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PhD Project Proposal:Effects of Simulated Mountain

Pine Beetle Attack on Vegetation and Below-Ground Attributes in Lodgepole Pine Forests of the

Western Alberta Foothills

Anne McIntosh

Macdonald Lab Lunch

May 7, 20082

What We Won’t Talk About Today(Pablo Pina’s PhD Project)

This project also seeks to determine initial effects of variable intensity of simulated MPB on stand water balance/hydrology

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Outline

• Introduction

• Objectives

• Methods

• Preliminary Results

• Discussion

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Mountain Pine Beetle (MPB)

Dendroctonus ponderosae

• Native bark beetle of western North America pine forests

• “Most damaging biotic disturbance agent in mature lodgepole pine in western Canada”

• The current BC outbreak is order of magnitude > in area and severity than all previous recorded

• Highly evolved mutualistic relationship withophiostomoid “blue stain” fungi

• Kills trees by girdling them – mass attack

MPB Life Cycle

a.Galleries in phloem

b. Eggs ingalleryc. Mature larvad. Pupae. Teneral/new

adultsf. mature adult 6

MPB as a Disturbance Agent

• Larger & older trees selectively killed – but remain standing (vs logging) � needles can remain 3-5 yrs+

• Understory & soil layers not directly affected (vs logging or fire)

• Return of nonvolatile nutrients to the soil & response of vegetation production are slower (vs stand-replacing fire)

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Lodgepole Pine(Pinus contorta var. latifolia)

• Fire-dependent pioneer species (*serotinous cones)

• Fire suppression changes trajectory

• In Alberta, pine represents ~ 41% of coniferous forests (7x106 ha)

MPB + PICO =From Green to Red…

• The majority of pine in Alberta islodgepole pine and jack pine (P.banksiana Lamb.)

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MPB Climate Change

Implications Are Big

(Kurz et al. 2008)

• BC cumulative impact 2000–2020 = 270 Mt C released (~36-g-C/m2/yr over 374,000 km2)

• Worst yr � impacts from MPB ~75% of mean annual direct forest fire emissions from all of Canada 1959–1999

• From sink � large net C source

Next Stop: Alberta

• MPB research has 1°focused on BC, > history of epidemics

• Former climatically hostile environments will become climatically benign, allowing MPB to significantly expand its range

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MPB Expansion:Jack Pine (Pinus banksiana)

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Native � Invasive

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Outline

• Introduction

• Objectives

• Methods

• Preliminary Results

• Discussion

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Objective 1 - Overstory

• Characterize the overstory forest structure for a set of mature lodgepolepine stands in the western Alberta foothills before, and 1 & 2 yrs after 4 levels of simulated MPB kill and/or forest management

– Baseline data for other aspects of the study

– Insight into standing above-ground C pools

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Objective 2 - Understory

• Quantify differences in the understory plant community composition before, and 1 & 2 yrs after 4 levels of simulated MPB kill and/or forest management in lodgepole pine forests in the western Alberta foothills

– Seedlings/Saplings (pine, spruce, balsam)

– Vascular plants (shrubs, forbs, graminoids)

– Non-vascular plants (bryophytes, lichens)

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Objective 2 - Hypothesis

As tree mortality increases there will be an increase in:– Vascular plant cover

– Plant diversity will peak with medium-level of disturbance (increased stand heterogeneity – more niches)

– Growth of seedlings/saplings (advance regeneration) present – but limited change in overall seedling/sapling abundance b/c of serotiny

Release from competition with trees for water, nutrients, & light* (likely not much change in the light over the duration of this study except salvage harvest– that will follow when needles drop)

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Objective 2a

• Examine the regeneration potential of these stands

• Investigate micro-site and neighborhood characteristics of advanced regeneration

• ?Cones

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Objective 2a - Hypothesis

There are more light, nutrients, and moisture available at safe micro-siteswhere seedlings/ saplings are developing, than other microsites in the stand

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Objective 2b - DWD

• Quantify the downed woody debris (DWD)

• Hypothesis: There will be an increase in DWD from fallen overstory mortality

– provide insight into standing above-ground C pools and susceptibility to fire 20

