Forest Adaptation and Close-to-Nature
Silviculture (CNS) – coherence or contradiction?
Andreas Bolte1, Peter Spathelf2, Ernst van der Maaten3
1Thünen Institute
of Forest Ecosystems, Eberswalde, Germany; 2Eberswalde University for Sustainable Development, Dept. Forest and
Environment, Eberswalde, Germany; 3University Greifswald, Institute of Botany and Landscape Ecology, Greifswald, Germany
IUFRO International Conference
Andreas Bolte, Peter Spathelf, Ernst van der Maaten
on Uneven-aged Silviculture,
Birmensdorf / Switzerland 2014
Outline
• Vulnerability concept and status
• Close-to-nature silviculture (CNS) - principles
• Adaptive capacity
• CNS versus forest adaptation – coherence and
conflicts
• Conclusions
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Andreas Bolte, Peter Spathelf, Ernst van der Maaten
9th IUFRO International Conference on Uneven-aged Silviculture
Impacts of CC: Vulnerability concept
Foto: M. Löf
Andreas Bolte, Peter Spathelf, Ernst van der Maaten
Foto: A. Bolte
Vulnerability concept
•
Exposure specifies the projected
changes in climate affecting a
system.
•
Sensitivity describes the degree
to which a system is responding
to direct climatic and indirect
(e.g. biotic) effects.
•
Adaptive capacity describes the
ability of a system to adapt to
changes (e.g. climate).
•
Vulnerability can be defined as
the degree to which a system is
susceptible to be affected by
adverse effects of climate
change.
(cf. Lindner et al., 2010)
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9th IUFRO International Conference on Uneven-aged Silviculture
Exposures: Projected changes in dryness
Source: IPCC, 2012
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9th IUFRO International Conference on Uneven-aged Silviculture
Exposures: Standardized cyclone track density
•
Northern central Europe is
often affected by storms;
•
An increase in extreme wind
intensities for this region is
projected (Leckebusch et al.,
2006).
Source: Leckebusch et al., 2008 (p 76)
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9th IUFRO International Conference on Uneven-aged Silviculture
Increase of forest vulnerability (Europe)
Windthrow
Exposure ↗ or Sensitivity ↗ ?
Increasing wood volume losses biased
by record high standing volume in
European forests? (cf. Bolte et al. 2009)
Bark beetle attacks
Vulnerability?
Biotic attacs following storm and
drought events are important drivers for
tree and stand mortality.
Source: Dobbertin & DeVries, 2008
(based on Schelhaas et al., 2003)
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Andreas Bolte, Peter Spathelf, Ernst van der Maaten
9th IUFRO International Conference on Uneven-aged Silviculture
Vulnerability - combined impacts (storm/drought)
Total stock dynamics at Siggaboda nature reserve 2004 to 2011
Source: Bolte et al., 2014
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Andreas Bolte, Peter Spathelf, Ernst van der Maaten
9th IUFRO International Conference on Uneven-aged Silviculture
Stand adaptation by succession from spruce to beech
High resistance to storm
(Storm damage, Spruce:
only 11% BA loss)
2004
Low resistance of
spruce towards
bark beetle attacks
(75% BA loss)
2011
Relative volume increment 2004 - 2011
ln[ivr] (%)
3
2005
Beech (n = 39):
y = 0.3841x + 1.7749
r² = 0.44, p<0.001
Beech
Spruce
2
1
Spruce (n = 33):
y = 0.1982x + 1.4619
r² = 0.18, p<0.05
0
-2
-1
0
1
Decrease competition index 2004 - 2011
ln[-iCI], no unit
Source: Bolte et al., 2010, 2014
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9th IUFRO International Conference on Uneven-aged Silviculture
2
Conceptual scheme of CC supported forest succession
and stand adaptation
Source: Bolte et al., 2014
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9th IUFRO International Conference on Uneven-aged Silviculture
Some interim conclusions/hypotheses
• Storm, heat/drought, and accompanying biotic impacts are
probably the most important exposures to CC of European
forests.
• Several exposures/impacts interact with each other (e.g. storm
damages, drought/heat waves and bark beetle infestations).
• Distinct disturbances (and not long-term CC effects) play a
major role for CC-supported forest succession.
• The availability of tolerant, adaptable, or resilient tree species,
populations, and specimens are essential for the vulnerability
status of forest stands.
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Close-to-nature silviculture - principles
Foto: A. Bolte
Andreas Bolte, Peter Spathelf, Ernst van der Maaten
Close-to-nature silviculture (CNS)
Principles of CNS (Central European perspective, sensu:
„Naturgemäße Waldwirtschaft“, cf. Pro Silva Principles 2012)
• Avoidance of clear-cuts
• Single-tree (and group) oriented interventions (no stand-scale!)
• Promotion of the natural and/or site-adapted tree species composition
• Promotion of mixed and ‘structured’ forests
• Promotion of natural regeneration
• Integration of forest ecosystem services (e.g. water, recreation) at small
spatial scales
 Aimed to mimicking small-scale disturbance regime
Source: Spathelf et al., 2014
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9th IUFRO International Conference on Uneven-aged Silviculture
CNS and silvicultural systems – a coherence?
Regular and irregular shelterwood system (Femelschlag) acc. to Röhrig et al. (2006)
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9th IUFRO International Conference on Uneven-aged Silviculture
Some interim conclusions/hypotheses
• CNS (C-E style) is rather a ‘philosophy’ that a certain
silvicultural system.
• CNS is tree-oriented (and groups as tree-competitor
associations).
• CNS can be included in different silvicultural systems but it is
rather difficult to ‘translate’ CNS into specific stand-scale
silvicultural systems.
• It may be interesting to use the principles directly for
evaluations.
