Climate change effect on forests Modelling perspective

1. Climate change effect on forestsModellingperspective Tomáš Hlásny NationalForest Centre – ForestResearchInstitute in Zvolen, Slovakia

2. Introduction • Forest cover30 % of Earth`s land area • Important rule of in global carbon cycle (ca. 75% of C in terrestrial ecosystems) with large variation in C storage among forest types (boreal, temperate, tropical …. ) and in C partitioning between soil and vegetation • Complex responses to CC because of varying sensitivity of forest components and processes, i.e. tree species, ground vegetation, pests and pathogens, regeneration, water cycling, etc. • Largeshare of forests is managed, thus coupled effect of management and environmental change needs to be considered • Drought, forestfires, increasingfrequencyofwindstorms, invasivespecies, changes in populationdynamicsofpests are amongthe most importantthreats • Forest longevity is important factor in the period of rapid environmental changes

3. Forestresponse to climatechange • Beneficial and adverse effects • Differing along altitudinal and latitudinal gradients, depending on environmental limits to forest persistence • Direct effect, such as effect on CO2 increase on tree physiology, increased nutrient input due to increased decomposition rates, etc. • Indirect effects, acting mainly through changes in forest disturbances, fires, floods, windthrows, pest outbreaks ... all climate sensitive • Disruption of synchrony in multitrofic systems; host, pest, predator, parasitoid …. • Species shift, tree line expansion, low range retraction has received large attention Ural Hungary

4. Example of species shift projection Hanewinkel, M., Cullmann, D. A., Schelhaas, M.-J., Nabuurs, G.-J., & Zimmermann, N. E. (2012). Climatechangemay cause severe loss in theeconomicvalueofEuropeanforestland. NatureClimateChange, advance on. doi:10.1038/nclimate1687

5. Forestvulnerabilityassessment • Vulnerability is a degree to which a system is susceptible to be affected by adverse effects of climate change • Assessmentof forestvulnerabilityfollowsgeneralprincipleofexposure, sensitivity, adaptivecapacity • Exposure describes projected changes in relevant climate elements, i.e. drought indices, biotemperature, etc. • Sensitivity describes degree to which a system may be affected • Adaptive capacity contains inherent mechanisms such as phenotypic plasticity or migration, and socio-economic mechanisms,. i.e. adaptive forest management • As exposure and sensitivity are given, S-E adaptive capacity is of prime interests of foresters. It contains factors such as country`s economic development, awareness issues, cross-sectoral cooperation, forestry infrastructure, etc. • Regional vulnerability assessments are presently being developed for some regions of Europe under various initiatives, e.g. Carpathian Convention or Danube Strategy + national programmes

6. Example: Climatic exposure of the Carpathians

7. Example: Climatic exposure of European beech in the Carpathians based on 4 RCMs

8. Forestmodelling To get knowledge about future forests development under diverse treatments and environmental conditions, and to optimize management to reach desired forest structure, distribution and provisionofecosystem services • Longhistory, startingwithyieldtables (1800) to standsimulators (2000) to presentintegrative hybrid models • Althoughvariousclassificationschemesexist, empirical and process based models are obviously distinguished • EM obviously suit better for forest management planning and optimization (usually simpler definition of inputs and calibration, based on yield tables thus familiar to foresters, etc.) • P-BM provide detailed description of BGC processes in ecosystems; needed for profound understanding of ecosystem functioning as well as for evaluation of some ecosystem services (carbon sequestration) • Rising importance of more robust multi-model estimates

9. Spatial scale • Stand-scale modelsPicus(BOKU), Silva (TUM), Sibyla(TU Zvolen), etc. • Single tree vs. big leaf approaches • Single tree-based approaches provide diverse informationneeded to supporttheforest management; e.g. species composition, tree dimensions, stands vertical structure, diversity, dead wood and regeneration distribution, etc. • Information on stand structure allow for linking simulated stands to range of ecosystems services • Landscape models, such as LANDIS II (Portland University), Muscatella(Swiss Federal Institute for Forest, Snow and Landscape Research), LandMod (Oregon State University), etc. • Models consider landscape context and configuration • Stress is laid on horizontal processes such as spread, migration, flows as well as on effect of forest disturbances and succession on the landscape • Used for example for the assessment of forest effect on gravitation hazards, supporting habitats, etc.

