An outbreak of laminated root rot at Hunter Park in Langley City has turned out to be worse than expected.
"It is spread throughout the park," Rick Bomhof, director of Engineering, Parks, and Environment told Langley City council Monday.
"All the firs and hemlocks will have to go."
The rot spreads through root-to-root contact between conifers and can remain viable for up to 50 years.
Bomhof said other types of trees in the park will remain, but warned some of those heathy trees might have to come down, too.
That's because isolated trees might become potential hazards during a wind storm without the protection of the fir and hemlock.
"Once all the (infected) trees are removed, we'll have a better idea," Bomhof said.
But the park will not become a "clear-cut" he said.
At the park on Tuesday, freshly cut stumps of apparently healthy trees revealed dark stains in the core, evidence of infection.
In other fallen trees, the infection was more advanced and the interior was rotted out.
Trees that get the fungal pathogen phellinus weirii die from failure to take up water and nutrients because the main roots are decayed.
The rot is one of the leading causes of dead and wind-thrown trees.
Expert foresters recommend removing infected trees and susceptible tree species within a 15-metre radius.
People who have Douglas firs and western hemlock on their properties and have concerns about possible infection are advised by the City to seek professional advice from a local tree company or arborist familiar with the disease as tree symptoms are not consistent.