hlp 2009 12 prsnttn infosessionpreliminaryevidenceofmixedseverityfireregimesineastslopesofrockymount
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http://foothillsri.ca/sites/default/files/null/HLP_2009_12_Prsnttn_InfoSessionPreliminaryEvidenceofMixedSeverityFireRegimesinEastSlopesofRockyMountains.pdfTRANSCRIPT
Preliminary Evidence of
Mixed‐Severity Fire Regimes in
the East Slopes of the Rocky Mountains
Mariano Amoroso, Lori Daniels, Mohammad Bataineh,
David Andison, Chris Stockdale
Background
• High‐severity, stand‐replacing fires:
– eliminate almost all vegetation
– even‐aged stands
– relatively distinct boundaries
• Low‐severity, stand maintaining fires:
– kill a small proportion of canopy trees
– uneven‐aged stands with trees with multiple fire scars
– indistinctive boundaries
• Mixed‐severity fire regimes include:
– high‐severity, stand‐replacing fires, and
– low‐ to moderate‐severity, stand‐maintaining fires at stand and landscape scales
• Structurally diverse vegetation patterns and complex dynamics
Background
Rationale
• High‐severity fires have been considered the dominant type in the Rocky Mountains of western Canada
• New evidence suggests low‐ and mixed‐severity fires have had a significant influence on historic forest structures and dynamics in the Canadian Rocky Mountains
Objective
To detect mixed‐severity fires and
reconstruct fire frequency and
their effects on forest structure and dynamics
in the Berland watershed
Site selection
Sampling
Mixed approach
• 1‐ha area circular plot (fire‐scarred trees, snags and logs)– fire scars: number per hectare, charcoal
– samples of 10+ trees with fire scars
• Plot list sampling (stand composition and structure)– 15 canopy and 15 subcanopy trees: species, DBH
– tree cores (age and growth history)
Results
Fire evidence per Ha.223
30
178
100
198
132
35
111 5
12 6
83
9 1220
85
107
HF1 HF2 HF3 HF4 HF5 HF6
Trees with fire scars Trees with > 1 fire scar Fire scars with charcoal
Fire scars
Fire scars
45 cm
8 cm
7 cm
Fire history
35 yrs
40 yrs
44 yrs
(167 yrs)
67 yrs
62 yrs
1886 1915 1956
1716 1756 1881 1915
1820 1889 1908
1719 1886
1711 1778 1834 1906
1811 1889 1934
Median Fire Interval
Fire intervals
0
1
2
3
1‐10
11‐20
21‐30
31‐40
41‐50
51‐60
61‐70
71‐80
81‐90
91‐100
101‐110
111‐120
121‐130
131‐140
141‐150
151‐160
161‐170
171‐180
Frequency
Fire Interval (years)
1711177818341906
1886
19561915
1881
17161756
182018891908
17191886
181118891934
1915
0
5
10
1710 1760 1810 1860 1910 1960 2010
Frequency
Establishment
HF1Sb
Sw
Pl
18861915 1956
5 cm
1915FIRE
1956FIRE
0
5
10
1710 1760 1810 1860 1910 1960 2010
Frequency
Establishment
HF2Sw
Pl 18811716 1756 1915
1716FIRE
0
5
10
1710 1760 1810 1860 1910 1960 2010
Frequency
Establishment
HF3Sw
Pl 18201889 1915
0
5
10
1710 1760 1810 1860 1910 1960 2010
Frequency
Establishment
HF4Sb
Pl17191886
0
5
10
1710 1760 1810 1860 1910 1960 2010
Frequency
Establishment
HF5Fb
Sb
Sw
Pl
17111778 19061834
0
5
10
1710 1760 1810 1860 1910 1960 2010
Frequency
Establishment
HF6Sb
Sw
Pl
18111889 1934
Summary
Evidence of low‐ to moderate‐intensity fires
Fire intervals 19‐167 years
Mixed‐severity fire regimes
Uneven‐ aged stand structures
What do we do next?
Is this pattern common to the rest of the
landscape?
What is the extent? What is the fire interval?
Implications for management at the stand
and landscape level?
Acknowledgements
• This research was a collaboration between the Foothills ResearchInstitute Natural Disturbance Program, Hinton Wood Products ‐West Fraser Mills Ltd. and the Tree‐Ring Lab at the University of British Columbia
• Rick Bonar for helping with the site selection, John Stadt and Nicole Barrett for their help in the field, and Raphael Chavardesand Julia Maddison for their assistance in the lab
• Funding was provided by the Foothills Research Institute NaturalDisturbance Program, West Fraser Mills and MITACS
Stand Structure
Stand Structure
Stand Composition
Site DensityComposition (BA%)
AgePl Sw Sb Fb
1 979 0.92 0.01 0.07 0 121
2 1932 0.63 0.37 0 0 121
3 2341 0.78 0.22 0 0 189
4 517 0.87 0 0.13 0 290
5 778 0.72 0.24 0.03 0.01 298
6 643 0.87 0.02 0.11 0 198
Site selection
• Stand stratification (AVI and fire history maps)
Not been logged or burned by high‐severity fire
during the 20th century
Lodgepole pine and/or Douglas‐fir
• Final selection: 6 sites with the most evidence of fire
were selected for historical reconstruction