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Technical Staff Mr. S. Snyders Mr. D. de Witt Mrs. J. Arnolds. 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. Climate Change and Plant Biodiversity. Barney S. Kgope
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Technical Staff Mr. S. Snyders Mr. D. de Witt Mrs. J. Arnolds 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
Climate Change and Plant Biodiversity Barney S. Kgope South African National Biodiversity Institute, Kirstenbosch Research Center, Kgope@sanbi.org
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.
Previous Climate We live on a predominantly cool-adapted planet!
Where are we now? Policy Behaviour Technology Uncertainty Detection Prediction Adaptation
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). Natural ecosystems - changes in structure and function. Water supply - decline due to potential decrease in rainfall. Climate Change Consequences
South Africa and Climate Change [PMG note: photograph not included]
How did past climate change affect this region? Climate reconstruction
18 Time (Kya) 15 12 -3.67ºC 6 0 -1.82ºC +0.05ºC
18 Pollen evidence? 1 12 6 Shi et al (1998)
Potential for more species. extinction ? Aloe dichotoma(quiver tree)
Elevated and sub-ambient CO2 work supporting mechanistic modeling Test ideas about impacts of fire and CO2 on vegetation structure and function[PMG note: photograph not included]
DGVM predictions for CO2 sensitivity of African mesic Savanna saplings
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
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 9:973-982 Bond W.J., Midgley G.F. & Woodward, F.I. (2003) What controls South African vegetation – climate or fire? South African Journal of Botany.69:1-13
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.
Acacia karroo [PMG note: photographs not included] 180 ppm 550 ppm
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)
What about potential impacts of the predicted increases in ambient temperatures?
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]
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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