CN114375750B

CN114375750B - Method for rapidly constructing coastal wind-proof sand-fixation salt-tolerant landscape community

Info

Publication number: CN114375750B
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: 2023-07-14
Anticipated expiration: 2041-12-28
Also published as: CN114375750A

Abstract

The invention discloses a rapid construction method of a coastal wind-proof sand-fixation salt-tolerant landscape community, and belongs to the technical field of ecological restoration. The quick construction method of the coastal wind-proof sand-fixation salt-tolerant landscape community comprises the following steps: site investigation; dividing a field; soil improvement; screening salt-tolerant plants; quick construction of salt-tolerant landscape communities; and (5) tending management. The salt-tolerant plants screened by the method are different in morphology, rich in flowers and leaves and high in ornamental value, and the plants with different salt tolerance grades are subjected to gradient configuration of different functional forest belts and stereoscopic collocation of arbor and shrub, 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 community with stable structure and rich biodiversity can be formed after 2 years of maintenance, the lasting restoration and soil improvement of the coastal saline-alkali soil are realized, and the construction method is suitable for popularization in Zhujiang delta or even in south China coastal areas.

Description

Method for rapidly constructing coastal wind-proof sand-fixation salt-tolerant landscape community

Technical Field

The invention relates to the technical field of ecological restoration, in particular to a method for quickly constructing a coastal windproof sand-fixation salt-tolerant landscape community.

Background

The coastal saline-alkali soil mainly forms due to seawater influence, soil transpiration, sea filling and field making engineering, forest cutting and surrounding lake salt production, and is characterized by high salt content and underground water level of the soil and low natural desalination rate of the soil; fresh water resources are lack, hydrology has daily variation and seasonal variation, vegetation varieties are poor in diversity and quantity, rural tree species and saline-alkali tolerant tree species grow slowly, and forests cannot be formed rapidly; the ecological environment is easily affected by typhoons, sea tides, salt dust and salt mist. Many established improvements are currently available, including mainly physical, biological, chemical and comprehensive improvements. The physical improvement measures adopt a physical method which is easy to implement and simple in condition to improve the soil and reduce the salt content of the soil, thereby meeting the growth requirement of plants. Chemical improvement measures reduce the alkalinity and salinity of soil by spraying chemical modifiers into saline-alkali soil. Most of the prior coastal barren lands are planted by treating soil by physical measures and chemical measures, but the prior coastal barren lands have weaker environmental adaptability than the prior coastal plants, the plants are more prone to explosion and attack in saline-alkali environments, 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 durable. The coastal saline-alkali ecological restoration not only improves the ecological environment of coastal areas, enriches the local greening landscape pattern, provides new habitats for biological diversity, but also can better solve the problems encountered in the environmental development and the economic development of the coastal areas, and provides wide space for realizing the 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-proof sand-fixation salt-tolerant landscape community.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a method for rapidly constructing a coastal windproof sand-fixation salt-tolerant landscape community comprises the following steps:

(1) Site investigation: every 667m in coastal saline-alkali soil ² Dividing into a to-be-planted district, and measuring the soil EC value of the to-be-planted district;

(2) Dividing the field: a grass irrigation sand fixation belt, a arbor irrigation wind prevention belt and an ecological landscape belt are respectively arranged from the near to the far from the coastline, and plant hedges are arranged between different forest belts;

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

(4) Screening of salt-tolerant plants: performing primary screening on the plants according to the growth indexes, windproof indexes, sand fixation indexes, ornamental indexes and literature records of the plants in the coastal areas, and performing potted salt stress tests on the primary screened plants;

(5) Quick construction of salt-tolerant landscape communities: respectively constructing a arbor and shrub wind-proof belt, a plant fence, an ecological landscape belt and a grass irrigation and sand fixation belt according to the sequence;

(6) Tending management: the tending management comprises moisture management, fertilization management, salinity management and supplementary planting management.

The soil EC value of each district is measured by adopting the conventional soil EC instrument, the operation of the instrument is simple and convenient, the salt content condition of the whole field can be rapidly and accurately mastered, the rapid alkaline earth improvement is carried out on the basis, the pertinence is strong, the method is simple and convenient, and the method is suitable for large-scale construction of salt-tolerant landscape communities of the saline-alkali field.

According to the invention, three forest belts with functions of wind prevention, sand fixation, salt resistance and landscape are reasonably arranged according to the climate, hydrologic characteristics and distance from coastline of the coastal saline-alkali soil, and different forest belts are arranged in a three-dimensional way according to the height and the distance, so that the stability and the biodiversity of communities are effectively considered, and the forming effect of the communities and the stable exertion of ecological landscape functions are facilitated.

