are recycled for 1-2 times every year, and the stones are soaked in clear water, washed clean and salted for reuse; in the tending period, the loose scales and stones are completely replaced once every 1-2 years; and the replanting management comprises the steps of respectively cleaning wilted and dead plants in a field and replanting in time after various seedlings are planted for 2 months and 1 year, and forming a stable coastal vegetation community after planting and growing for 2 years. The invention adopts the method of covering the plant roots with the pine scales, can reduce the water evaporation of the roots and adsorb the soil salt in the root system range. The adopted tending measures such as moisture, fertilization, replanting and the like do not need to depend on excessive manpower, can effectively improve the survival rate of the plants on the premise of low maintenance, and ensures the quality of the forest land and the stability of the community.

As the method for quickly constructing the coastal windproof sand-fixing salt-tolerant landscape community, the grass irrigation and sand-fixing zone is 0-20m away from the seashore line; the arbor and shrub windbreaker strip is 20-60 m away from the seashore line; the ecological landscape zone is 60-100 m away from the seashore line; the width of the hedgerow is 2-5 m, and the height is 1-4 m.

According to the climate and hydrological characteristics of the coastal saline-alkali site, the invention flexibly sets the forest and grass belts with different widths and structures, each forest and grass belt is provided with salt-tolerant plants with different functions, so that multiple purposes of wind prevention, sand fixation and saline-alkali restoration can be realized, and the proper site arrangement and construction method is combined, so that the coastal landscape community with rich layers, complete functions and ecological stability can be quickly formed.

As the method for quickly constructing the coastal windproof sand-fixing salt-tolerant landscape community, drainage ditches are also arranged in the arbor and shrub windproof zone and the ecological landscape zone; the drainage ditch is in an H shape along the vertical direction of the coastline; the width and the depth of the drainage ditch are 40-60 cm, the length of each community is 80-110 m, and the bottom of the ditch keeps 1-5% of drainage gradient.

The H-shaped drainage ditch provided by the invention is beneficial to drainage and salt discharge in rainy seasons, and can create a good soil environment for the growth of plants, so that the survival rate of plant transplantation and field planting and the formation effect of landscape communities are improved.

As the method for quickly constructing the coastal windproof, sand-fixing and salt-tolerant landscape community, geotextiles with the width of 2.4-3.0 m and the length consistent with that of the drainage ditch are paved in the drainage ditch; the volume ratio of the filled drainage ditch is 2: 1, and the filling thickness of the mixed stone is 20-30 cm.

The invention selects the green zeolite and the ceramsite to form mixed stone, and the adsorption and ion exchange capacity of the green zeolite and the ceramsite can stably adsorb and improve soil salt ions for a long time. The green zeolite has excellent adsorption capacity and high cost, the ceramsite has good adsorption effect and low cost, the green zeolite and the ceramsite are mixed according to a proper proportion and filled in the drainage ditch, and the geotextile is combined, so that the stone is convenient to recycle, clean and reuse, and the total salt amount accumulated in the ditch can be effectively transferred.

As the method for quickly constructing the coastal windproof, sand-fixing and salt-tolerant landscape community, the plowing depth of a grass-irrigating and sand-fixing zone in soil improvement is 10-20 cm, and the plowing depth of a arbor-irrigating and windproof zone and an ecological landscape zone is 30-50 cm; the alkaline earth improvement comprises alkaline earth improvement on a tree and shrub windbreak area and an ecological landscape area, wherein 0.01-0.02% of humic acid water solution is sprayed in a district with an EC value lower than 4mS/cm, 0.02-0.04% of humic acid water solution is sprayed in a district with an EC value of 4-18 mS/cm, 0.04-0.08% of humic acid water solution is sprayed in a district with an EC value exceeding 18mS/cm, and 300-600L of humic acid solution is sprayed in each district.

The invention adopts different soil raking and improving measures aiming at the functions of different forest belts, can effectively block the capillary conduction of soil salinity, wherein the grass irrigation and sand fixation belt is often influenced by tide, and the alkaline earth improvement of the soil is not needed.

As the method for quickly constructing the coastal windproof sand-fixing salt-tolerant landscape community, the arbor and shrub windproof zone can be divided into an upper layer, a middle layer and a lower layer and is planted in a mixed crossing mode; at least one of Pinus thunbergii, casuarina equisetifolia, phellodendron amurense rupr and syzygium jambos is planted on the upper layer; the middle layer and the lower layer are selected and planted with at least one of silver date, hibiscus syriacus, Pandanus armandii, dracaena cochinchinensis and hibiscus hamabo.

