SPRUCING UP EASTERN CANADIAN MIXEDWOODS:
Do white spruce (Picea glauca)
trees respond to partial cutting?
Jessica Smith, candidate M.Sc. Biology
B.Harvey PhD, A.Koubaa PhD, S.Brais PhD
jessica.smith@uqat.ca, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec Canada
INTRODUCTION
Canadian Boreal Forest
• 90% of forested land in Canada
Canadian Boreal Forest
British
Columbia
Quebec
(Baldwin et al., 2012)
Newfoundland
1
INTRODUCTION
Canadian Boreal Forest
• 90% of forested land in Canada
Canadian
Boreal Forest
Province
of Québec
Region: Abitibi–Témiscamingue
48°14'55.0"N 79°20'11.7"W
Boreal Mixedwood Forest
2
INTRODUCTION
Boreal Mixedwood Forest
• Transitional phase of succession (Bergeron and Harvey, 1997)
• Shade intolerant broadleaf and shade tolerant conifers
Licher
Stone Lane Gardens
trembling aspen
white birch
(Populus tremuloides) (Betula papyrifera)
shade intolerant
Tigner
white spruce
(Picea glauca)
Fewless
black spruce
(Picea mariana)
shade tolerant
Maine Forest Service
balsam fir
(Abies balsamea)
3
INTRODUCTION
Boreal Mixedwood Forest
• Mature aspen: suitable for harvest
• Pre-mature white spruce: has not reached maximum
growth potential
Licher
Stone Lane Gardens
trembling aspen
white birch
(Populus tremuloides) (Betula papyrifera)
shade intolerant
Tigner
white spruce
(Picea glauca)
Fewless
black spruce
(Picea mariana)
shade tolerant
Maine Forest Service
balsam fir
(Abies balsamea)
4
INTRODUCTION
Boreal Mixedwood Forest
• Mature aspen: suitable for harvest
• Pre-mature white spruce: has not reached maximum
growth potential
Licher
Stone Lane Gardens
trembling aspen
white birch
(Populus tremuloides) (Betula papyrifera)
shade intolerant
Tigner
white spruce
(Picea glauca)
Fewless
black spruce
(Picea mariana)
shade tolerant
Maine Forest Service
balsam fir
(Abies balsamea)
4
INTRODUCTION
Why partial cutting?
Ecosystem based management
• Diversify silvicultural strategies
• Emulate natural succession dynamics
• Maintain residual stand with complex
structure and attributes
Industry
• Residual trees show accelerated
radial and volume growth rates
following “release”
(Youngblood, 1991; Yang, 1991; Man and Greenway, 2004;
Grover et al. 2014)
• Larger stems
5
STUDY SITE
Boreal Mixedwood Forest
Rouyn-Noranda, Abitibi–Témiscamingue, Québec, Canada
Pre-treatment species
distribution by basal area
Partial Cutting Treatments: 2002
Control
0% harvested
75% aspen
50% aspen
BA harvested
20% white spruce
65% aspen
BA harvested
3% balsam fir
1% black spruce
1% white birch
100% aspen
BA harvested
6
STUDY SITE
Experimental Units
Control
1
2
3
42.65
40.32
46.91
50%
65%
100%
Initial BA (m2·ha-1)
37.50
44.19
51.08
53%
64%
93%
Aspen removed
25.69
26.20
14.12
Residual BA (m2·ha-1)
37.88
34.40
31.65
52%
74%
100%
25.92
16.82
11.44
38.79
41.30
58.04
52%
61%
99%
22.32
23.49
10.03
7
OBJECTIVE
Evaluate radial and volume growth responses of residual
white spruce trees, 10 years after the implementation of
the partial cutting treatments
HYPOTHESES
1.
Post-treatment radial and volume growth rates will be
higher in intermediate treatments (50% and 65%) than in
the extreme treatment (100%)
2.
Tree social status will influence post-treatment radial
and volume growth rates, with dominant and co-dominant
trees having superior growth rates to suppressed trees
8
METHODS
Experimental Design
1
1
1
2
2
2002
1
2
4 treatments
3 replications
12 Experimental Units
2
2012
2 trees
3 social status
3
3
0%
50%
65%
100%
3
3
Scale 1:10,000
6 Trees/ Experimental Unit
72 Trees
9
METHODS
Sampling and Data Collection
11
10
9
8
7
6
5
4
3
2 (130 cm)
1 (30 cm)
(Chhin et al., 2010)
10
METHODS
Annual Ring Width Measurements
Win Dendro (Regent Instruments)
• annual radial growth rate (mm·year-1)
• 3 radii per disk
• 5 years pre-treatment
• 10 years post-treatment
Stem Analysis
Win Stem (Regent Instruments)
• annual volume growth rate (dm3·year-1)
11
METHODS
Statistical Analysis
Linear mixed effect model
Response Variable
Explanatory Variables
Fixed effects
1. Annual Radial Growth
at 1.3 m (mm·year-1)
treatment intensity
social status
time
time2
mean growth rate 5 years pre-treatment
2. Annual Volume Growth
(dm3·year-1)
treatment intensity : time
treatment intensity : time2
social status : time
social status : time2
Random effects
experimental unit
tree number
12
RESULTS
Annual Radial Growth 1.3 m
A) Suppressed
B) Co-dominant
C) Dominant
13
RESULTS
Annual Radial Growth 1.3 m
A) Suppressed
B) Co-dominant
C) Dominant
In the 100% aspen removal treatment,
average annual radial growth rates at 1.3m were:
23.5% higher for dominant trees
67.7% higher for co-dominant trees
154.3% higher for suppressed trees
as compared to the control treatment over the 10 year post-treatment period
13
RESULTS
Annual Radial Growth 1.3 m
A) Control
C) 65% Aspen BA removal
B) 50% Aspen BA removal
D) 100% Aspen BA removal
14
RESULTS
Annual Volume Growth
A) Suppressed
B) Co-dominant
C) Dominant
15
RESULTS
Annual Volume Growth
A) Suppressed
B) Co-dominant
C) Dominant
In the 100% aspen removal treatment,
average annual volume growth rates were:
7.2% higher for dominant trees
24.1% higher for co-dominant trees
65.6% higher for suppressed trees
as compared to the control treatment over the 10 year post-treatment period
15
RESULTS
Annual Volume Growth
A) Control
B) 50% Aspen BA removal
C) 65% Aspen BA removal
D) 100% Aspen BA removal
16
RESULTS
Validating Hypotheses
1.