In the tending management of the landscape community, water management is that in the initial stage of planting of various seedlings, the seedlings are manually watered for 1-3 times according to the drought condition of soil; natural precipitation irrigation is adopted in rainy season, and water supplementing is not needed in other periods; the fertilization management is to improve the adaptability of the initially planted seedlings to the saline-alkali soil and promote the vigorous growth of plants, 0.01% of brassin+1.0% of compound fertilizer aqueous solution is irrigated to the root of each plant (bush) of arbor and large shrub for 1-3 times, the concentration of small shrubs and herbaceous plants is halved, and the foliar spraying is carried out for 1-3 times; the salinity management is to plant arbor and shrub in ecological landscape zone and arbor and shrub wind-proof zone, and the root radius is 1m or 1m x 1m, and one layer of pine scales with thickness of 2-4 cm is covered. Recovering the loose scales covered by the root and the stones filled in the drainage ditch for 1-2 times each year, soaking the loose scales and the stones in the drainage ditch by using clear water, washing the loose scales and the stones to clean the loose scales and the stones, and recycling the loose scales after salting; in the tending period, the loose scales and stones are replaced every 1-2 years; the supplementary planting management is to clean and timely supplementary plant wilting and death in the field after planting various seedlings for 2 months and 1 year, and form stable coastal vegetation community after planting and growing for 2 years. The method for covering plant roots by pine scales can reduce the evaporation of water in the roots and adsorb soil salt in the range of the roots. The adopted tending measures such as moisture, fertilization, supplementary planting and the like do not need to depend on excessive manpower, so that the survival rate of plants can be effectively improved on the premise of low maintenance, and the quality of forest lands and the stability of communities are ensured.

As the rapid construction method of the coastal windproof sand-fixation salt-tolerant landscape community, the grass-irrigation sand-fixation belt is 0-20m away from the coastline; the arbor and shrub wind-proof belt is 20-60 m away from the coastline; the ecological landscape zone is 60-100 m away from the coastline; the width of the plant hedge is 2-5 m, and the height is 1-4 m.

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

As the rapid construction method of the coastal wind-proof sand-fixation salt-tolerant landscape community, drainage ditches are also arranged on the arbor-irrigation wind-proof belt and the ecological landscape belt; the drainage ditch is H-shaped along the vertical direction of the coastline; the width and depth of the drainage ditch are 40-60 cm, the ditching length of each district is 80-110 m, and the drainage gradient of the ditch bottom is kept at 1-5%.

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

As the rapid construction method of the coastal windproof sand stabilization 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 filling volume ratio in the drainage ditch is 2:1 and green zeolite, and the mixed stone is filled with the thickness of 20-30 cm.

The invention selects the green zeolite and the ceramsite to form the mixed stone, and the adsorption and ion exchange capacity of the green zeolite and the ceramsite can be used for stably carrying out the adsorption improvement of soil salt ions for a long time. The green zeolite has excellent adsorption capacity, high cost, good adsorption effect of the ceramsite and low cost, and the green zeolite and the ceramsite are mixed according to a proper proportion to fill the drainage ditch, and the green zeolite and the ceramsite are combined with geotextile to facilitate the recovery, cleaning and reutilization of stones, so that the total salt accumulated in the ditch can be effectively transferred.

As the rapid construction method of the coastal wind-proof sand-fixation salt-tolerant landscape community, the ploughing depth of the grass-irrigation sand-fixation belt in the soil improvement is 10-20 cm, and the ploughing depth of the arbor-irrigation wind-proof belt and the ecological landscape belt is 30-50 cm; the alkaline earth improvement comprises alkaline earth improvement of a arbor and shrub wind-proof belt and an ecological landscape belt, wherein 0.01-0.02% of humic acid aqueous solution is sprayed on a cell with an EC value lower than 4mS/cm, 0.02-0.04% of humic acid aqueous solution is sprayed on a cell with an EC value between 4 and 18mS/cm, 0.04-0.08% of humic acid aqueous solution is sprayed on a cell with an EC value exceeding 18mS/cm, and 300-600L of humic acid aqueous solution is sprayed on each cell.

Aiming at the functions of different forest belts, the invention adopts different soil turning and improving measures, and can effectively block the capillary conduction of soil salinity, wherein the grass irrigation and sand fixation belt is often affected by tides, and the soil is not required to be improved by alkaline earth.

As the rapid construction method of the coastal wind-proof sand-fixation salt-tolerant landscape community, the arbor-irrigation wind-proof belt can be divided into an upper layer, a middle layer and a lower layer, and is planted in a mixed mode; the upper layer is selected from at least one of black pine, casuarina equisetifolia, wampee and typha peaches; the middle layer and the lower layer are selected from at least one of planting silver date, hibiscus, paphiopedilum, dragon tree and hibiscus.