The windproof belt for arbor and shrub adopts a mixed mode to build the windproof forest belt, wherein the upper layer of the forest belt is selected from big trees with higher growth speed, and the middle and lower layers are selected from middle and small trees and shrubs with medium or slightly slow growth speed. Each 667m²The initial planting density is 167, the mixed planting of not less than 3 kinds of tree species is carried out, wherein the number of the large trees is not less than 1, the mixed planting proportion is not more than 70%, and the selected seedling specification is preferably the engineering large seedling with the diameter at breast height of 6-10 cm or the diameter of land of 3-6 cm. The method comprehensively considers the position and the width of the forest belt, the upper and lower structures of the forest and the wind and sand prevention effect of the salt-tolerant plants, reasonably sets the initial planting density, the quantity of mixed tree species, the mixed planting proportion and the seedling specification of the forest belt, has strong adaptability of the screened salt-tolerant plants to the coastal saline-alkali soil, can guide the fast construction of the arbor irrigation wind-resistant forest belt, and is beneficial to the realization and the stable exertion of the functions of the forest belt.

As the method for quickly constructing the coastal windproof sand-fixing salt-tolerant landscape community, the hedgerow is planted in a strip or block manner; the plant hedgerow is selected to plant at least one of oleander, elaeostereum paulosum, syzygium jambos and panda trees.

Hedges of the present invention are present per 667m²The initial planting density is not less than 222 plants, and the specification of the planted seedlings is preferably cluster large seedlings with the ground diameter of 5-10 cm. The invention adopts the clustered evergreen shrubs to build the hedges, reasonably arranges the planting form, the planting width and the primary planting density of hedge belts (blocks), and the screened halophilic shrubs which are suitable for growing can be quickly planted between the forest beltsAnd a compact plant buffer wall is formed quickly, so that the invasion of sea wind and sea sand near the ground is effectively retarded, and the stability of the small environment inside the community is ensured.

As the method for quickly constructing the coastal windproof sand-fixing salt-tolerant landscape community, the ecological landscape zone is planted in a mixed mode; the ecological landscape zone is selected and planted with acacia confusa, hibiscus syriacus, lagerstroemia speciosa, cercis chinensis, melancholia, frangipani, oleander, phyllanthus urinaria, cajeput, and the like; the suitable shrub and herb plant mainly comprises at least one of Ipomoea batatas, lantana camara, Delaware, Iris florida, Arundina floribunda and Wedelia chinensis.

The invention adopts a mixed mode to build the ecological landscape forest belt. Not less than 6 plants are mixed, and not less than 4 arbors and shrubs are mixed; each 667m of arbor and shrub²The planting density is not less than 42 plants, the coverage of the shrubs and the herbaceous plants is not less than 75% of the open space area of a small area, and the sizes of the planted trees and shrubs are preferably large engineering seedlings with the diameter at breast height or the diameter of land of 4-10 cm, and container seedlings of the shrubs and the herbaceous plants are preferably grown for 1-2 years. The invention adopts a garden design method of three-dimensional configuration of 'arbor, shrub and grass' to construct an ecological landscape forest belt, reasonably sets the initial planting density, the mixed planting number and the seedling specification, also considers the ornamental property and the species diversity, and the screened arbor, shrub and herbaceous plants can well adapt to the offshore salinization soil, guide the rapid construction of the ecological landscape forest and contribute to the stable performance of the ecological landscape function of the forest belt.

As the method for quickly constructing the coastal windproof sand-fixing salt-tolerant landscape community, the grass-irrigating sand-fixing zone is planted in a mixed planting mode; planting single-leaf vitex rotundifolia and pittosporum tobira selectively in the grass irrigation sand fixation belt; the suitable growth herb mainly comprises at least one of thick vine and seaside evening primrose.

The invention adopts a mixed planting mode to build the grass irrigation sand stabilization belt. The mixed planting species is not less than 2 species, wherein the primary planting density of shrubs per 1m2 is not less than 4 plants, the primary planting density of herbaceous plants per 1m2 is not less than 9 plants, the specifications of the planted shrubs are suitable for large seedlings with 1-3-year-old containers, and the herbaceous plants are suitable for 1-year-old container seedlings. The invention adopts the shrub and grass plants with high salt tolerance and sprawling property and utilizes the mixed planting method to build the shrub and grass sand-fixing belt, reasonably sets the mixed planting type, the initial planting density and the seedling specification, considers the deep root property of shrubs and the wide distribution property of grass fibrous roots, has strong adaptability of the screened shrubs and grass plants to coastal sandy land, and is beneficial to quickly realizing the wide coverage and the stable root-fixing of the sandy land.