Post-treatment radial and volume growth rates will be
higher in intermediate treatments (50% and 65%) than in
the extreme treatment (100%)
2.
Tree social status will influence post-treatment radial
and volume growth rates, with dominant and co-dominant
trees having superior growth rates to suppressed trees
17
RESULTS
Validating Hypotheses
1.
Post-treatment radial and volume growth rates will be
higher in intermediate treatments (50% and 65%) than in
the extreme treatment (100%)
2.
Tree social status will influence post-treatment radial
and volume growth rates, with dominant and co-dominant
trees having superior growth rates to suppressed trees
17
RESULTS
Validating Hypotheses
1.
Post-treatment radial and volume growth rates were
higher in 100% aspen removal treatment
2.
Tree social status will influence post-treatment radial
and volume growth rates, with dominant and co-dominant
trees having superior growth rates to suppressed trees
17
RESULTS
Validating Hypotheses
1.
Post-treatment radial and volume growth rates were
higher in 100% aspen removal treatment
2.
Tree social status will influence post-treatment radial
and volume growth rates, with dominant and co-dominant
trees having superior growth rates to suppressed trees
√
17
CONCLUSIONS
Annual Radial and Volume Growth
1. Effect of partial cutting in 100% aspen removal treatment
2. Treatment effect changes through time following a
quadratic form
• Radial Growth: peaking 6 years post-treatment
• Volume Growth: plateau for suppressed and co-dominant trees,
continuing linearly for dominant trees
3. Treatment effect across time is the same for all social statuses
4. Dominant and co-dominant trees superior to suppressed trees
5. Relative growth increases greatest for suppressed trees, least
for dominant trees, and intermediary for co-dominant trees 18
RECOMMENDATIONS
1. Remove high proportion of dominant, shade intolerant
broadleaf species
2. Monitor regeneration and mortality
Schreiber
Savioja
19
ACKNOWLEDGEMENTS
Arun Bose,
Marc Mazerolle,
Manuella Strukelj,
Igor Drobyshev,
Suzie Rollin,
Fred Coulombe,
Field Crew
Photos
Fewless, Gary. http://www.uwgb.edu/biodiversity/herbarium/gymnosperms/picmar01.htm
Licher, Max. http://swbiodiversity.org/seinet/taxa/index.php?taxon=3892
Maine Forest Service. https://www.maine.gov/dacf/mfs/archive/balsamfirtipblight.htm
Savioja,Jouko.http://www.cbc.ca/news/canada/thunder-bay/appearance-of-dry-dead-trees-alarms-residents-1.1253376
Stone Lane Gardens. http://stonelanegardens.com/shop/betula-papyrifera-paper-birch-or-canoe-birch/
Tigner, Daniel. Canadian Forest Tree Essences. http://www.mnr.gov.on.ca/en/Business/ClimateChange/2
ColumnSubPage/267351.html
References
Baldwin et al. Canadian Regional Team of the Circumboreal Vegetation Map Project. Natural Resources Canada, Canadian Forest Service, Great Lakes
Forestry Centre (2012).
Bergeron Y, Harvey B. Basing silviculture on natural ecosystem dynamics: an approach applied to the southern boreal mixedwood forest of Quebec.
Forest Ecology and Management (1997) 92:235-242
Chhin S et al. Growth–climate relationships vary with height along the stem in lodgepole pine. Tree physiology (2010) 30:335-345
Grover et al. White spruce understory protection: From planning to growth and yield. The Forestry Chronicle (2014) 90:38-43.
Man R, Greenway KJ. Meta-analysis of understory white spruce response to release from overstory aspen. The Forestry Chronicle (2004) 80:694-704.
Yang R. Growth of white spruce following release from aspen competition: 35 year results. The Forestry Chronicle (1991) 67:706-711.
Youngblood AP. Radial growth after a shelterwood seed cut in a mature stand of white spruce in interior Alaska. Canadian Journal of Forest Research
(1991) 21:410-413