Scientists from Nanyang Technological University in Singapore and an international research team predict that by 2050, "mangroves" will not be able to withstand rising sea levels unless global carbon emissions are reduced.
Scientists have used the sediment archives from the time when the Earth's ice deteriorated to ten thousand years, and they estimated the possibility of mangroves to remain below sea level rise rates corresponding to two climatic scenarios, low emissions and high carbon.
And when sea level rise rates exceeded 6 mm per year, which is consistent with what is estimated under the high emission scenarios of 2050, researchers found that the likelihood of mangroves ceasing to grow at the required speed is very likely "a probability of more than 90%."
In contrast, mangroves can survive by building themselves vertically when sea level rise remains less than 5 mm per year, which corresponds to that expected in low emission scenarios during the 21st century.
Lead researcher Professor Neil Santillan from the Department of Earth Sciences and Environment at Macquarie University says the sea-level rise threshold of 6 mm "can be easily crossed" on tropical coasts if society does not make concerted efforts to reduce carbon emissions.
"We know that sea-level rise is unavoidable due to climate change, but little is known about how the different levels of sea-level rise affect the growth of mangroves, an important ecosystem for the health of the earth," Santillan added.
Mangrove and its environmental importance
Mangroves are known to be a shrub that grows in coastal saltwater or salt water. It is scattered throughout the world in the tropics and subtropics, mainly between latitudes 25 ° N and 25 ° S.
The total mangrove forest area in the world is over 137 million square kilometers, covering 118 countries and regions.
Mangroves withstand the salinity, and adapt to life in harsh coastal conditions. It has a complex filtration system and root system to deal with saltwater flooding and wave action. It adapts to the conditions of low oxygen in the flooded mud.
As the roots rise from under the mud, mangrove holders grow in a process called vertical accumulation.
This feature is important for its ecosystem because it helps absorb greenhouse gas emissions "carbon sequestration" at much greater densities than other forests, and provides a barrier between land and sea, which helps protect people from devastating floods.
Reducing greenhouse gas concentrations
The study, published on June 5 in the journal Science, which covered 78 sites, revealed how mangroves responded when the rate of sea level rise slowed from more than 10 mm annually for ten thousand years to almost stable conditions after 4000 years. .
As the reduction in carbon coincides with the expansion of mangrove forests during this time, it reduces greenhouse gas concentrations.
The study found that mangroves will naturally penetrate inside if their ability to accumulate vertically is impaired.
In doing so, mangroves will have to compete with other land uses and may become compressed behind coastal protection.
"Most of what we know about the mangroves' response to sea level rise comes from observations over several years to decades when elevation rates are slower than expected later in this," says Associate Professor Nicole Khan, co-author, University of Hong Kong, as quoted by Eurek Albert. Century. "
This paper provides new insights because we looked deeper into the past when sea-level rise rates were rapid and reached those expected in high emission scenarios.
The results of the study confirm the importance of reducing emissions and adopting coastal management and adaptation measures that allow mangroves to expand naturally in low-lying coastal areas to protect these valuable ecosystems.