As the method for quickly constructing the coastal windproof sand-fixing salt-tolerant landscape community, the salt stress test method adopted by the screening of the salt-tolerant plants is as follows: stopping water supplement to 1-2 year old potted plantlets 1 week before the test begins, and respectively pouring 0.5-1.0L of 0.2% NaCl solution into each pot of plants when the plantlets show water shortage symptoms; then, the same amount of NaCl solution is poured in each time when the water shortage is approached. Stopping watering when half of the tested plants are wilted or dead, calculating the total NaCl mass accumulated for watering and dividing the salt tolerance grade.

The screening method of the salt-tolerant plants adopted by the invention comprises field investigation of the current state of vegetation, reference research of literature data and salt stress test of the salt-tolerant plants, and the method is advanced layer by layer. The primary screening of the salt-tolerant plants comprehensively considers the wind and sand prevention effect of the plants in the typhoon weather, the growth adaptability and the ornamental characteristics of the saline-alkali field, the simple quantitative potting watering method is adopted in the potted salt stress test, the real salt-tolerant capability of each plant can be rapidly and accurately tested and applied to the construction of different forest belts, the screening method is clear in purpose and strong in guidance, and the reasonable utilization of the suitable plants and the construction effect of salt-tolerant landscape communities can be ensured.

The invention has the beneficial effects that: the invention provides a method for quickly constructing a coastal wind-prevention, sand-fixation and salt-tolerance landscape community, screened salt-tolerance plants are different in shapes, rich in flower leaves and high in ornamental value, and the plants with different salt-tolerance grades are subjected to echelon configuration of forest belts with different functions and three-dimensional matching of arbor and shrub grasses, so that the purposes of wind prevention, sand fixation and salt resistance can be effectively realized, and a good ecological landscape effect can be quickly formed; the construction method is simple, convenient and practical, the tending management is simple, the coastal vegetation communities with stable structures and rich biodiversity can be formed after 2-year maintenance, the durable repair and soil improvement of the coastal saline-alkali soil can be realized, and the method is suitable for being popularized in the Yangtze delta of Zhujiang and even coastal areas of south China.

Drawings

FIG. 1: investigating salt-tolerant arbor and shrub and herbaceous plants in the coastal saline-alkali soil;

FIG. 2: primarily selecting potted salt stress test of 1-2 year seedlings of plants;

FIG. 3: observing different watering times and plant salt damage symptoms in a potted plant salt stress test;

FIG. 4: adopting arbor irrigation windproof forest belts built by medium-high salt-tolerant plants;

FIG. 5: ecological landscape forests built by medium and low salt-tolerant plants and grass irrigation sand stabilization belts built by high salt-tolerant plants are adopted;

FIG. 6: adopting hedgerow built by tung cotton with high salt tolerance;

FIG. 7: covering the roots of the plants with pine scales, and adsorbing a large amount of crystalline salt on the surfaces of the pine scales after 3 months;

FIG. 8: the green zeolite washed before use adsorbed a large amount of crystalline salts on the surface of the green zeolite after 3 months of use.

Detailed Description

The present invention will be described in further detail with reference to the following examples.

Example 1 investigation and screening of coastal salt-tolerant plants

1. Investigation and preliminary screening of salt tolerant plants

From 2010 to 2018, the inventor and the group thereof successively carry out field investigation of a wide range of trees and shrubs and herbaceous plants according to the current vegetation status of forests, woodlands, greenbelts and the like in coastal areas of the Yangtze delta, and investigate 96 kinds of 240 genera of the coastal vascular bundle plants in total according to the growth conditions of the plants in the coastal saline-alkali areas. Combining the field observation and evaluation of the wind prevention and sand fixation effects before and after the coming of the annual typhoon, and referring to the literature data of the saline-alkali tolerance research of related plants, preliminarily screening a batch of coastal halophilic plants.

