Mountain Pine BeetleNatural Disaster

orNatural Consequence?

Presentation Overview

Meet the Mountain Pine Beetle (MPB) Importance of Lodgepole Pine in BC Life Cycle of the bug Green – Red – Gray Attack Population Dynamics Pine – Beetle – Fire Ecology Management Tactics

Meet the MPB

MPB - a small beetle, the size of a grain of rice Range western N.A. (and is now expanding) MPB is an important part of the ecosystem

but it can have dramatic effects Preferred host is lodgepole pine

Importance of Lodgepole Pine in BC BC – has a vast amount of lodgepole pine Some figures:

95 million ha (hectares) – size of BC 60 million ha – forested land 25 million ha – “operational forests” 15 million ha – lodgepole pine forest (~25% of BC’s forest) 13.5 million ha – MPB outbreak

0.2 million ha harvested per year

When the outbreak is finished … 80% of the mature lodgepole pine in BC will be dead

The Outbreak !!

Videos – Ministry of Forests

Cumulative Damage –of current outbreak (from 1999)

After viewing an animation, when you hit the “back” button to return to this presentation you may see a window that asks whether you want to open, save or cancel – select open to return to this slide.

Life Cycle

Typical 4 stages of an insect (with complete metamorphosis):

Adult Egg Larva Pupa

Adult Adults emerge from under

the bark in late summer Need to fly! Female seeks out a suitable

host Larger (older) pine is

preferred (kairomones) Once suitable host is found

… pheromones female-perfume &

males-cologne (=party time!) Mating pair then tunnels into

the cambial zone Inoculate tree with blue

stain fungus “No vacancy” pheromone

once tree is fully occupied

Egg

Parents bore a gallery in the inner bark / cambial region

Gallery is vertical Eggs are laid

alternately along the sides of the gallery

Larva Larva hatch after 1-2

weeks Larva create feeding

tunnels at right angles Inner bark (phloem) is full

of sugar!

Larva overwinter under the bark …

… and continue feeding next spring

Pupa

Pupal stage occurs the following year

Takes about 2-4 weeks to change from a larva to an adult

Life Cycle Review

1) Summer (adults emerge & attack)

2) Over winter (as larva under the bark)

3) Next Spring (larva continue feeding, then pupate)

4) Next Summer (next generation of adults emerge)

Blue Stain Fungus

Ceratocystis spp. (Ophiostoma) Ascomycetes (not a decay fungus) Brought in with the beetle Fungus infects sapwood

Blocks water flow Reduces ability to ‘pitch out’ beetle Retains moisture – good for beetle brood Provides critical nutrition for young adults

Green – Red – Gray Attack

In the year a pine tree is attacked (summer) it remains green

The following year it dies … and turns bright red (but beetles are gone)

After that the foliage turns gray and falls off

Only the green attack trees contain beetles

Susceptible Stands

Susceptibility increases with Age (>80 years are at highest risk) Size (> 25 cm diameter @ breast ht.) Stand composition (higher % of pine, higher risk) Stand density (750 – 1,500 trees/ha) Temperature (lower latitude/elevation, higher risk)

Population Dynamics (4 Stages) 4 Stages:

Endemic – “normal” level – natural thinning agent Incipient – building phase Epidemic – outbreak! – stand replacing agent Collapse (back to endemic)

Factors favoring the outbreak Abundant food source (Pl forest) Drought stress (late ’90’s and 2003) Nice weather for beetle flight (summer) Mild winters

Collapse Factors Lack of food Cold weather

-40C ‘spike’, -30C prolonged, -20C in shoulder season

Reminder

This outbreak is the largest in BC recorded history

After it is done … ~80% of the lodgepole pine will be dead

Reasons for outbreak: Abundance of pine Mild winters Warm summers

MPB – Fire – Lodgepole Pine Fire & the MPB play a complex role in regenerating

lodgepole pine (video) you will have the option to download a video from the Canadian Forest Service (CFS) web site; video is about 5 minutes and VERY good after viewing the video, when you hit the “back” button to return to this presentation, you may see a window that asks whether you want to open,

save or cancel – select open to return to this slide

Low intensity fires act as a thinning agent High intensity fires act as a stand replacing agent We fight fires … so we now have denser (more

stressed) stands AND we have more area with older lodgepole pine than ever before (3 x’s)

Natural fires ~500,000 ha … now ~23,000 ha fire Remember the MPB likes older, stressed lodgepole

pine

Management Options – aimed at MPB Annual Monitoring

(aerial/ground surveys, pheromone traps) Mass Trapping – often with other trtmts

(with pheromones, ineffective in epidemic)

“Go after the beetle” Sanitation Logging – a control tactic

(get the green attack before beetle flight) Spot Treatment – for isolated patches

(insecticide (MSMA) or fall & burn, before flight) Broadcast Fire - mimic nature

(with control measures)

Hauling Restrictions – no hauling during beetle flight (less of an issue in vast epidemic)

Salvage Logging – not a control tactic(get the red/gray attacked trees)

Abandon – for out of control epidemic(just “walk away”)

Protective Insecticide – for urban setting(Carbaryl (Sevin) on trunk before flight)

Pheromone Repellant - verbenone, looks promising (“no vacancy” scent)

Trunk Screen- fiberglass wrapped around trunk – urban setting

Management – Aimed at Pine Log most susceptible

stands first (80+ yr, 25+ cm dbh, etc.)

Create an age class mosaic within a watershed

Utilize a shorter rotation (harvest) age

Promote mixed species (planting & spacing)

Remove pine from mixed stands (during outbreak) (speed succession)

“Beetle proof” pine stands reduce density <500 sph (light/temp, wind, vigour)

Summary

Outbreaks result from an abundant food source and favourable weather (warm summers & mild winters)

In spite of best efforts, outbreaks will occur … they are natural

Best time for action is at the incipient stage Long term management should focus on

lodgepole pine, not the MPB

This presentation was brought to by… the Tree Doctor

That’s all folks!