The arbor and shrub wind-proof belt is built in a mixing mode, wherein the upper layer of the forest belt is selected from large arbor with high growth speed, and the middle and lower layers are selected from medium and small arbor and large shrubs with medium or slow growth speed. Every 667m ² The initial planting density is 167 plants, the number of mixed-planted tree species is not less than 3, the number of big trees is not less than 1, the mixed-planted proportion is not more than 70%, and the selected seedling specification is chest-cutEngineering seedlings with diameters of 6-10 cm or ground diameters of 3-6 cm are suitable. The invention comprehensively considers the positions and the widths of the forest belts, the structures above and below the forest and the wind prevention and sand fixation effects of the salt-tolerant plants, reasonably sets the primary planting density, the number of mixed tree species, the mixed planting proportion and the seedling specification of the forest belts, has strong adaptability of the screened salt-tolerant plants to coastal saline-alkali soil, can guide the rapid construction of arbor and shrub wind prevention forest belts, and is beneficial to realizing and stably playing the functions of the forest belts.

As the rapid construction method of the coastal wind-proof sand-fixation salt-tolerant landscape community, the hedges are planted in a strip or block mode; the hedge is selected from at least one of oleander, tung cotton, typha and paphiopedilum.

The hedge of the invention is every 667m ² The initial planting density is not less than 222 plants, and the specifications of the planted seedlings are suitable for large cluster seedlings with the ground diameter of 5-10 cm. The invention adopts clustered evergreen shrubs to construct plant hedges, reasonably sets the planting form, the planting width and the initial planting density of hedge strips (blocks), and the screened adaptive salt-tolerant shrubs can quickly form a compact 'plant buffer wall' between the forest strips, thereby effectively blocking the attack of sea wind and sea sand near the ground and ensuring the stability of small environments in communities.

As the rapid construction method of the coastal wind-proof sand-fixation salt-tolerant landscape community, the ecological landscape zone is planted in a mixed mode; the ecological landscape zone is selected from Taiwan acacia, hibiscus, crape myrtle, cercis chinensis, russianchau, russiantree, plumeria rubra, oleander, leaf flowers, cajeput and the like; the suitable small shrubs and herbs mainly comprise at least one of Longhua, lantana camara, delphinium, iris coreana, phragmites communis, and wedella.

The invention adopts a mixing mode to construct the ecological landscape forest belt. Not less than 6 plants are mixed, wherein not less than 4 arbor shrubs are used; arbor and shrub each 667m ² The primary planting density is not less than 42 plants, the coverage of the small shrubs and the herbaceous plants is not less than 75 percent of the empty land area of a district, the specifications of the planted arbor shrubs are that the engineering big seedlings, the small shrubs and the herbaceous plants with the diameter of the chest or the diameter of the land of 4-10 cm are in a 1-2 annual container Miao Weiyi. The invention adopts the arbor-shrub standThe ecological landscape forest belt is built by a garden design method of body configuration, initial planting density, mixed planting number and seedling specification are reasonably set, ornamental value and species diversity are also considered, the screened arbor shrubs and herbaceous plants can be well adapted to offshore salinized soil, rapid construction of ecological landscape forests is guided, and stable exertion of ecological landscape functions of the forest belt is facilitated.

As the rapid construction method of the coastal wind-proof sand-fixation salt-tolerant landscape community, the grass-irrigation sand-fixation belt is planted in a mixed planting mode; the grass-filling sand-fixing belt is used for selectively planting fructus viticis, erythrina grass; the suitable herb mainly comprises at least one of caulis Sargentodoxae and radix Oenotherae Erythrosepalae.

The invention adopts a mixed planting mode to construct the grass-irrigation sand-fixation belt. The mixed planting variety is not less than 2, wherein the initial planting density of shrubs is not less than 4 plants per 1m2, the initial planting density of herbaceous plants is not less than 9 plants per 1m2, the planted shrubs are in 1-3 annual container seedlings and the herbaceous plants are in 1 annual container Miao Weiyi. The invention adopts the grass-irrigation plants with high salt tolerance and vining property and utilizes the mixed planting method to construct the grass-irrigation sand-fixation belt, reasonably sets the mixed planting type, the primary planting density and the seedling specification, combines the deep rooting property of shrubs and the broad distribution property of herb fibrous roots, has strong adaptability of the screened shrubs and herb plants to the beach sand, and is beneficial to rapidly realizing the wide coverage and stable rooting of the sand.

As the rapid construction method of the coastal wind-proof sand-fixation salt-tolerant landscape community, the salt stress test method adopted by the screening of the salt-tolerant plants comprises the following steps: stopping supplementing water to the 1-2 year old potted seedlings 1 week before the start of the test, and respectively pouring 0.5-1.0L of 0.2% NaCl solution into each pot of plants when the seedlings show water deficiency symptoms; and then pouring the same amount of NaCl solution when water is lack. Stopping watering when half plants to be tested wilt or die, calculating the total mass of NaCl in accumulated watering and classifying salt tolerance grades.

