Climate Change and its impact on Forests in Europe and North America

1. Climate Change and its impact on Forests in Europe and North America Andrew J. R. Gillespie, Ph. D. United States Environmental Protection Agency

2. Goal of Presentation • Overview of climate science relevant to forests • Implications for forests in Europe and North America • What we are doing about it

3. Climate – long term (~30 year) trends in atmospheric behaviors such as temperature, rainfall, humidity, wind patterns, and storms. • Weather – short term (days) atmospheric behavior • Climates are always changing – dynamic systems, not constant • Difference today is the rate at which climate is changing: • Evidence that it is more rapid than usual for last 800,000 years • Evidence that it is due to fossil fuels and deforestation

4. How do we know climate is changing? • Direct measurements since the mid 1800s • Daily temperature, precipitation/many locations • Glacier shrinkage • Multiple other lines of research prior to 1800s • Ice cores • Tree rings • Pollen analysis • Geologic evidence of ice ages, warm periods

6. Climate Change Impacts in the United States: The Third National Climate Assessment

10. Likely Aspects of Climate Change • Increase in heat retained in ocean and atmosphere • Slight increase (~2-4 degrees) in average global temperature by the end of the century • More change at the poles • Hotter summers, milder winters • Warmer oceans • More energy = more extreme weather • Hurricanes, blizzards, heat waves, wind storms • Change in rain patterns • More precipitation but uneven distribution • More droughts, floods • Rising sea levels as ice melts

11. Relationship between Climate and Forests Ecological Niche Set of environmental conditions which enable a species to survive and thrive. Combination of multiple factors: Climate: temperature, precipitation, storm events Physical: soil characteristics, elevation, aspect Analogous to concept of terroir for wine making… Change in climate => change in niche Animals can migrate to follow niches Trees move much more slowly…

12. Relationship between Climate and Forests Change in climate => change in niche Change in niche => existing forests come under stress Increase in stress => vulnerability to other threats disease, insects, fire, loss of biodiversity Loss of forest => more CO2 in atmosphere => more climate change

13. Likely changes in forest ecosystems • Warmer average temperatures • Longer growing season • CO2 fertilization effect • Increased precipitation, changes in rainfall patterns • More extreme weather (ice storm, wind storm, drought, flood) • Changes in soil moisture – wetter and drier seasons • Increased insect/disease presence due to less winter die-off Net result is general increase in ecosystem stress, resulting in increased forest vulnerability to other threats

14. Likely forest ecosystem response • Northward migration of some tree species • Changes in forest species composition, succession • Increased tree mortality, fire risk • Increased spread of invasive species • Loss of biodiversity, genetic resources, ecosystem services

15. Climate and Forests: North America Canada: ~397 million ha US: ~327 million ha Mexico: ~ 50 million ha TOTAL: ~774 million ha (~ 80 x area of Hungary) North America forest extends from subtropical to boreal Many different forest types, ecological conditions

17. Relationship between Climate and Forests • Successful forest fire prevention => overstocked forests • Overstocking causes stress • Climate-related drought adds to stress • Insects able to infest stressed forests Result is greatly increased tree mortality, higher fire risk Illustrates need for systems thinking, sustainability perspective

19. Impacts of Climate Change on European Forests and Options for Adaptation European Forest Institute et al.

20. Climate Change and Ecosystem Response: Temperate Continental Region • Changes in rainfall distribution Wetter winters = flooding, wind damage, ice storms Dryer, longer summers = more drought stress • Warmer temperatures => increased pest problems Bark beetles, gypsy moth, Phytophthora Increase insect, disease populations due to less winter die-off Increased northern ranges

21. Climate Change and Forest Response: Hungary

22. Climate Change and Forest Response: Hungary • Example: European beech in Hungary (C. Mátyás et al.) • Beech at southern limit of range in Hungary • Xeric limit: genetically determined dryness tolerance • Northward shift in xeric limit could lead to complete loss of beech, replacement with oak • Permanent loss of genetic diversity

23. Climate Change and Forest Response: Hungary

24. Strategies for Managing Forests in a Changing Climate • Mitigation – reduce C emissions, increase C sequestration by growing forests • Adaptation – manage forests to maintain health, reduce vulnerability • Transformation – change society expectations, behaviors regarding what people want, need from forests – and what we are willing to give back

25. Scale Matters • Adaptive strategies are synergistic across large areas: • More ecological niches to work with • More resources (financial, intellectual) to work with Argues for benefit to international cooperation • Certainly at continental scale • Also at global scale

26. Need for Action Continue research to provide good foundation Need to move beyond research to action Adaptive management, systems thinking: Plan – Act – Measure – Analyze … and repeat

27. WinterSummer is coming…

28. Thank you for your Attention Andrew Gillespie Gillespie.andrew@epa.gov Twitter: @ajrgillespie1