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Mountain Pine Beetle Natural Disaster or Natural 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. - PowerPoint PPT Presentation
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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!