Method for afforestation in coastal saline-alkali land

Abstract

The invention provides a method for afforestation in coastal saline-alkali land, which comprises the following steps of: searching dominant saline-alkali tolerant tree species in a local area, searching dominant indigenous tree species in the local area, searching dominant landscape greening tree species in the local area, and screening saline-alkali tolerant landscape greening tree species. Carrying out expanding propagation on rhizosphere microorganisms of the saline-alkali-tolerant tree species, and then preparing planting soil from the collected active culture medium and saline-alkali soil according to the volume ratio of 3: 7 to cultivate the screened saline-alkali-tolerant tree species. According to the method, a previous simple and rough afforestation method is abandoned, appropriate afforestation dominant tree species are selected according to the characteristics of afforestation soil and climate conditions, huge economic loss and resource waste are avoided, and a systematic and feasible scientific method is provided for large-scale afforestation, especially saline-alkali soil afforestation.

Description

Technical Field

[0001] The invention belongs to the field of gardening and relates to a method of afforestation, in particular to a method of afforestation in coastal saline-alkali land. Background Art

[0002] China has a long coastline with a large amount of coastal saline-alkali soil. There have always been many problems in afforestation on coastal saline-alkali land. Among them, low afforestation survival rate and low plant diversity are the current status of afforestation on coastal saline-alkali land. The design or construction unit carries out large-scale saline-alkali land planting construction according to the plant planting list provided by Party A, and at the same time takes measures such as digging ditches for drainage, soil improvement of planting holes, and adding isolation layers. However, most of the tree species still die or weaken after one or several years, causing significant economic losses to the society and slowing down the pace of urban ecological civilization construction.

[0003] The plant list provided by Party A may include a large number of salt-tolerant tree species, as well as a large number of garden landscape plants. These plants often show significant differences in adaptability when planted in different climatic conditions and in different regions.

[0004] How to select the dominant pioneer tree species suitable for afforestation in saline-alkali land in the region is the key factor for the success of afforestation in saline-alkali land. The present invention takes the principle of suitable trees for suitable land as the goal, selects the tree species that are suitable for the growth conditions of saline-alkali land in the region, and creates the best growth conditions for them. Summary of the invention

[0005] In view of the above technical problems in the prior art, the present invention provides a method for afforestation in coastal saline-alkali land, which aims to solve the technical problems of low survival rate and low plant diversity in afforestation in coastal saline-alkali land in the prior art.

[0006] The present invention provides a method for afforestation in coastal saline-alkali land, comprising the following steps:

[0007] 1) A step of searching for dominant salt-alkali tolerant tree species in the region, selecting dominant tree species types of representative 1-5 years old saline-alkali land shelterbelts in the region, wherein the dominant tree species are characterized by vigorous growth, no insect pests, and stable growth, and are written into the list of salt-alkali tolerant tree species selected for afforestation in saline-alkali land in the region; if there are no 1-5 years old forests in the saline-alkali land in the region, selecting dominant tree species types of 6-10 years old saline-alkali land shelterbelts in the region, and writing them into the list of salt-alkali tolerant tree species selected for afforestation in saline-alkali land in the region;

[0008] 2) A step to find the dominant native tree species in the region. Native tree species refer to the naturally distributed tree species in the region or the foreign tree species that have been introduced for 6-10 years and have always performed well in the local area. The dominant native tree species in the region that grow vigorously, are pest-free, and have stable growth are included in the list of selected native tree species for afforestation in saline-alkali land in the region;

[0009] 3) A step of finding dominant landscape greening tree species in the region. If the list of selected saline-alkali land afforestation formed by steps 1) and 2) does not meet the total number of plant species required for large-scale saline-alkali land afforestation, dominant tree species are extracted from the catalog of commonly used landscape tree species in the region and added to the list of selected saline-alkali land afforestation landscape greening tree species in the region;

[0010] 4) A step of screening salt-alkali tolerant tree species for afforestation in saline-alkali land, selecting tree species from the list formed in step 3) for salt-alkali tolerance screening, and selecting salt-alkali tolerant dominant tree species; tree species are preferably all included in the list of steps 1) and 2), and the remaining ones are selected from the list of step 3) from the beginning to the end. For each selected tree species, 10 strong seedlings of tree species over 10 years old are selected and planted in the representative saline-alkali area of ​​the planned afforestation area, normal drainage ditches are dug, and the planting is carried out during Qingming Festival, and the growth status of each tree species is observed after Qingming Festival the following year;

[0011] The selected tree species are divided into four categories: the first category is the "strong salt-alkali tolerance" tree species with a survival rate of 100% and strong growth potential; the second category is the "medium salt-alkali tolerance" tree species with a survival rate of less than 100%, but a survival rate of more than 60% and strong growth potential; the third category is the "weak salt-alkali tolerance" tree species with a survival rate of less than 50%; the fourth category is the "alive rate less than 60% but more than 50% and average growth potential" tree species.

