2. 1 salt-tolerant plants 2. 1. 1 coastal beach greening plants like mangrove plants are the most salt-tolerant plants. Due to the influence of warm current, some of them can be distributed in the subtropical zone. Due to the influence of tides, some species are amphibious at the edge of the highest tide. Among them, date palm, cotinus coggygria, hibiscus and Hernandia are also suitable for planting on land. The native plants on the beach are drought-tolerant, salt-tolerant, thin-ridged, heat-resistant and moisture-resistant. Among them, IPO moeapse-Caprie-Canavalia Maritima-Scaevola Sericea is the most widely distributed and representative psammophyte community in the beach zone. The coastal greening plants mainly include trees: Nereis, Casuarina equisetifolia, Ficus microcarpa, Elemene, Erythrina, Kapok, Elemene, Elemene, Mu Fu (Garcinia Multiflora), Acacia formosana, Acacia mangium, Pinus thunbergii (Pinus thunbergii), Podocarpus, Bambusa (Podocarpus), Melaleuca, and Lindera (Lindera). Chinese soft-shelled turtle) and so on. Shrubs: Pittosporum, Taiwan Province Pittosporum, Asian Sea Lily, Cycas, Murraya etc. Ground cover plants: wedelia, peanut, lantana. Wait. Lawn: Bermuda grass, Bermuda grass, etc. 2. 1. There are 2 species of terrestrial palmae in courtyard greening: tree shrew, mallow, mallow, philipla, Davidia involucrata, phoenix tree, phoenix tree, date palm (canary date), short-eared anemone (small-fruited anemone) and queen anemone (Roman betel nut). Aralancome, Bodhi Tree, Rubber Tree, Indian rosewood, Araucaria heterophylla, Araucaria heterophylla, Melaleuca, Platanus acerifolia, African mahogany, Liquidambar formosana, Bauhinia, Melia azedarach, lampstand tree, willow, Siamese chestnut and Tamarix longifolia. Plumeria. , eucalyptus citriodora, banana (Ravenala madagascariensis), Phoenix in Jinfo Mountain, Luan tree in Taiwan, pomegranate, etc. Shrubs and ground cover plants; Nerium. , mignonette, magnolia, oleander, Zhu Jin. , Dryopteris nephrolepis, Ficus alternifolia, Lagerstroemia indica, Acacia stenophylla, Agave, mana microphylla, Catharanthus roseus, Camptotheca acuminata, Yucca yucca, Ficus pumila, Ophiopogon japonicus, Lygodium japonicum and Lygodium japonicum. Canna grandiflora, Dianthus. , rose, jujube, wedelia, etc. Climbing plants: bougainvillea, camptotheca grandiflora, wisteria, grapes, honeysuckle (honeysuckle), Parthenocissus tricuspidata, pueraria lobata, etc. Lawn: carpet grass, Bahia grass, Zoysia sulcata, etc. Other species: reed, vetiver, etc. 2.2. Salt-tolerant plants, such as palm, sorbus sorbus, Solanum nigrum, Christmas coconut, betel nut, mango, Lagerstroemia speciosa, jackfruit, white orchid, Sabina vulgaris, murraya murraya, red mulberry, forsythia suspensa, gardenia, loblolly pine, centipede grass, etc. 3 Selection of wind-resistant plants Generally speaking, evergreen trees have stronger wind resistance than deciduous trees, trees with developed roots and tough materials have stronger wind resistance than trees with shallow roots and soft materials, and trees with thick tops and full winter buds have stronger wind resistance. The strength of wind resistance can be divided into three categories. The first type is suitable for windbreaks, the second type is not suitable for windbreaks but resistant to wind, and the third type is not recommended for planting except in leeward areas. 3. 1 Saposhnikovia plants among saline-alkali tolerant plants on land, green plants along coastal beaches and palms among plants in courtyard greening. Chongyang wood (Jatropha curcas), Prynne, hibiscus, Ficus, Phoenix wood, Ficus macrophylla, Cinnamomum camphora, Qiu Feng, litchi, Ficus altissima, potted plants (Jatropha curcas), Indian rosewood, pseudopodia, almond, Du Ying, kapok, Podocarpus, Koelreuteria formosana, red thorn forest investment, pandou tree and blue-green pandou tree. 3.2 Wind-resistant plants: Yinxiang, Lagerstroemia speciosa, Melia azedarach, Betula alnoides, Almonds, Dipterocarpus, Huanghuai, Hainan Red Bean, Liquidambar formosana, Senecio scandens, Magnolia grandiflora, Sour Bean, Eucalyptus, Indus indus, Hainan Peach Tree, Lemon Eucalyptus, Hibiscus, Bauhinia, Pineapple, Red sandalwood, weeping willow, big tree, etc. 3.3 Strong wind-intolerant plants: ferns, tourist bananas, redwood (Swietenia mahagoni), eucalyptus urophylla, bodhi tree, bauhinia, torch tree (Spathodea campanulata), mango, Broussonetia papyrifera, eucalyptus urophylla, Pinus massoniana, Pueraria lobata, Campanulata, poinsettia, etc. 4. Planting point 4. 1 density The appropriate planting density is 0.35~0.60 with ventilation coefficient (referring to the ratio of the average wind speed in the belt height range at the leeward side of the forest belt 1m to the average wind speed in the corresponding height range in the wilderness). The minimum weak wind area of this forest belt appears at the height of 3~5 times of the leeward area, and the relative effective windproof distance is 25 times of the height of the forest belt. At the same time, the photo pair in the forest is weak, which can reduce water evaporation and inhibit the surface salt return. 