Forest Adaptation and Close-to-Nature Silviculture (CNS) – coherence or contradiction?

1. Forest Adaptation and Close-to-Nature Silviculture (CNS) – coherence or contradiction? • Andreas Bolte1, Peter Spathelf2, Ernst van der Maaten3 • 1Thünen Institute ofForestEcosystems, 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 on Uneven-aged Silviculture, • Birmensdorf / Switzerland 2014

2. Outline • Vulnerability concept and status • Close-to-nature silviculture (CNS) - principles • Adaptive capacity • CNS versus forest adaptation – coherence and conflicts • Conclusions 9th IUFRO International Conference on Uneven-aged Silviculture

3. Impacts of CC: Vulnerability concept Foto: M. Löf Foto: A. Bolte

4. Vulnerabilityconcept • 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) 9th IUFRO International Conference on Uneven-aged Silviculture

5. Exposures: Projected changes in dryness Source:IPCC, 2012 9th IUFRO International Conference on Uneven-aged Silviculture

6. 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) 9th IUFRO International Conference on Uneven-aged Silviculture

7. Increaseofforestvulnerability (Europe) Bark beetleattacks Windthrow • Increasingwoodvolumelossesbiasedbyrecord high standingvolume in European forests? (cf. Bolte et al. 2009) Exposure↗ orSensitivity↗? 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) 9th IUFRO International Conference on Uneven-aged Silviculture

8. Vulnerability- combinedimpacts (storm/drought) • Total stock dynamicsatSiggabodanaturereserve 2004 to 2011 Source:Bolte et al., 2014 9th IUFRO International Conference on Uneven-aged Silviculture

9. Stand adaptation by succession from spruce to beech Source:Bolte et al., 2010, 2014 9th IUFRO International Conference on Uneven-aged Silviculture

10. Conceptual scheme of CC supported forest succession and stand adaptation Source:Bolte et al., 2014 9th IUFRO International Conference on Uneven-aged Silviculture

11. 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. 9th IUFRO International Conference on Uneven-aged Silviculture

12. Close-to-nature silviculture - principles Foto: A. Bolte

13. Close-to-nature silviculture (CNS) • Principles of CNS (Central European perspective, sensu: „NaturgemäßeWaldwirtschaft“, 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 9th IUFRO International Conference on Uneven-aged Silviculture

14. CNS andsilviculturalsystems – a coherence? • Regular andirregularshelterwoodsystem (Femelschlag) acc. to Röhrig et al. (2006) 9th IUFRO International Conference on Uneven-aged Silviculture

15. 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. 9th IUFRO International Conference on Uneven-aged Silviculture

16. Adaptive capacity (trees and populations) Foto: J. Müller

17. 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 9th IUFRO International Conference on Uneven-aged Silviculture

18. Species range shifts and local adaptation (‘rear edge‘) Source:Hampe and Petit, 2005 9th IUFRO International Conference on Uneven-aged Silviculture

19. Beechdistributionmargins (North-eastern C-E) 9th IUFRO International Conference on Uneven-aged Silviculture

20. Evolutionaryadaptationofrearedge-populations (youngbeechplants!) Source:Czajkowski and Bolte, 2006 9th IUFRO International Conference on Uneven-aged Silviculture

21. Phenotypicplasticityof European beech(old-growth stand) • Projected cumulative increment deviations • (PCR scenarios, model CLIMTREG), European beech (Hainich National Park) 2ndcalibrationperiod (1982-2006) 1stcalibrationperiod (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 9th IUFRO International Conference on Uneven-aged Silviculture

22. Adaptive capacitytomajor CC impacts 9th IUFRO International Conference on Uneven-aged Silviculture

23. CNS versus forest adaptation – coherences and conflicts

24. Contradictoryaspectsof CNS andforestadaptation 9th IUFRO International Conference on Uneven-aged Silviculture

25. Treespeciesselection/changesprefered Source:Spathelf et al., 2014 9th IUFRO International Conference on Uneven-aged Silviculture

26. 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. 9th IUFRO International Conference on Uneven-aged Silviculture

27. Thank you for your attention!

28. 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): UnterschiedlicheReaktiondeutscher und polnischerHerkünfte der Buche (Fagussylvatica L.) auf Trockenheit. Allg. Forst- u. J.-Ztg. 177: 30-40 (in German with English summary). • DobbertinM.; 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) 9th IUFRO International Conference on Uneven-aged Silviculture