Q.Is Ganoderma root rot contagious to other decediduos trees?
We have several full grown decdidious trees, specifically maple trees, on our property that have been there since our purchase of the property. After reading your article, it is definite that one of those an older maple trees has Ganoderma root rot fungus. My question is this: Is Ganoderma root rot contagious or transferrable to other decediduos trees on our property, or is Ganoderma root rot a “one & done” type fungus or disease? If it is transferrable, how far can the fungus travel?
Thank you for your time, knowledge, and expertise….
Concerned property owner

Here is some more information:
Because gandoderma fungi invade the heartwood primarily, which is inactive tissue, a systemic fungicide is not appropriate for treatment. And also, since the living growing and conductive layers may be intact and functioning, the foliar crown may appear normal. So a big concern is that tree owners sometimes don't take the structural issues seriously because the tree looks okay. But as the woody interior decays the tree may become structurally unsound and prone to failure.
This article from Missouri Botanical Garden recommends removal on the first sign of gandoderma conks. But in my opinion you have an option to employ a consulting arborist who has ability and electronic equipment for an "advanced risk assessment". This is where electronic decay detection systems are used to assess the extent of internal decay vs solid wood around the circumference. Resistograph, Sonic Tomography and Tree Radar are the three primary professional modalities. Some old school arborists like myself use a manual method with a long drill bit for assessment.
Advanced risk assessment doesn't come cheap. But your home and family safety is at stake. And besides the heartbreaker of losing a tree, the cost of tree removal is often pretty hefty, so it may be worth taking the guess work out of determining structural integrity and timing for removal, or not.

Yes the disease can spread to other trees, by spores dispersed from the fungal fruiting bodies (conks). But disease transmission will be less likely to occur if you follow this advise from the article: " Use the best cultural practices to keep your trees as healthy as possible, and avoid damaging trunks and roots when you work in the yard."
Best cultural practices includes good soil and water management, fertilization and appropriate irrigation, not too much or too little.
The article says: "You won’t find anything available in commerce to control this type of disease", which is true as far as controlling an advanced infection. But I recommend proactive, preventive methods and materials like use of the excellent products from Growth Products company, Essential Plus and Companion biological fungicide, combined in a tank mix and applied as a soil drench in a 3 foot radius or more area around the tree trunks.
https://www.domyown.com/essential-plus-p-17626.html
https://www.domyown.com/companion-biological-fungicide-p-17627.html
Hope that helps, Don