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