Global Warming Effects Around the World

Cape Floral Region, South Africa

Top Impact

Ecosystems (Land)

Other Impacts

Temperature (Air)

Freshwater (Extreme dry)

Coral- hued proteas bloom in South Africa's Cape Floral Region

The distinctive land ecosystem of South Africa's Cape Floral Region boasts one of the world's highest densities of plant species—including various flowering proteas, such as the one shown here. Unless we act now to rein in climate change, warming and drying of the region's Mediterranean climate could wipe out proteas and other varieties of shrubby vegetation known as fynbos, which are found only in this region.1

Key Facts

South Africa's Cape Floral Region is a small area densely packed with an exceptionally high number of plant species.2 This United Nations World Heritage Site7 and biodiversity hotspot8 is at grave risk from climate change.

  • Many of the region's 2,285 recorded plant species are endemic: they live only here.5
  • Proteas are the most common, best-recognized species of fynbos—vegetation unique to the region. Scientists project that global warming could cause 21-40 percent of proteas to disappear.2,23
  • Unless we make deep and swift cuts in our heat-trapping emissions, the fynbos plant community could lose about two-thirds of its area.22,23

Details

The Cape Floral Region of South Africa-which accounts for only one-half of one percent of Africa-has the world's widest variety of plants packed into such a small area.2,5 Many of the recorded plant species in the Cape Floral Region are endemic: they live only here.3 Global warming threatens the survival of these unique species, known as fynbos.4

The region boasts some 2,285 plant species- one-fifth of the flora in Africa,4 and more than found in North America.5,6

Because of the richness and diversity of species and the high percentage of plants uniquely found in the region, the United Nations has designated it a World Heritage Site.7 The Cape Floral Region is also one of 34 designated "biodiversity hotspots" worldwide.7,8

Although together these biodiversity hotspots account for only 2.3 percent of the Earth's land area, about half the world's plant species live only in those 34 places.8 What the biodiversity hotspots also have in common is that they have already lost more than 70 percent of their native vegetation.8, 9,10

Fynbos-which means fine bush-is a type of vegetation dominated by hard-leaved, evergreen, fire-prone shrubs.8,11 Fynbos include four kinds of plants: proteas, large shrubs with big, colorful flowers; ericas, heath-like, low-growing shrubs with tubular flowers; restios, reed-like plants that resemble horsetails; and geophytes, bulbs that occur mainly in wetland areas and are prominent after fires.2,11,12,13

Proteas-also known as sugarbushes-are the most common, best-recognized species in South Africa, with the king protea honored as the national flower.8 The fynbos ecosystem is adapted to fire: the vegetation needs to burn about every 15 years for new growth to occur, and to ensure healthy plant and animal communities.11

Two bird species-the cape sugarbird and the orange-breasted sunbird-depend on the fynbos, and live only in the Cape Floral Region.14 Sugarbirds, in particular, have a symbiotic relationship with the fynbos, distributing the seeds of certain proteas.14

The global trend of rising surface temperature is affecting Africa,15 and the continent's warming trend has accelerated since the 1960s.16 South Africa warmed by an average of 0.2 to 0.5° F (0.1 to 0.3° C) per decade in the second half of the twentieth century, with minimum temperatures increasing slightly faster than maximum or mean temperatures.16,17 One of the signature responses to global warming seen worldwide is minimum temperatures that rise faster than maximum temperatures.18

The Mediterranean climate of the Cape Floral Region has seen rising temperatures and declining rainfall-especially in winter.4 Along with climate change, pressures from agriculture, urbanization, and invasive plants have already transformed 30 percent of the Cape Floral Region.2,18 Conservation restrictions now protect only 20 percent of the region-and reserves with the highest degree of protection cover only half that.2,20

What the Future Holds

Scientists project that average temperatures in the Cape Floral Region will warm by roughly 3.2° F (1.8° C) by midcentury.4 The region is also expected to become drier, intensifying stress on the fynbos.4

Studies show that climate change is likely to eliminate the range of nearly one-fifth of protea species in the Cape Floral Region, and to reduce the range of another two-fifths.4 Although the range of some protea species is expected to expand, the majority of those would need to migrate, as present and future ranges are not likely to overlap.4

