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The B.C. Red Tide – ebbs and flows The mountain pine beetle, Dendroctonus ponderosae, in B.C. Lorraine Maclauchlan

Ministry of Forests & Range Southern Interior Region Kamloops, BC


How we got here and what lies ahead The most recent chapter in B.C.’s story of the mountain pine beetle How biology, population dynamics, climate, our landscapes and our forests have accelerated this exercise in forest succession Here today. . . gone tomorrow


The mountain pine beetle is the most destructive insect of mature pine in western North America Normally, MPB populations are small and innocuous, existing in weakened trees or with other insects (e.g. Ips) Periodically, as host & climatic conditions allow, large-scale outbreaks occur MPB attacks all native pines & some exotic species . . . And sometimes make mistakes!


The birth of an outbreak. Initially, very small spots are observed.

# of beetles

Epidemic

CRITICAL PATH

Declining

Incipient Endemic Time


Gradually, these spots expand and coalesce.

# of beetles

Epidemic

Declining

Incipient Endemic Time


# of beetles

Epidemic

Declining

Incipient

Ultimately, these spots die off . . . or an outbreak Endemic ensues with landscape level impacts Time


Community impacts


Juniper Ridge, east of Kamloops 2007


Juniper Ridge, east of Kamloops May 2008


All sizes and ages of lodgepole & Ponderosa pine are now being attacked.


Recreation and urban impacts

Prince George Golf course (2005)


Red Rock Nursery, Prince George - 2006


There are three main phases of a bark beetle's life history:

1.Dispersal

2.Colonization

3.Production


Dispersal Except for a short dispersal flight (24-48 hrs), MPB spend all their one year life under the bark of host pine trees.


Beetles disperse within stands and between stands seeking optimal hosts for colonization. Critical factors: Synchrony of emergence & dispersal; time seeking suitable host. 2005

093G072_350_351

2006


Critical factors: Long range dispersal “challenges� the MPB.

Dispersing beetles must find suitable, susceptible hosts, with enough critical mass to colonize successfully.


Landscapes . . . Barriers to dispersal Climatic limitations Wind/air movements Inhospitable ecosystems


Landscapes . . . Monotonous topography, age classes and species No impediments to dispersal Favourable climate Wind/air movements Suitable ecosystems


Colonization Females initiate attack releasing pheromones that attract males & other females.

Keys to success: Mass Attack!! To avoid overcrowding, MPB then produces an antiaggregation pheromone called verbenone.

• mass attack = many MPB attack a tree in a short time period

• MPB carry a fungus that rapidly stops transpiration and resin production (changing moisture content of tree)


MPB preferentially attacks large, old pine trees (>80 yrs). Seldom over 80% stems in a stand are killed; remaining trees often suppressed, small (resistant??).

Trees respond to attack by trying to “pitch out� beetles.


Colonization: MPB & Ophiostoma Colonization success . . . Host resistance . . . MPB nutrition Spores acquired and disseminated via mycangia & hairs on beetle; inoculated as beetles bore into bark; disrupt transpiration and terminate resin production by trees


MPB making mistakes - attack on spruce


MPB making mistakes attack in young pine (20-50 years)


August - overwinter

Larva

Eggs

Late July-August

Mountain Pine Beetle Life Cycle

Production >80% brood mortality for population decline

Following summer ~June

Pupa Adult


Natural mortality factors Various beetles, flies, wasps and many other organisms are predatory or parasitic on life stages of MPB.

Clerid beetle larva

Woodpeckers feed on MPB


Climatic Influences • Summer temperatures (timing/duration of warm spells) • drought (affects host & insect) • unseasonable temperatures (fall/spring) • cold winters (periods of severe cold, -40°C)


Southern Interior Region


10.0 mill ha red attack mapped in 2007

Peace

Alberta


Annual Red-Attack in B.C.

Millions of Hectares

10,040,182

10 9 8 7 6 5 4 3 2 1 0

9,300,000 8,736,068

7,021,886

4,066,817

1,968,641 785,497 284,041 164,567

1999

2001

2003

2005

2007


78% (vs. 82% last year)


MPB population assessment “r-values” r-value

Population trend

0.0 – 2.5

Decreasing

2.6 – 4.0

Static

>4.0

increasing


R

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ot e

y

n

ke

a

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La M ou

na

m bi

2006

ol u

Ar ro w

2005

Ko

ap

rit t

sw

M er

Sh u

ps

at er

2004

C

O K

rw

m lo o

le a

Ka

C

Average "R" per District

Annual average r-values in Southern Interior B.C. 2004-2007

25 2007

20

15

10

5

0


Annual average r-values in South Central Interior B.C. 2004-2007 20

Average "R" value

16 14 12 10

2004

2005

2006

2007

Young pine

18

8 6 4 2 0 Quesnel

Central Cariboo

Chilcotin

100 Mile House

Headwaters


Average r-values in the Peace 2007-2008 Average Minimum Maximum DBH (cm)

