Large-scale plantation of foreign trees along exposed coastlines after the 2004 Tsunami in Indian Ocean is no guard against future storms warns a team of international scientists.
The team also warns against planting alien tree species along exposed coastlines on the pretext that it would only destroy local ecosystems and displace people.
In the wake of the December 2004 many conservation organisations and some scientists claimed that coastal vegetation could reduce the damage caused by Tsunamis.
These claims led to large scale efforts to plant belts of foreign trees along exposed coasts in the hope of protecting people from future Tsunamis or from storm surges produced during tropical storms, such as Hurricane Katrina or Cyclone Nargis.
However, after reviewing over 30 papers on the subject, researchers from Australia, Bangladesh, Belgium, France, Guam, India, Sri Lanka and the US conclude that most of the original claims were false.
A case study from Andhra Pradesh in India reveals that Tsunami relief funding is being used to continue development programmes, which include planting exotic species such as Casuarina for firewood, rather than providing any meaningful protection against Tsunami.
“Even more extraordinarily, local topography such as sand dunes, which can provide protection against surges, are being bulldozed to make way for ‘bioshields’ (belts of coastal trees) of exotic species,” says Kartik Shanker of the Indian Institute of Science.
“The UNDP has provided millions of dollars for ‘bioshield’ construction,” which “are being placed beside or even behind coastal villages, where they can’t possibly provide protection against ocean surges”, says Sudarshan Rodriguez of Dakshin Foundation, India.
“There is very little evidence for the idea that coastal vegetation provides meaningful protection from these major surge events,” says Rusty Feagin of Texas A & M University, who led the study.
“Also, planting-introduced foreign tree species as ‘bioshields’ are doing extraordinary environmental damage,” adds Feagin.
“The best way to protect human lives against Tsunamis or large storm surges is through education, early warning and evacuation planning,” says Andrew Baird of the ARC Centre of Excellence for Coral Reef Studies at James Cook University.
“The technology is available for adequate early warning. If this is backed up by sensible evacuation planning, there is no reason for anyone to die in a Tsunami or a storm surge nowadays,” he says.
These findings are slated for publication in Conservation Letters.