The salt-tolerant plant screening method comprises the steps of field investigation of the current situation of vegetation, reference research of literature data and salt stress test of salt-tolerant plants, and the method is progressive layer by layer. The method is characterized in that the primary screening of the salt-tolerant plants comprehensively considers the wind-proof sand-fixation effect of the plants in typhoon weather, the growth adaptability and ornamental property of the saline-alkali field, and a simple potted plant quantitative irrigation method is adopted in a potted salt stress test, so that the true salt-tolerant capability of each plant can be rapidly and accurately tested and applied to construction of different forest belts, the screening method is clear in purpose and strong in guidance, and 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 rapid construction method of a coastal windproof sand-fixation salt-tolerant landscape community, wherein the screened salt-tolerant plants are different in form, rich in flowers and leaves and high in ornamental value, and the plants with different salt-tolerant grades are subjected to gradient configuration of different functional forest belts and stereoscopic collocation of arbor and shrub grass, so that the aims of windproof, sand-fixation and salt resistance can be effectively realized, and a good ecological landscape effect is rapidly formed; the construction method is simple, convenient and practical, the tending management is simple, the coastal vegetation community with stable structure and rich biodiversity can be formed after 2 years of maintenance, the lasting restoration and soil improvement of the coastal saline-alkali soil are realized, and the construction method is suitable for popularization in Zhujiang delta or even in south China coastal areas.

Drawings

Fig. 1: investigation of salt-tolerant arbor shrubs and herbaceous plants in coastal saline-alkali lands;

fig. 2: potted salt stress test of 1-2 year old seedlings of the primary selected plants;

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

fig. 4: arbor and shrub windproof forest belts built by adopting medium-high salt-tolerant plants;

fig. 5: an ecological landscape forest built by middle and low salt-tolerant plants and a grass-irrigation sand-fixation belt built by high salt-tolerant plants are adopted;

fig. 6: a hedge constructed by tung cotton with high salt tolerance is adopted;

fig. 7: covering plant roots with pine scales, and adsorbing a large amount of crystal salt on the surfaces of the pine scales after 3 months;

fig. 8: the green zeolite washed before use was used, and after 3 months, a large amount of crystalline salt was adsorbed on the surface of the green zeolite.

Detailed Description

The above-described aspects of the present invention will be described in further detail below with reference to specific embodiments in the form of 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 team thereof sequentially conduct field investigation of arbor shrubs and herbaceous plants according to the current vegetation situation of the existing forests, woodlands, greenlands and the like in the coastal region of the bead delta, and the total of 96 plants in 240 families and 352 species of the coastal vascular bundle plants are investigated according to the growth condition of the plants in the coastal saline-alkali region. The method combines the field observation and evaluation of the wind prevention and sand fixation effects before and after typhoons every year, and refers to literature data of related plant saline-alkali tolerance research to primarily screen a batch of coastal suitable saline-alkali plants.

Wherein, preliminary screening index includes: (1) growth conditions: the plant can normally grow in coastal saline-alkali areas, and branches and leaves without bad symptoms or harmful salt symptoms do not exceed 5% of the whole plant; (2) windproof effect: the branches and leaves of the plants are dense, the crown is full, and no main branches are broken or broken branches do not exceed 10% of the whole plant after typhoons pass; (3) sand fixation effect: the root systems of the arbor and the shrub are developed, and no lodging occurs after typhoons occur or the lodging rate of the same area is not more than 5%; the low shrubs and herbaceous plants have strong vinability, and the ground coverage can reach more than 75%; (4) ornamental properties: the arbor is suitable for evergreen, the shrub plant is evergreen or fallen leaves, and the herb plant is suitable for multiple years; two (and more) or one of the two (and more) of the flower, fruit, leaf and shape is provided; (5) literature basis: industry technical regulations or experimental researches show that the plants with the salt tolerance of more than 0.2 percent or dominant tree species of islands, beaches, bays and other places recorded in authoritative literature are associated with mangrove forest.

