Mangrove Trees

Mangrove trees are a species of trees specially adapted to salty, marine environments where no other trees can survive. They grow in tropical and sub-tropical environments along coastlines around the globe. Mangrove trees are the only trees that can survive in harsh saline water, but why can mangroves also grow in freshwater?

Mangrove trees aren’t picky when it comes to salt or freshwater. While they certainly grow in either freshwater or saltwater, mangrove trees grow best in water that is a mix of 50% saltwater and 50% freshwater. This mixture of freshwater and saltwater is called brackish water.

Most plants, especially trees, can’t tolerate much salt in the ground, but mangrove trees have adapted to these climates. They grow very well in salty, tidal areas as well as in brackish water where most other plants wouldn’t survive the high salt levels. Read on to find out more about these amazing trees!

Can Mangroves Grow In Freshwater?

As long as mangrove trees are not completely submerged in water they can grow in freshwater or saltwater. You won’t typically find many mangrove trees growing in freshwater areas though because there is a lot of competition in these environments compared to the minimal competition in saltwater areas.

Mangrove trees also rely on tidal fluctuations for seed dispersal. The tide coming in and washing out helps to spread seeds far and wide instead of staying in one place. 

Mangrove trees can certainly grow well in freshwater environments but there are a few reasons why you won’t usually find many mangrove forests along lakes, riverbeds, or swamps. Let’s expand on these reasons.

You can lean more in our other article about the most common trees that grow in freshwater here!

Too Much Competition For Mangroves To Grow In Freshwater

These trees have carved themselves a niche as the only trees that can survive in the salty environment that they prefer. The only competition for space in these areas is from other mangrove trees

There are many more species of trees that can survive in freshwater, which makes it harder for mangrove trees to come in and get a foothold.

Just a few freshwater trees that thrive along riverbanks, and freshwater swamps include cypress trees, gum trees, willow trees, aspen trees, birch trees, and a few species of oak trees. These trees have been growing in these areas for centuries!

Tidal fluctuations are required for mangrove seed dispersal and since these seeds won’t flow upstream to freshwater locations, mangrove trees won’t settle in these areas on their own.

No Tidal Fluctuation In Freshwater Locations

In coastal areas where mangrove trees flourish the fluctuating tide provides several benefits. Seed dispersal is dependent on these tidal surges. The tide helps to remove waste and bring in clean water. In freshwater environments, there is usually very little fluctuation in water level.

Unless the climate plays a role in water levels, the waterline of freshwater bodies takes much longer to rise or fall. Droughts can shrink the waterways over time, while periods of heavy rains can make the banks swell, but the ocean tides fluctuate daily.

The seeds on mangrove trees have adaptations that help them grow in the harsh salty environment these trees call home. For one, they germinate while still hanging in the branches. They can stay on the tree for up to three years, growing a long root so that they have an early start when they reach solid ground.

Mangrove seeds will also float when they drop into the water. This trait lets some seeds travel miles away before they reach solid ground. Once there, they establish quickly because they’ve already started growing roots.

Less Competition In Saltwater

If mangrove trees were growing along riverbanks, when the seeds fall, they would end up getting washed along the banks where other trees are already growing. This would make it tougher for them to begin growing because there isn’t much real estate.

That is until the seeds get washed into brackish waters where other plants can’t tolerate the salt.

It’s easier for mangrove trees to establish and continue to grow where there is little to no competition. No other trees can grow in brackish or salty water, so these areas are where mangrove trees really thrive.

Few plants have ways to deal with saltwater. Other than mangrove trees, seaweeds, seagrass, algae, and a few types of ferns, can withstand saline water. Mangrove trees are the only tree species that have ways to deal with saltwater.

If you’d like, you can read more about the most common trees that grow in saltwater here!

Why Can’t Most Plants Survive Saltwater?

First off, saltwater will dehydrate plants. Salt in the soil absorbs water and then creates drought-like conditions for the plant and it dries out. When a plant absorbs salty water, it essentially gets dehydrated.

We all know we shouldn’t drink salt water because it speeds up dehydration in humans. In the same way, we get dehydrated by saltwater, plants also dry out because of salt in the water.

Another reason salt water is an issue for plant life is that when salt is dissolved in water, the sodium and chloride ions split up and separate. The roots of plants will readily absorb chloride ions, which are then transported to the leaves. There, these ions will accumulate to toxic levels and eventually lead to quick degradation the plant.

