Mangrove is a forest growing in seawater, and it is a unique forest vegetation growing in intertidal zone of tropical and subtropical coasts and estuaries. Their roots are well developed and intertwined, standing on the beach. They have tough green leaves that shine. Like lotus flowers, they emerge from the mud without being stained. At high tide, they are submerged by the sea, or just show their green crowns, as if holding up a green umbrella on the sea. When the tide recedes, it becomes a lush forest.
Mangrove coast is mainly distributed in tropical areas. The east and west coasts of South America, the West Indies and the west coast of Africa are the main areas where mangroves grow in the western hemisphere. In the east, Sumatra Island in Indonesia and the west coast of Malay Peninsula are the central distribution areas. Mangroves grow along the Bay of Bengal-India-Sri Lanka-Arabian Peninsula to the east coast of Africa. Mangroves are also widely distributed along the coast of Australia. Indo-Philippine-Indo-China Peninsula is also distributed in the coastal areas of Guangdong, Hainan, Taiwan Province and Fujian. Due to the influence of Kuroshio warm current, the mangrove coast has been distributed to Jiuzhou, Japan.
Hainan Province is the most developed province on the mangrove coast of China, with a wide variety and a vast area. There are many kinds of mangrove plants, including shrubs and trees. Because its bark and wood are reddish brown, it is called mangrove and mangrove. Mangrove leaves are not red, but green. The leafy mangroves form a green barrier along the coast.
Mangroves grow on beaches. There are few other plants here, only mangroves are resistant to wind and waves, forming a unique mangrove coast.
Mangroves have physiological characteristics of high osmotic pressure. Because of high osmotic pressure, mangroves can absorb water and nutrients from swamp saline soil, which is an important condition for mangrove plants to take root and grow in beach saline soil. The roots of mangroves are divided into columnar roots, tabular roots and respiratory roots. A mangrove can have more than 30 columns. These pillars are like the most stable tripod structure to support objects, supporting the trunk from different directions, so that the mangrove wind can't blow down and the waves can't beat down. This mangrove forest plays an important role in protecting coastal stability. For example, the devastating storm in Florida in 1960 caused thousands of mangroves along the coast to be destroyed, but rarely uprooted. The main damage is that the bark is scraped or peeled off by a tornado.
The respiratory roots of mangrove plants, as the name implies, play a role in respiration. In the swamp environment, the air in the soil is extremely scarce. In order to adapt to this anoxic environment, the respiratory roots of mangrove plants are extremely developed. The respiratory roots are rod-shaped and knee-shaped. Some are slender, with a diameter of only 0.5 cm, while others are stout, with a diameter of 10-20 cm. The flat roots of mangrove plants are developed from respiratory roots. Plate roots are beneficial to the respiration and support of mangrove plants. The special function of mangrove root system enables it to grow when it is submerged by water at high tide. It is amazing that mangrove plants adapt to their growing environment with such a complex and rigorous structure.
The most interesting phenomenon is viviparous reproduction of mangrove plants. The seeds of mangrove plants germinate on the mother tree after maturity. After the seedlings mature, they leave the mother tree and fall into the soil due to gravity. This "viviparous" phenomenon is rare in the plant kingdom. What is even more surprising is that after a few hours, the seedlings can take root and sprout in the mud. Sometimes the seedlings falling from the mother tree lie flat in the soil, and they can also grow roots and take root in the soil. When the seedlings fall into the water, they drift with the current. Sometimes it floats in the sea for months or even a year, but it can't find the soil it needs to grow. But once you meet the right soil, you will immediately take root and grow sturdily. Although mangrove grows in water, it is a plant that is not afraid of waterlogging. However, its leathery leaves can reflect light, and the pores on the leaves are hollow and fluffy, which can reduce evaporation at high temperature and has a drought-tolerant ecology. Salt-discharging glands on its leaves can remove salt from seawater. In addition to embryo germination, mangrove plants also have the ability of asexual reproduction, that is, germination. After they were cut down, new plants soon sprouted on the base stem.