[0012] If the statistical results of "strong salt-alkali tolerance" tree species account for more than 50%, all "strong salt-alkali tolerance" tree species will be added to the afforestation list; if the "strong salt-alkali tolerance" tree species account for less than 50% and do not meet the requirements of the target afforestation tree species, "medium salt-alkali tolerance" tree species will be selected to make up 50% to ensure that the target salt-alkali tolerance tree species are screened;

[0013] 5) A step of propagating rhizosphere microorganisms of salt-alkali tolerant tree species: taking out the rhizosphere soil, including the root system, of the "strong salt-alkali tolerant" tree species and the "medium salt-alkali tolerant" tree species in step 4), respectively, and mixing them with garden waste or any decomposed agricultural and forestry waste in a mass ratio of 5: (80-120) to cover the seedling tray, sowing crop seeds with strong root systems in the seedling tray, watering the seedlings normally, harvesting all underground parts including the root system and cultivation substrate after 3 or 4 weeks and marking them, and collecting half of the underground part, retaining the other half, adding new garden waste, mixing, and continuously propagating microorganisms to obtain an active cultivation substrate;

[0014] 6) Collect the active cultivation matrix in step 5) and the saline-alkali soil in the native habitat of the tree species in a volume ratio of 3:7 to prepare planting soil for cultivating the selected salt-alkali tolerant tree species.

[0015] Furthermore, the crop seeds with strong root systems are any one of corn, wheat or soybeans, or a combination of two or more thereof.

[0016] Further, 100 tree species are selected from the list formed in step 3) for salt-alkali tolerance screening, and 50 salt-alkali tolerant superior tree species are selected from them; the 100 tree species are preferably all included in the list of steps 1) and 2), and then the remaining ones are picked from the list of step 3) from the front to the back, and 10 strong seedlings of tree species over 10 years old are selected from each of the 100 tree species, and a total of 1,000 seedlings are planted in representative saline-alkali areas in the proposed afforestation area, normal drainage ditches are dug, and planting is carried out during Qingming Festival, and the growth status of each tree species is observed after Qingming Festival in the following year.

[0017] Specifically, this region refers to coastal cities belonging to the same climate zone.

[0018] Compared with the prior art, the present invention has a positive and obvious technical effect. The present invention abandons the simple and crude afforestation method in the past, selects suitable dominant tree species for afforestation according to the characteristics of afforestation soil and climatic conditions, avoids huge economic losses and waste of resources, and provides a set of systematic and feasible scientific methods for large-scale afforestation, especially afforestation in saline-alkali land. DETAILED DESCRIPTION

[0019] Example 1

[0020] The present invention provides a method for afforestation in coastal saline-alkali land, which specifically comprises the following steps:

[0021] 1. Find the dominant salt-alkali tolerant tree species in the region: The mature forests of early urban coastal afforestation often have a single vegetation type and gradually move away from the coastline. Due to the long growth period and rich humus in the surface soil, they present a relatively stable growth state. The dominant tree species are not suitable as candidate species for new saline-alkali land afforestation pioneers.

[0022] The newer the saline-alkali land, the more representative its tree species are and the better they can adapt to the growth under the current climate and soil conditions.

[0023] It is advisable to select dominant tree species of the new saline-alkali land protection forest in the region that are 1 to 5 years old, which often show the characteristics of vigorous growth, no pests, and stable growth, and write them into the list of selected tree species for afforestation in the new saline-alkali land in the region. The tree species with weak growth potential and easy to be diseased should be written into the list of prohibited tree species for afforestation in the new saline-alkali land in the region. If there is no new afforestation of 1 to 5 years old in the saline-alkali land in the region, it is advisable to select dominant tree species from the newest saline-alkali forest in the region (6-10 years old). Prepare the list of selected tree species and the list of prohibited tree species for afforestation in the saline-alkali land in the region.