30.1

17.8

37.4

% larval mortality

93.7

85.4

99.7

r-value

1.3

0.1

4.0


Our Predictions for MPB are holding true • The outbreak has peaked in much of the central interior of B.C. • Climate has played a major role in promoting this outbreak but will unlikely cause a premature collapse • The MPB is accelerating in the south portions of B.C. • MPB getting desperate & making mistakes


Tweedsmuir Park - 1999


Sigutlat Lake, Tweedsmuir Park- 2007


Area of MPB in Provincial and National Parks in the Southern Interior Region in 2007 Total number of Parks

305

Number of Parks with MPB

164

Total Provincial Park area

2,849,595 ha

Total National Park area

429,300 ha

Area of MPB in Provincial Parks

345,254 ha

Area of MPB in National Parks

12,501 ha


Lac le Jeune Provincial Park – MPB harvest 2006


Lac le Jeune Provincial Park – harvested again 2007


“Desperate House Bark Beetles wives”” Overwhelmed!!

B.C. MPB

Biological/physical control agents

Natural Balance in Endemic Phase


Area (ha) of mountain pine beetle mapped in BC: 2007 1,600,000

1,000,000 800,000

Southern Interior Region

Northern Interior Region

Coastal Region

1,200,000

600,000 400,000 200,000

M K D PG D PC D VA D JA D N D

D

SS D

M H D C C D Q U D C H

S C D

D

A K D

W D

H

S O D

D

R

M

B D

A

L K D

O C D

FR

0

C

Ha affected by MPB

1,400,000

303,208 ha MPB mapped in Kamloops District 1.183 mill ha mapped in Quesnel District


Area of MPB red attack in the Okanagan Shuswap from 1980-2007 180

153,352 ha mapped in 2007

160

Not yet peaked - increasing

120 100 80 60 40 20

06 20

04 20

02 20

00 20

98 19

96 19

94 19

92 19

90 19

88 19

86 19

84 19

82 19

80

0 19

Ha red attack

140


Okanagan TSA July 11, 2007


350

Peaked & on the decline

250

Kamloops –

303,208 ha in 2007

200 150 100 50

06 20

04 20

02 20

00 20

98

96

19

19

19

94

92 19

90 19

19

88

86 19

84 19

82 19

80

0

19

350 300

200 150 100 50

06 20

04 20

02 20

00 20

98 19

96 19

94 19

92 19

90 19

88 19

86 19

84 19

19

82

0 80

320,060 ha in 2007

Not yet peaked - increasing

250

19

Cascades –

Ha red attack

Ha red attack

300


Bonaparte Lake, Kamloops District July 2007


Hectares affected by MPB 2003-2004 in the Cariboo 1,600,000

2003

2004

2005

2006

2007

1,400,000

Ha affected by MPB

1,200,000 1,000,000 800,000 600,000 400,000 200,000 0

Quesnel

Central Cariboo

Chilcotin


Quesnel 2007 old greys, recent harvest & attack in young stands


Hectares affected by MPB 2003-2004 in 3 northern Districts 1,400,000 2003

2004

2005

2006

2007

Ha affected by MPB

1,200,000 1,000,000

All on the decline 800,000 600,000 400,000 200,000 0 Prince George

Nadina

Mackenzie


The dynamics have changed: mature host depletion; warm climate; and, huge aerial mass movements of MPB.

MPB and young pine.

61


In 2003-2004 localized stands of young pine were identified as having scattered, localized MPB attack. In 2005, 2006 and 2007 significant areas of young pine were affected throughout the range of the outbreak area. The 2006 beetle flight (2007 reds) was particularly aggressive with significant expansions seen in the more southern districts of the province (e.g. Kamloops, 100 Mile House & Cascades).


Mountain pine beetle, Ips pini and other bark beetles are moving into young, and small, pine


Aerial assessments of young pine: 2005-2007 Summary statistics 2005

2006

2007

% stands w MPB

49%

74%

83%

% stands w >50% red atk

4.3%

9%

16.8%

Pine <10 cm diameter are being attacked and mortality will continue for 1-2 years after MPB subsides in surrounding mature stands. Attack densities very high in young pine but brood survival/emergence is low. Therefore little contribution to overall beetle population . . . but enough to have continuing, low levels of attack in affected young stands.


