A high-elevation high-salinity sandy beach mangrove afforestation method

Abstract

The application discloses a high-elevation high-salinity sandy beach mangrove afforestation method. The method comprises the following steps: building a temporary sand-retaining and flow-retarding dam along the coastline direction in the near sea of a to-be-afforested area, using wood piles to be punched into the beach surface with a spacing of 5-10 cm, with 60-80 cm of the wood piles exposed above the ground and 30-50 cm of the wood piles embedded in the soil, and the wood piles are removed after the mangrove seedlings are successfully planted; digging shallow pits with a depth of 5-15 cm and a width of 10-20 cm in the difficult site parallel to the coastline direction, and the distance between each shallow pit is 45-50 cm; planting the nutrient bag seedlings with strong salt-tolerant capacity outside the shallow pits in the ideal season of the mangrove afforestation; digging planting holes in the shallow pits from March to August every year, and then inserting the embryonic axis of the medium salt-tolerant seedlings into the planting holes filled with nutrient soil, and the embryonic axis is fixed by using a bamboo stick; and maintaining the forest land. The method can increase the biodiversity of the high-elevation high-salinity sandy beach mangrove, and restore the degraded mangrove wetland ecosystem.

Description

Technical Field

[0001] This invention relates to the field of marine management, and in particular to a method for afforestation of mangroves in high-elevation, high-salinity sandy tidal flats. Background Technology

[0002] Mangroves are both forests and wetlands, functioning as both the "lungs" of the Earth (forests) and the "kidneys" of the Earth (wetlands), making them one of the most ecosystems on Earth in terms of ecosystem service (Costanza et al., 2014). Since 2000, my country has continuously increased its investment in mangrove protection and restoration. However, current mangrove restoration efforts primarily focus on increasing area, with some projects involving the extensive planting of easily surviving tree species. The loss of biodiversity is the most serious problem facing mangroves (Wang Wenqing et al., 2021).

[0003] Recent domestic and international studies have shown that natural forests and mixed forests with high biodiversity have higher productivity and stability than monoculture forests. A monolithic structure is one of the main problems in mangrove afforestation in my country, especially in high-elevation, high-salinity sandy tidal flats (hereinafter referred to as challenging sites) (elevation above 2.0m). These sites suffer from severe water and sediment loss, and after high-temperature transpiration following low tide, salinity increases (>30‰). Seedlings of some species with low salt tolerance have high mortality rates, ultimately surviving only species adapted to sandy soils and with strong salt tolerance. This exacerbates biodiversity loss, leads to frequent outbreaks of pests and diseases, and ultimately, mangrove ecosystem degradation. Currently, there are no effective technical measures for establishing mangrove forests in high-elevation, high-salinity sandy tidal flats. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the above-mentioned technologies by providing a method for afforestation of mangroves in difficult-to-establish sites. This method can increase the biodiversity of mangroves in sandy tidal flats with high elevation and high salinity, and restore degraded mangrove wetland ecosystems.

[0005] To achieve the above objectives, the present invention provides a method for afforestation of mangrove forests in high-elevation, high-salinity sandy tidal flats, characterized by comprising the following steps:

[0006] S1 Slow Flow: A temporary sand-blocking and slow-flowing dam is built along the coastline in the nearshore area of ​​the afforestation area. Wooden piles are driven into the beach at a density of 5-10cm, with 60-80cm protruding above the ground and 30-50cm driven into the soil. The dam is removed after the mangrove seedlings are successfully planted.

[0007] S2 land preparation: After removing invasive species, dig shallow pits 5-15cm deep and 10-20cm wide parallel to the coastline on difficult sites, with a distance of 45-50cm between each pit.

[0008] S3 Planting: After the shallow pits are dug, during the ideal season for mangrove afforestation, plant salt-tolerant tree species outside the shallow pits. Select 2-3 year old seedlings in nutrient bags, with a planting density of 45-55cm*45-55cm. Then, from March to August each year, dig planting holes of 8-12cm*8-12cm in the shallow pits. After filling the planting holes with nutrient soil, insert the hypocotyls of moderately salt-tolerant tree species. Select mature hypocotyls of viviparous tree species. To prevent them from being washed away by waves, fix the hypocotyls with bamboo sticks. The insertion depth is 1 / 4-1 / 2 of the hypocotyl length, with a planting density of 45-55cm*45-55cm.

