Climate Change and Biodiversity

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Climate Change Group Dr. G. Midgley (leader) Dr.
C. Musil Dr. M. Rutherford Dr. W. Thuiller Mr.
Les Powrie Mr. B. Kgope Mr. G. Hughes
Technical Staff Mr. S. Snyders Mr. D. de
Witt Mrs. J. Arnolds
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Climate Change and Plant Biodiversity

• Barney S. Kgope
• South African National Biodiversity Institute,
  Kirstenbosch Research Center,
• Kgope_at_sanbi.org

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Background

• What is climate? - An aggregate of daily weather
  - whose variables interact to support life on
  earth.
• Climate system includes processes involving -
  land, ocean and sea and these influence -
  atmosphere.
• Biodiversity - variety of life on Earth -
  significantly influences climate.

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Is the climate changing?
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Previous Climate
We live on a predominantly cool-adapted planet!
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Human Influence - fossil fuels
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Where are we now?
Policy Behaviour Technology
Uncertainty Detection Prediction
Adaptation
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Climate Change Consequences

• Natural ecosystems - changes in structure and
  function.
• Water supply - decline due to potential decrease
  in rainfall.

• Human and animal health - e.g. heat and diseases.
• Agriculture - food security (warming and drying).
• Sea level rise - melting polar ice caps
  (potential to submerge coastal cities).

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South Africa and Climate Change
PMG note photograph not included
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5 spatially dominant biomes - SA
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How did past climate change affect this region?
Climate reconstruction
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Time (Kya)
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-3.67ºC
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0
-1.82ºC
0.05ºC
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Pollen evidence?
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Shi et al (1998)
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Potential Future ?
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Water impacts on physiology
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Potential shift with climate change (2050)
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Potential for more species. extinction ?
Aloe dichotoma(quiver tree)
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Elevated and sub-ambient CO2 work supporting
mechanistic modeling Test ideas about impacts
of fire and CO2 on vegetation structure and
functionPMG note photograph not included
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DGVM predictions for CO2 sensitivity of African
mesic Savanna saplings
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Implications and tests

• Past contraction of woody elements with LGM low
  CO2 (180ppm) paleoecological record
• Bush encroachment since the pre-industrial, and
  accelerating into the future with significant
  implications for livelihoods, ecosystem function
  and carbon sequestration empirical experiments

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Modelled effects of CO2 level alone on tree
success (i.t.o. LAI)using a DGVM
  Bond W.J., Midgley G.F. Woodward, F.I.
(2003) The importance of low atmospheric CO2 and
fire in promoting the spread of grasslands and
savannas. Global Change Biology 9973-982 Bond
W.J., Midgley G.F. Woodward, F.I. (2003) What
controls South African vegetation climate or
fire? South African Journal of Botany.691-13
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Experimental tests on 3 Savanna woody species and
1 C4 grass

• Plants exposed to a full range of CO2 levels viz.
  180, 280, 370, 550, 700 and 1000 ppm, in Open Top
  Chambers
• Plants - Acacia karoo, Acacia nilotica,
  Dichrostachys cinerea and Themeda triandra.

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Acacia karroo
PMG note photographs not included
180 ppm
550 ppm
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From pre-industrial to current CO2 levels? Trees
have increased world-wide in savannas
Open savanna, S. Africa 1955
PMG note photograph not included
Same place, 1998
(from T. Hoffmann, IPC)
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What about potential impacts of the predicted
increases in ambient temperatures?
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Scale up research - biogeochemical cycles

• Long Term Ecological Research Sites
• Scale up leaf-canopy-ecosystem-regional-global
• Integrative studies
• Networks Afri-flux

PMG note photograph not included
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Recommendations

• Support Assessment of Impacts and Adaptation to
  Climate Change (AIACC)
• Support International efforts to curb/limit
  greenhouse gas emissions
• Key intervention - policies promoting sustainable
  management of biodiversity on private and
  communal land.
• Expansion of protected areas an important
  adaptation option being implemented in SA
• Increase capacity of research on climate change
  and sustainable development in South Africa

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Science is Fun
Thank you