According to Purdue University, salt is bad for plants. Not only are chloride ions bad for plants, but sodium ions can also damage plants. Sodium ions in the ground will replace essential nutrients that plants need such as potassium, magnesium, and calcium.

Mangrove Trees Are Unique

What makes mangrove trees unique, is they have ways to remove up to 90% of the salt from the water. They can either separate and store the salt away by storing it in older leaves and bark. The bark is then replaced with new, and the old leaves drop to the ground, taking the excess salt with them.

Other mangrove trees can excrete salt from pores in their leaves. Some species have small pores at the base of the leaves, while others excrete the salt along the sides and top of the leaves. These leaves may even have crystals of salt on them.

The last way mangrove trees deal with excessive salt is to block it from entering completely. Red mangrove trees can block out over 90% of the salt that comes in contact with their roots. These adaptations make mangroves unique and allow them to grow in salty conditions.

Mangroves Can’t Deal With Cold Temperatures

Cold temperatures and mangrove trees don’t mix. Mangrove trees love the hot temperatures of tropical areas. Cold weather will stunt mangrove growth or freeze them out altogether.

Many freshwater-loving tree species will simply go dormant when winter sets in. They lose their leaves and slow down their growth rate so that they can survive cold winters, mangrove trees can’t deal with freezing temperatures.

These trees do well in USDA Hardiness Zones 9-12 where the temperatures tend to stay warmer year-round. Mangrove trees can tolerate a lot of salt, but they can’t deal with freezing temperatures.

Instead if cold-weathered areas, you can read our detailed guide on the most common places to find mangrove trees here!

Freshwater Mangrove Forest Found In Mexico

Down in Mexico, along the Yucatan Peninsula, scientists have recently made an exciting discovery that had previously been hidden from the modern world. Along the San Pedro Mártir River, in Tabasco, they discovered a 50-mile stretch of mangrove trees!

A Monumental Find For Mangrove Trees

What’s special about this forest of mangroves, is that they were found over 70 miles away from the nearest saltwater coast, and some 85 to 120 feet above sea level.

Meaning in 2016, the first freshwater mangrove forest was discovered. As you can plainly see—yes, mangrove trees can really grow in freshwater, and they do.

This find is significant because it can give us a glimpse into an ecosystem that has been untouched by modern hands for approximately 110,000 years ago.

This freshwater mangrove ecosystem is thought to have been created when the last ice age caused sea levels to rise. As the ocean slowly receded and was replaced by freshwater, the mangrove trees remained and adapted to a new life on the river.

Not only did we know that mangrove trees could in fact grow in freshwater, but we have recently found irrefutable proof that freshwater mangrove forests can, and do exist.

The Importance Of Mangroves In The Environment

Mangrove forests are extremely important to the environment for a number of reasons.

For one, they create a vast, biodiverse home for fish and other wildlife who depend on these areas. Mangrove trees also help the environment by cleaning pollutants in the water and sequestering carbon from the air.

These trees also help protect coastlines from erosion, they create a buffer from storm surges and tropical storms.

Mangroves Are Natural Fish Hatcheries

The tangle of roots from red mangroves reaches into the salty water, down into the muddy bottom creating places for small fish to hide from larger predators.

Many adult species of fish come to the mangrove roots to spawn, including sharks and rays. Once these fish get bigger, they move out of the mangroves into larger bodies of water and then repeat the process.

Mangroves also take back in the nutrients from fish as well! You can read more about what mangrove trees actually eat here.

Mangroves Help Clean The Environment

According to the Florida Department of Environmental Protection, mangrove forests remove pollutants before they can make it to coral reefs and seagrass habitats. Mangrove peat also helps to absorb excess water during periods of heavy rain, thus reducing the probability of flooding along the coast.

Mangrove trees are also adept at removing carbon dioxide from the atmosphere. These trees pull in carbon dioxide, then store it in the leaves, trunks, and roots of the tree. When the leaves fall or the tree reaches it end, that carbon is then deposited into the ground, this is called carbon sequestering.

According to work published in GreenBiz, mangrove forests sequester about 24 million metric tons of carbon from the environment every year. Some studies suggest that mangrove forests—pound for pound— can store away 4 times as much carbon from the atmosphere as rainforests can. This makes mangrove forests important not only for wildlife but for the entire planet.

Grow Mangrove Trees At Home

These trees are at home in tropical settings where it’s hot and humid, and they like their roots in salty water. I don’t mind dipping my toes in warm tropical waters too! But did you know you can grow them at home wherever you live?