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9th IUFRO International Conference on Uneven-aged Silviculture
Adaptive capacity (trees and populations)
Foto: J. Müller
Andreas Bolte, Peter Spathelf, Ernst van der Maaten
Adaptive processes
(1) Long-term evolutionary adaptation
- over one or more generations
- due to selection processes
(2) Phenotypic plasticity (acclimation)
- ensuring short-term persistence of several years
or a decade
- due to individual alternation of plant morphology
and/or physiology
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Species range shifts and local adaptation (‘rear edge‘)
Source: Hampe and Petit, 2005
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Beech distribution margins (North-eastern C-E)
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9th IUFRO International Conference on Uneven-aged Silviculture
Evolutionary adaptation of rear edge-populations
(young beech plants!)
Source: Czajkowski and Bolte, 2006
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9th IUFRO International Conference on Uneven-aged Silviculture
Phenotypic plasticity of European beech
(old-growth stand)
Projected cumulative increment deviations
(PCR scenarios, model CLIMTREG), European beech (Hainich National Park)
2nd calibration period (1982-2006)
1st calibration period
(1957-1981)
Measured series
1st calibration period 1957 to 1981
2nd calibration period 1982 to 2006
Scenario based on 1st calibration period
Scenario based on 2nd calibration period
Source: Beck et al., 2013
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9th IUFRO International Conference on Uneven-aged Silviculture
Adaptive capacity to major CC impacts
Sensitivity to
Phenotypic
plasticity
(individual level)
Evol. Adaptation
(population level)
Succession / tree
species change
(species level)
Heat
low
medium
high
Drought
medium
medium
high
Storm
medium
medium
high
Biotic agents
low
medium
high
Total
low - medium
medium
high
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9th IUFRO International Conference on Uneven-aged Silviculture
CNS versus forest adaptation – coherences
and conflicts
Andreas Bolte, Peter Spathelf, Ernst van der Maaten
Contradictory aspects of CNS and forest adaptation
Major
CNS principles
Single-tree or group
management (no clearcuts)
Promotion
mixed/structured forests
Natural regenaration
Natural tree
composition
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Phenotypic
plasticity
(individual level)
Evol. Adaptation
(population level)
Succession / tree
species change
(species level)
o.K.
o.K.
Less light-demanding
pioneer species
o.K.
o.K.
o.K.
o.K.
No assisted migration No assisted migration
(provenances)
(tree species)
o.K.
o.K.
No assisted migration
(tree species)
0
1
3
Andreas Bolte, Peter Spathelf, Ernst van der Maaten
9th IUFRO International Conference on Uneven-aged Silviculture
Tree species selection/changes prefered
Source: Spathelf et al., 2014
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Andreas Bolte, Peter Spathelf, Ernst van der Maaten
9th IUFRO International Conference on Uneven-aged Silviculture
CNS and forest adaptation to CC – some conclusions
CNS is a meaningful system (or ‘philosophy’) to support forest adaptation
to CC mainly on tree (individual) and sometimes population level.
However there are shortcomings when regarding the species level
(promoting succession) by:
• the avoidance to introduce ‘neo-native’ tree species and provenances
• the promotion of mid- and late-successional species that limits the
occurrence of stress-tolerant pioneer tree species.
Thus, ‘active adaptation’ measures and ‘human-induced’ assisted
migration are restricted.
Thus, a strict application of CNS may limit the silvicultural options
necessary for a successful adaptation of forest to CC.
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9th IUFRO International Conference on Uneven-aged Silviculture
Thank you for your attention!
Andreas Bolte, Peter Spathelf, Ernst van der Maaten
References
Beck, W.; Sanders, T.G.M.; Pofahl, U. (2013): CLIMTREG - detecting temporal changes in climate-growth reactions - a computer
program using intra-annual daily and yearly moving time intervals of variable width. Dendrochronologia (in press).
Bolte, A.; Ammer, C., Löf, M.; et al. (2009): Adaptive forest management in Central Europe - climate change impacts, strategies and
integrative concept. Scand. J. For. Res. 24, 6: 473-482.
Bolte, A. ; Hilbrig, L.; Grundmann, B. M.; Roloff, AS. (2013): Understory dynamics after disturbance accelerate succession from spruce
to beech-dominated forest – the Siggaboda case study. Ann. For. Sci., DOI 10.1007/s13595-013-0283-y (Online)
Czajkowski, T.; Bolte, A. (2006): Unterschiedliche Reaktion deutscher und polnischer Herkünfte der Buche (Fagus sylvatica L.) auf
Trockenheit. Allg. Forst- u. J.-Ztg. 177: 30-40 (in German with English summary).
Dobbertin M.; DeVries W (2008): Interactions between climate change and forest ecosystems. In: Fischer, R. (ed.) Forest ecosystems
in a changing environment: identifying future monitoring and research needs. Report and Recommendations COST Strategic
Workshop 11–13 March 2008, Istanbul, Turkey. http://www.icp-forests.org/pdf/COST.pdf. Accessed 07 April 2013.
Hampe, A.;Petit, R.J. (2005): Conserving biodiversity under climate change: the rear edge matters. Ecology Letters 8: 461-467.
Lindner, M.; Maroschek, M.; Netherer, S.; et al. (2010): Climate change impacts, adaptive capacity, and vulnerability of European
forest ecosystems. Forest Ecology and Management 259: 698–709.
Puettmann, K. Coates, K.D.; Messier, C. (2009) A critique of silviculture: Managing for complexity. Island Press, Washington, DC.,206
p.
Spathelf, P.; Bolte, A. (in review): Is Close-to-Nature Silviculture (CNS) an adequate concept for adapting forests to climate change?
Annals of Forest Science (in review)
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