Frequency of MPB attack in stands aerially surveyed 2005-2007 700 2005

2006

2007

Number stands surveyed

600

500 400

Increasing frequency of stands w >50% attack

300

200

100 0 0

5 0 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 0 5 1- 6-1 1-1 6-2 1-2 6-3 1-3 6-4 1-4 6-5 1-5 6-6 1-6 6-7 1-7 6-8 1-8 6-9 1-9 -10 9 96 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1

Percent MPB attack


Ave % MPB attack in attacked stands

50

~50% attack in all stands

100%

40

96%

30

91%

100%

Numbers on bars indicate % stands with attack

20

80% 10 0 20-25

26-30

31-40

41-50

51-55

Stand Age Ave % MPB attack in attacked stands

Average MPB attack (%) in attacked stands

Central Cariboo

40

~35% attack in all stands

96%

30

20

88% 90%

10

50%

71%

0 20-25

26-30

31-40

41-50

51-55

Chilcotin


Kamloops young pine aerial survey results â&#x20AC;&#x201C; 2007 (310 stands assessed)

MPB attack (%) % stands no attack

4.0%

1-5% attack

9.5%

6-10% attack

7.7%

11-20% attack

6.8%

21-50% attack

23.4%

>50% attack

43.7%

Mayson Lake July 12, 2007


Low adjacent pressure but high in-stand attack from massive aerial dispersal of beetles


Quesnel young pine aerial survey results â&#x20AC;&#x201C; 2007 (220 stands assessed)

MPB attack (%) % stands 4.1%

no attack 1% attack 1-5% attack 6-10% attack 11-20% attack 21-50% attack

3.6% 9.1% 10.0% 11.8% 32.3%

>50% attack

32.7% Sept 7, 2007


Cascades young pine aerial survey results â&#x20AC;&#x201C; 2007 (237 stands assessed)

MPB attack (%) % stands no attack

22.8%

1% attack

14.3%

1-5% attack

21.1%

6-10% attack

11.8%

11-20% attack

10.5%

21-50% attack

21.1%

>50% attack

12.7%

July 31, 2007


â&#x20AC;&#x153;Râ&#x20AC;?-values in young & mature pine "R" value (mature) Minimum Golden Merritt Vernon

1.49 0.53 0.03

Maximum 3.74 4.79 3.92

"R" value Mature Young Kamloops - 1 Kamloops - 2 Merritt - Pike Mtn Merritt - Placer Cr

0.35 0.32 0.73 0.80

0.22 0.24 6.53 1.06


• Conventional verbenone application overlaid on an old spacing trial in 2006. • Some (but minimal) protection was observed • Density, stem size, verbenone interaction


2007 Verbenone Flake Trial • 6.7 kg/ha (15% a.i. by weight; 1,000 gm a.i. per ha)

• Successful 2007 MPB attack range: 2.2% to 17.6% in control blocks; and, no attack to 2.1% in treated blocks

Conclusion – verbenone flakes effectively protected young pine under a light-moderate MPB immigration pressure


Young pine stands in Georges Creek, Kamloops District


Implication of mortality in young stands: • Mid-term timber supply issues • Regeneration/rehabilitation of young stands (?) • Wildlife habitat concerns (connectivity) • Fire concerns Model has been developed to estimate future impact to young pine stands.


Resilient landscapes . . . Young stands will remain at risk for 2 to 4 years, to varying degrees in BC, depending upon location and course of outbreak in mature pine resource.


Mixed species

MPB-killed young pine

Deciduous


2005

Polygon/stand specific aerial surveys of young pine have been conducted throughout B.C. for 3 years (2005-2007) A photograph is taken of every stand assessed (not all stands are surveyed each year). The following are some examples.

2006


2006

092P084_873

2007


Resilient landscapes . . .

2006

2007


2006

093F083_1150

2007


2006

093B056_183

2007


Resilient landscapes . . .

2006

093F083_1096

2007


093G015_569

2006

2005

2007


2006

Resilient landscapes . . .

2007


Resilient landscapes . . .

2005

092P066_567

2007


2006

093G016_941

2007


2005

093G072_241

2006


Summary

As beetle pressure declines and large aerial dispersals cease the outbreak will continue within stands not totally overrun.


mature pine

The landscape will be a mosaic of new harvest, regenerating stands, intermediate age classes, standing dead, deciduous species . . . resilience recent harvest for MPB

young pine


Some facts and predictions Approximately 40% of the merchantable pine volume in B.C. has likely already been killed The outbreak is projected to continue to cause significant damage for at least 3 more years It is estimated that >80 million m3 will be killed annually until 2009 At this point, the outbreak may rapidly decline due to the loss of mature pine in which the beetle can build up significant brood There is significant variability in the timing of the peak in the infestation in different areas of B.C.


How will the outbreak decline? Young pine and non-host species (spruce) are acting as “beetle sinks” As the core of the outbreak area “burns out”, the beetle’s long-distance dispersal may decline Without a “critical mass” in long-distance dispersal, high beetle mortality will occur as they encounter unsuitable habitat Areas on the periphery of the outbreak may see less damage than the current model predicts . . . uncertainty about young pine


Thank You!


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