Mangrove trees are evergreen deciduous plants that have settled on tropical and subtropical coasts and have adapted to life in conditions of constant ebb and flow. They grow up to 15 meters and have bizarre types of roots: stilted (raise the tree above the water) and respiratory (pneumatophores), sticking out of the soil, like straws, and absorbing oxygen.
Few plants would survive in s alt water, but this is not the case with mangroves. They developed filtering mechanisms. The water sucked up by their roots contains less than 0.1% s alt. The remaining s alt is excreted by the leaves through special leaf glands, forming white crystals on the surface.
The soil on which mangrove trees grow is always saturated with water, there is not enough oxygen in it. Under such conditions, anaerobic bacteria release nitrogen, phosphates, iron, methane, sulfides, etc., which create the specific smell of trees. The roots, as was said, absorb the missing oxygen from the air, and the nutrients from the soil.
The leaves of these plants are hard, leathery, juicy, bright green. Given the salinity of the soil and the lack of fresh water, they have adapted to a limited lossmoisture. Leaves can regulate the opening of their stomata for gas exchange during photosynthesis and turn to avoid hot sunlight.
Mangrove trees grow in belts, each of which is dominated by certain species. This is due to the frequency and duration of flooding, the nature of the substrate (sandy or silty), the ratio of sea and fresh water (at river mouths). The front line is occupied by rhizophores with blood-red wood, the color of which is determined by the high content of tannin. This species is underwater about 40% of the time. They are followed by Avicenia, Lagularia and others.
As the mangrove tree itself is atypical, so are its fruits (seeds) unusual. They are covered with an airy tissue, due to which they are able to swim for a certain time, changing their density if necessary. Many mangroves are "viviparous". Their seeds, not separated from the tree, germinate. The seedling moves either inside the fruit or out through the fruit. By the time of separation, he is ready to feed himself through photosynthesis.
After detaching from the tree (usually at low tide), the seedling falls and quickly fixes itself in the soil. Or carried away by water, perhaps for a decent distance. It is so tenacious that it can wait up to a year for a favorable moment to take root.
Mangrove forests provide shelter and habitat for many organisms. Algae, oysters, barnacles, sponges, bryozoans need to attach to something when filtering food. Numerous rootsgreat for this. Tropical fish, arthropods, snakes live in the water near the root systems. Hummingbirds, frigatebirds, parrots, gulls and other birds settled in the branches of trees.
Mangrove trees, rapidly forming thickets, protect the coast from erosion by sea waves. They, advancing on the sea, conquer new areas from it. Densely intertwined roots retain the applied silt, helping to drain the soil. The local population uses the reclaimed land, creating plantations of coconut palms, citrus fruits and other crops.
