Tree Decay Fungi Chelsi Abbott, MSc The Davey Tree Expert Company
Overview Dangers in Tree Care Industry What are fungi? Why wood decay fungi are important Different groups Specific types of decay & wood decay fungi
Why the Concern? 153 tree care related incidents in 2016 (TCIA) Tree Failure can Harm: People Utility Lines Buildings Vehicles
Fungi Eukaryotic Non-photosynthetic Decompose and absorb organic matter Mushrooms, mold, mildews, rusts etc.
Fungi Beneficial fungi Damaging fungi Crucial to the life cycle of the forest
Three components of Disease 1. Host 3. Environmental conditions 2. Pathogen
Disease Triangle Pathogen Disease Host Environment
Wood Decay Fungi Two main groups: Basidiomycetes: Most common group of fungi for wood decay. They have mushrooms/conks as fruiting bodies Ascomycetes: Second most common group of fungi, with only a few wood rotter's. Small, irregular fruiting bodies
Signs vs. Symptoms A sign is physical evidence of a causal agent Mushroom Spores A symptom is the plants reaction/expression to the infection Chlorosis Leaf spot Death of tissue
Tree Decay Fungi: Mushroom and conks are obvious sign Some trees do not show above ground symptoms Significantly affect the health and structural integrity of the tree Create hazardous trees- our goal is to protect people and property
Just because you don t see doesn t mean it s not there!
Things to look for: Fungal fruiting bodies: Conks, mushrooms, etc. Canopy decline - if canopy is declining it could be a problem from below Remember! A full canopy does not mean structurally sound!
Symptoms associated with wood rots Crown dieback Leaf chlorosis and necrosis Wood rot Bark peeling away Discolouration of bark Eventual death
3 Types of Wood Decay White rot Most common decay fungi - hardwoods Leave behind white residue Brown rot More frequently found on conifers Leave behind brown residue Soft rot Not visibly different than brown or white rot in living trees
Types of Wood Decay White rot: Leaves a white or bleached appearance to wood Wood feels moist, soft and spongy Degrade lignin (constituent of cell walls) & erode cellulose Significant strength loss only in more advanced stages of decay Example: Armillaria spp.
Types of Wood Decay Brown Rot: More frequently found in conifers than hardwoods Brown, brittle lignin Decays cellulose and hemicellulose Significant amount of strength loss in initial stages of decay Example: Chicken of the Woods
Types of Wood Decay Soft Rot: Attacks cellulose Attacks links between cell walls and lignin Loss in wood structural quality Example: Kretzschmaria deusta
How Do Wood Rots Gain Entry? Stressed trees Construction damage Soil compaction Mechanical damage Insect/animal damage
Important Wood Decay Fungi Armillaria Spp. Ganoderma Spp.- Artist s conk & Varnish conk Laetiporus sulphureus - Chicken of the woods Inonotus dryadeus Xylaria polymorpha - Dead Man s Fingers Kretzschmaria deusta
Armillaria Root Rot Hosts: Many deciduous trees and conifers Also called: Shoe-string rot and Honey mushrooms Multiple species Infects stressed trees through wounds Can infect roots via rhizomorphs Aggressive
3 Signs of Armillaria
Not to be confused with Velvet shank www.gallowaywildfoods.com Jack o lantern
Ganoderma applanatum Hosts: Most hardwoods, Maples, Oaks, etc. Also known as Artist s conk Perennial conk Infect via wounds Decay can extend 1-2ft above and below conk White rot Aggressive
Ganoderma applanatum
Ganoderma applanatum- Artist s Conk G. Jones
Ganoderma lucidum Hosts: Most hardwoods, honey locust, Maples, oaks Also known as Varnish Conk Annual conk Kills cambial tissue of roots White rot Moderately aggressive
Ganoderma lucidum
Chicken of the Woods (Laetiporus sulphureus) Hosts: Most hardwoods, oaks, black cherry, etc. Choice edible Fruiting body emerges from summer to fall Brown rot Causes extensive decay
Chicken of the woods
Hen of the woods Hosts: Hardwoods, predominately oaks Choice edible Fruiting body emerges from September to October White rot Weak pathogen Theforagerpress.com
Inonotus dryadeus Hosts: Hardwoods, Oaks, etc. Also known as weeping conk Annual but persistent Slow progressing white rot Excessive decay could mean trees are at risk for windthrow Found at crown (close to ground) or on roots
Inonotus dryadeus
Dead Man s Fingers (Xylaria polymorpha) Hosts: Hardwoods including Maples and beech Black finger-like structures (stomata) appear in spring White rot of base and roots Can kill cambium Only attack stressed trees
Dead Man s Fingers
General Wood Rot Management No management available once infected Destroy fungal fruiting bodies Avoid wounding the tree General plant health care
Things to take home Always ask if you re not sure Presence of a conk is (usually) a bad sign Just because there isn t a fruiting body, doesn t mean there isn t decay