All told, scientists find that more than half of protea species are at highest risk of becoming extinct as the climate of the Cape Floral Region changes.4 Given a mid-range scenario for heat-trapping emissions,21 global warming could cause 21-40 percent of the Proteaceae family to disappear, with the higher end of the range occurring if the species do not disperse.2,22

Unless we make deep and swift cuts in our heat-trapping emissions, the unique diversity of the Cape Floral Region is at risk. The fynbos plant community stands to shrink significantly along its northern edge, especially in inland plains along the west coast,4 and could lose 65 percent of its area if temperatures warm as much as now projected.23,24

Disappearance of the fynbos would affect other species in the region, including birds. The Cape sugarbird and the orange-breasted sunbird face loss of one-fifth to one-quarter of their habitat by mid-century, if our carbon emissions continue to rise at today's rates.14,21

Climate change is also likely to increase the frequency and extent of fires in the region, favoring varieties of fynbos that require fire to germinate and reducing tree cover.23,25 A doubling of atmospheric carbon dioxide, for example, is expected to double the risk of fires in the fynbos.23,26

Credits

Endnotes

  1. Photograph courtesy of the United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage, David Smith. Accessed 28 Aug 2010 at http://www.ourplaceworldheritage.com/ photolibrary/ photos/ SF06NADS_003.JPG.
  2. Hannah, L., G. Midgley, G. Hughe, and B. Bomhard. 2005. The view from the Cape: Extinction risk, protected areas, and climate change. BioScience 55(3):231-242.
  3. McDonald, D.J., and R.M. Cowling. 1995. Towards a profile of an endemic mountain fynbos flora: Implications for conservation. Biological Conservation 72:1-12.
  4. Midgley G., L. Hannah, W. Thuiller, and A. Booth. 2002. Developing regional and species-level assessments of climate change impacts on biodiversity in the Cape Floristic Region. Biological Conservation 112:87-97.
  5. Simmons, M.T., and R.M. Cowling. 1996. Why is the Cape Peninsula so rich in plant species? An analysis of the independent diversity components. Biodiversity and Conservation 5:551-573.
  6. Sisk, T.D., editor. 1998. Perspectives on the land-use history of North America: A context for understanding our changing environment. USGS/BRD/BSR 1998-0003 (revised September 1999). Reston, VA: Biological Resources Division, U.S. Geological Survey. Online at http://biology.usgs.gov/ luhna/chap4.html. Accessed June 11, 2010.
  7. United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites: Cape Floral Region Protected Areas. Online at http://whc.unesco.org/ en/ list/ 1007. Accessed May 7, 2010.
  8. Biodiversity Hotspots. 2010. Conservation International. Online at http://www.biodiversityhotspots.org/ xp/ Hotspots/ hotspots_by_region/ Pages/ default.aspx. Accessed May 10, 2010.
  9. Myers, N., R.A. Mittermeier, C.G. Mittermeier, G.A.B. daFonseca, and J. Kent. 2000. Biodiversity hotspots for conservation priorities. Nature 403(6772), 853-858.
  10. Mittermeier R.A., P. Robles Gil, M. Hoffman, J. Pilgrim, T. Brooks, C. Goettsch Mittermeier, J. Lamoreux, and G.A.B. da Fonseca. 2005. Hotspots revisited: Earth's biologically richest and most endangered terrestrial ecoregions. Washington, DC: Conservation International,.
  11. Table Mountain National Park. 2010. Flora. South African National Parks. Online at http://www.sanparks.org/ parks/ table_mountain/ conservation/ flora.php#fynbos. Accessed May 10, 2010.
  12. Richardson J.E., F.M. Weitz, M.F. Fay, Q.C.B Cronk, H.P. Linder, G. Reeves, and M.W. Chase. 2001. Rapid and recent origin of species richness in the Cape Flora of South Africa. Nature 412:181-183.
  13. Cowling R.M. 1992. The ecology of fynbos: Nutrients, fire and diversity—Cape Town (South Africa). Oxford, UK: Oxford University Press.
  14. Simmons, R.E., P. Barnard, W.R.J, Dean, G.F. Midgley, W. Thuiller, and G. Hughes. 2004. Climate change and birds: Perspectives and prospects from southern Africa. Ostrich 64(4):295-308.