Finally, 66 coastal suitable saline-alkali plants are screened, and the main steps are as follows: cortex et radix Populi, herba Ephedrae, cortex Hibisci, herba Pini, herba Origani, radix Pulsatillae, cerbera Mangifera, rhizoma Yustamen, YINGYESHU, radix Ilicis Pubescentis, herba Typhonii gigantei, hainan Duying, hainan Red bean, semen Sojae Preparatum, herba Melaleucae Lepidatae, cortex Melaleucae Leuca, herba Vernici Fordii, fructus Viticis, cinnamomum, herba Verniciae Fordii, semen Sonchi, rhizoma Alpiniae Officinarum, carthami flos, lagerstroemia speciosa, oleander, herba Melastomatis Candii, cotinus, huarun-Murrah, gao Shanrong, herba Duchesneae Indicae, radix Rhodomyrti Diels, radix Rhodomyrti Punicae Japonicae, fructus Rhodomyrti, fructus Rosae Rugosae, semen Strychni Pulveratum Cercis chinensis, plumeria rubra, herba tiethri, lagerstroemia speciosa, silver date, cinnamomum camphora, caulis Polygoni Multiflori, lythrum, canna, oleander, lantana camara, iris coreana, graptopetalum, caulis Sargentodoxae, kenaf, hibiscus syriacus, pogostemon cablin, phragmites communis, cuneata viridis, berberis, longhua, small leaf olive kernel, semen Cassiae pterocarpi, hairpekoe, orthosiphon aristatus, blunt pennisetum, leaf flower, alternanthera, wedelia, etc. The plants have different forms, rich leaf colors and high ornamental value, and reasonable collocation of arbor, shrub and grass is carried out on the salinized plants, so that a beautiful coastal ecological landscape community can be created.

2. Test screening of salt tolerant plants

Aiming at salt-tolerant plants screened in the preliminary step, 45 of the salt-tolerant plants are subjected to potted salt stress tests by adopting 1-2 annual seedlings respectively in combination with nursery seedling and market seedling supply conditions so as to test specific salt tolerance. In the test, 10 plants of 1-year-old or 2-year-old container seedlings with consistent plant types are selected from each tested plant, and are uniformly transplanted and maintained for 1 month by adopting gallon pots made of the same materials and transplanting matrixes with the same components and quality. Stopping water irrigation of potted seedlings 1 week before the start of the test, and respectively pouring 0.5L of 0.2% NaCl solution and 1.0L of 0.2% NaCl solution into each pot of 1-year-old seedlings and 2-year-old seedlings when the seedlings show water deficiency symptoms; and then, pouring the same amount of NaCl solution when the water is near to the shortage. And stopping watering when half of plants of each plant wilt or die (salt damage symptoms).

The initially selected plants were classified into 3 classes according to their salt tolerance according to the number of times of watering of the test plants and the total mass of NaCl accumulated for watering. Specifically, the results are shown in Table 1.

Table 1 salt tolerant plants and salt tolerant grades thereof

Note that: plants with few watering times reaching 6 times but still not reaching half of the salt damage symptoms are treated with high salt tolerance.

As can be seen from table 1: the initially screened plants can be subjected to more than 1 time of NaCl solution irrigation, which shows that the plants have certain salt tolerance. Of the 45 plants tested, 13 were able to withstand 2 NaCl solution drenches, accounting for 28.9% of the total, with cumulative NaCl drenches up to 0.4% of the total mass. 14 kinds of the materials can withstand 3 times of NaCl solution irrigation, and account for 31.1% of the total; 9 plants which can withstand 4 times of NaCl solution irrigation and account for 20.0% of the total number, and the total mass of NaCl accumulated by the two treatments is up to 0.8% and accounts for more than 50% of the total number of plants to be tested. 10 plants can be irrigated by NaCl solution for more than 5 times, accounting for 22.2 percent of the total number of the tested plants, and the total mass of the accumulated irrigated NaCl exceeds 1.0 percent; wherein, the irrigating times of the fructus viticis and the erythrina grass reach 6 times, but no obvious salt damage symptoms appear, which is consistent with the salt tolerance property that the two plants are beach saphens and can withstand tidal flushing.

According to the result of test screening, the obtained salt-tolerant plants are classified according to plant types and salt tolerance, so that the rapid construction of salt-tolerant landscape communities in coastal areas can be guided. In combination with the actual use of the seedlings in the seashore landscape engineering in the bead triangular area, representative plants with large-scale application characteristics are screened, and specific classifications are shown in table 2.

TABLE 2 representative plants suitable for the construction of salt tolerant landscape communities in the bead triangular area

Note that: some trees are often used for bush cultivation, and some bushes can also grow into a tree shape, and strict distinction is not made here.

The plants have different forms, rich flowers and leaves and higher ornamental value, the plants with different salt tolerance capacities are reasonably configured, and the wind-proof, sand-fixing and salt-tolerant community is constructed, meanwhile, a good ecological landscape effect can be formed, so that the method is suitable for popularization and application in Zhujiang delta and even in south China coastal areas.

Example 2

Aiming at the proper salt-tolerant plants screened in the embodiment 1, the inventor and team thereof are popularized and applied in more than ten coastal landscape greening engineering projects under the establishment of companies, and the construction of the arbor and shrub wind-proof belt, the ecological landscape belt, the grass-shrub sand-fixing belt and the plant hedge is implemented in specific projects.