Mangrove trees can grow really tall, but if you keep them trimmed they will stay short. They are easy to make into dwarf trees. This especially is helpful in colder climates when you have to take them inside before the winter sets in.

If you don’t have a greenhouse you can keep mangrove trees in pots inside your house when cold weather arrives. They need a lot of sunlight—about 10-12 hours worth—and they need to be kept very warm. A seed mat will help with these temperatures, you can try the Seedling Heat Mat.

This heat mat increases the temperature of the rooting area anywhere from 10-20℉ above the ambient air temperature, which makes it perfect for indoor gardening, and allows for better plant growth, and flower seed germination.

Mangrove Trees As Aquarium Plants

Mangrove trees, especially the red mangrove variety adapt well to aquarium and pond lifestyles. It doesn’t matter the type of water either, be it saltwater, freshwater, or brackish, these plants will do well as long as they are kept away from freezing temperatures!

Freezing temperatures will ruin your mangrove trees.

As these plants are fast-growing, they will need a moderate amount of trimming to keep them small and compact. If you would like to grow these amazing plants at home you can get seedlings like these 8 Healthy Strong Red Mangrove Seedlings.

That’s All For Now!

Mangrove trees are fascinating specimens that can withstand the harsh salty waters in tropical climates all around the globe. They are essential for a lot of species of fish, mollusks, birds, and much more. These trees thrive in salty and brackish waters because there is so little competition in this kind of environment.

And we now know that mangrove trees can and do grow in freshwater. Because of climate, competition, and tidal flows, mangrove trees don’t usually grow in freshwater. When the conditions are right, mangrove trees do grow well in freshwater.

Thanks for sticking around with us and learning why mangrove trees can live in freshwater!

References

Aburto-Oropeza, O., Burelo-Ramos, C. M., Ezcurra, E., Ezcurra, P., Henriquez, C. L., Vanderplank, S. E., & Zapata, F. (2021). Relict inland mangrove ecosystem reveals Last Interglacial sea levels. Proceedings of the National Academy of Sciences, 118(41).

Adame, M. F., et al. “Carbon stocks and soil sequestration rates of riverine mangroves and freshwater wetlands.” Biogeosciences Discussions 12.2 (2015).

Jiang Jiang, Douglas O. Fuller, Su Yean Teh, Lu Zhai, Hock Lye Koh, Donald L. DeAngelis, Leonel da Silveira Lobo Sternberg, Bistability of mangrove forests and competition with freshwater plants, Agricultural and Forest Meteorology, Volume 213, 2015, Pages 283-290, ISSN 0168-1923. 

Liangmu Wang, Meirong Mu, Xiaofei Li, Peng Lin, Wenqing Wang, Differentiation between true mangroves and mangrove associates based on leaf traits and salt contents, Journal of Plant Ecology, Volume 4, Issue 4, December 2011, Pages 292–301.

Sepúlveda-Lozada, A., Mendoza-Carranza, M., Wolff, M. et al. Differences in food web structure of mangroves and freshwater marshes: evidence from stable isotope studies in the Southern Gulf of Mexico. Wetlands Ecol Manage 23, 293–314 (2015).

Mangroves grow along intertidal and coastal waterways as you may have seen them sticking out of the water along the coast. They look like thick-leaved trees on stilts as the tide rushes in around them. Living in the salty water as they do, you’ve probably wondered, do mangrove trees eat anything to stay nourished?

Mangrove trees don’t truly eat anything, but they do extract nutrients from the ground through their roots with the help of other organisms in the habitat mangrove trees help to create. Waterlogged soil provides nutrients from waste from organisms such as bacteria, fish, and mollusks.

Keep reading on to find out more about these fascinating trees, how they create such a diverse ecosystem among themselves, and find out how and what exactly mangrove trees eat!

What Are Mangroves?

Mangrove trees are specific trees that grow in tropical areas around or near the equator that have adapted to life in areas with low oxygen content soil. In total, there are 80 species of mangrove trees that can potentially make up mangrove forests.

These trees are often found along coastal sea waters or areas of brackish water. Mangrove forests are recognized by their intertwined roots that reach into the water and keep the trunks and leaves above the waterline.

These dense tangles of roots get flooded with the rising of the tide and help protect against erosion, slow the movement of the tides which helps sediments settle to the bottom, and can help buffer the coast from tsunamis, rising waters, and hurricanes!

Most typically, mangrove trees are known to grow in salt water in the most general gist!