Objective 3 – Below-Ground

• Quantify differences in below-ground attributes before, and 1 & 2 yrs after 4 levels of simulated MPB kill and/or forest management in lodgepole pine forests in the western Alberta foothills– Microbial biochemical activity (community-

level-physiological profiling (CLPP))

– Nutrient availability

– Soil characteristics – moisture, temperature

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Objective 3 - Hypothesis

With increasing tree mortality there will be a change in:

– Microbial biochemical activity

– Nutrient availability

– Soil moisture

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Outline

• Introduction

• Objectives

• Methods

• Preliminary Results

• Discussion

Foothills

Montane / Alpine

Mixedwood

Parkland

Boreal

Boreal – Canadian Shield Study Area

MPB Aerial Survey Sites

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STUDY AREA

• Lodgepole pine

• ~ 100-110 yrs (‘mature’)

• Medium site index

• Sandy soils

• Mid-elevation

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Experimental Treatments

• Control (untreated),

• Simulated MPB attack (50% overstory kill)

• Simulated MPB attack (100% overstory kill)

• Clearcut - harvested to simulate “salvage logging” management

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Repeated Measures Study

• Three growing seasons

– 2008

– 2009 (“1 yr post-kill”)

– 2010 (“2 yr post-kill”)

*Trees will be killed in late spring 2009 using Triclopyr herbicide to simulate MPB kill

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NRH Block Meteorological Towers

• Each of 4 NRH plots has tower - data continuously recorded.

• Equipment on the tower includes:– Radiometer

– Wind direction

– Wind speed

– Relative humidity

– Temperature

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Three Vegetation

Blocks

North Ridge Hydro (NRH)

Horse Train Loop (HTL)

Power Shack Hill (PSH)

Note: There is now a large clearcut East of NRH block

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Plot DesignMain Plots = 120 x 180 m (2.2 ha) 4 treatments (below) x 2.2 ha = 8.8 ha total

Stand water balance subplot (80 x 80 m; 0.64 ha)Vegetation subplot (80 x 60 m; 0.48 ha)

Control (undisturbed) 50% MPB kill 100% MPB kill Salvage logged (harvested) plot- no trees left standing

* 1 tree height (20m) exterior treated buffer between measurement plots & adjacent stand in all plots

Additional replicated vegetation plots = 120 x 100 m (1.2 ha ea) 4 treatments (below) x 2 replicates = 9.6 ha total

Control (undisturbed) 50% MPB kill 100% MPB kill Salvage logged (harvested) plot- no trees left standing

Study duration 3 yrs (1 yr pre-treatment, 2 yr. post-treatment)

- no trees left standing

Vegetation subplot (80 x 60 m; 0.48 ha)

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Vegetation Plots (0.48 ha)

80-m

60-m

10-m x 10-m

1-m x 1-m understory, LAI-

2000, soil moisture, temp

5 8-m radius (0.02 ha) tree

plots, hemispherical

photopoints

4-m radius, shrubs

Seedling/sapling neighborhood plots

19.8-m

woody debris

transects

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Methods – Objective 1: Overstory

• Tree plots (~8-m fixed radius plots – O.02 ha) (?5/plot)– Species

– Live status

– Dbh

– Ht

– ?Vigor (crown)

– ?Stem mapped

– ?Tagged – follow change

including falling

• ?Basal area sweeps (BAF4)

• Hemispherical Photography

• Leaf Area Index

– Crown radii (live)

– Decay class (dead)

– 2 perpendicular increment cores ?subset

• age

• radial growth

• Sapwood thickness (translucence, on-site – used to scale canopy leaf area and transpiration )

Hemispherical Photography

Photo points revisited after leaf out each year

Indirect Site Factor (ISF) to capture changes in cover over time

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Leaf Area Index (m2/m2) LAI-2000

• Rapid, non-destructive measurements of LAI

• Measure at multiple times in the season– Early growing season (June)

– Mid growing season (July)

– Late growing season (August)

• Measure at multiple heights:– At the forest floor layer

– Below the tall shrub layer

– Above the tall shrub layer

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Methods - Objective 2: Understory

– Seedlings/Saplings (pine, spruce, balsam)

