They cover just 0.1 percent of the planet’s surface, but mangroves are a vital carbon capturing ecosystem.
The coastal trees found in over a hundred countries are increasingly being discussed as a cornerstone of various environmental policies and protection initiatives. These plants are capable of withstanding conditions unlike any other trees - all while fighting climate change and supporting local economies.
Simply put, a mangrove is a small tree or shrub which grows along the coast in brackish or saline water. In the broadest sense, we use ‘mangroves’ to describe entire ecosystems and habitats created by these salt-loving plants, often referred to as mangrove swamps or forests.
Mangroves are present in over 100 countries, all within tropical and subtropical regions. Nearly half of the world’s mangroves are in Asia, which is unsurprising when you learn that Indonesia contains 14,380 square miles (23,140 km2) of mangrove forests - more than the next five countries combined.
So, why are they so important? The answer is multi-faceted. These plants aren’t just important for one key reason, they play many roles in supporting the health of our planet - which is why they matter so much.
Carbon sequestration: Although we think of the Amazon rainforest as the ‘lungs’ of our planet, the saline mangrove forests can absorb between double and quadruple the amount of carbon dioxide that mature tropical rainforests take in, and they store three-five times more carbon than places like the Amazon rainforest. In short, mangroves are one of the keys to preventing climate change.
Water quality: As well as growing in the sea, mangrove forests are found in brackish water where river meets ocean. The impressive network of underwater roots acts as a filter for sediments, working to clean up our waterways. They also help maintain water quality for other living organisms nearby, like coral reefs - and they can even prevent mass bleaching events.
Biodiversity: They may only take up a fraction of the earth’s surface - just 0.1 per cent - but mangroves are home to nearly 60 unique species. There are 40 bird, 10 reptile, six mammal, and one amphibian species which can only be found in this specific ecosystem. And the forests are important for species that aren’t endemic too, like lemon sharks which prefer to give birth in the shallows. The young sharks spend their first year in the swamps to stay safe.
Livelihoods: It’s not just flora and fauna which benefit from mangroves either; there are communities around the world where the forests are an essential source of income. From small-scale fishing to sustainable logging, mangroves are integral to many people’s way of life.
Safety: Mangroves also serve as vital buffers along shorelines. With sea levels rising and natural disasters increasingly common, the plants’ thick, impenetrable roots help protect coastal communities from flooding and storms.
In many countries, unfortunately, mangroves are under increasing threat from deforestation, but the good news is that scientists and ecologists are now managing to get the importance of these ecosystems into mainstream thinking. And there are increasing numbers of projects dedicated to the revitalisation, protection and regrowth of mangroves too. From the WWF’s work in this area to EcoViva’s alliance of grassroots-led projects, action is being taken around the world.
It's not just mangroves that have the power to capture carbon at significantly superior rates to rainforests. Seagrass meadows and peat bogs, both have carbon capturing power that's 30 times greater.
The four year project, which has just started, aims to greatly increase the extent of seagrass meadows along Britain's south coast by dropping seeded biodegradable bags to the sea floor. More...