Mangroves Are A Diverse Ecosystem

A mangrove forest creates a densely populated ecosystem on its own from the roots in the water to the branches above.

Fish, mollusks, manatees, algae, and more all rely on the roots of the mangrove trees for survival while several bird species, amphibians, and reptiles call the branches and canopy home.

Mangroves Offer Homes For Animals, Fish, And Insects

Mangrove roots are specialized to let tidal water submerge them without letting the tree drown. All trees need oxygen to live, and they need that oxygen in all parts of the tree; from the leaves to the trunk, and down to the roots. Most plants will eventually die if their roots are constantly submerged in water.

To get enough oxygen to survive in the water, mangrove trees grow what are called aerial roots. These roots stick out of the water and have specialized pores in them called lenticels that allow oxygen to enter but not water or salt.

The tangle of roots from a mangrove forest that reaches into the tidal basin creates shelter and attracts food for a host of marine animals.

Some of the creatures you would find living among mangrove roots include mudskippers, shellfish, sharks, fish, reptiles such as turtles, snakes, crocodilians, and even mammals such as dolphins, and manatees.

The roots of mangrove forests offer hiding places for small fish, snails, and other creatures at the bottom of the food chain, which in turn brings in those larger predators.

In fact, many fish species lay their eggs among the mangrove roots because the tangle of roots provides shelter from larger predators.

For instance, lemon sharks are known to birth live young among the mangrove roots!

These dense areas of mangrove trees offer shelter for their young and provide them with plenty of food. When these sharks are grown, they return to the place they were born to birth their own pups, so mangroves are very important for these sharks.

Mangrove Canopies House Birds, Insects And Animals

Amongst the branches and leaves of mangrove trees, you’ll find many different species as well.

Ferns, orchids, spiders, insects, tree-climbing crabs, birds, and monkeys call the mangrove trees home. When the mangrove trees flower, hummingbirds and bats come to feed off the nectar, which pollinates the flowers to drop seeds for new mangrove trees.

Mangrove trees are extremely important for many animal species for food and shelter. Without them, many species of animals would have a hard time surviving.

How Mangrove Trees Eat And Get Nutrients

Mangrove trees, like all trees, create their own food by photosynthesis in their leaves. But like most other plants and trees they need to draw some of their nutrients through their roots in the soil.

The muddy, sandy, coastal waters where mangrove trees grow are usually very nutrient-lacking areas. Mangrove trees live in oxygen-poor, and nutrient-poor conditions, so how do they make up for the lack of nutrients.

Fortunately for mangrove trees, there is usually a bacteria in the top layer of the soil that can convert fish waste, often in the form of ammonium deposits, into nitrates, which plants need.

The trees then help to feed the bacteria and other small invertebrates when the mangrove trees drop dead leaves. These leaves slowly decompose and provide more food for the bacteria, snails, and other small animals.

Fish come along to feed on the snails, plankton, and bacteria and drop their waste, which continues the cycle. Mangrove trees don’t actually eat anything in the sense that humans do, but they do absorb nutrients from the salty, muddy soil, thanks to bacteria.

How Mangrove Trees Grow In Saltwater

There aren’t many plants or trees that can live in harsh, salty regions. The rich salinity of seawater will kill most plants. In fact, mangroves are the only trees that can live submerged in saltwater. Some trees have adapted to live along coastal regions where salt spray is common, but if the roots get submerged by salt water, they won’t last for too long.

Mangrove trees still need plenty of fresh water to survive, so how do they get enough life-sustaining non-saline water? Mangrove trees have several unique adaptations that allow them to get enough water to not only survive but flourish.

You can learn more about where the most common places to find mangrove trees is here!

Dealing With Evaporation

The leaves of a mangrove tree are very similar to succulent plants. The leaves are thick and broad to be able to store a lot of water in them. Some also have a waxy coating that helps to keep the precious water inside and reduces evaporation when the sun is beating down.

Some species of mangrove trees have tiny hairs on them that deflect sunlight and wind, which would evaporate a lot of water when the leaves pass gasses during photosynthesis. Others have pores on the bottom of the leaves instead of the sides and the upper face of the leaves.

Mangrove tree leaves also utilize a type of sap or milky latex type substance that keeps insects and other leaf-eating animals away. This way the tree can keep more moisture inside it since freshwater is hard to come by when the roots are completely submerged in saltwater.

The Leaves Remove Salt

Another adaptation to harsh, salty environments is the ability of mangrove trees to extract salt from seawater. With their roots constantly submerged in saltwater, it would be difficult for mangrove trees to get freshwater, even when it rains, but these trees can filter out the salt.