– Vascular plants (shrubs, forbs, graminoids)

– Non-vascular plants (bryophytes, lichens)

– Woody debris/fuels

– Data will be collected using PDAs

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Methods – Objective 2: UnderstorySampling Protocol

• Seedlings/sapling - very few on the landscape – neighborhood approach

• ?1-m x 1-m quadrats – low shrubs, forbs, graminoids, non-vascular plants

• 4-m radius plots – tall shrubs

• Line-intercept method – woody debris

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Vegetation Plots (0.48 ha)

80-m

60-m

10-m x 10-m

1-m x 1-m understory, LAI-

2000, soil moisture, temp

5 8-m radius (0.02 ha) tree

plots, hemispherical

photopoints

4-m radius, shrubs

Seedling/sapling neighborhood plots

19.8-m

woody debris

transects

Understory Seedlings/Saplings

Balsam fir Lodgepole pine Spruce

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Methods - Objective 2: Seedlings/saplings – neighborhood approach

• tagged, GPSed

• height

• diameter

• terminal leader growth

• # of living branches for each whorl

• nutrient availability (PRS)

• soil moisture, temp

• light

• free-to-grow competitors (stems within 1.78-m) ht, diameter

• Very little advanced regeneration currently present

• Closed cones suggest that seeds are in large supply, but…

• seed predators

• Damping-off fungi (fungal-caused mortality from germination to just after seedling emergence) that kill seedlings

• it’s not getting warm enough in the absence of fire…

Club-moss (Lycopodium annonitum)bunchberry (Cornus canadensis)

The Understory

Bog cranberry (Vaccinium vitis-idaea), moss Studded leather lichen (Peltigera aphthosa)

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Labrador tea (Ledum groenlandicum) Green alder (Alnus crispa)

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Methods - Objective 2: 1-m x 1-m quadrats

• Species (?Genus or other grouping for non-vascular)

• % cover– Cover classes (e.g. <1, 1–3, 4–10, 11–25, 26–50, 51–75, >75%)

• Plant species

• Bare rock

• Woody debris (?by decay class)

• Litter – needles, cones

• Forest floor depth in 4 corners of the quadrat (cm)

• LAI

• ?hemispherical photos

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Methods - Objective 2: Beyond 1-m x 1-m vascular plants

• In larger area of the plot identify rarespecies not captured by the transects/quadrats

– size (e.g., Kurulok & MacDonald 100-m2 area)

– time

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Methods - Objective 2: 4-m radius tall shrub plots (0.05 ha)

• Species

• % cover– Cover classes

(e.g., <1, 1–3, 4–10, 11–25, 26–50, 51–75, >75%)

(Daubenmire - 0-1, 1-5, 5-25, 25-50, 50-75, 75-95, 95-100%)• Basal diameters of individual woody stems

(e.g., green alder)

Methods – Objective 2b Down Woody Debris/Fuels

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Methods – Objective 2b Down Woody Debris/Fuels

• Brown’s (1971) planar intersect method

• Total # of transects – min. 100 DWD pieces

• Diameter size classes � theoretical amt of time needed to respond to changes in atmospheric moisture (timelag)

• For each 19.8-m transect:

– # pieces 0-0.64 cm (1-h timelag) 0.64-2.54 cm (10-h timelag) from 1.5 to 3.6 m;

– # 2.54-7.62 cm (100-h timelag) diameter fuels tallied from 1.5 to 6.1 m

– fuels > 7.62 cm (1,000-h timelag) tallied from 1.5 to 19.8 m.

• 1,000-h fuels measure: diameter, decay class (1-5)50

Methods – Objective 3: Below-ground

• Microbial biochemical activity –community-level physiological profiling

• Nutrient availability (PRS probes)

• Soil moisture

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Methods – Objective 3: Below-ground

• Microbial biochemical activity –Community-Level Physiological Profiling (CLPP)

Bacteria

Who are

they?

What are they

doing?