1. Introduction to project site

In a construction project of an ecological landscape in a new area of a coastal bay of Dongguan city, which is established by a company, wind-proof forests, sand-fixing grass belts and hedges are required to be established in coastal areas which are 0-60 m away from coastlines due to the protection requirement of the ecological landscape; wherein, the construction area of the ecological garden landscape area 29273m ² Area 27846m for building wind-proof forest region ² Construction area 22198m of coastal sand fixation area ² . The fields are all coastal saline-alkali lands and are often affected by coastal storms and sea sand.

2. Site investigation and soil preparation

(1) According to the current situation of the field, the field is divided into 667m ² The method is divided into a planned planting district, wherein the ecological landscape district is 44 districts, the wind forest district is 42 districts, the sand fixing district is 33 districts, and the total amount of the districts is 119 districts. And measuring the soil EC value of each planting district by adopting a soil EC instrument, measuring 9-12 points in each district, and calculating the average EC value. Wherein, the soil EC value range of the ecological landscape area is 1.6-11.8, belonging to the middle and light saline-alkali soil type; the EC value range of the soil in the wind-proof forest area is 2.7-17.4, and the wind-proof forest area belongs to the type of medium-low saline-alkali soil; the EC value range of the soil in the coastal sand-fixing area is 3.4-25.7, and the soil comprises high, medium and low saline-alkali soil types, but the whole soil is mainly moderate saline-alkali soil.

(2) Mechanically ploughing soil in the ecological landscape area and the windproof forest area to a depth of 30-50 cm; manually turning over and raking the sand in the coastal sand-fixing area, wherein the depth is 10-20 cm. Then, 300 to 600L of 0.01 to 0.02 percent of humic acid aqueous solution is sprayed on the cells with the average EC value lower than 4mS/cm in the ecological landscape area and the windbreak forest area, and 300 to 600L of 0.02 to 0.04 percent of humic acid aqueous solution is sprayed on the cells with the average EC value between 4 and 18mS/cm for improvement.

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

3. Construction of salt-tolerant landscape community

(1) Building a arbor and shrub wind-proof belt: in coastal region 20-60 m from coastline, arbor and shrub with high salt tolerance are selected for the construction of mixed wind-proof forest, wherein the upper layer of the forest belt is made of herba Ephedrae with rapid growth, and the lower layer is made of typha, zizyphi fructus, pachyrhizus lupeus and oleander with moderate growth rate. When in planting, the initial planting density of each district 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 seedling is engineering big seedling with 6-10 cm chest diameter or 3-6 cm ground diameter.

After the conventional water and fertilizer management maintenance is carried out for 1 year, 3 cells are randomly selected from the wind forest area, and the survival rate and the salt damage occurrence rate of all salt-tolerant plants in the cells are investigated and counted. Wherein, the survival rate is the ratio of the number of the grown plants to the total number of the planted plants in the sampling district; the salt damage incidence rate is that 3 representative sample strains are randomly selected in each cell, and the quantity of branches and leaves with salt damage symptoms accounts for the average proportion of the total quantity of the branches and leaves of the whole plant. The statistical results are shown in Table 3.

Table 3 statistics of survival of salt tolerant plants in arbor and shrub windproof forest belts

As can be seen from table 3: the average survival rate of the main mixed wood species of the casuarina equisetifolia is up to 95.6%, and the plant has no salt damage symptom, which indicates that the casuarina equisetifolia is very suitable for constructing coastal salt-tolerant plants in arbor and shrub wind-proof bands. The survival rate of other mixed tree species is above 90%, especially the survival rate of the paphiopedilum and oleander is as high as 100%; besides the slight salt damage symptoms of the silver date leaves, other tree species have almost no salt damage or the salt damage incidence rate is less than 5 percent, and the silver date leaves have strong salt adapting and salt tolerance. And calculating the overall survival rate of the mixed tree species in the arbor and shrub wind-proof belt, wherein the average survival rate can reach 96.7%.

(2) Construction of an ecological landscape belt: and in an offshore area beyond 60m from the coastline, ornamental arbor shrubs with medium-low salt tolerance and partial high salt tolerance are selected to construct an ecological landscape forest belt from herbaceous plants. The ornamental arbor and shrub mainly comprises black pine, crape myrtle, cajeput, plumeria rubra and phyllanthus; the small shrubs and herbs mainly comprise lantana camara, delphinium, wedella and the like. During field planting, the primary planting density of ornamental trees and large shrubs in each cell is not less than 42 plants, and the coverage of small shrubs and herbaceous plants is not less than 70% of the vacant area in the cell. The arbor and shrub specification is engineering big seedling with chest diameter or ground diameter of 4-10 cm, and the herb is container seedling with 1-2 years old.

After the water and fertilizer management maintenance is carried out for 1 year according to the conventional water and fertilizer management, 3 cells are randomly selected from a landscape forest area, and the survival rate of all the mixed plants in the cells is investigated and counted. The statistics are shown in Table 4.