According to the American Museum of Natural History, mangrove trees can filter up to 90% of salt out of seawater that is absorbed by its roots. Some mangrove trees use glands in their leaves to expel the salt, which can form crystals on the leaves.

Other trees store excess salt in leaves and bark that have outlived their usefulness. The old leaves and bark then fall off the tree, which gets rid of the excess salt and minerals. The tree not only renews itself but gets rid of salty waste at the same time.

Even Mangrove Seeds Are Adapted To Life In The Sea

Mangrove seeds will germinate while still hanging on the tree. If they fall during low tide and hit the ground, the roots will spread very quickly and anchor themselves in the mud before the high tide returns. If the seeds fall when the tide is in, the seeds will float until they reach solid ground where they can start growing.

It has been thought that some mangrove seeds have floated on the currents for years before coming to rest on a distant shore, and growing into a tree. On the ground, the seeds need to grow fast or they could be washed away. In fact, some mangrove trees will grow more than two feet in their first year so they can get above the waterline.

Some species of mangrove seeds will form roots while still attached to the parent tree. After one to three years, the roots will detach from the parent tree and either start growing nearby or be carried to another shore.

The way mangrove trees propagate, in a matter of a decade, one solitary seed can become a new, small forest of mangrove trees.

While mangrove trees can grow in freshwater, they do prefer saltwater!

Benefits Of Mangroves

Mangrove forests are extremely important to the global environment. They provide a home for a vast, biodiverse array of animals from microscopic, single-celled organisms to top of the food chain predators, some of which are only found among the mangroves.

Coastal Stabilization

Groups of these trees help to stabilize coastlines from erosion caused by storms, waves, and incoming tides.

The roots hold together the soil while the dropped leaves help to provide nutrients to areas that are nearly empty in nutrients. The trunks and canopies help to reduce floods, and rising waters and slow down winds from big storms.

This natural barrier is more effective than artificially produced seawalls at protecting local, coastal communities. It’s also much less expensive to grow trees than it is to build walls.

Protect Water Quality

Mangrove forests filter pollutants from stormwater drainage before it reaches coral reefs.

These contaminants could damage and destroy coral reefs, but mangrove trees help to buffer these pollutants.

Important To Reducing Carbon

One of the most important factors of mangrove trees that directly affects us is the ability to store large amounts of carbon.

According to The Role of Mangroves Forests in Decarbonizing the Atmosphere, the forest of mangrove trees can store 3 to 4 times as much carbon dioxide as tropical rainforest can.

Mangrove trees also store that carbon in their leaves, trunks, and roots where they are simply an ultra-effective carbon filter!

So, mangroves are essential in the battle against climate change.

Mangroves Are Being Threatened

Whether it’s tourism, agriculture, coastal development, or shrimp farming, the mangrove forests are being threatened and wiped out. The most devastating of these are shrimp farming and coastal development.

Shrimp farmers come in, wipe out the trees, and place shallow ponds in their way for crowded shrimp hatcheries. Generally, many chemicals are used to keep the overcrowded shrimp healthy, which eventually affects everything around the area.

Pretty soon even the shrimp can’t live there, and the shrimp farmers move off to another area, leaving the destroyed landscape in their wake.

This isn’t to say ALL shrimp farmers, but thats the main idea.

With coastal development, the mangrove trees are cut down or damaged by all the pollutants that come along with building structures and roads. Eventually, these pollutants are too much for the mangrove forests to handle and they begin to fade away if they aren’t cut down and removed before development.

What You Can Do To Help The Mangroves

There are ways you can help the world’s mangrove forests. If you consume shrimp, look for sustainable alternatives to farmed shrimp that come from mangrove areas.

You can grow your own mangrove trees at home (near saltwater), and you can also donate to conservation sites, and help people who live in the coastal areas by purchasing directly from them.

Some people keep beehives along the mangroves and sell mangrove honey from these hives. These small farmers use sustainable means to provide a living for themselves and their families all while helping to protect the mangrove forests.

Grow Your Own Mangrove Tree

If you’d like to grow your own mangrove trees, you can start with these mangrove seedlings 8 Healthy Strong Red Mangrove Seedlings. You can grow these trees outdoors if you live in USDA Hardiness Zones 9-12. Mangroves will also grow in ponds, aquariums, or pots.