Wherein, the preliminary screening index comprises: (1) and (3) growth conditions: the plant can normally grow in coastal saline-alkali areas, and branches and leaves without adverse symptoms or salt damage symptoms are not more than 5 percent of the whole plant; (2) the windproof effect is as follows: the branches and leaves of the plants are dense, the crowns are full, and no main branch is broken or the broken branches do not exceed 10 percent of the whole plants after typhoon; (3) sand fixation effect: the root systems of the arbor and the shrub are developed, and the arbor and the shrub do not fall after typhoon or the falling rate of the same area is not more than 5%; the low shrubs and the herbaceous plants are strong in tendril-like property, and the ground coverage can reach over 75 percent; (4) the ornamental characteristic is as follows: trees are evergreen, shrubs are evergreen or leaves are fallen, and herbaceous plants are perennial; has two (or more) of flower, fruit, leaf and shape or one of them as main; (5) the literature is based on: the industrial technical regulation or experimental research shows that the salt tolerance of the plant is more than 0.2 percent, or the predominant species of islands, beaches, gulfs and the like and mangrove associated plants are recorded in authoritative documents.

Finally, 66 seashore halophilic alkali plants are screened out, and the plants mainly comprise: the plant growth regulator is prepared from the following raw materials, by weight, wampee bark, ephedra, hibiscus, black pine, elaeagnus mollis, Chinese holly root, syzygium jambos, kadsura japonica, kadsura longipedunculata, kadsura japonica, longhairy tree, vitex, trifoliate chastetree, Thysandra filiformis, longzhugu, garcinia lanceolata, drynaria fragrans, fig, wintersweet, crape myrtle, oleander, lindera glauca, syzygium sinensis, frangipani, edgeworthia chrysantha, cratoxylum hance, crape myrtle, silver sea jujube, cinnamomum camphora, celastrus sinensis, celastrus trifoliata, passionflower herb, berberis sinensis, berberis thunbergii, hibiscus thunbergii, shrubby bluebeard, crabapple, cocklebur fruit, arbour fruit, cocklebur fruit, arbour fruit, cocklebur fruit, arbour fruit, cocklebur fruit, tree, cocklebur fruit, arbour fruit, cocklebur fruit, tree, cocklebur fruit, tree, cocklebur fruit, tree, cocklebur fruit, tree, arbour fruit, crataenia herb, cocklebur fruit, tree, tre, etc Blumea, leafflower, aleurites, wedelia, etc. The plants have different shapes, rich leaf colors and high ornamental value, and the reasonable matching of arbor, shrub and grass is carried out on the halophilic plants, so that beautiful coastal ecological landscape communities can be built.

2. Experimental screening of salt tolerant plants

Aiming at the preliminarily screened salt-tolerant plants, 1-2 year seedlings are respectively adopted for carrying out potted salt stress tests on 45 of the preliminarily screened salt-tolerant plants by combining nursery seedling culture and market seedling supply conditions so as to test the specific salt tolerance. During the test, 10 seedlings of 1-year or 2-year container seedlings with the same plant type are selected from each test plant, gallon pots made of the same material and transplanting matrixes with the same components and quality are adopted, and the seedlings are transplanted and maintained for 1 month in a unified mode. Stopping watering the potted plantlets 1 week before the test begins, and respectively watering 0.5L of 0.2% NaCl solution and 1.0L of 0.2% NaCl solution for 1-year and 2-year seedlings in each pot when the plantlets show water shortage symptoms; the same amount of NaCl solution was poured in each time the water shortage was approached. Stopping watering when half of plants in each plant are wilted or dead (salt damage symptom).

And dividing the primary selected plants into 3 grades according to the salt tolerance of the primary selected plants according to the irrigation frequency of the test plants and the accumulated total NaCl mass. Specifically, the results are shown in Table 1.

TABLE 1 salt tolerant plants screened in the test and their salt tolerance grades

Note: a few plants which had been watered 6 times but did not reach half of the symptoms of salt damage were treated with high salt tolerance.

As can be seen from Table 1: the preliminarily screened plants can be watered with NaCl solution for more than 1 time, which shows that the plants have certain salt tolerance. Of the 45 plants tested, 13 were able to withstand 2 douches with NaCl solution, accounting for 28.9% of the total, and the total mass of NaCl accumulated in the douches amounted to up to 0.4%. 14 NaCl solution can be irrigated for 3 times, accounting for 31.1 percent of the total amount; the 9 types of plants can be irrigated by NaCl solution for 4 times, accounting for 20.0 percent of the total number, and the total mass of NaCl accumulated in the two types of treatments can reach up to 0.8 percent and account for more than 50 percent of the total number of the tested plants. 10 plants can be irrigated by NaCl solution for more than 5 times, accounting for 22.2% of the total number of the tested plants, and the total accumulated NaCl content in the irrigated plants exceeds 1.0%; wherein the watering times of the vitex rotundifolia and the pittosporum pratense reaches 6 times but no obvious salt damage symptom appears, which is consistent with the salt tolerance of the two plants which are sandy beach and can bear tidal scour.

