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