# What's a Mangrove? And What Does It Do? | AMNH - Real Title: What's a Mangrove? And What Does It Do? | AMNH ## Highlights ### id253494222 mangroves excrete salt > Many mangrove species survive by filtering out as much as 90 percent of the salt found in seawater as it enters their roots. Some species excrete salt through glands in their leaves. These leaves, which are covered with dried salt crystals, taste salty if you lick them. A third strategy used by some mangrove species is to concentrate salt in older leaves or bark. When the leaves drop or the bark sheds, the stored salt goes with them. - [View Highlight](https://amnh.org/explore/videos/biodiversity/mangroves-the-roots-of-the-sea/what-is-a-mangrove?__readwiseLocation=1%2F1%2F9%2F1%2F3%2F1%2F9%2F3%2F31%3A105%2C1%2F1%2F9%2F1%2F3%2F1%2F9%2F3%2F31%3A542#:~:text=Many%20mangrove%20species%20survive%20by%2Cstored%20salt%20goes%20with%20them.) This would be cool for people from [[Nakayrande]] to sell salt. ### id253494224 mangrove leaves store fresh water > **hoard fresh water**: Like desert plants, mangroves store fresh water in thick succulent leaves. A waxy coating on the leaves of some mangrove species seals in water and minimizes evaporation. Small hairs on the leaves of other species deflect wind and sunlight, which reduces water loss through the tiny openings where gases enter and exit during photosynthesis. On some mangroves species, these tiny openings are below the leaf's surface, away from the drying wind and sun. - [View Highlight](https://amnh.org/explore/videos/biodiversity/mangroves-the-roots-of-the-sea/what-is-a-mangrove?__readwiseLocation=0%2F0%2F3%2F9%2F1%2F3%2F1%2F9%2F3%2F31%3A0%2C1%2F3%2F9%2F1%2F3%2F1%2F9%2F3%2F31%3A455#:~:text=hoard%20fresh%20water%3A%C2%A0Like%20desert%20plants%2C%2Cthe%20drying%20wind%20and%20sun.) ### id253494226 mangroves breathe via roots > **breathe in a variety of ways**: Some mangroves grow pencil-like roots that stick up out of the dense, wet ground like snorkels. These breathing tubes, called pneumatophores, allow mangroves to cope with daily flooding by the tides. Pneumatophores take in oxygen from the air unless they're clogged or submerged for too long. - [View Highlight](https://amnh.org/explore/videos/biodiversity/mangroves-the-roots-of-the-sea/what-is-a-mangrove?__readwiseLocation=0%2F0%2F5%2F9%2F1%2F3%2F1%2F9%2F3%2F31%3A0%2C1%2F5%2F9%2F1%2F3%2F1%2F9%2F3%2F31%3A294#:~:text=breathe%20in%20a%20variety%20of%2Cor%20submerged%20for%20too%20long.) ### id253494322 trees need oxygen or they drown > Root systems that arch high over the water are a distinctive feature of many mangrove species. These aerial roots take several forms. Some are stilt roots that branch and loop off the trunk and lower branches. Others are wide, wavy plank roots that extend away from the trunk. Aerial roots broaden the base of the tree and, like flying buttresses on medieval cathedrals, stabilize the shallow root system in the soft, loose soil. In addition to providing structural support, aerial roots play an important part in providing oxygen for respiration. Oxygen enters a mangrove through lenticels, thousands of cell-sized breathing pores in the bark and roots. Lenticels close tightly during high tide, thus preventing mangroves from drowning. - [View Highlight](https://amnh.org/explore/videos/biodiversity/mangroves-the-roots-of-the-sea/what-is-a-mangrove?__readwiseLocation=0%2F13%2F1%2F3%2F1%2F9%2F3%2F31%3A0%2C0%2F13%2F1%2F3%2F1%2F9%2F3%2F31%3A737#:~:text=Root%20systems%20that%20arch%20high%2Cthus%20preventing%20mangroves%20from%20drowning.) ### id253494333 mangrove seeds germinate on the branch > Ready-to-Roll Seeds > The mangroves' niche between land and sea has led to unique methods of reproduction. Seed pods germinate while on the tree, so they are ready to take root when they drop. If a seed falls in the water during high tide, it can float and take root once it finds solid ground. If a sprout falls during low tide, it can quickly establish itself in the soft soil of tidal mudflats before the next tide comes in. A vigorous seed may grow up to two feet (about 0.6 m) in its first year. Roots arch from the seedling to anchor it in the mud. Some tree species form long, spear-shaped stems and roots while still attached to the parent plant. After being nourished by the parent tree for one to three years, these sprouts may break off. Some take root nearby while others fall into the water and are carried away to distant shores. - [View Highlight](https://amnh.org/explore/videos/biodiversity/mangroves-the-roots-of-the-sea/what-is-a-mangrove?__readwiseLocation=0%2F15%2F1%2F3%2F1%2F9%2F3%2F31%3A0%2C0%2F17%2F1%2F3%2F1%2F9%2F3%2F31%3A821#:~:text=Ready-to-Roll%20Seeds%0A%20%20%20%2Ccarried%20away%20to%20distant%20shores.) ### id253494345 how mangroves spread > A World Traveler > Botanists believe that mangroves originated in Southeast Asia, but ocean currents have since dispersed them to India, Africa, Australia, and the Americas. As Alfredo Quarto, the head of the Mangrove Action Project, puts it, “Over the millions of years since they've been in existence, mangroves have essentially set up shop around the world.” The fruits, seeds, and seedlings of all mangrove plants can float, and they have been known to bob along for more than a year before taking root. In buoyant seawater, a seedling lies flat and floats fast. But when it approaches fresher, brackish water—ideal conditions for mangroves—the seedling turns vertical so its roots point downward. After lodging in the mud, the seedling quickly sends additional roots into the soil. Within 10 years, as those roots spread and sprout, a single seedling can give rise to an entire thicket. It's not just trees but the land itself that increases. Mud collects around the tangled mangrove roots, and shallow mudflats build up. From the journey of a single seed a rich ecosystem may be born. - [View Highlight](https://amnh.org/explore/videos/biodiversity/mangroves-the-roots-of-the-sea/what-is-a-mangrove?__readwiseLocation=0%2F19%2F1%2F3%2F1%2F9%2F3%2F31%3A0%2C0%2F21%2F1%2F3%2F1%2F9%2F3%2F31%3A1071#:~:text=A%20World%20Traveler%0A%20%20%2Crich%20ecosystem%20may%20be%20born.)