  15. United Nations Environment Programme. 2008. Africa: Atlas of our changing environment. Nairobi, Kenya: Division of Early Warning and Assessment. Online at http://www.unep.org/ dewa/ africa/ africaAtlas/ PDF/ en/ Africa_Atlas_Full_en.pdf. Accessed May 10, 2010.
  16. Boko, M., I. Niang, A. Nyong, C. Vogel, A. Githeko, M. Medany, B. Osman-Elasha, R. Tabo, and P. Yanda. 2007. Africa. In: Climate change 2007: Impacts, adaptation and vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Edited by M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden, and C.E. Hanson. Cambridge University Press, pp. 433-467.
  17. Kruger, A.C., and S. Shongwe, 2004: Temperature trends in South Africa, 1960-2003. International Journal of Climatology 24:1929-1945.
  18. Trenberth, K.E., P.D. Jones, P. Ambenje, R. Bojariu, D. Easterling, A. Klein Tank, D. Parker, F. Rahimzadeh, J.A. Renwick, M. Rusticucci, B. Soden and P. Zhai, 2007: Observations: Surface and Atmospheric Climate Change. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
  19. Rouget, M., D.M. Richardson, and R.M. Cowling. 2003. The current configuration of protected areas in the Cape Floristic Region, South Africa: Reservation bias and representation of biodiversity patterns and processes. Biological Conservation 112:129-145.
  20. Rouget, M., D.M. Richardson, R.M. Cowling, A.W. Lloyd, and A.T. Lombard. 2003. Current patterns of habitat transformation and future threats to biodiversity in terrestrial ecosystems of the Cape Floristic Region, South Africa. Biological Conservation 112:63-85.
  21. Thomas et al., (2004) investigated impacts to the Proteaceae family using an emissions scenario causing CO2 increases of 500-550 p.p.m.v. and associated temperature increases of 1.8-2.0° C by 2050. Simmons et al., (2004) examined impacts to the Cape sugarbird and the orange-breasted sunbird using the climate projections for ~2050 (averages for 2040-2065) derived from a General Circulation Model (Hadley Centre Model, HADCM3) for the A2 emissions scenario from the Intergovernmental Panel on Climate Change (IPCC).
  22. Thomas, C.D., A. Cameron, R. E. Green, M. Bakkenes, L. J. Beaumont, Y. C. Collingham, B. F. N. Erasmus, M. Ferreira de Siqueira, . Grainger, L. Hannah, L. Hughes, B. Huntley, A. S. van Jaarsveld, G. F. Midgley, L. Miles, M. A. Ortega-Huerta, A. T. Peterson, O. L. Phillips and S. E. Williams 2004. Extinction risk from climate change. Nature 427:145-148.
  23. Fischlin, A., G.F. Midgley, J.T. Price, R. Leemans, B. Gopal, C. Turley, M.D.A. Rounsevell, O.P. Dube, J. Tarazona, and A.A. Velichko. 2007. Ecosystems: Their properties, goods, and services. In: Climate change 2007: Impacts, adaptation and vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Edited by M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden, and C.E. Hanson. Cambridge University Press, pp. 211-272.
  24. Thomas, C.D., S. E.Williams, A. Cameron, R. E. Green, M. Bakkenes, L. J. Beaumont, Y. C. Collingham, B. F.N. Erasmus, M. Ferreira de Siqueira, A. Grainger, L. Hannah, L. Hughes, B. Huntley, A. S. van Jaarsveld, G. F.Midgley, L.Miles, M. A. Ortega-Huerta. 2004. Biodiversity conservation: Uncertainty in predictions of extinction risk/Effects of changes in climate and land use/Climate change and extinction risk (reply). Nature 430:34. doi:10.1038/nature02719
  25. Bond, W.J., G.F. Midgley, and F.I. Woodward. 2003. The importance of low atmospheric CO2 and fire in promoting the spread of grasslands and savannas. Global Change Biology 9:973-982.
  26. Midgley, G.F., R.A. Chapman, B. Hewitson, P. Johnston, M. De Wit, G. Ziervogel, P.Mukheibir, L.Van Niekerk,M. Tadross, B.W.VanWilgen, B. Kgope, P.D. Morant, A. Theron, R.J. Scholes, and G.G. Forsyth. 2005. A status quo, vulnerability and adaptation assessment of the physical and socio-economic effects of climate change in the Western Cape. Report to the Western Cape Government, Cape Town, South Africa. ENV-S-C 2005-073. Stellenbosch, South Africa: Council for Scientific and Industrial Research Environmentek.
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