While it certainly wouldn't hurt to get the assessment of a certified arborist, it may not be necessary just yet. (Nor would they be able to intervene much if the tree is ailing, though in that case a diagnosis would be useful so the same stress factors that impacted this tree don't impact another.) Tree decline often takes years to manifest and can be a very gradual process, though it can depend on the specific factors causing the tree stress coupled with its degree of vulnerability to those stresses. If the mushrooms appear with greater frequency as we move into autumn (especially when we get more regular rains and hurricane remnants this time of year), then an arborist consult would be prudent.

Healthy trees can occasionally lose roots to dieback, since they are capable of re-growing replacements. A wide array of wood-decay fungi produce prominent mushrooms, and since the roots of a mature tree extend well past its canopy edges, they can appear far from its trunk. Some fungi are opportunistically active pathogens in addition to decaying old wood, but others solely use the nutrients in already-dead tissues, be they wood or those of herbaceous (non-woody) perennial vegetation. The mushrooms appearing far from the tree could be utilizing either dead wood or dead herbaceous growth, but those at the trunk's base strongly suggest they are consuming wood, dead or otherwise. (Wood at the center of a trunk and major branches is naturally dead; the living wood contributing to growth is only a relatively thin layer just underneath the bark.)

Mushroom identification is very difficult as many species look superficially alike, and key differentiating details are not easy to capture in photos or without a microscope. Regardless of type, there is nothing that can be done to eliminate them, though you can pluck and dispose of any visible if you are concerned a child or pet would try to eat them. The body of the fungus itself is unseen below ground and will re-develop more mushrooms (akin to the blooms on a plant) as conditions allow - usually after wet weather.

Since Norway Maples (like variety 'Crimson King') are non-native and not well-suited to our warm climate, we'd recommend starting the process of considering a suitable replacement. A native tree species would be ideal (especially an oak, for high wildlife value), but even a non-invasive non-native species would be an ecological improvement over the riskier Norway Maple. Your tree's currently dense canopy and apparent good growth are encouraging signs, but not always a reliable indicator of long-term vitality, so monitor it for changes. We can't predict how long a hypothetically infected tree would survive, but an arborist making an assessment in person would have more informed input to generate an educated guess.

Miri

Mira,

Thanks very much for the comprehensive and quick response.  I was reading about the honey fungus and  so wanted to check to see if the mushroom pictures I took today could be used to determine if that’s the type found around the tree.

We will monitor the health and any reoccurrences and seek a arborist’s opinion as necessary.

Regards,

Dave Sharlip

You're welcome.