According to the results of the test screening, the obtained salt-tolerant plants are classified according to plant types and salt tolerance, and the rapid construction of salt-tolerant landscape communities in coastal areas can be guided. Combining the reality of seedlings for coastal landscape engineering in bead triangle areas, representative plants with large-scale application characteristics are screened, and the specific classification is shown in table 2.

TABLE 2 representative plants suitable for the creation of salt-tolerant landscape communities in the Kyobalanopsis

Note: part of the trees are often used as shrubs for cultivation, and part of the shrubs can grow into the shape of trees, and the parts are not strictly distinguished.

The plants are different in shape, rich in flower leaves and high in ornamental value, the plants with different salt tolerance capacities are reasonably configured with trees, shrubs and grasses, a good ecological landscape effect can be formed while a windproof sand-fixing salt-tolerant community is built, and the method is suitable for popularization and application in the Zhujiang delta and even the south coast region.

Example 2

Aiming at the halophilic plants screened in the embodiment 1, the inventor and the team thereof are popularized and applied in more than ten coastal landscape greening engineering projects built by a company, and the construction of the arbor and shrub windproof belt, the ecological landscape belt, the shrub and grass sand-fixing belt and the hedgerow is implemented in specific projects.

1. Introduction to project site

In an ecological landscape construction project in a new coastal bay area of Dongguan city, which is built by a company, a wind-prevention forest, a sand-fixing grass belt and a plant hedge need to be built in a coastal area 0-60 m away from a coastal shoreline due to the protection requirement of ecological landscape; wherein, the area of construction of the ecological garden landscape region is 29273m²Area 27846m for building wind-break forest²Area 22198m for constructing coastal sand-fixing area². The fields are coastal saline-alkali lands and are often disturbed by coastal storms and sea sand.

2. Site investigation and soil preparation

(1) According to the current situation of the field, willEvery 667m of the field²The method is divided into a planting-planning district, wherein the ecological landscape district is 44 districts, the windbreak forest district is 42 districts, the sand fixation district is 33 districts, and the total number of the planting-planning districts is 119 districts. And measuring the soil EC value of each planting cell by adopting a soil EC instrument, measuring 9-12 point positions of each cell, and calculating the average EC value. Wherein the EC value range of the soil in the ecological landscape area is 1.6-11.8, and the soil belongs to medium-light saline-alkali soil types; the soil EC value range of the windbreak forest area is 2.7-17.4, and the windbreak forest area belongs to medium and low saline-alkali soil types; the EC value range of the soil in the coastal sand consolidation area is 3.4-25.7, the soil comprises high, medium and low saline-alkali soil types, but the whole soil mainly comprises medium saline-alkali soil.

(2) Mechanically ploughing the soil of the ecological landscape area and the windbreak forest area to a depth of 30-50 cm; and (4) manually raking the sand land in the coastal sand consolidation area, wherein the depth is 10-20 cm. And then, spraying 300-600L of 0.01-0.02% humic acid aqueous solution to the residential areas with the average EC value of the ecological landscape area and the windbreak area lower than 4mS/cm, and spraying 300-600L of 0.02-0.04% humic acid aqueous solution to the residential areas with the average EC value of 4-18 mS/cm for improvement.

(3) After soil preparation and soil improvement are completed, an H-shaped drainage ditch is excavated in the vertical direction of a coastline, the width and depth of the ditch are all 40-60 cm, and the bottom of the ditch keeps about 2% of gradient so as to facilitate site drainage.

3. Construction of salt-tolerant landscape community

(1) Constructing the arbor irrigation windbreak belt: in a coastal area 20-60 m away from a coastal shoreline, arbor and shrub with high salt tolerance are selected for building a mixed windbreak forest, wherein the upper layer of the forest belt is selected from casuarina equisetifolia with rapid growth, and the middle and lower layers are selected from syzygium jambos, silver phoenix dactylifera, Pandanus paulownia and nerium indicum with medium growth speed. When the plants are built, the initial planting density of each cell is 167 plants, wherein the planting proportion of the casuarina equisetifolia is 60 percent, and the planting proportion of other plants is 40 percent. The specification of the nursery stock is an engineering large seedling with the diameter at breast height of 6-10 cm or the diameter at ground height of 3-6 cm.

