Mountain Pine Beetle

Question 1

Define Semivoltine

Answer 1

Two year life cycle

Question 2

What are the Five Direct Control Tactics?

Which is most USED?

Answer 2

1) Burning
2) Mechanical Treatments
3) Sanitation Logging
4) Chemical Tactics
5) Semiochemical Tactics

Question 3

Define Epidemiology

Answer 3

The study of the patterns, causes, and effects of health and disease conditions in defined populations

Question 4

Describe Indirect Control?

MPB Management Stratagies

Answer 4

Treatments aimes at increasing stand vigour

Preventative management

Primarily done before the outbreak

Key princibles in application are the consistant use of well planed forestry practices

Question 5

Define univoltinism

Answer 5

One year life cycle

Question 6

What are Four Population Phases

Describe?

Answer 6

1. Endemic - Principly in small DBH trees that are weakened. Interactions with other lower bole beetles is important for MPB establishment an survival
   (Good chance at stopping it)
2. Incipient Epidenmic - Develop when larger diameter host trees can be successfully colonized (host resistance lowers or increase favorable breeding conditions or both)
   Becomes more significantly difficult to stop at this stage
3. Epidemic - Exists at a landscape level.
   Nearly impossible to stop at this stage
4. Post Epidemic - Populations decline due to adverse weather or depletion of host.

Question 7

Describe Direct Control?

MPB Management Stratagies

Answer 7

Treatments aimed at reducing beetle populations.

Reactive Approach

Key princibles are timeliness and thoroghness

Question 8

6 Effects of a Major MPB Outbreak

Answer 8

1. Extensive timber loss (volume:decay/stunted growth. MPB hits tree before its reached merchantable value
   value: more pulp, less saw log)
2. Increased fuel loading
3. Altered successional trajectories
4. Reduced watershed quality
5. Altered wildlife composition
6. Altered recreational values

Question 9

Describe efficient dispersal as a Critical aspect of life history to establishment and survival of IBM

Answer 9

In stand, short range (30m or less), in canopy dispersal

Wide initial dispersal; Out of stand, long range (up to 300km) if carried by extreme, warm convective currents

Question 10

Describe efficient host seletion as a critical aspect of life history for IBM

Answer 10

Efficient host selection:
COLONIZE LARGER STEMS (>20cm DBH);
Tree’s size main determinant of tree’s potential to produce beetles because of increased bark thickness (more bark scales, less breakage) and increased phloem thickness (lay more eggs=bigger brood=higher survival)
COLONIZE OLDER STEMS: the older the tree, more susceptible, older trees less capable to fight off blue stain fungus;
COLONIZE HIGHER DENSITY STANDS: Reduced tree vigor as density increases; MOre favourable microclimate for MPB as density increases; These stands are common due to fire suppression

Question 11

Describe how highly evolved mutualistic relationship with blue stain fungi aids in overcoming host resistance for MPB

Answer 11

• Conflicts with optimum conditions because trees MPB perfers are healthy, blue stain helps to break down those defences
• Blue stain fungi is one of two defences (other is disruption of tree physiology via gallery creation in phloem)
• Blue stain is acquired and disseminated via adult beetle’s exoskeleton, fungal spores inoculated into trees as beetle bores; terminates trees resin defenses by causing dessication and disruption transpiration
• Blue stain fungi also assists MPB by: protecting broods from antagonistic fungi; improving moisture composition of phloem for larvae; providing nutrients to complete development

Question 12

Describe how stage specific development thresholds ensuring synchrony of development in and among growing seasons are a critical part of MPB establishment

Answer 12

• Cold Tolerance:
  largest single source of mortality in MPB;
  Acquired through production and accumlation of glycerol;
  Larvae are the most cold tolerant because they overwinter;
  High amounts of adults survive winter and attack early, but the progeny they produce have little chance to contribute to population fluctuations because their life cycles dont coincide with greater MPB populations (mass attack)

Question 13

Describe the relationship of Temperature to MPB’s life cycle

Answer 13

• life cycle stages delegated by stage specific responses to temperature;
• Emergence and dispersal, host selection and colonization, mating, etc occur late July to mid August;
• Larvae reach 3rd or 4th instar before temps are too cold to halt development, then resume feeding when temps warm in spring
• Complete development and transform to pupae by June
• Pupae are new adults by late June and mid July, need one or two weeks to mature and ready for emergence and dispersal

Question 14

Discuss development rates specific to subpopulations that ensure one year life cycles over a large part of the geographical range

Answer 14

• MPB has evolved regional differences in development rates to adapt;
• Northern populations of MPB develop faster for a given input of temperature than southern populations
• adverse weather conditions won’t prevent outbreaks or reduce populations as long as univoltine life cycles are maintained
• In most northern and high elevation environments, MPB has become semivoltine, but populations aren’t expected to meet epidemic levels because:
  higher mortality
  exposure to natural enemies for longer periods
  reduced colonization success because of reliance on ‘mass attack’

Question 15

How can long term mitigation of large-scale epidemics be achieved?

Answer 15

Through management strategies that reduce Pl susceptibility over the landscape. Direct control not viable at epidemic levels, Indirect management becomes the only option.

Question 16

Lodepole pine fire dynamics and MPB breakouts

Answer 16

• natural fire cycle for Pl in BC is 60 years-coincides with high stand susceptibility to MPB attack
• Intro of fire mgmt has allowed large numbers of fire suppressed stands to enter susceptible age class for MPB
• Result is 3x more susceptible Pl to MPB compared to pre-fire supression

Question 17

Describe Climatic influences as an outbreak dynamic for MPB

Answer 17

• Favorable climate allows MPB to expand into previously unaffected areas
• Warmer temps increase beetle survival during winter and flight periods
• Tree and stand resistance reduced during drought periods
• Combined with fire dynamics, settings are ideal for MPB attack
• Susceptible Pl is transitional phenomena-unlikely large amounts of susceptible pine will be seen again

Question 18

When are direct control tactics useful?