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

As shown in Table 4, the average survival rate of all the mixed plants in the arbor and shrub windproof forest zone is as high as 93.9%, which shows that the screened medium-low salt-tolerant plants have strong adaptability to offshore medium-low saline-alkali soil which is slightly far from the coast. Except for leaf flowers, the survival rate of the mixed plants of the arbor and shrub windproof forest belts is over 90 percent, and the survival rate of She Zihua is only 85.7 percent, which is possibly related to the difference of the salt tolerance of different varieties of the leaf flowers, and the consistency of test varieties and practical application varieties is also needed to be paid attention to when the salt tolerance landscape is constructed.

(3) Construction of grass irrigation and sand fixation belts: selecting small shrubs with high salt tolerance and tendrils and perennial herbaceous plants in coastal sand with the distance of 0-20m from the coastline, and constructing a grass-irrigation and sand-fixation belt by adopting a mixed planting method. The shrub is selected from Vitex agnus-castus, and the herb is selected from caulis Sargentodoxae and Oenotherae Erythrosepalae. Every 1m during field planting ² The primary planting density of shrubs is 4 plants, and herbs are 9 plants; the fructus Vitics Simplicifoliae, caulis Sargentodoxae, and radix Oenotherae Erythrosepalae are 1 year old container seedlings.

After the water and fertilizer are managed and maintained for 1 year according to the conventional water and fertilizer, 3 sample formulas with the diameter of 3m multiplied by 3m are randomly selected from the grass-irrigation sand-fixation belt, and the survival rate of the mixed plant in the sample formulas is investigated and counted. The specific statistics are shown in table 5.

TABLE 5 survival statistics of plants in grass-irrigation and sand-fixation tape-like squares

As can be seen from table 5: the mixed planting survival rate of the single leaf fructus viticis, the thick vine and the common evening primrose on the coastal sand is more than 90%, wherein the survival rate of the single leaf fructus viticis is the highest and reaches 97.2%. Since the influence of the tide on the beach sand is very obvious, the salt content of the sandy loam is relatively high, usually around 1.0% or even higher, and thus the high salt tolerance of these mixed plants is also verified. The single leaf fructus viticis, the thick vine and the common evening primrose have good creeping growth property or vining property, the coverage rate of the mixed plant on the sand is more than 90% in field investigation, and the statistical average survival rate can reach 94.4%.

(4) And 2 hedge is built by adopting evergreen shrubs with medium and high salt tolerance and multiple branches between the grass irrigation sand fixation belt, the arbor irrigation wind prevention belt and the ecological landscape belt so as to prevent the wind sand near the ground from invading the plant community. During field planting, oleander with ground diameter of 6-7cm and cotton plant with width of 3m and length of 667m are used for planting blocks ² The initial planting density is 296 strains.

After the management and maintenance of the conventional water and fertilizer for 1 year, 4 3m multiplied by 9m sample formulas are randomly selected from the hedge, and the survival rate of oleander and tung cotton in the sample formulas is investigated and counted. The specific statistics are shown in table 6.

TABLE 6 survival statistics in hedge squares

As shown in Table 6, the oleander survival rate in 2 hedges reaches 97.9%, the tung cotton survival rate reaches 100.0%, and both plants can be well adapted to the soil environment of coastal saline-alkali soil. After field planting for 2 years, the plants grow well and have luxuriant branches and leaves, wherein the closing degree of the hedges constructed by using the oleander clusters reaches more than 0.9, and the hedges constructed by using the tree cotton clusters achieve complete coverage of the ground, and the closing degree reaches 1.0.

3. Comprehensive evaluation of salt-tolerant landscape communities: through the construction of the arbor and shrub wind-proof belt, the ecological landscape belt, the shrub grass and sand fixation belt and the plant hedge, after the arbor and shrub wind-proof belt, the ecological landscape belt, the shrub grass and sand fixation belt and the plant hedge are implemented and maintained for 2 years, the wind-proof sand fixation and landscape effect of the landscape community is re-investigated and evaluated.

(1) Wind-proof aspect: the wind power on the coast is usually from level 4 (5.5-7.9 m/s) to level 6 (10.8-13.8 m/s), and the wind power near the space of 0-20m on the ground is effectively blocked and weakened due to the construction of the arbor irrigation wind-proof belt, the ecological landscape belt and the hedge, and the wind power at the edge of the ecological landscape belt is monitored to be stable from level 2 (1.6-3.3 m/s) to level 3 (3.4-5.4 m/s).

(2) Sand fixation: the coverage rate of the grass-irrigation sand-fixation belt to the beach area reaches more than 90%, so that the bare and flowing of the beach sand area is effectively reduced, and meanwhile, due to the three-dimensional blocking of the hedge and arbor-irrigation wind-proof belt, the PM2.5 at the edge of the ecological landscape forest belt is detected to be 52 mug/m from the current year to the average month ³ Down to 23. Mu.g/m ³ 。

(3) Salt resistance: investigation and statistics show that the overall survival rate of the mixed plant species in the arbor and shrub wind-proof 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 the mixed plants in the shrub and shrub sand-fixing zone reaches 94.4%, the average survival rate of the cluster plants in the hedge reaches 98.9%, and the screened and applied plant species show very high salt adapting and salt tolerance.