After 1 year of management and maintenance according to the conventional water and fertilizer, randomly selecting 3 cells from the windbreak forest area, investigating and counting the survival rate and the salt damage occurrence rate of all salt-tolerant plants in the cells. Wherein, the survival rate is the proportion of the number of surviving plants in the sampling cell to the total number of the planted plants; the salt damage occurrence rate is the average proportion of the branch and leaf quantity of the salt damage symptom of 3 representative sample plants randomly selected in each cell to the total quantity of the whole plant. The statistical results are shown in table 3.

TABLE 3 statistics of survival of salt-tolerant plants in arbor-shrub windbreaker

As can be seen from Table 3: the average survival rate of main mixed tree species casuarina equisetifolia reaches up to 95.6 percent, and the plant does not have the salt damage symptom, which indicates that casuarina equisetifolia is a coastal salt-tolerant plant very suitable for building a tree and shrub windbreaker strip. The survival rate of other mixed trees is over 90 percent, and particularly the survival rate of the Pandanus communis and the Nerium indicum is as high as 100 percent; except that the leaves of the silver date have slight salt damage symptoms, other tree species have almost no salt damage or the salt damage occurrence rate is less than 5 percent, and the tree species show strong salt adaptability and salt tolerance. And calculating the overall survival rate of the mixed tree species of the arbor and shrub windproof belt, wherein the average survival rate can reach 96.7%.

(2) Constructing an ecological landscape zone: and (3) selecting ornamental trees, shrubs and herbaceous plants with low salt tolerance and partial high salt tolerance to build an ecological landscape forest zone in the offshore area 60m away from the coastal line. The ornamental arbor and shrub mainly comprises Pinus thunbergii, Lagerstroemia speciosa, Melaleuca aleuca, frangipani and leafflower; the shrub and herb plants are selected from WU SE MEI, LU LI, and Wedelia chinensis. During field planting, the initial planting density of each cell of the ornamental trees and the big shrubs is not less than 42, and the coverage of the small shrubs and the herbaceous plants is not less than 70% of the vacant area in the cell. The specification of the arbor and shrub is an engineering large seedling with the diameter at breast height or the diameter at ground height of 4-10 cm, and the herbaceous plant is a 1-2 year old container seedling.

After 1 year of management and maintenance according to the conventional water and fertilizer, randomly selecting 3 cells from the landscape forest area, investigating and counting the survival rate of all mixed plants in the cells. The statistics are shown in table 4.

TABLE 4 survival statistics of salt tolerant plants in ecological landscape zones

As can be seen from Table 4, the average survival rate of all mixed plants in the arbor and shrub windstral zone is as high as 93.9%, which shows that the screened medium and low salt-tolerant plants have strong adaptability to the offshore medium and light saline-alkali soil slightly far from the offshore. Except for the leaf flowers, the survival rate of the mixed plants in the arbor-shrub and divaricate saposhnikovia root forest belt is over 90 percent, the survival rate of the leaf flowers is only 85.7 percent, which is probably related to the difference of salt tolerance of different varieties of the leaf flowers, and the consistency of the tested varieties and the actually applied varieties needs to be paid attention to when the salt-tolerant landscape is constructed.

(3) Constructing a grass irrigation sand fixing belt: and selecting small shrubs and perennial herbaceous plants with high salt tolerance and tendril property in coastal sandy land 0-20m away from the seashore line, and constructing a grass irrigation and sand fixation belt by adopting a mixed planting method. The shrub is selected from Simpleleaf shrub, and the herb is selected from thick vine and evening primrose. At the time of field planting, every 1m²The primary planting density of shrubs is 4 plants, and the herbaceous plants are 9 plants; the vitex rotundifolia, the thick vine and the evening primrose are all selected from 1-year-old container seedlings.

After 1 year of conservation according to the conventional water and fertilizer management, randomly selecting 3 sample prescriptions with the size of 3m multiplied by 3m from the grass irrigation sand fixation belt, and investigating and counting the survival rate of the mixed planting plants in the sample prescriptions. Specific statistics are shown in table 5.

TABLE 5 statistics of survival rates of plants in shrub and grass sand-fixation zone

As can be seen from Table 5: the survival rate of the mixed planting of the vitex rotundifolia, the pachyrhizus and the evening primrose on coastal sandy land is over 90 percent, wherein the survival rate of the vitex rotundifolia is the highest and reaches 97.2 percent. Since coastal sandy land is very obviously affected by tide, the salt content of sandy loam is higher, usually about 1.0% or even higher, so that the high salt tolerance of the mixed-planted plants is also verified. The vitex rotundifolia, the thick vine and the evening primrose have good creeping growth or tendril-leaved growth, the coverage rate of the mixed plants on sand is over 90 percent through field investigation, and the statistical average survival rate can reach 94.4 percent.

