Roleybushcare chairman Ian Colquhoun said ‘marri canker’ was killing trees along Albany, Brookton and South Western highways, and 50 or 60 had died in the Canning River valley along Croyden Road.
He said residents were asking why their own trees were dying.
A marri with the canker grows a fungus under its bark, the bark lifts and black inky matter seeps out.
Wood rots, branches die and eventually the tree dies.
Large marris, also called red gums, are vital habitat for marsupials and birds, including threatened black cockatoos.
A Department of Parks and Wildlife spokeswoman said the Department was aware of the problem and the proposed Forest Management Plan recognised its potential impact when setting State forest logging quotas for the next decade.
She said that stressed trees were more vulnerable to the canker and that declining rainfall might increase stress in natural ecosystems.
She said there were no solutions yet, but the department had partnered with Murdoch University’s Centre of Excellence for Climate Change, Woodland and Forest Health, which had secured a grant to study the problem.
Centre director Giles Hardy said ‘disturbed’ populations, along highways and those remaining on farmland, were the worst hit.
‘A lot of the trees on South Western Highway will disappear in five to 10 years ‘