(4) Landscape and ecological aspects: the arbor shrubs and herbaceous plants used for screening and constructing are mainly evergreen, and are mixed with few fallen leaves or colored leaves, so that the arbor shrubs and herbaceous plants have two (or more) or one of the two or more of flower observation, fruit observation, leaf observation and shape observation, and can maintain a better landscape effect throughout the year. After field planting for 2 years, the survival rate of salt-tolerant plants in each forest belt is over 90%, the canopy density of the arbor and shrub wind-proof belt and the plant hedge is over 0.9, the coverage of the grass and sand-fixing belt is over 90%, the ecological landscape forest belt is used for removing landscape facilities and matched lands, the canopy density of arbor and shrubs and the coverage of herbaceous plants are also 80%, and the coastal salt-tolerant landscape community formed by the echelon configuration of different forest belts and the stereo collocation of arbor and shrubs presents good growth stability and ecological diversity, and realizes the lasting restoration and soil improvement of coastal saline-alkali soil.

Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the scope of the present invention, and although the present invention has been 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 to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for rapidly constructing a coastal windproof sand-fixation salt-tolerant landscape community is characterized by comprising the following steps:

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

(6) Tending management: the tending management comprises moisture management, fertilization management, salinity management and supplementary planting management;

the grass-irrigation sand-fixation belt is 0-20m away from the coastline; the arbor and shrub wind-proof belt is 20-60 m away from the coastline; the ecological landscape zone is 60-100 m away from the coastline; the width of the plant hedge is 2-5 m, and the height is 1-4 m;

drainage ditches are also arranged on the arbor and shrub wind-proof belt and the ecological landscape belt; the drainage ditch is H-shaped along the vertical direction of the coastline; the width and depth of the drainage ditch are 40-60 cm, the ditching length of each district is 80-110 m, and the drainage gradient of the ditch bottom is kept at 1-5%;

the arbor and shrub wind-proof belt can be divided into an upper layer, a middle layer and a lower layer, and is planted in a mixed mode; the upper layer is selected to plant casuarina equisetifolia; planting typha and silver date, paphiopedilum, and oleander in the middle layer and the lower layer;

the ecological landscape zone is planted in a mixed mode; the ecological landscape zone is selected to be planted with black pine, crape myrtle, cajeput, plumeria rubra and phyllanthus; the suitable shrubs and herbs mainly comprise five-color plums, delphinium, wedella;

the grass irrigation and sand fixation belt is planted in a mixed planting mode; the grass-irrigation sand-fixation belt is used for selecting and planting single-leaf fructus viticis; the suitable herb mainly comprises caulis Sargentodoxae, and radix Oenotherae Erythrosepalae;

the hedges are planted in a strip or block mode; the hedge is selected to be planted with oleander and tung cotton;

geotextile with the width of 2.4-3.0 m and the length consistent with that of the drainage ditch is paved in the drainage ditch; the filling volume ratio in the drainage ditch is 2:1 or mixing stones of the green zeolite or the ceramsite and the green zeolite, and filling the mixing stones with the thickness of 20-30 cm;

the salt stress test method adopted by the screening of the salt-tolerant plants comprises the following steps: stopping supplementing water to the 1-2 year old potted seedlings 1 week before the start of the test, and respectively pouring 0.5-1.0L of 0.2% NaCl solution into each pot of plants when the seedlings show water deficiency symptoms; and then 0.5-1.0 LNaCl solution is poured when water is near to a shortage, the irrigation is stopped when half of plants to be tested wilt or die, the total mass of accumulated irrigated NaCl is calculated, and the salt tolerance grade is divided.

2. The method for quickly constructing the coastal wind-proof sand-fixation salt-tolerant landscape community according to claim 1, wherein the ploughing depth of the grass-irrigation sand-fixation belt in the soil improvement is 10-20 cm, and the ploughing depths of the arbor-irrigation wind-proof belt and the ecological landscape belt are 30-50 cm; the alkaline earth improvement comprises alkaline earth improvement of a arbor and shrub wind-proof belt and an ecological landscape belt, wherein 0.01-0.02% of humic acid aqueous solution is sprayed on a cell with an EC value lower than 4mS/cm, 0.02-0.04% of humic acid aqueous solution is sprayed on a cell with an EC value between 4 and 18mS/cm, 0.04-0.08% of humic acid aqueous solution is sprayed on a cell with an EC value exceeding 18mS/cm, and 300-600L of humic acid aqueous solution is sprayed on each cell.