The fungus attacks the cambium layer which leaves large white section on the bark. High value trees need to be treated immediately once diagnosed.
Lack of nutrients is another reason for urban tree decline. In the forest, the leaves and dead branches fall to the ground. They make a layer of organic matter that decomposes and will fertilize the tree naturally. This is called "nutrient recycling". In the urban environment, this layer is cleaned up and discarded. Trees need to be fertilized annually to make up for this loss of nutrients.

Tree Care and Aboriculture