BANGKOK (AlertNet) – Around half of Cambodia’s seasonal wetlands have been lost to intensive commercial rice farming and abandonment of traditional low-intensity agriculture, according to research from a UK university that warns of the imminent loss of the entire ecosystem.
Researchers from the University of East Anglia found that the grassland area around Tonle Sap, Southeast Asia’s largest freshwater lake, decreased from 3,349 square kilometres in 1995 to 1,817 in 2005, a loss of 46 percent.
Despite conservation efforts in some areas, a further 19 per cent of the floodplain was lost between 2005 and 2009, said a statement from the university.
“The loss of this entire ecosystem from Southeast Asia is imminent without immediate intervention,” research leader Charlotte Packman said in the statement.
“Flooded grasslands in Thailand and Vietnam have already been almost completely lost. Only a strong political commitment to protection and restoration can prevent the impending loss of the last major flooded grassland in Southeast Asia.”
Tonle Sap’s seasonally-flooded grasslands are home to 11 threatened bird species and provides a vital fishing, grazing, and traditional rice farming resource for 1.1 million people.
The area is “hugely important to both biodiversity and the livelihoods of some of the world’s poorest communities. Our research shows that these grasslands are disappearing at an alarming rate,” Packman said.
INTENSIVE FARMING A MAJOR CAUSE
The research, published Monday in the journal Conservation Biology, “quantifies for the first time the area’s catastrophic loss of tropical flooded grassland,” said the statement.
Researchers compared aerial photographs taken in 2005 with land cover maps from 1995 and 1996. They also used ground surveys.
They found grassland in the southeast of Tonle Sap declined from 923 square kilometres to 751 square kilometres between 2005 and 2009.
“Almost all of this loss was attributable to either intensive rice cultivation, which had risen by 666 per cent during that period, or associated newly constructed reservoirs,” the university said.
Intensive commercial rice production by private companies - which involves the construction of huge irrigation channels and reservoirs - is denying local communities access to these wetlands on which their livelihoods depend, said Packman.
It is also destroying the habitat for threatened wildlife, she added.
Traditional, low-intensive agricultural practices such as burning and cattle-grazing help to maintain the grasslands and prevent scrubland from invading, Packman said.