Add Soil Sample

Incubate

20°C

Cleavage of chemical substrates due to enzymatic activities releases purple dye that can be quantified spectrophotometrically

Microtiter Plate Assays for Each Sample

31 C-substrates with 3 reps /plate

One sample per growing season

Assess functional diversity of microbes

Methods – Objective 3: CLPP

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CLPP Multivariate Analysis – NMS(e.g., bigleaf maple canopy soil vs ground)

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Methods – Objective 3: Below-groundNutrient Availability – PRS Probes

• - and + ion-exchange resin membranes

• Nutrient sorption phenomena closely resemble plant root surface

• Assesses nutrient supply rates by continuously adsorbing charged ionic species over the burial period

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Nutrient Availability – PRS Probes• Install (+/-) centered at 10 cm

depth in mineral soil

• Install adjacent to seedlings, and at random 1-m

2quadrat

centers

• ?Sampling efficiency – have $ for 30/plot/yr

• Capture growing season in one measurement vs.– Early growing season (June – mid-

July)

– Later growing season (mid-July –September 56

Methods – Objective 3: Below-groundSoil Moisture

• Time-domain-reflectrometry (TDR) long-term measurements in all plots systematically (Kevin Bladon taking lead)

• Spot measurements at each of the 35 1-m

2quadrats

– Recorded at least monthly during the growing season

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Outline

• Introduction

• Objectives

• Methods

• Preliminary Results

• Discussion

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Preliminary Results - Overstory

Basal area at mean plot level ranges from ~30-50 m2/ha

BA vs Block

0

10

20

30

40

50

60

70

HTL NRH PSH

Block

Bas

al

Are

a (

m2/h

a)

BAF BA vs Block

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

HTL NRH PSH

Block

Bas

al

Are

a (

m2/h

a)

Series1

Circular

Plots

BAF4

Prism

Sweeps

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Preliminary Results - Overstory

Mean Basal Area vs Block

0

10

20

30

40

50

60

HTL NRH PSH

Block

Bas

al

Are

a (

m2/h

a)

BAlive

BAdead

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Preliminary Results - Overstory

Mean TPH vs Block

0

500

1000

1500

2000

2500

3000

HTL NRH PSH

Block

TP

H tphlive

tphdead

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Preliminary Results - Overstory

Tree Count (7.5-m radius plot) vs Block

0

10

20

30

40

50

60

HTL NRH PSH

Block

Tre

e C

ou

nt

(>5

cm

db

h)

countlive

countdead

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Preliminary Results – OverstoryMean DBH vs Block

0

5

10

15

20

25

30

HTL NRH PSH

Block

Mean

db

h (

cm

)

dead

live

N=86 111 175 313 47 90

25 cm dbh � shift from beetle sinks to beetle sources (Safranyik et al. 1974)

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Preliminary Results - Overstory

25 cm dbh � shift from beetle sinks to beetle sources (Safranyik et al. 1974)

Mean Basal Area by Block and Treatment

0

10

20

30

40

50

60

100%

kill

50%

kill

co

ntr

ol

salv

age

100%

kill

50%

kill

co

ntr

ol

salv

age

100%

kill

50%

kill

co

ntr

ol

salv

age

HTL HTL HTL HTL NRH NRH NRH NRH PSH PSH PSH PSH

Block and Treatment

Basal

Are

a (

m2

/ha)

dbh<25 cm

dbh>=25 cm

Total

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Preliminary Results –Seedlings/saplings

• In sampling 24 7.5-m radius plots in the three blocks:

– 23 seedling/saplings: 54/ha (0.3 – 1.8 m tall)

– 7 PICO seedling/saplings: 17/ha

* 11 of the spruce seedling/saplings were in a single

plot of HTL

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Preliminary Observations Understory species census

• Species tend to be clumped in patches

• Low diversity of species

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Outline

• Introduction

• Objectives

• Methods

• Preliminary Results

• Discussion

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Discussion

• Methods for understory

– Line intercept vs 1-m x 1-m quadrats

– Cover classes vs absolute estimates

– Litter

– Capturing patchiness of the understory

• Standardization of methods – the ideal scenario!

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Acknowledgements

• NSERC – Canada Graduate Scholarship

• Foothills Model Forest

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Questions?

Species 2

Species 1

Total/Combined

The Line-Intercept Method

Cover = (Understory Distance)*100

(Transect Length)

Species 3