[0009] S4 Forest Maintenance: The afforestation area is fenced off to prevent ships from damaging the afforestation land. Seedlings are replanted in the forest for three consecutive years, and marine debris is cleaned up in a timely manner.

[0010] Furthermore, the ideal season for mangrove afforestation is from March to June each year.

[0011] Furthermore, the planting density of the seedlings in the nutrient bags is 50cm*50cm.

[0012] Furthermore, the density of the planting holes is 10cm*10cm.

[0013] Furthermore, the bamboo stick has a diameter of 1cm and a length of 20-30cm.

[0014] Furthermore, the insertion depth of the hypocotyl is 1 / 3 of the hypocotyl length, and the insertion density is 50cm*50cm.

[0015] The principle of this invention: Excessive elevation in sandy tidal flats leads to water and nutrient loss. Furthermore, high-temperature evaporation increases soil salinity, increasing the stress of salinity and drought on newly planted seedlings and reducing survival rates. Topographical adjustments (digging shallow pits) can retain some water and nutrients. The hypocotyl length of *Kandelia candel*, *Rhizophora stylosa*, and *Melia azedarach* is on average over 18cm. The planting depth should be 1 / 3 of the hypocotyl length (approximately 6cm). The shallow pit should be dug to a depth of 3-6cm after low tide, ensuring that the seawater does not submerge more than 2 / 3 of the hypocotyl. Two years after planting, the survival rates of *Kandelia candel* and *Rhizophora stylosa* in areas without shallow pits were 30.1%-44.4% and 21.1%-26.3%, respectively. In areas with shallow pits, the survival rates were 85.4%-90% and 68.5%-80.7%, respectively. White mangrove is suitable for growing in sandy soil, while tree species such as Kandelia candel, Rhizophora stylosa, and horned horn are suitable for growing in silty soil. The soil ball and topsoil of the seedlings in the nutrient bags can meet the growth and development needs of seedlings of various tree species in a short period of time.

[0016] The beneficial technical effects of this invention are as follows: Mangroves in high-altitude, high-salinity sandy tidal flats have a simple structure and are severely degraded, making them susceptible to invasion by invasive species such as Spartina alterniflora, resulting in low survival rates when directly afforested. The method of this invention can improve the survival rate of moderately salt-tolerant mangrove species in high-altitude, high-salinity sandy tidal flats, increase biodiversity, and enhance the stability of the mangrove ecosystem. Simultaneously, the terrain micro-adjustment has a tidal absorption function, promoting siltation, retaining moisture and nutrients, improving the physical and chemical structure of sandy soil, and making it more suitable for mangrove growth and reproduction.

[0017] The method of this invention helps to increase the biodiversity of mangroves in difficult sites and has important application value for the ecological restoration and healthy development of mangroves in my country. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of afforestation based on the technical solution of this invention. Detailed Implementation

[0019] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0020] Example 1: A method for afforestation of mangrove forests in high-elevation, high-salinity, and highly hydrodynamic sandy tidal flats

[0021] The steps are as follows:

[0022] (1) Slow flow: Temporary sand-blocking and slow flow low dams are built around the afforestation area (the sea area of ​​Zhulin Salt Field in Beihai City, Guangxi). Eucalyptus tree stumps with a diameter of 6cm and a length of 2m are driven into the beach at a density of 5cm, with 60cm exposed above the beach and 40cm buried in the soil. The dams are removed after the mangrove seedlings are successfully planted.

[0023] (2) Land preparation: 1935 mu of Spartina alterniflora were removed in the afforestation area by digging or cutting. In the difficult site of high salinity and strong hydrodynamic sandy tidal flats, shallow pits with a depth of about 10 cm and a width of about 10 cm were dug parallel to the coastline. The distance between each shallow pit was 50 cm.