(4) Hedgerow campBuilding 2 plant fences by adopting evergreen shrubs with high salt tolerance and multiple branches between a grass irrigation sand fixation zone, a tree irrigation wind prevention zone and an ecological landscape zone so as to prevent the invasion of wind sand on the near-ground to the interior of a plant community. During field planting, oleander and tung cotton clump seedlings with the ground diameter of 6-7cm are respectively adopted, blocky planting is carried out on oleander, banded planting is carried out on tung cotton, the width of each band (block) is 3m, and each 667m is planted²The initial planting density was 296 strains.

After 1 year of maintenance according to conventional water and fertilizer management, 4 sample prescriptions of 3m multiplied by 9m are randomly selected from the hedges, and the survival rates of the oleander and the tung cotton in the sample prescriptions are investigated and counted. Specific statistics are shown in table 6.

TABLE 6 survival statistics in hedgerow format

As can be seen from Table 6, the survival rate of oleander in 2 hedges reaches 97.9%, the survival rate of tung cotton reaches 100.0%, and both plants can be well adapted to the soil environment of coastal saline-alkali land. After 2 years of planting, the plants grow strongly and have luxuriant branches and leaves, wherein the canopy density of the hedges built by the clustered oleander reaches over 0.9, the hedges built by the clustered elaeagnus mollis realize the complete coverage of the ground, and the canopy density reaches 1.0.

3. Comprehensive evaluation of salt-tolerant landscape communities: by constructing the arbor and shrub wind-prevention zone, the ecological landscape zone, the grass-irrigation sand-fixation zone and the hedgerow, after the implementation and maintenance are carried out for 2 years, the wind-prevention sand-fixation and landscape effects of the landscape community are investigated and evaluated again.

(1) In the aspect of wind prevention: wind power on the coast is usually 4-level (5.5-7.9 m/s) to 6-level (10.8-13.8 m/s), and due to the construction of the arbor and shrub windbreak zone, the ecological landscape zone and the hedges, the wind power in a space of 0-20m close to the ground is effectively blocked and weakened, and the wind power at the edge of the ecological landscape zone is monitored and found to be stable at 2-level (1.6-3.3 m/s) to 3-level (3.4-5.4 m/s).

(2) In the aspect of sand fixation: because the coverage rate of the grass irrigation sand stabilization belt on the beach zone reaches more than 90 percent, the uncovering and flowing of the coastal sandy land are effectively reducedMeanwhile, the PM2.5 at the edge of the ecological landscape forest belt is monitored and found to be 52 mu g/m averaged in the month from the previous year due to the three-dimensional blocking of the hedge and arbor and shrub windproof belt³Reduced to 23. mu.g/m³。

(3) Salt tolerance: investigation and statistics show that the overall survival rate of mixed trees in the arbor and shrub windbreak zone reaches 96.7%, the average survival rate of all mixed plants in the ecological landscape zone reaches 93.9%, the average survival rate of mixed plants in the shrub and shrub sand-fixing zone reaches 94.4%, the average survival rate of clustered plants in hedgerows reaches 98.9%, and the screened and applied plant species show high salt adaptability and salt tolerance.

(4) Landscape and ecological aspects: the arbor, shrub and herbaceous plant used for screening and construction are mainly evergreen, and the small number of fallen leaves or color-leaf plants are mainly or alternatively two (or more) of flower, fruit, leaf and shape, so that a relatively good landscape effect can be maintained throughout the year. After 2 years of field planting, the survival rate of the salt-tolerant plants in each forest zone is over 90 percent, the canopy density of the windproof zones of trees and shrubs and hedges is over 0.9, the coverage of the shrub and grass sand-fixing zones is over 90 percent, the ecological landscape forest zones remove landscape facilities and supporting land, the canopy density of trees and shrubs and the coverage of herbaceous plants are also over 80 percent, the coastal salt-tolerant landscape communities formed by the echelon configuration of different forest zones and the three-dimensional matching of trees and shrubs present good growth stability and ecological diversity, and the durable restoration and soil improvement of the coastal saline-alkali land are realized.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for quickly constructing a coastal wind-prevention, sand-fixation and salt-tolerance landscape community is characterized by comprising the following steps:

(1) site investigation: in coastal saline-alkali field by each unit667m²Dividing the soil into a planting cell, and measuring the soil EC value of the planting cell;

(3) soil improvement: ploughing and alkaline-earth improving the field soil;

2. The method for rapidly constructing the coastal wind-prevention, sand-fixation and salt-tolerance landscape community as claimed in claim 1, wherein the grass-irrigation and sand-fixation zone is 0-20m away from the seashore line; the arbor and shrub windbreaker strip is 20-60 m away from the seashore line; the ecological landscape zone is 60-100 m away from the seashore line; the width of the hedgerow is 2-5 m, and the height is 1-4 m.

