Is partial cutting a good way to
manage black spruce forest on
hydromorphic soils?
⊷ By Samuel Roy Proulx, ⊷ Yves Bergeron (UQAT), Sylvain Jutras (Université Laval) and Alain Leduc (UQAM)
International Boreal Forest Research Association, Laxenburg, Austria, September 2018
Why is this territory vulnerable to successional paludification? ⊷ The last glaciation⊷ Cold climat⊷ Low decomposition rate⊷ Time between fire events⊷ Traditionnal forest management
• Clear Cut• What about partial cutting?
References: Bergeron et al., 2006; Bergeron et Fenton, 2012; Fenton et al ., 2005; Lafleur et al., 2010; McRae et al. 2001
2Source image: Fenton et Bergeron 2011
Organic soil
Mineral soil
Water table
Clear Cut
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• Regeneration
• Paludification
Partial cutting
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?
? ? ?
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• Interception
• Evapotranspiration
Organic soil
Mineral soil
Water table
Girdling
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• Interception
• Evapotranspiration
Organic soil
Mineral soil
Water table
Objectives
Quantify the water table variations following partial
cutting and girdling treatments.
Study the influence of water table variations on black spruce growth and on
bryophyte communities.
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• The main driving force of the water table one year after partial cutting is the interception of the tree cover.
• The reduction of evapotranspiration will not have a significant effect on the water table one year after the treatment.
• The girdling will isolate the effect of interception and remove the evapotranspiration on the water table.
• The water table variation and the removal of tree cover will have an effect on wood cell deposit of residual black spruce.
Hypothesis
Methodology⊷ Study area• Northwestern Quebec (Abitibi)• Black spruce-feathermoss domain• Clay Belt⊷ Study duration• Growing season (May-Sep)• 2 years ⊷ Silvicultural treatment 40%• Partial cutting 3x• Girdling 3x• Control 3x⊷ Before After Control Impact
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20m
20m
Partial cutting
Girdling
Control
~200m x 200m
Block
Parcelle
Methodology
20m
20m
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• Water table• Interception• Precipitation
• Dendrometers on 45 black spruce• Micro-coring on 45 black spruce
Hydrology
Dendrology
• Identification of bryophytes species• Sphagnum growth• Shift in bryophytes species
Ecology
Methodology
Hydrology
Changes in canopy openness
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Results
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Hydrology model result:
Rain events + Temperature + Block + Canopy + JDAY
POT HT HAN
0 - 365
List of variables:TemperatureJDAYRain eventsRain events with one day delay
List of factors: Canopy opennessYearTreatmentsPeriodBlock
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Results
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Results
Drought periods
Rain events
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Drought periods:
Significant factors: Temperature + Block
Rain events:
Significant factors: Rain events + Temperature +Block
Results
POT HT HAN
POT HT HAN
POT HT HAN
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Results : Drought periods
Results: Rain events
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Discussion
Hypothesis: The main driving force on the water table one year after partial cutting is the interception of the tree cover.
Hypothesis: The reduction of evapotranspiration will not have a significant on the water table one yearafter the treatment.⊷We did not find any significant effect of
the treatments.
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Discussion
• Hypothesis: The girdling will isolate the effect of interception on the water table.
⊶ The effect of interception is not significant on the water table.
Dendrology
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Results
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Discussion
Hypothesis: The water table variation and the removal of tree cover will have an effect on wood cell deposit of residual black spruce. ⊶ Black spruce radial growth may
change after a few years.⊶ This bioclimatic domain dynamic is slow.
Reference: Thorpe et al. 2007
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Conclusion
⊷Hopefully, those results will helppromote partial cutting in black spruce forest on hydromorphic soils.⊷What’s next? • Follow the water table, black
spruce and sphagnum growth on the long term.
Thanks to the partners of the
project!
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ReferencesBergeron, Y., D. Cyr, C. R. Drever, M. Flannigan, S. Gauthier, D. Kneeshaw, È. Lauzon, A. Leduc, H. L. Goff, and D.
Lesieur. 2006. Past, current, and future fire frequencies in Quebec's commercial forests: implications for thecumulative effects of harvesting and fire on age-class structure and natural disturbance-based management.Canadian journal of forest research 36:2737-2744.
Bergeron, Y., and N. J. Fenton. 2012. Boreal forests of eastern Canada revisited: old growth, nonfire disturbances,forest succession, and biodiversity. Botany 90:509-523.
Fenton, N., N. Lecomte, S. Légaré, and Y. Bergeron. 2005. Paludification in black spruce (Piceamariana) forests ofeastern Canada: Potential factors and management implications. Forest Ecology and Management 213:151-159.
Fenton, N. J., and Y. Bergeron. 2011. Dynamic old-growth forests? A case study of boreal black spruce forestbryophytes. Silva Fennica 45:983-994.
Jutras, S., A. P. Plamondon, H. Hökkä, and J. Bégin. 2006. Water table changes following precommercial thinning onpost-harvest drained wetlands. Forest Ecology and Management 235:252-259.
Lafleur, B., D. Paré, N. J. Fenton, and Y. Bergeron. 2010. Do harvest methods and soil type impact the regeneration andgrowth of black spruce stands in northwestern Quebec? Canadian journal of forest research 40:1843-1851.
McRae, D., L. Duchesne, B. Freedman, T. Lynham, and S. Woodley. 2001. Comparisons between wildfire and forestharvesting and their implications in forest management. Environmental reviews 9:223-260.
Thorpe, H., S. Thomas, and J. Caspersen. 2007. Residual-tree growth responses to partial stand harvest in the blackspruce (Picea mariana) boreal forest This article is one of a selection of papers published in the Special ForumIUFRO 1.05 Uneven-Aged Silvicultural Research Group Conference on Natural Disturbance-Based Silviculture:Managing for Complexity. Canadian journal of forest research 37:1563-1571.
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POT2-10
POT2-14
POT2-18
POT2-29
POT2-31
POT2-30
POT2-2
Girdled trees
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Results : Dendrology