[0024] 2. Find the dominant native tree species in the region: The tree species in the list of saline-alkali land afforestation tree species in step 1 are often small in number (3 to 10 species) (related to the regional afforestation planning and design), which is not enough to support the large-scale (more than 10,000 mu) saline-alkali land afforestation plant selection (50 to 100 species or more). You can write 10 to 20 or more dominant native tree species in the region into the list of saline-alkali land afforestation tree species.

[0025] 3. Find the dominant landscape greening tree species in the region: The list of tree species for afforestation in saline-alkali land formed in step 2 (10 to 30 species) is still insufficient to support large-scale saline-alkali land afforestation plant selection (50 to 100 species or more). The remaining tree species are often collected from the catalog of commonly used landscape tree species in the region and screened from literature. These tree species are the most widely used and have no saline-alkali land practice data support, so they need to be verified in practice. Landscape tree species have abundant market nursery resources and are the main force in afforestation, but they are also the group with the most casualties in afforestation. How to scientifically select salt-alkali tolerant landscape greening tree species is the key to successful afforestation.

[0026] 4. Scientifically select salt- and alkali-tolerant landscape greening tree species: select 100 advantageous landscape greening tree species from the catalog of commonly used landscape tree species in the region (obtained from relevant greening industry departments or through self-investigation) and literature materials (with the goal of selecting 50 salt- and alkali-tolerant tree species, and the actual afforestation target will be determined based on needs), select 10 strong seedlings (over 10 years old) of each species, and plant a total of 1,000 trees in the most serious saline-alkali area within the proposed afforestation area. Dig normal drainage ditches about 1 meter deep, without any other improvement measures (soil improvement, fertilization, isolation layer, etc.), and plant them during Qingming Festival, and observe the growth of each tree species after Qingming Festival the following year.

[0027] The screened tree species are divided into four categories: those with a survival rate of 100% and strong growth potential are defined as "strong salt-alkali tolerance" tree species; those with a survival rate of more than 60% and relatively strong growth potential are defined as "medium salt-alkali tolerance" tree species; those with a survival rate of less than 50% are defined as "weak salt-alkali tolerance" tree species; those with a survival rate of 50% to 60% and average growth potential are defined as alternative tree species.

[0028] If the statistical results of "strong salt-alkali tolerance" tree species account for more than 50% (calculated as 100 species), all "strong salt-alkali tolerance" tree species will be added to the afforestation list; if the "strong salt-alkali tolerance" tree species account for less than 50% and do not meet the requirements of the target tree species for afforestation, "medium salt-alkali tolerance" tree species will be selected to make up 50% to ensure that the target 50 salt-alkali tolerance tree species are screened.

[0029] The screening test includes plants in the tree species list of step 1 and step 2, namely the dominant salt-alkali tolerant tree species and dominant native tree species in the region. Step 4 basically and scientifically formulates the list of dominant tree species for afforestation in saline-alkali land in the region. In the later afforestation process, the total amount of "strong salt-alkali tolerance" tree species should account for 50% or more of the total amount.

[0030] 5. Propagation of rhizosphere microorganisms of salt-alkali tolerant tree species: The transplantation of tree species, especially the transplantation technology of tree species on saline-alkali land, plays a key role in the survival and growth of tree species. The root system is severely damaged during the transplantation of tree species, and a large number of symbiotic bacteria in the rhizosphere and roots are lost, which provides an obstacle to their later repair. Garden construction workers will occasionally apply beneficial microbial agents sold on the market when transplanting trees. The market for microbial agents is relatively chaotic, with a single strain, limited efficacy, and the specific matching with the host needs to be considered. Nature is a huge microbial resource library. Due to limited technology, the types of microorganisms isolated by humans are very limited, but this does not prevent humans from using microbial resources.

[0031] The "strong salt-alkali tolerance" and "medium salt-alkali tolerance" tree species in step 4 have been rooted in the soil for a year or longer, and their roots have re-recruited a group of beneficial microbial populations that have adapted to the saline-alkali environment. How to inoculate the new microbial populations into the later large-scale saline-alkali land afforestation is another key factor for the success of afforestation.

