the international tundra experiment (itex)...atqasuk utqiaġvik 13 the field sites were within the...
TRANSCRIPT
The International Tundra Experiment
(ITEX)
Arctic Ecology ProgramGrand Valley State
University
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Grand Valley Researchers
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Bob Hollister, PhD: Principle Investigator
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Jacob Harris: graduate student
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Katlyn Betway: Undergraduate Researcher
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Hana Christoffersen: Undergraduate Researcher
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Kailey Keenan-Whittemore: Undergraduate Researcher
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Brief Project History
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13 Utqiaġvik
The original International Tundra Experiment sitesagreed on a common warming manipulationto simulate climate change
Proposed in 1990
1994
2007
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Part of the
Arctic Observatory Network Collaborative Research: Sustaining and amplifying the ITEX AON through automation and increased interdisciplinarity of observations Funding: National Science Foundation Collaborators: FIU, Florida International University
UTEP, University of Texas at El PasoUAA, University of Alaska at Anchorage
Beginning in 2009
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Research Sites
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AtqasukDry Heath
Dry Heath
Wet Meadow
Wet MeadowUtqiaġvik 12
Atqasuk
Utqiaġvik
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Hollister MS Thesis
Open Top Chambers (OTC’s) effectively warm by ~2°C
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Experimental Design
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• Plant phenology• Plant growth• Plant reproduction
Plant traits
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• Plant cover• Canopy height• Species diversity
Community composition
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Why Plants are important
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Cooler Warmer
CarbonRelease
Microbial Decomposition
CarbonRelease
Carbon Budget
Why Plants are important
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Cooler Warmer
CarbonRelease
Microbial Decomposition
CarbonRelease
Carbon Budget Energy Balance
Why Plants are important
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Cooler Warmer
CarbonRelease
Microbial Decomposition
CarbonRelease
Carbon BudgetTrophic
InteractionsEnergy Balance
Why Plants are important
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Recent Findings
Plant Species Composition Changes
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Cove
r (%
)
Atqasuk Dry (AD)Ambient (control plots) Warmed (experimental plots)
Cove
r (%
)
Barrow Dry (BD)
(moss)
Control Warmed Recent FindingsAtqasuk Dry Site
Utqiaġvik Dry Site
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Cove
r (%
)
Atqasuk Dry (AD)Ambient (control plots) Warmed (experimental plots)
Cove
r (%
)
Barrow Dry (BD)
(moss)
Control Warmed Recent FindingsAtqasuk Dry Site
Lichen decrease
Shrubs increase
Utqiaġvik Dry Site
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Cove
r (%
)
Atqasuk Dry (AD)Ambient (control plots) Warmed (experimental plots)
Co
ver (
%)
Atqasuk Wet (AW)
Co
ver (
%)
Year Year
Barrow Wet (BW)
(moss)
Control Warmed Recent FindingsAtqasuk Wet Site
Barrow Wet SiteUtqiaġvik Wet Site
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Cove
r (%
)
Atqasuk Dry (AD)Ambient (control plots) Warmed (experimental plots)
Co
ver (
%)
Atqasuk Wet (AW)
Co
ver (
%)
Year Year
Barrow Wet (BW)
(moss)
Control Warmed Recent FindingsAtqasuk Wet Site
Utqiaġvik Wet Site
Bryophyte (moss) decrease
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Recent Findings
Plants Grow Taller
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Change in height over time
Synthesis of Control Plots
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Change in height over timeplants got taller
Synthesis of Control Plots
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Relation to Climate Change Mechanisms
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Albedo
Positive Feed Back 1:Less snow Warmer Less snow
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Positive Feed Back 2:Taller plants Warmer Taller plants
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C.E. Tweedie
Carbon Release
Positive Feed Back 3:Carbon releaseWarmer Carbon release
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IPCC (Intergovernmental Panel on Climate Change) 2007.
Current
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IPCC (Intergovernmental Panel on Climate Change) 2007.
Current Projected
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IPCC (Intergovernmental Panel on Climate Change) 2007.
Current Projected
It is estimated that shrub and tree expansion may magnify regional warming by a factor of 2-7
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Summary: Impacts of climate change on the Arctic
• Melting snow & ice (less white)• Release of carbon• Taller vegetation
– increased solar absorptionObserved changes with regional warming
Increase in shrubs (especially tall shrubs at warmer sites)
Warming experiments suggestFurther increases in shrubs Decreases in lichen and moss
Possible Local effectsChanges in forage for local animals: More Geese, Less Caribou? Long term changes influence food for game animals
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Summary: Impacts of climate change on the Arctic
• Melting snow & ice (less white)• Release of carbon• Taller vegetation
– increased solar absorptionObserved changes with regional warming
Increase in shrubs (especially tall shrubs at warmer sites)
Warming experiments suggestFurther increases in shrubs Decreases in lichen and moss
Possible Local effectsChanges in forage for local animals: More Geese, Less Caribou? Long term changes influence food for game animals
Possibly as much asfossil fuel burning
38
Summary: Impacts of climate change on the Arctic
• Melting snow & ice (less white)• Release of carbon• Taller vegetation
– increased solar absorptionObserved changes with regional warming
Increase in shrubs (especially tall shrubs at warmer sites)
Warming experiments suggestFurther increases in shrubs Decreases in lichen and moss
Possible Local effectsChanges in forage for local animals: More Geese, Less Caribou? Long term changes influence food for game animals
Possibly as much asfossil fuel burning
Potential to magnify regional warming by 2-7 X
39
Summary: Impacts of climate change on the Arctic
• Melting snow & ice (less white)• Release of carbon• Taller vegetation
– increased solar absorptionObserved changes with regional warming
Increase in shrubs (especially tall shrubs at warmer sites)
Warming experiments suggestFurther increases in shrubs Decreases in lichen and moss
Possible Local effectsChanges in forage for local animals: More Geese, Less Caribou? Long term changes influence food for game animals
Possibly as much asfossil fuel burning
Potential to magnify regional warming by 2-7 X
40
Summary: Impacts of climate change on the Arctic
• Melting snow & ice (less white)• Release of carbon• Taller vegetation
– increased solar absorptionObserved changes with regional warming
Increase in shrubs (especially tall shrubs at warmer sites)
Warming experiments suggestFurther increases in shrubs Decreases in lichen and moss
Possible Local effectsChanges in forage for local animals: More Geese, Less Caribou? Long term changes influence food for game animals
Possibly as much asfossil fuel burning
Potential to magnify regional warming by 2-7 X
41
Thank you for all the support over the years! 42
Any Questions?
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