Around half of Cambodia's tropical flooded grasslands have been lost in just 10 years according to new research from the University of East Anglia.
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| Tonle Sap, Cambodia |
The seasonally flooded grasslands around the Tonle Sap, Southeast Asia's largest freshwater lake, are of great importance for biodiversity. It is a refuge for 11 globally-threatened bird species. They are also a vital fishing, grazing, and traditional rice farming resource for around 1.1 million people.
Research published today in the journal Conservation Biology quantifies for the first time the area's catastrophic loss of tropical flooded grassland.
The grassland area spanned 3349 km² in 1995, but by 2005 it had been reduced to just 1817 km² -- a loss of 46 percent.
Despite conservation efforts in some areas, it has continued to shrink rapidly since, with a further 19 percent lost in four years (2005-2009) from the key remaining grassland area in the southeast of the Tonle Sap floodplain.
Factors include intensive commercial rice farming with construction of irrigation channels, which is often illegal. Some areas have also been lost to scrubland where traditional, low-intensity agricultural activity has been abandoned.
The research has been led by Dr Charlotte Packman from UEA's school of Environmental Sciences, in collaboration with the Wildlife Conservation Society Cambodia Program and BirdLife International. It was funded by the Critical Ecosystem Partnership Fund.
Dr Packman said: "Tropical and flooded grasslands are among the most threatened ecosystems globally. The area around the Tonle Sap lake is the largest remaining tropical flooded grassland in Southeast Asia. It 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.
"These unique grasslands are home to many threatened birds including by far the largest remaining population of the critically endangered Bengal florican -- the world's rarest bustard. This bird has experienced a dramatic population decline of 44 percent in seven years due to the destruction of its grassland habitat. Other birds under threat in this area include sarus cranes, storks, ibises and eagles.
"Rural communities have been left vulnerable to land-grabbing and privatization of communal grasslands. Traditional, low-intensity use of the grasslands by these communities, such as burning and cattle-grazing, help to maintain the grasslands and prevent scrubland from invading.
"Intensive commercial rice production by private companies, involving the construction of huge channels and reservoirs for irrigation, is denying local communities access to the grasslands on which their livelihoods depend and destroying a very important habitat for threatened wildlife. More