They will need a lot of heat and about 12 hours of full sun each day. If you want to grow them indoors in a pot, you will need a heating pad to keep the soil warm. Try out this highly rated heated grow mat, MET certified Seedling Heat Mat!

That’s A Wrap!

That’s all we’ve got for now!

Mangrove trees don’t really eat anything, they aren’t carnivorous plants like the Venus flytrap. But like all plants do require nutrients that they draw up through their roots and nutrients they make using photosynthesis.

Mangrove trees are fascinating, one-of-a-kind trees that provide a ton of benefits to the global environment, and positively affect each one of us. For these reasons and more, mangrove trees should be recognized for their usefulness and be protected.

Thank you so much for reading!

References

Feller, I.C., McKee, K.L., Whigham, D.F. et al. Nitrogen vs. phosphorus limitation across an ecotonal gradient in a mangrove forest. Biogeochemistry 62, 145–175 (2003).

Golley, Frank, Howard T. Odum, and Ronald F. Wilson. “The structure and metabolism of a Puerto Rican red mangrove forest in May.” Ecology (1962): 9-19.

Ruth Reef, Ilka C. Feller, Catherine E. Lovelock, Nutrition of mangroves, Tree Physiology, Volume 30, Issue 9, September 2010, Pages 1148–1160.

Thomas, Nathan, et al. “Distribution and drivers of global mangrove forest change, 1996–2010.” PloS one 12.6 (2017): e0179302.

Mangrove trees are a specialized type of tropical tree that grows partially submerged, often in saltwater marshes. Mangrove trees are the only species that can tolerate the high salinity of oceans and seas. So they must love water, but where are some of the most common places to find mangrove trees?

Mangrove trees and shrubs grow along tropical and subtropical estuaries, rivers, and shores. Most grow in muddy, waterlogged soil, but some can grow in sand, peat, and places too harsh for other tree species. Mangroves live in the water nearly 100 times more saline than other plants can tolerate. 

Mangrove trees are found across the globe, so let’s take a deeper look into some of the most common places mangrove trees can be found!

Mangrove Trees In America

Mangrove trees can be found in tropical and subtropical climates near the equator. They can tolerate and thrive in some of the saltiest water, and are one of the few types of trees that can grow near salt water, but they can’t stand the cold.

There are a few places in the US where mangroves grow naturally, while some places had mangrove trees artificially introduced. They can survive in USDA growth zones from 9-12. These places are very hot, don’t have cold snaps very often, and are typically coastal areas. 

Florida Mangrove Trees

Along the southern edges of the coast of Florida, you might run into up to three different species of mangrove trees. The red mangrove grows along the coastal edge and is recognized by its finger-like roots reaching into tidal areas. These roots stretch down into the water to help stabilize the tree. 

Black and white mangroves live further inland respectively. These trees still love salty, marshy areas, but they can’t stand being submerged as much as their red mangrove cousins. White mangroves grow in higher elevations, farther back from the shore, and do not have exposed roots like black and red mangrove trees.  

1. Red Mangroves

Red mangrove trees are the ones you are most likely to recognize because of the roots that intertwine in the salty waters. They anchor their roots in soft, muddy waters where they spread out like stilts, keeping the trunks straight and out of the reach of tidal waters.

You will find red mangrove trees along the Atlantic coast of Florida and around the Gulf of Mexico. 

Red mangroves can live in such salty, nutrient-lacking environments because of specialized adaptations to deal with moisture sapping saltwater. These trees can block out up to 90% of the salt from entering the roots. If it wasn’t for this ability, the salt water would dry out the tree and it couldn’t survive. Talk about adaptability!

The roots of these trees also have specialized pores called lenticels which can let oxygen inside while blocking water when the tide comes in. The roots and trunks of trees need oxygen to survive, but they are unable to get the gas when they are completely submerged. When the tide goes out, and the lenticels are exposed, the tree can “breathe,” it then stores oxygen in small cavities until it is needed.

2. Black Mangroves

Black mangrove trees are identified by pencil-like roots that stick up from the ground around the tree. These roots are called pneumatophores and allow the tree to obtain oxygen from the air. Often, the soil black mangrove trees live in is saturated with salt water. 

These trees don’t usually live directly in the water like red mangrove species, but they still live close enough where high tides can saturate the ground around them. If their pneumatophores are covered with silt, or submerged too long, they won’t survive. 

The leaves on black mangrove trees use excretion to remove the salt from the water they absorb. Often the leaves will have crystallized salt covering them. 