Answer 18

• Only when treated at endemic and possibly incipient epidemic phase
• MPB pops expand too quickly to control after a certain point-not economically feasible

Question 19

3 management principles needed for direct control to have any chance of success:

Answer 19

1. Early Detection
2. Aggressive direct control tactics employed promptly and thoroughly
3. Control programs must be continuous until the desired population level is achieved

As long as the character of the stand remains the same, future outbreaks may be expected whenever tree vigor is seriously reduced (eg:drought). Suppression failed in the past because the three principles weren’t followed.

Question 20

Name the 4 main strategies used to control MPB epidemic in BC:

Answer 20

1. Suppression/prevention: aggresive direct control tactics used to reduce populations to endemic levels
2. Holding: Efforts aimed at keeping population levels at current level, until more resources are available or underlying cuase of infestation subsides
3. Salvage: aggressive options unlikely to succeed so dead timber is recovered while it still holds value
4. Monitor: only realistic and appropriate strategy in inaccessible or inoperable regions and in parks and protected areas

Question 21

What are the two parts preventative mangement AKA indirect control can be broken down to

Answer 21

1. Landscape planning to prevent expansion to epidemic outbreaks
2. Stand management to prevent incipient infestations

Question 22

What makes preventative management vital to have any chance to manage MPB outbreaks

Answer 22

1. Fire suppression has increased area occupied by mature Pl in BC from 2.5 million ha to 8 million+ ha
2. recent warming trends have expanded (and will continue to expand) range of MPB in BC
3. Pl is largest contributor to commercial timber harvest in western Canada
4. Difficulty high when trying to successfully implement direct control strategies when MPB pops exceed endemic levels

Question 23

Three conditions needed for landscape level outbreak to occur:

Answer 23

1. Several years of mild winters and warm, dry summers, leading to small patch incipient infestations
2. Some of the incipient infestations must develop unchecked by weather or mgmt action to the point where high MPB numbers are produced
3. Must be an abundance of susceptible stands on landscape to sustain high beetle populations

Question 24

What’s the basis of long and short term planning for MPB?

Answer 24

Long term planning: requires ranking of pine stands based on relative susceptability

Short term planning: requires ranking of stands for risk of significant loss over the short term

Question 25

Name 5 operational landscape planning strategies for MPB

Answer 25

1. Manage for shorter rotations in susceptible stands(80 years or less if possible)
2. REduce large, bordering parcels of highly susceptible stands
3. Develop access into areas of high susceptibility
4. Consider species conversion where appropriate/possible
5. Manage density in both existing mature and young, developing stands

Question 26

What are the pros and cons of MPB ground surveys?

Answer 26

PROS

• only reliable and realistic method to detect and map green attack
• most reliable source of info regarding responsible damage agent
• possible to accurately estimate attack density
• survey intensity levels can be altered depending on mgmt objectives(EG: walkthroughs:non systematic, looking at levels, location of attack; probes: Systematic, collecting info on stage of attack, %green/red, more detailed)

CONS

• HIgher per ha cost
• data must be processed post field survey to enable further analysis

Question 27

What are the methods, pros and cons of Aerial Surveys for MPB?

Answer 27

METHODS:

• overview sketch mapping
• heli based GPS surveys
• aerial photography(analogue)

PROS:

• lower per ha cost than ground surveys

CONS:

• accuracy is suspect
• attack density difficult to estimate
• data has to be processed post field survey to enable further analysis

Question 28

what are the pros and cons of Remote sensing satellite surveys for MPB

Answer 28

PROS

• lower per ha cost if used on a large scale and for right purpose
• offers high positional accuracy
• effecient integration with forest inventory databases
• provides continuous data
• eliminates interpreter bias

CONS

• costs can be high if required resolution is high
• current technology cant replace accuracy and detail of ground survey

Question 29

what contributes to the reduced value of solid wood products (due to MPB)

Answer 29

• Blue stain fungi: stains timber, limits export. Efforts to market as ‘denim pine’ have minor success so far;
  Drying accelerated which means more splitting and checking;
  doesn’t affect structural soundness of wood but some perception in some markets believe it does;
• Limited shelf life of Pl:
  recovery values decrease with amount of time dead trees are left standing(value reduced to zero after 3 years)
• Fibre volume losses:
  dead stems more susceptible to breakage;
  processing equipment at mills not equipped for delicate handling required;
  spiral checking seriously reduces recovery
• INcreased processing costs:
  harvesting production slowed;
  milling dry wood takes more energy(dull blades)
  kiln drying a challenge(moisture levels inconsistent between green and dry timber)
  additional sorting required
  beetle dust a danger at mills

Question 30

What are potential solid wood opportunities for MPB affected timber

Answer 30

Bioenergy production (Fuel pellets, cogeneration and other alt. energy forms)

• viability depends on economics more than technical ease
• large volumes needed for consumption(secure wood supply)
• anything that couldnt be provided via residual processing not economically worth it

Question 31

What effects does MPB affected timber have on pulp and paper production

Answer 31

• Reduced processing production: blue stain gives higher proportion of pinchips and fines(quality issue), unsuitable for pulp production; Lower kraft pulp yields.
• Lots of unknowns. more research needed.