[0032] The rhizosphere soil (including a small amount of root system) of the "strong salt-alkali tolerance" tree species and the "medium salt-alkali tolerance" tree species in step 4 is taken out respectively, mixed with garden waste (or any decomposed agricultural and forestry waste products) at a ratio of 5:100 (mass ratio), and spread on the seedling tray. Seeds of crops with strong root systems such as corn, wheat, and soybeans are sown in the seedling tray, and the seedlings are watered normally. After 3 or 4 weeks, all underground parts including the root system (crushed into 1-2 cm small segments) and the cultivation medium are harvested and marked. At the same time, half of the underground part can be collected, and half can be retained to add new garden waste and mix well to continuously expand the microorganisms to obtain an active cultivation medium; this method provides a guarantee for the expansion and preservation of beneficial microorganisms in the rhizosphere of the "strong salt-alkali tolerance" tree species and the "medium salt-alkali tolerance" tree species. The storage time should not be too long, and it is best to use it up in the planting holes of the "strong salt-alkali tolerance" tree species and the "medium salt-alkali tolerance" tree species during the afforestation process within one year.

[0033] 6. Collect active cultivation matrix and saline-alkali soil from the original habitat of the tree species in a volume ratio of 3:7 to prepare planting soil for cultivating the selected salt-alkali tolerant tree species.

[0034] Example 2

[0035] Take the example of afforestation of 100 mu of shelterbelt in Jinshan, Shanghai, where 2,000 trees are planned to be planted and 20 salt-tolerant tree species are selected from 40 tree species.

[0036] Look for five dominant salt-alkali tolerant tree species in the region, namely Metasequoia, Ellipse pine, Baldcypress, Cinnamomum camphora, and Ligustrum lucidum; look for five dominant native tree species in the region, namely Broussonetia, Talleus, Willow, Sophora japonica, and Melia azedarach; look for 30 dominant landscape and greening tree species in the region, namely Plane tree, Osmanthus fragrans, Beech, Koelreuteria paniculata, Cinnamomum camphora, Sapindus mukorossi, Hackberry, Five-needle pine, Cedrus, Poplar, Magnolia, Michelia lechangensis, Oak Nata, Red maple, Ginkgo, Acer, Hackberry, Ligusticum chuanxiong, Acer haizhouensis, Catalpa, Photinia, Crape myrtle, Oleander, Peach, Magnolia grandiflora, Plum, Holly, Albizzia julibrissin, and Begonia.

[0037] 40 tree species were planted in the saline-alkali land of Jinshan (a small representative area was opened in the afforestation target plot). The planting soil in the planting holes was 30% by volume of garden waste (or agricultural and forestry waste) and 70% by volume of native saline-alkali soil. There were 10 trees of each species, for a total of 400 trees.

[0038] The survival rates were calculated after one year, with 5 species having a 100% survival rate, 18 species having a survival rate of over 60%, and 17 species having a survival rate of less than 50%.

[0039]

[0040]

[0041] In the later stage of afforestation, 500 trees of 5 tree species with a survival rate of 100% are planted, 100 trees of each species; 18 tree species with a survival rate of less than 100% but above 60% are selected from the top 15 species (because the goal is to plant 20 tree species) according to the survival rate, and 1,500 trees are planted, 100 trees of each species; after the list of 20 dominant salt-alkali tolerant tree species is screened out, the preparation of the later planting soil is as follows:

[0042] The rhizosphere soil, including the root system, of the above-mentioned tree species with a survival rate of 100% and the tree species with a survival rate of less than 100% but above 60% are taken out separately, mixed with garden waste (or any decomposed agricultural and forestry waste products) at a ratio of 5:100 (mass ratio), and spread on the seedling trays. Corn, wheat, soybean and other crop seeds with strong root systems are sown in the seedling trays, and the seedlings are irrigated normally. After 3 or 4 weeks, all the underground parts including the root system (crushed into 1-2 cm small segments) and the cultivation medium are harvested and marked. At the same time, half of the underground part is collected, and the other half is retained, new garden waste is added, mixed, and microbial propagation is continuously carried out to obtain an active cultivation medium.

[0043] Then, the above-collected active cultivation matrix and the saline-alkali soil in the native habitat of the tree species are used to prepare planting soil in a volume ratio of 3:7 to cultivate the selected salt-alkali tolerant tree species.

[0044] According to statistics, the overall survival rate of afforestation has reached over 80%.