Black mangrove trees are the most tolerant of cooler temperatures of the three species found in Florida. They can be found the farthest north in the state, but like all mangrove species, they still can’t tolerate freezing temperatures for long. 

3. White Mangroves

White mangrove trees live in higher elevations than the previous two. For this reason, the white mangrove does not have surface roots like the red and black mangrove varieties. These trees are still prized for their ability to help stop erosion and provide a natural buffer from storms and water surges. 

Just below the base of the leaves, there are two pores called petioles which excrete excess salt buildup. 

Like other mangrove trees, this tree’s seeds germinate while still hanging on the branch. They have to grow fast in the harsh climate so a root will start sprouting while on the tree. How cool is that? Once the seed falls, it already has a head start and doesn’t take long to become established. 

Louisiana Mangrove Trees

Along the coastal regions of Louisiana, black mangroves have been growing at a steady pace. These trees are the coldest tolerant of the mangroves and can stand the quick cold snaps of the state. 

There are areas along the southern border of Louisiana that used to have plenty of bald cypress trees growing in the marshes, but over the years the salinity has been increasing. This increase in saltwater has made the environment too saline for the cypress to stand in, so black mangroves have started to move in.

In fact, since 1990, black mangroves have been increasing along the coast of Louisiana because there are no other trees that can withstand such a salty environment. 

Texas Mangrove Trees

In Texas, along the mouth of the Rio Grande through Laguna Madre, and other salty, sandy, tidal areas, you will find black mangrove trees. These trees can grow up to 60 feet tall and the temperature stays hot all the time. 

Even along the Gulf of Mexico, the temperatures in Texas can dip down to freezing. Because of the occasional cold spell, the black mangrove trees in Texas are often little more than shrubs. The cold often freezes the new, top growth of black mangroves which stunts the trees. They rarely grow taller than 3 feet. 

Hawaiian Mangrove Trees

According to the USDA, there were no species of mangrove trees growing in Hawaii before the early 1900s. In 1902 the red mangrove was introduced to the island chain to help stabilize some of the coastal mudflats. 

No one counted on how quickly these trees could establish themselves and expand. Now the red mangrove is considered an invasive species in Hawaii. These fast-growing trees have reduced the habitat for endangered waterfowl such as the Hawaiian Stilt, started overgrowing archaeological sites, and caused drainage and aesthetic problems. 

Mangrove Trees Around The World

Now, let’s take a quick look where mangrove trees grow in the rest of the world.

India: Home Of The Largest Mangrove Forest In The World

In India, the Sundarbans Forest Reserve is the largest mangrove forest in the world. It encompasses some 140,000 hectares along the Bay of Bengal. This huge mangrove forest is home to many endangered species such as the Royal Bengal Tiger.

In this hot, jungle-like climate, mangrove trees grow in great abundance. These trees are critical for this environment and the creatures that call the Sundarbans Forest Reserve home. There are innumerable species of fish, crustaceans, birds, and mammals that depend on mangrove trees. Thank goodness for those mangroves!

Mangrove Trees In Indonesia

The country of Indonesia consists of 17,000 tropical islands and has the largest amount of mangrove forest cover of all other countries. Indonesia alone contains 23% of the world’s mangrove forests and includes the richest concentrations of different mangrove species.

Unfortunately, this area is also being deforested at an alarming rate. These mangrove forests are being cleared out for shrimp and fish farming ponds as well as for palm oil plantations. Palm oil production has removed tens of millions of acres of mangrove forest for palm oil that is used in a multitude of products. 

Some may say that removing trees and planting more trees isn’t that bad, but mangrove trees are special in that one acre of mangroves removes more carbon dioxide from the environment than an acre of rainforest. Mangrove trees are being removed from the environment faster than rainforest deforestation. 

Mangrove Forests In Brazil

In Brazil, the Bahia mangrove forest covers the majority of the country’s coastal region. This tropical rainforest gets over 55 inches of rain per year. The excessive rainfall does not stop the red mangrove trees from flourishing here. 

This area covers over 800 square miles of dense mangrove forest land. It is not continuously forested but is broken up by various river estuaries. These areas are not easily accessible and are not studied much, but they are also threatened as human populations continue to spread toward the coast, especially in the northeastern areas. Mangroves need their space, just like us!

These mangroves, like all mangrove forests, play a critical role in fish nurseries and places for mollusks, crabs, and shrimps to live. They also provide places for many waterfowl species such as the great egret, snowy egret, and many migratory species to nest and feed. 