4.2 Structure Because the amount of salt ions deposited on the edge of the forest in salt fog is five times that in the forest, and the salt fog resistance of broadleaf trees is stronger than that of coniferous trees, the wind resistance of evergreen trees is stronger than that of deciduous trees. Therefore, forest belts and trees are suitable for the mixture of broad-leaved trees and evergreen trees, and each has its own place. 4.3 Provenance of seedling size (1): Try to choose the seedlings cultivated on the nursery ground with similar green space conditions. The main roots of cuttings and high-pressure seedlings are not obvious or developed, and the overall root system fixation is weak, which is easy to lodging in the strong wind. (2) Size: Medium seedling is the most suitable. They are more conducive to the growth of strong roots, and the root development of large seedlings is limited in a certain period after planting, and it is easy to lodging in strong winds or damage the roots in swaying. (3) Soil ball: The soil ball of seedlings is about 20cm larger than the usual specifications, and the roots should be fixed early. (4) Crown type: the crown is 1/3~ 1/2 of tree height. At the same time, according to the growth characteristics of the corresponding tree species, similar crown types are adopted. The tree shape and crown should not be skewed, and the height of leaf curtain should be high and the density should be moderate. The cup-shaped and umbrella-shaped crown can reduce the strong wind pressure on the front. (5) Quality: The root system of underground part develops normally, and there should be a certain number of lateral roots and fibrous roots. The seedlings maintain good metabolic ability. 4.4 Engineering Technology and Maintenance Management (1) Land preparation: it is suitable to dig 20cm deep, and it is best before the rainy season comes in late spring and early summer. (2) Planting holes and saline-alkali isolation layer: The diameter of roadside tree holes is generally1~1.2m. The bottom of the hole should be as big as the upper part to avoid digging into the bottom of the pot. First, lay 20cm thick straw, gravel or ceramsite at the bottom of the cave, then lay 10cm thick furnace ash slag or coarse sand, 10cm thick peat soil or fine sand mixed with organic fertilizer, and then lay 50~80cm sandy loam mixed with a small amount of organic fertilizer to form a saline-alkali isolation layer. If it is a severe saline-alkali land, it should be sealed with plastic film around the pit. (3) Planting: The seedlings should be planted shallowly and buried horizontally, so that the original soil elevation of the seedlings is 1~5cm above the original ground. Cover the soil layer with the ground, but not higher than the ground, in order to prevent the accumulation of saline-alkali at the roots of seedlings. Building a small ridge around the tree pit is beneficial to irrigation and accumulating rainwater to leach saline-alkali land. When the surface is slightly dry, loosen the soil and cover it with dry soil, bark, straw or plastic film to keep moisture and prevent salt return. The ridge should be renovated frequently in rainy season. (4) Loosening: Loosening the topsoil, cutting off soil capillaries and reducing water evaporation before the soil salt content reaches the limit that plants can tolerate, which is beneficial to prevent soil from returning to salt and accelerate soil desalination. It is best to loosen the soil before the rainy season or rainy day, about 4 times a year. (5) Pruning: firstly, pruning competitive branches and double branches, and keeping small side branches. Pay attention to pruning the inner branches. Conclusion Because of the complex mechanism of salt-tolerance of plants, the varieties listed in this paper only have certain salt-tolerance characteristics, and the specific degree of resistance needs to be tested on the spot. In fact, most commonly used landscaping plants can grow well on the improved land with moderate saline-alkali content (0.2%~0.4%). Therefore, land improvement and maintenance management have an important impact on the saline-alkali tolerance of plants. Although the roots and materials of plants are prerequisites for wind resistance, neglect of pruning and maintenance is often the direct cause of trees being blown down. Multi-level communities can play the greatest role in salt-alkali resistance and typhoon prevention. Therefore, the greening in coastal areas can not only focus on a certain characteristic of a certain variety, such as the windbreak belt of Casuarina equisetifolia or Pinus massoniana along the coast. Multiple varieties should cooperate and give play to their respective advantages in different positions. Moreover, in the planting design, in addition to defining the specifications of seedlings, we should also put forward relevant suggestions on planting engineering and maintenance management to ensure the overall greening effect.