3. The method for rapidly constructing the coastal windproof, sand-fixing and salt-tolerant landscape community according to claim 1, wherein drainage ditches are further arranged in the arbor and shrub windproof zone and the ecological landscape zone; the drainage ditch is in an H shape along the vertical direction of the coastline; the width and the depth of the drainage ditch are 40-60 cm, the length of each community is 80-110 m, and the bottom of the ditch keeps 1-5% of drainage gradient.

4. The method for rapidly constructing the coastal wind-prevention, sand-fixation and salt-tolerance landscape community as claimed in claim 3, wherein geotextiles with the width of 2.4-3.0 m and the length consistent with that of the drainage ditches are laid in the drainage ditches; the volume ratio of the filled drainage ditch is 2: 1, the filling thickness of the mixed stone is 20-30 cm.

5. The method for rapidly constructing the coastal windproof, sand-fixing and salt-tolerant landscape community according to claim 1, wherein the plowing depth of the grass-irrigating and sand-fixing zone in the soil improvement is 10-20 cm, and the plowing depth of the arbor-irrigating and windproof zone and the ecological landscape zone is 30-50 cm; the alkaline earth improvement comprises alkaline earth improvement on a tree and shrub windbreak area and an ecological landscape area, wherein 0.01-0.02% of humic acid water solution is sprayed in a district with an EC value lower than 4mS/cm, 0.02-0.04% of humic acid water solution is sprayed in a district with an EC value of 4-18 mS/cm, 0.04-0.08% of humic acid water solution is sprayed in a district with an EC value exceeding 18mS/cm, and 300-600L of humic acid solution is sprayed in each district.

6. The method for rapidly constructing the coastal windproof, sand-fixing and salt-tolerant landscape community as claimed in claim 1, wherein the arbor-shrub windproof zone can be divided into an upper layer, a middle layer and a lower layer, and is planted in a mixed mode; at least one of Pinus thunbergii, casuarina equisetifolia, phellodendron amurense rupr and syzygium jambos is planted on the upper layer; the middle layer and the lower layer are selected and planted with at least one of silver date, hibiscus syriacus, Pandanus armandii, dracaena cochinchinensis and hibiscus hamabo.

7. The method for rapidly constructing a coastal wind-prevention, sand-fixation and salt-tolerance landscape community as claimed in claim 1, wherein the hedges are planted in a strip or block manner; the plant hedgerow is selected to plant at least one of oleander, elaeostereum paulosum, syzygium jambos and panda trees.

8. The method for rapidly constructing a coastal wind-prevention, sand-fixation and salt-tolerance landscape community as claimed in claim 1, wherein the ecological landscape zone is planted in a mixed mode; the ecological landscape zone is selected and planted with at least one of acacia confusa, hibiscus syriacus, lagerstroemia speciosa, cercis negundo, melancholia, frangipani, oleander, phyllanthus urinaria and cajeput roseum; the suitable shrub and herb plant mainly comprises at least one of Ipomoea batatas, lantana camara, Delaware, Iris florida, Arundina floribunda and Wedelia chinensis.

9. The method for rapidly constructing the coastal windbreak, sand-fixation and salt-tolerance landscape community as claimed in claim 1, wherein the grass-irrigation and sand-fixation zone is planted by a mixed planting method; planting single-leaf vitex rotundifolia and pittosporum tobira selectively in the grass irrigation sand fixation belt; the suitable growth herb mainly comprises at least one of thick vine and seaside evening primrose.

10. The method for rapidly constructing the coastal wind-prevention, sand-fixation and salt-tolerance landscape community as claimed in claim 1, wherein the salt stress test method adopted by the screening of the salt-tolerance plants is as follows: stopping water supplement to 1-2 year old potted plantlets 1 week before the test begins, and respectively pouring 0.5-1.0L of 0.2% NaCl solution into each pot of plants when the plantlets show water shortage symptoms; and then pouring 0.5-1.0L NaCl solution when water shortage is approached, stopping pouring when half of the tested plants are wilted or dead, calculating the total NaCl mass accumulated for pouring, and dividing the salt tolerance grade.