There have also been sightings of five different species of sea turtles swimming among the mangrove roots. These species include the loggerhead sea turtle, olive ridley, leatherback, hawkbill, and green sea turtles. All of these sea turtles are considered endangered. 

Mangrove Trees In Nigeria

Nigeria has the largest mangrove forest in Africa. This forest alone stands for over 50% of mangrove forests in West Africa. Nigeria is also the largest mangrove ecosystem in all of Africa. 

60% of local people depend on these mangroves for survival. The mangrove trees offer therapeutic and medicinal remedies, cultural traditions, spiritual significance, as well as food and sources of income for locals. 

Many of the people living in these areas fish for themselves and sell their catch to make ends meet. In a healthy mangrove ecosystem, a single hectare of space can support 1.08 tons of fish yearly.

Local Nigerians harvest mangrove wood for household and domestic use as well. Some of the uses of mangrove wood include cooking, and smoking foods, housing material, fishing stakes, scaffolding, and much more. 

As you can see, mangrove forests are not only essential for the wide array of animals living on, around, and among the trees, but they are essential for the livelihood of residents as well.  

Australian Mangrove Trees

Australia contains the third largest area of mangrove forests in the world after Brazil and Indonesia. There are 41 different mangrove species found around Australia and approximately 6.4% of the world’s total mangrove area. These appear in nearly all the states of Australia except for Tasmania. 

The most common mangrove tree in Australia is the higher elevation loving white mangrove. There are about 80 different species of mangroves in the world, and Australia contains half of all the species. Australia also has a species that grows nowhere else in the world; the Avicennia Integra, or what the locals call an api api tree. 

Indigenous Australians have traditionally used mangrove forests for sources of food and timber. They would fish for clams, barramundi fish, and crabs. They would also gather mangrove fruit for food. The timber from mangrove trees used to be used for canoes, paddles, shields, and spears as well as boomerangs. 

Commercial Uses of Mangrove Trees

When mangrove trees are grown as a renewable resource the commercial uses are quite impressive. Nearly every part of the tree can be used for something. Tannins from mangrove tree bark, especially the black mangrove, are used for leather tanning and dyes. The timber is used in construction, and even the leaves have medicinal qualities. 

The wood of many species of mangrove trees produces hot burning charcoal, and the timber can be used in building houses, boats, and furniture.

The wood is also naturally termite resistant, very hard, and resistant to water and rot, making it a great wood for boats and canoes. In Malaysia, pneumatophores are even used in basket weaving, as well as fishing corks and floats. 

Mangrove Leaves

Some cultures used the leaves of mangroves for medicinal purposes. Other cultures would use mangrove leaves as an alternative to tobacco, tea, and feed for livestock. 

Don’t go out and start snacking on mangrove tree leaves whenever you come across them though. There are many different species of mangrove trees, some of which contain leaves that are not edible!

Mangrove Honey

Some species of mangrove trees flower year-round, which is great for beekeepers because they have a constant supply of food for their bees. Florida is one area that is starting to utilize mangroves for honey production. If you are a honey lover who enjoys trying all the different types of honey, try out this Raw Mangrove Honey from Florida!

Wrapping It Up

As you see, mangrove trees can be found all over the place in tropical zones where the land meets the sea. The largest and most common areas for mangrove forests are Indonesia, India, Brazil, Australia, Nigeria, and even the southern states of the United States that border the Gulf of Mexico. 

Mangrove forests are extremely important to the global environment, animals that call these forests home, and humans.

If you want to grow your own mangrove trees you certainly can. They grow well in zones 9-12, and also make great potted, or pond plants. They just don’t tolerate cold temperatures!

If growing mangrove trees sounds like a good time, here are some Red Mangrove Seedlings to get you started. Best of luck!

References

Ball, M. C. (1980). Patterns of secondary succession in a mangrove forest of southern Florida. Oecologia, 44(2), 226-235.

Hutchison, J., Manica, A., Swetnam, R., Balmford, A., & Spalding, M. (2014). Predicting global patterns in mangrove forest biomass. Conserv. Lett. 7, 233–240.

Michot, T. C., Day, R. H., & Wells, C. J. (2010). Increase in black mangrove abundance in coastal Louisiana. Louisiana Natural Resources News, 4-5.

Schaeffer-Novelli, Y., Cintrón-Molero, G., Soares, M. L. G., & De-Rosa, T. (2000). Brazilian mangroves. Aquatic Ecosystem Health & Management, 3(4), 561-570.