In a document recently sent to the Dong Nai People's Committee, the UNESCO office in Vietnam has advised against construction of the Ma Da Bridge that would connect the provinces of Dong Nai and Binh Phuoc as well as a national highway running through the core area of the Dong Nai Biosphere Reserve.
The office said these constructions would "cause serious impacts to the core area of Dong Nai biosphere reserve by fragmentation of ecosystems leading to a loss of continuity.
"The disrupted linkage of biodiversity corridors will affect the habitat of rare and precious animals and shall cause death of wildlife due to vehicle traffic on the road. This will also result in pollution of the land, water and air induced by the road construction itself and other effects due to increased human activities.
"These impacts will lead to environmental degradation, habitat and biodiversity loss and failure to meet the criteria and functions of a core area of a biosphere reserve."
The UNESCO document also said that construction of the Ma Da Bridge and the highway would not be in compliance with Vietnam's objective of forest protection and biodiversity conservation as stated in national laws.
Binh Phuoc had proposed construction of the Ma Da Bridge as well as the upgrade of an existing provincial road into the 13C National Highway to improve regional connectivity.
In response, Dong Nai has asked for adjustments to the plan, expressing concern that the constructions would encroach on and impact its biosphere reserve negatively.
The Dong Nai Culture-Nature Reserve, the core area of the Dong Nai Biosphere Reserve, spans 100,000 hectares and is part of the Truong Son ecosystem. It was named a world biosphere reserve by UNESCO in 2011.
Dong Nai has the largest forest coverage in southeast Vietnam - 169,000 hectares.
Of nearly 8,000 readers who'd responded to a VnExpress survey as of Tuesday evening, 83 percent disapproved of the highway and only 11 percent supported it.