Mushrooms Growing On Your Tree?

Many landscapes in Grand Blanc have mature trees. Throughout their life trees are subjected to attacks and stressors like insects, diseases, construction damage and improper maintenance practices. A lot of damage to trees is away from the trunk of the tree – on leaves or branches. This location can make it easier for a tree to recover. Many trees drop their leaves in the fall and a damaged branch can be pruned off the tree. But what happens when the trunk of the tree is attacked? Fungi, or mushrooms, growing on or near the trunk of the tree could be an indication of a serious problem for a tree – especially a mature landscape tree.

Why do fungi feed on the trees?

It’s all about the sugar. All living things require carbon, hydrogen, and oxygen for fuel and structural building blocks. When we eat carbohydrates, our bodies break the carbohydrate molecule apart and repurpose the carbon, hydrogen, and oxygen it contains into fuel or building materials. Even your automobile runs on carbon, hydrogen, and oxygen in the form of hydrocarbons. Trees are made of carbon, water, and oxygen also, put together into complex molecules to build structural wood. The skeleton of the tree is made up of what’s called cellulose and a binding matrix to that holds the cellulose together, called lignin, which also gives the tree skeleton its strength.

How to fungi feed on trees?

The fungi use enzymes to break these complex molecules apart, rearranging them to build and feed its own structures that resemble long interconnected threads called mycelium. When mature, a basidiomycete fungus completes its life cycle by producing a fruiting body (mushroom) that contains spore releasing structures under the fruiting body. When temperature and humidity are advantageous for reproduction the spores are released into the air. The mushroom is a very small part of the fungi body itself. Picture an apple on a tree as the mushroom and the tree itself as the mycelium.

Can trees defend themselves against fungi?

Yes, trees are well adapted to fight many fungi if they are healthy and have the resources to do so. Bark is its first line of defense. A healthy bark stops the fungi from entering the tree. Damage to the trunk from storms, lawn maintenance equipment, or even unqualified tree workers using spikes to climb a tree are common entry points for decay. Damage to branches during storms, improper pruning cuts and root damage during construction are also entry points for fungi. If the tree is healthy enough it uses a system of compartmentalization to wall off the fungi from moving freely inside the tree.

If you are seeing a mushroom on your tree or growing out of the ground, its more than likely in group of fungi called basidiomycetes.

This group is commonly called (club fungi) as its spores are produced on club-like structures on the mushroom called basidium. Within this group you have Saprophytes, Parasites, and Saprophytic Parasites, and Beneficial fungi. The importance of understanding and identification are paramount to a certified arborist’s assessment of tree health and safety.

Saprophytes

Saprophytic fungi are beneficial as they break down dead plant material like leaves and wood, and cause little to no harm to living plants. They are extremely important to soil nutrient health as well as the global carbon cycle. Saprophytes can enter a tree through a wound and feed on the inside of trunk (heartwood) causing decay but unable to feed on the living structural wood of a tree. It’s not uncommon for a tree to be heavily decayed and hollow but structurally sound. Just like your home is hollow on the inside, it is structurally sound. In many cases this is true for trees as well, and could be determined by a certified arborist trained in tree fungi identification.

Parasitic fungi

These fungi feed on the living parts of the tree, which is the layer behind the bark of the tree called the cambium. This layer is actively moving water and nutrients up the tree to the leaves and moving carbohydrates made during photosynthesis to the roots. It’s a very nutrient dense area for the fungi to attack. Feeding on this area causes structural damage to the tree, decline, and possibly death. It’s also very common for there to be no visual symptoms of a parasitic fungi in the tree like dieback or mushrooms before the tree fails structurally and falls.

Saprophytic parasites

Some fungi are mostly saprophytic, feeding on dead plant structures but can also become parasitic. A potentially dangerous and common fungi (Ganoderma sessile) can cause hazardous conditions by feeding on living cellulose and lignin as well as feeding on dead heartwood. These fungi typically let you know of their existence by the large Polyporus mushrooms growing at the base of the tree.

Beneficial fungi

Mycorrhizae fungi are very beneficial to trees and other plant life. These fungi have a symbiotic relationship with plant roots. They form sheaths around the plant’s fibrous roots, or grow into the roots themselves. They then grow into the soil in search for nutrients the plant needs and have been documented to grow great distances. The fungi then trade these nutrients with the root system for carbohydrates the fungi need. This is a win-win situation for both the fungi and the tree. It’s not uncommon to see mycorrhizal mushrooms sprouting above a tree’s root system, and should be viewed as a good sign for tree health; but not all mycorrhizae produce mushrooms. It is also very common for certified arborists to include these fungi in deep root fertilization mixes as urban soils typically have low populations of mycorrhizae.

What to do if you suspect you have a fungus in your tree?

Consult with a certified arborist in Grand Blanc that is trained in fungi identification, morphology, and potential risks to the health and structural integrity of your tree. Some arborists that service Grand Blanc will have equipment like the Resistograph Decay Detection Tool which can measure the amount of decay in a tree. Just because a tree has a fungus doesn’t mean it needs to be removed. Many options exist to improve tree health and mitigate risk which can result in a saved tree, and many times at a reduced cost compared to tree removal.

Call Owen Tree Service today if you find mushrooms growing on, or around, your trees. The sooner a problem is diagnosed, the better the chances that your tree can be saved.