The role of Ontario protected areas
in beech bark disease research
John McLaughlin
Ontario Forest Research Institute
Sault Ste. Marie, Ontario
Richard Wilson Forest Health & Silviculture Section
OMNR, Sault Ste. Marie, Ontario
Active Living Centre
Huntsville, ON
April 18, 2013
Putting Conservation
Science into Practice
Beech Bark Disease
What is it?
An invasive disease of beech trees
associated with two non-native causal
agents:
beech scale (Cryptococcus fagisuga)
&
Neonectria faginata
Origin and History
introduced from Europe to the Halifax area
~1890 on European Be seedlings
by 1930s tree mortality from BBD was
observed in the Maritimes and Maine
confirmed in Quebec - 1965
first report of tree mortality in Ontario in 1981
at a site north of Toronto. Scale and cankers
observed, but fungal pathogen not confirmed.
Epidemiology
(infection & spread)
The infection process – beech scale feeding
Scale feeding alters the outer bark
making it receptive for infection by
N. faginata.
Scale population builds rapidly as each adult scale
lays 4-7 unfertilized eggs (parthenogenesis). Tiny
“crawlers” emerge, find a safe niche in the bark,
moult and begin to feed.
Epidemiology
(infection & spread)
The infection process – fungal infection
In late summer or fall bright
red fruiting bodies erupt
from colonized bark tissue
and release infective
ascospores.
The pathogen infects the
bark at scale feeding
sites and grows inwards
towards the cambium,
causing bark cankers.
Epidemiology
(infection & spread)
Spread (natural)
tiny crawler stage can move from tree
to tree on wind currents;
on birds, insects, mammals?
spores dispersed by wind
Spread (assisted)
on firewood & logs
The infection process – spread
Stages of Spread
The Advancing Front
…is characterized by…
arrival and colonization of trees by scale
alone
Starting with very few scale,
the populations can
increase exponentially
through parthenogenetic
asexual reproduction to…
…number in the millions on
a single tree.
Stages of Spread
The Killing Front
…is characterized by…
very high level of scale infestation;
abundant Neonectria infection and canker
development;
mature tree mortality >50%.
BBD Impact at N Ril Lake Rd Site
BBD Impact at N Ril Lake Rd Site
Stages of Spread
The Aftermath Zone
…is characterized by…
lower scale populations;
residual, defective and declining trees;
some disease-tolerant trees with superficial
cankers
a few fully resistant trees.
Current Collaborative BBD
Research in Protected Areas
Network of research plots studying the dynamics
of development of BBD
Rise and fall of scale infestation
Arrival and spread of the disease
Impacts on health of beech
Impacts on other species (proposed…research
partners?)
Current Collaborative BBD
Research in Protected Areas
Firewood study Trees felled, bucked, split and stacked in each
of four seasons
Viability of mature scale, crawlers and pathogen
monitored as wood dries
Life cycle of scale insect followed throughout
the year
Current Collaborative BBD
Research in Protected Areas
Assessing Hazard Trees
“Beech snap” - a Parks Concern
Beech snap & campers
don’t mix!
Not Yet Included…
Carolinian remnant forests
Jackson-Gunn Old Growth Forest – heavy scale!
Backus Woods – scale has arrived
Sinclair’s Bush – soon?
Protected Areas Collaborators
Ausable Bayfield Conservation Authority
Catfish Creek Conservation Authority
Credit Valley Conservation Authority
Grey Sauble Conservation Authority
Upper Thames River Conservation Authority
Ontario Parks
• Killbear Provincial Park
• Arrowhead Provincial Park
• Kawartha Highlands Provincial Park
• Silent Lake Provincial Park
• Awenda Provincial Park