University of B.C. scientists say they have discovered why a certain type of fungus is killing poplar trees.

The researchers’ study, published this week in the The Proceedings of the National Academy of Sciences, found that the fungus, Mycosphaerella populorum, uses extra genes to produce a toxin that can cause fatal lesions on the leaves, stems and branches of poplar trees.

The extra genes were found through genome sequencing, the mapping of an organism’s DNA, according to the report.

Lead researcher Richard Hamelin, a forestry professor at UBC, says the discovery will help scientists develop better methods to detect the fungus and prevent it from spreading. He says the extra genes could be the result of random events in nature.

The fungus threatens poplar trees in plantations and is mostly found in eastern North America, according to a release from UBC on Wednesday.

It was not widespread in B.C. until an outbreak in 2005 at a poplar plantation in Harrison Mills, a farming community west of Agassiz in the Fraser Valley.

Hamelin says there are ecological concerns the fungus will eventually jump into native poplar trees, specifically black cottonwoods along B.C.’s coast. He adds that the black cottonwoods help improve water quality, provide for wildlife habitat and prevent erosion.