Trees protecting livelihoods?

Mangroves are a type of forest providing humans with important ecological services. More work on restoring and planting mangroves needs to be done in order to maximise their important role in forming a natural protection to life-threatening storm surges and flooding from climate change. 

What are mangroves? 

Mangroves consist of tropical trees that cover vast areas of the tropics and the subtropics – in total they cover 137,800 sq. km2 of the world. Unlike many trees they are able to tolerate and be survivors in salty coastal waters.

 To be able to function to the low oxygen and saline conditions they have a complex salt filtration system that keeps the salt out and a complex root system that stops the plants falling down from the shifting sediments that they are in. 

Figure 1: A mangrove forest in Loxahatchee, Florida
(Source: https://oceanservice.noaa.gov/facts/mangroves.html)

How do mangroves mitigate the impact of climate-induced events? 

Mangroves form a natural protection from the impacts of flooding and other climate-induced events that pose risks to vulnerable and densely populated coastlines. 

Their aerial roots are able to prevent sediment from shifting and prevent erosion. Whilst their canopy as well as their roots and trunks reduce the force of waves and storm surges heading to the coastline. This limits the damage these storms can pose on individual livelihoods who are already socially disadvantaged. 

For countries such as the Philippines mangroves have paramount importance in protecting coastlines. A team from the World Bank WAVES (Wealth Accounting and the Valuation of Ecosystem Services) found that without mangroves in Philippines’s coastal waters, damages to infrastructure, property and people would increase by 25% each year. 

 Not only can mangroves limit the impact of storm surges, but they also take in a significant amount of carbon dioxide through photosynthesis. They sequester a far greater amount of carbon than tropical rainforests. The fact that mangroves can store huge amounts of carbon is partially due to the rich organic soils in which they grow. Therefore, planting new mangrove forests could prove vital for mitigating the damage that climate change may bring to our future world. 

Figure 2: The impact of mangroves (Source: https://www.oceanographicmagazine.com/news/mangrove-forests-flood-protection/)

How can we utilise mangroves to protect vulnerable communities? 

Reducing the impact of flooding provides communities on these vulnerable islands a chance of a better livelihood. The World Bank WAVES team found that mangroves reduce flooding to 613,000 people in the Philippines each year and 23% of these people live below the poverty line. This makes it clear, mangroves are vital for communities to rebuild their livelihoods and find a way to live with the dangers of increased number and intensity of storms due to climate change. 

However, mangroves are one of the world’s most threatened tropical ecosystems, as 35% of the mangroves in the world have disappeared. They are threatened and destroyed to make room for a variety of human activities. These include megatourism, logging, coastal development and agriculture. 

But there is hope. The restoration of mangroves as well as planting mangroves can be done. There are many examples of the restoration of vulnerable coastlines. According to the World Bank, 37,000 mangroves have been planted across the low-lying islands of Kiribati (the islands of North and South Tarawa, Aranuka, Butaritari, Maiana and Makin). 

We need to encourage and support more community projects to plant mangroves, allowing us to form a natural barrier to protect vulnerable coastal communities from the harsh impacts of climate change. Otherwise, whole communities living on the low-lying islands of the world will be wiped out as sea level continues to rise in the future.