Claims

1. A method for afforestation in coastal saline-alkali land, characterized in that: The steps include: 1) A step of searching for dominant salt-alkali tolerant tree species in the region, selecting dominant tree species types of representative 1-5 years old saline-alkali land shelterbelts in the region, wherein the dominant tree species are characterized by vigorous growth, no insect pests, and stable growth, and are written into the list of salt-alkali tolerant tree species selected for afforestation in saline-alkali land in the region; if there are no 1-5 years old forests in the saline-alkali land in the region, selecting dominant tree species types of 6-10 years old saline-alkali land shelterbelts in the region, and writing them into the list of salt-alkali tolerant tree species selected for afforestation in saline-alkali land in the region; 2) A step to find the dominant native tree species in the region. Native tree species refer to the naturally distributed tree species in the region or the foreign tree species that have been introduced for 6-10 years and have always performed well in the local area. The dominant native tree species in the region that grow vigorously, are pest-free, and have stable growth are included in the list of selected native tree species for afforestation in saline-alkali land in the region; 3) A step of finding dominant landscape greening tree species in the region. If the list of selected saline-alkali land afforestation formed by steps 1) and 2) does not meet the total number of plant species required for large-scale saline-alkali land afforestation, dominant tree species are extracted from the catalog of commonly used landscape tree species in the region and added to the list of selected saline-alkali land afforestation landscape greening tree species in the region; 4) A step of screening salt-alkali tolerant tree species for afforestation in saline-alkali land, selecting tree species from the list formed in step 3) for salt-alkali tolerance screening, and selecting salt-alkali tolerant dominant tree species; tree species are preferably all included in the list of steps 1) and 2), and the remaining ones are selected from the list of step 3) from the beginning to the end. For each selected tree species, 10 strong seedlings of tree species over 10 years old are selected and planted in the representative saline-alkali area of ​​the planned afforestation area, normal drainage ditches are dug, and the planting is carried out during Qingming Festival, and the growth status of each tree species is observed after Qingming Festival the following year; The selected tree species are divided into four categories: the first category is the "strong salt-alkali tolerance" tree species with a survival rate of 100% and strong growth potential; the second category is the "medium salt-alkali tolerance" tree species with a survival rate of less than 100%, but a survival rate of more than 60% and strong growth potential; the third category is the "weak salt-alkali tolerance" tree species with a survival rate of less than 50%; the fourth category is the "alive rate less than 60% but more than 50% and average growth potential" tree species. If the statistical results of "strong salt-alkali tolerance" tree species account for more than 50%, all "strong salt-alkali tolerance" tree species will be added to the afforestation list; if the "strong salt-alkali tolerance" tree species account for less than 50% and do not meet the requirements of the target tree species for afforestation, "medium salt-alkali tolerance" tree species will be selected to make up 50% to ensure that the target salt-alkali tolerance tree species are screened; 5) A step of propagating rhizosphere microorganisms of salt-alkali tolerant tree species: taking out the rhizosphere soil and root system of the "strong salt-alkali tolerant" tree species and the "medium salt-alkali tolerant" tree species in step 4), respectively, mixing them with garden waste or any decomposed agricultural and forestry waste in a mass ratio of 5: (80-120) and spreading them on the seedling tray, sowing crop seeds with strong root systems in the seedling tray, watering the seedlings normally, harvesting all underground parts including the root system and cultivation substrate after 3 or 4 weeks and marking them, and collecting half of the underground part, retaining the other half, adding new garden waste, mixing, and continuously propagating microorganisms to obtain an active cultivation substrate; 6) Collect the active cultivation matrix in step 5) and the saline-alkali soil in the native habitat of the tree species in a volume ratio of 3:7 to prepare planting soil for cultivating the selected salt-alkali tolerant tree species.

2. A method for afforestation in coastal saline-alkali land according to claim 1, characterized in that: The crop seeds with strong root systems are any one of corn, wheat or soybean, or a combination of two or more thereof.

3. A method for afforestation in coastal saline-alkali land according to claim 1, characterized in that: Select 100 tree species from the list formed in step 3) for salt-alkali tolerance screening, and select 50 salt-alkali tolerant superior tree species; the 100 tree species shall preferably include all the tree species in the lists of steps 1) and 2), and then the remaining ones shall be picked from the list of step 3) from the front to the back, and 10 strong seedlings of tree species over 10 years old shall be selected for each of the 100 tree species, with a total of 1,000 seedlings planted in representative saline-alkali areas within the proposed afforestation area, dig normal drainage ditches, and plant during Qingming Festival, and observe the growth status of each tree species after Qingming Festival in the following year.

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