10. Assessment of climate change impact on production of temperate forests We use combined assessments by Biome-BGC and Sibyla tree growth simulator. Biome-BGC is well know here, so … • Sibyla is EM, single tree, 1-year step, climate sensitive, distance-based • Inter- and intra-specific competition is considered • Parameterized for 6 temperate tree species, other species can be simulated on the basis of physiological and morphologic resemblance • Versatile initial stand definition, number of standard stand treatments pre-defined • Outputs are production, carbon, assortments, stand structural indices, economic indicators, etc.

11. Experimental design • European beech, oak(s) and Norway spruce were addressed • Number of simulation plots arranged at elevation gradient with plausible species mixtures • Single climate change scenario, no management, plot structure characterizing vegetation zone • Three time periods addressed – 1961-1990, 2021-2050 and 2071-2100

12. Sibyla-based assessment of CC impact on forest production Hlásny, T., Barcza, Z., Fabrika, M., Balázs, B., Churkina, G., Pajtík, J., Sedmák, R., Turčáni, M. (2011). Climatechangeimpacts on growthandcarbon balance offorests in CentralEurope. ClimateResearch, 47(3), 219–236.

13. Biome-BGC based simulations • Three forest monitoring plots addressed • Calibration data 1997-2009 • Continuous stand development 1925-2100

14. Combined assessment by Sibyla and Biome-BGC Hlásny, T., Barcza, Z., Fabrika, M., Balázs, B., Churkina, G., Pajtík, J., Sedmák, R., Turčáni, M. (2011). Climatechangeimpacts on growthandcarbon balance offorests in CentralEurope. ClimateResearch, 47(3), 219–236.

15. Combined assessment by Sibyla and Biome-BGC • Unmanaged mountain Norway spruce stand, High Tatras Mts. • Simulation period 1939-2100 for Biome-BGC, 1997-2100 for Sibyla • 4 CC scenarios, 1 statistically generated stable climate 1939-2100 • Simulation design: Sibyla× Biome BGC 1 × Biome BGC 11 × Biome BGC 111 × 4 CC scenarios x 50 stochastic simulations • Simulations under stableclimate

16. Climate change effect on main carbon pools and fluxes Differences “scenario – stable climate”

17. Variability decomposition • Effect of models architecture, CC scenarios, mortality assumptions and models stochasticity need to be explored to understand the presented simulations • We used specific ANOVA design to attribute parts of variability of final estimates to respective factors • Such control differed between quantities simulated and time periods

18. Link to ecosystem services and functions • Range of ESF is provided by forests; productive (biomass, roundwood, fruits, mushrooms), environmental (water, air quality, weather regulation, carbon sequestration, erosion preventions, biodiversity ...), and social (recreation, education, research …) • Effects of CC on forest structure and composition affects ESF; various linker functions are sought to describe such relationships • Coupled effect of CC and management modifies future ESF provided by forests, hence simulation exercises are used to evaluate such developments • Simulations are used to optimize forest management to reach the desired ESF provision; stakeholders` involvement is needed to specify the desired ESF portfolio

19. Concluding remarks • Forest models are used to test the effect of various forest treatments to reduce negative effects and take advantage of positive effectsofclimatechange as well as to allow for fundamental understanding of forest functioning • Large uncertainty is associated to simulation outputs at longer runs; limited knowledge of the effects of management and future disturbance regimes are key factors • Multimodel approaches needs to be further developed to increase the robustness and reliability of modelling outputs • Linking modellingoutputs to diverse ESF is becoming key concept of forest modelling • Although most of projects on CC impacts include stakeholder interactions, information transfer to practice is largely insufficient

20. Climate change effect on forestsModellingperspective Tomáš Hlásny NationalForest Centre – ForestResearchInstitute in Zvolen, Slovakia Thank you for your attention

21. Mortality and disturbances • Disturbanceslargely limit theinterpetationof • Substantial simplification is needed to include complex disturbance regimes into modeling • Survival probability functions based on past records are obviously used • SP is evaluated either in each simulation step or in simulation post-processing http://www.feric.ca/