The Amazonian wilderness is at risk of unprecedented damage from an ambitious plan to improve transport, communications and power generation in the region, conservationists warned yesterday.

Development plans have been drawn up to boost trade links between 10 economic hubs on the continent, but threaten to bring "a perfect storm of environmental destruction" to the world's oldest rainforest, according to a report from Conservation International.

Projects to upgrade road and river transport, combined with work to create dams and lay down extensive power and communications cabling, will open up previously inaccessible parts of the rainforest, raising the risk of widespread deforestation that could see the loss of the entire Amazon jungle within 40 years, the environmental group said.

Tim Killeen, a scientist with Conservation International, examined the projects funded under the multinational government-backed Initiative for the Integration of the Regional Infrastructure of South America (IIRSA). He found that the environmental impact of individual projects had often been well assessed, but there had been a failure to look at their collective impact on the region.

Part of the planned improvements will see motorway-style roads built from the Andes, across the Amazon to the Cerrado tropical savannah, linking the Pacific to the Atlantic.

"Failure to foresee the full impact of IIRSA investments, particularly in the context of climate change and global markets, will bring about a combination of forces that could lead to a perfect storm of environmental destruction," Dr Killeen said.

Damage to the ecosystem could have wide-ranging implications, according to the report. The Amazon river basin is the world's largest reserve of fresh water, while the surrounding wilderness regulates the continental climate and rainfall that drives a multimillion pound agricultural industry. Improved transport networks throughout the Amazon will make it easier for inaccessible areas to be logged and burned, disrupting the ecosystems that support native species and indigenous populations, the report concludes.

The group urged the governments backing the IIRSA to take greater account of the ecological impact of the projects and encourage more sustainable use of the region's resources. If Amazonian countries agreed to reduce deforestation rates by 5% a year for 30 years, the saved forest would potentially qualify as a reduction in greenhouse gas emissions and generate more than £3bn a year over the lifetime of the agreement, Dr Killeen said.

Biofuel crops, such as sugar cane, could be planted on the 65m hectares (250,000 square miles) of land that has already been deforested, and fish farms could exploit the natural water reserves, he said.