In this news, we discuss the Coastal mangrove biodiversity under threat of existence.
Mangrove forests face a “triple threat” to their sustainability and long-term survival, according to a new study.
The study, published in Environmental Research Letters, indicates that mangrove forests are under pressure from three distinct threats: rising sea levels, lack of mud, and crowded habitats.
Mangrove forests, having great biodiversity, are among the most valuable ecosystems in the world that provide coastal protection.
The research, carried out by an international team of experts including Dr Barend van Maanen of the University of Exeter, identifies not only how these coastal forests are pushed against their shores, but also what causes the loss of their diversity.
It shows the negative effects of river dams which diminish the supply of mud that might otherwise lift mangrove soils, while buildings and dykes largely take up the space mangroves need to survive.
Coastal mangrove forests are valuable and highly diverse ecosystems that protect coastal communities from storms.
Mangroves resist tidal flooding and capture mud to elevate their soils. But since mangrove trees cannot survive if they are underwater for too long, the combination of rising sea levels and decreasing mud supplies to rivers pose a serious threat.
New computer simulations show how coastal forests retreat towards land as a result of rising sea levels, especially in coastal areas where the mud in the water decreases. The simulations include the interactions between tides, mud transport and, for the first time, several species of mangroves.
“The loss of mangrove cover and the loss of diversity go hand in hand when this retreat to land is limited by city expansion, agriculture or flood protection works,” said Dr van Maanen, Senior Lecturer at the University of Exeter and Project Supervisor.
The model also shows that mangroves with dense roots retain mud more effectively and can prevent it from reaching forest areas further inland.
“This causes trees farthest from the earth to be inundated for longer periods of time, an effect that is intensified by the rise in sea level,” said Danghan Xie, lead author of the study.
“The increase in inland flooding then seriously reduces biodiversity.
“Human land use prevents mangroves from escaping flooding by migrating inland, reducing the mangrove area and further endangering biodiversity.”
A narrow mangrove area is much less effective in protecting the coast from storms or, in the worst case, completely loses its protective properties.
“The loss of mangrove species will have dramatic ecological and economic implications, but fortunately there are ways to help save these ecosystems,” said co-author Dr Christian Schwarz, environmental scientist at the University of Canada. Delaware.
“Securing or restoring the flow of mud to the coasts is essential to counter the negative effects of sea level rise.
“For coasts where mud supplies remain limited, removing barriers that hinder inland migration is of the utmost importance to avoid the loss of mangrove forests and biodiversity,” Schwarz said.
The biodiversity of coastal mangroves threatened with existence
New research identifies ‘triple problem’ for mangrove shores