[0024] (3) Planting: After the shallow pits are dug, in November, select about 2-year-old Avicennia marina and Rhizophora stylosa, which are salt-tolerant tree species, and plant them outside the shallow pits using nutrient bags. The row spacing is 50cm and the plant spacing is 50cm, which is equivalent to 6003 plants / mu. From March to August of the following year, dig planting holes of 10cm*10cm in the shallow pits. After filling the planting holes with nutrient soil, insert the hypocotyls of moderately salt-tolerant tree species Kandelia candel and Rhizophora stylosa. The hypocotyls are fixed with bamboo sticks with a diameter of 1cm and a length of 20cm. The insertion depth is 1 / 3 of the length of the hypocotyl, with a row spacing of 50cm and a plant spacing of 50cm, which is equivalent to 6003 trees / mu.

[0025] (4) Forest maintenance: The afforestation area is fenced off to prevent ships from damaging the afforestation area. Seedlings are replanted in the forest area for three consecutive years, and marine debris is cleaned up in a timely manner.

[0026] Comparative example: Areas without shallow pits, all others are the same.

[0027] Results: Two years after the hypocotyls were planted, the survival rates of Kandelia candel and Rhizoma campestris in the area without shallow pits (i.e., the comparative example) were 30.1%–44.4% and 21.1%–26.3%, respectively, while the survival rates of Kandelia candel and Rhizoma campestris in the area with shallow pits (the scheme of this invention) were 85.4%–90% and 68.5%–80.7%, respectively.

[0028] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A method for afforestation of mangrove forests in high-elevation, high-salinity sandy tidal flats, characterized in that, Includes the following steps, S1 Slow Flow: A temporary sand-blocking and slow-flowing dam is built along the coastline in the nearshore area of ​​the afforestation area. Wooden piles are driven into the beach at a density of 5-10cm, with 60-80cm protruding above the ground and 30-50cm driven into the soil. The dam is removed after the mangrove seedlings are successfully planted. S2 land preparation: After removing invasive species, dig shallow pits 5-15cm deep and 10-20cm wide parallel to the coastline on difficult sites, with a distance of 45-50cm between each pit. S3 Planting: After the shallow pits are dug, during the ideal season for mangrove afforestation, plant salt-tolerant tree species outside the shallow pits. Select 2-3 year old seedlings in nutrient bags, with a planting density of 45-55cm*45-55cm. Then, from March to August each year, dig planting holes of 8-12cm*8-12cm in the shallow pits. After filling the planting holes with nutrient soil, insert the hypocotyls of moderately salt-tolerant tree species. Select mature hypocotyls of viviparous tree species. To prevent them from being washed away by waves, fix the hypocotyls with bamboo sticks. The insertion depth is 1 / 4-1 / 2 of the hypocotyl length, with a planting density of 45-55cm*45-55cm. S4 Forest Maintenance: The afforestation area is fenced off to prevent ships from damaging the afforestation land. Seedlings are replanted in the forest for three consecutive years, and marine debris is cleaned up in a timely manner.

2. The afforestation method for high-elevation, high-salinity sandy tidal flat mangroves as described in claim 1, characterized in that, The ideal season for mangrove afforestation is from March to June each year.

3. The afforestation method for high-elevation, high-salinity sandy tidal flat mangroves as described in claim 1, characterized in that, The planting density of the seedlings in the nutrient bags is 50cm*50cm.

4. The afforestation method for high-elevation, high-salinity sandy tidal flat mangroves as described in claim 1, characterized in that, The density of the planting holes is 10cm*10cm.

5. The afforestation method for high-elevation, high-salinity sandy tidal flat mangroves as described in claim 1, characterized in that, The bamboo stick has a diameter of 1cm and a length of 20-30cm.

6. The afforestation method for high-elevation, high-salinity sandy tidal flat mangroves as described in claim 1, characterized in that, The insertion depth of the hypocotyl is 1 / 3 of its length, and the insertion density is 50cm*50cm.

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