current & future ecological responses to climate change dr. heather throop nmsu biology...
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Current & Future Ecological Responses to Climate Change
Dr. Heather Throop
NMSU Biology
2090-2099IPCC, 2007
Climatology is easy…
Complexities of understanding biological responses- interactions between organisms- short vs. long term patterns- extremes, not averages, may be important
2090-2099IPCC, 2007
Climate Change Does Not Occur in a Vacuum
• Increasing urbanization and sprawl• Landscape fragmentation • Air & water pollution
• Elevated atmospheric CO2
Ways to Study Ecological Impacts
• Observations
• Manipulative experiments
• Computer simulations
Natural Environment Research Council, UK
• 4th Assessment Report -- 2007
• Consensus report• >1200 authors• >2500 expert reviewers• >130 countries
There is medium confidence that approximately 20-30% of species assessed so far are likely to be at increased risk of extinction if increases in global average warming exceed 1.5-2.5ºC (relative to 1980-1999). As global average temperature exceeds about 3.5ºC, model projections suggest significant extinctions (40-70% of species assessed) around the globe.
IPCC, SPM 2007
Biological Impacts
• Physiology
• Phenology (timing)
• Community composition & disease
• Range shifts
Biological Impacts
• Physiology
• Phenology (timing)
• Community composition & disease
• Range shifts
EXTINCTIO
NS
Phenology
• Timing of a biological activity
• Examples:– Spring leaf-out– Fall leaf drop– Migratory bird arrival
Earlier Spring Events
• Documented Shifts Earlier:
– Flowering & leafing, Europe & N. America (1 - 3 days earlier/decade)
– Butterfly breeding, UK
– Amphibian breeding, UK
– Bird migration & breeding, Europe & N. America
Summary of spring phenology: 61 studies, 694 species, past 50 years
Root et al. (2003) Nature
Both et al. (2006) Nature
Pied Flycatcher, The Netherlands
Mismatch between timing of hatching & food abundance population declines
Early caterpillar peak
Latecaterpillar peak
Later Fall Events?
• Less clear than spring
• Delay of leaf color changes in Europe
Community Composition
• Climate changes may affect species differentially
• Changes in abundance of one species (including pathogens) may affect other species
Walther et al. 2002 Nature
Southern Switzerland
C. D. Harvell et al. (2002) Science
Climate change likely to increase severity/frequency of disease outbreaks
population declines & extinctions
Protozoan on monarchs
Distemper outbreak - lions
Fungus - sea fans
Fungus - leaves
Benning et al. (2002) Proc. Natl. Acad. Sci.
Harvell et al. (2002) Science
Hawai’i~60 of 100 endemic bird species currently extinct
Coral Bleaching
Photos: Wikipedia.org
• Corals highly vulnerable to thermal stress• 1-3ºC sea surface temperature increases: frequent bleaching, widespread mortality
Range Shifts
• Climate changes affect species range
• Changes in – Latitude (towards poles)– Elevation
Summary including >1,700 species:• recent biological trends match climate change predictions• range shifts average:
6.1 km/decade toward the poles OR 6.1 m/decade upward
Parmesan & Yohe (2003) Nature
Range Shifts
Other Range Shifts
• Treeline: Europe & New Zealand
• Arctic & alpine plants: Alps, Alaska – 1-4 m/decade
• Birds in Britain– 19 km N in 20 years
• Foxes, Canada
Can we count on range shifts as a “solution”?
“ I hope I have justified the conviction, shared by many thoughtful people from all walks of life, that the problem can be solved. Adequate resources exist. Those who control them have many reasons to achieve that goal, not least their own security. In the end, however, success or failure will come down to an ethical decision, one on which those now living will be defined and judged for all generations to come.”
E.O. Wilson (2001)The Future of
Life