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Biological response to climate change on a tropical mountain


Recent warming has caused changes in species distribution and abundance1,2,3, but the extent of the effects is unclear. Here we investigate whether such changes in highland forests at Monteverde, Costa Rica, are related to the increase in air temperatures that followed a step-like warming of tropical oceans in 1976 (refs4, 5). Twenty of 50 species of anurans (frogs and toads) in a 30-km2 study area, including the locally endemic golden toad (Bufo periglenes), disappeared following synchronous population crashes in 1987 (68). Our results indicate that these crashes probably belong to a constellation of demographic changes that have altered communities of birds, reptiles and amphibians in the area and are linked to recent warming. The changes are all associated with patterns of dry-season mist frequency, which is negatively correlated with sea surface temperatures in the equatorial Pacific and has declined dramatically since the mid-1970s. The biological and climatic patterns suggest that atmospheric warming has raised the average altitude at the base of the orographic cloud bank, as predicted by the lifting-cloud-base hypothesis9,10.

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Figure 1: Trends and fluctuations in dry-season precipitation and stream flow.
Figure 2: Trends and fluctuations in dry-season air temperatures.
Figure 3: Changes in the bird community of the 1,540-m plot.
Figure 4: Declines in populations of anoline lizards and anurans.


  1. Parmesan, C. Climate and species' range. Nature 382, 765–766 (1996).

    Article  ADS  CAS  Google Scholar 

  2. Veit, R. R., McGowan, J. A., Ainley, D. G., Wahls, T. R. & Pyle, P. Apex marine predator declines 90% in association with changing oceanic climate. Global Change Biol. 3, 23–28 (1997).

    Article  ADS  Google Scholar 

  3. McGowan, J. A., Cayan, D. R. & Dorman, L. M. Climate–ocean variability and ecosystem response in the northeast Pacific. Science 281, 210–217 (1998).

    Article  CAS  Google Scholar 

  4. Trenberth, K. E. & Hurrell, J. W. Decadal atmosphere-ocean variations in the Pacific. Clim. Dyn. 9, 303–319 (1994).

    Article  Google Scholar 

  5. Graham, N. E. Simulation of recent global temperature trends. Science 267, 666–671 (1995).

    Article  ADS  CAS  Google Scholar 

  6. Pounds, J. A. & Crump, M. L. Amphibian declines and climate disturbance: the case of the golden toad and the harlequin frog. Cons. Biol. 8, 72–85 (1994).

    Article  Google Scholar 

  7. Pounds, J. A., Fogden, M. P. L., Savage, J. M. & Gorman, G. C. Tests of null models for amphibian declines on a tropical mountain. Cons. Biol. 11, 1307–1322 (1997).

    Article  Google Scholar 

  8. Pounds, J. A. in Monteverde: Ecology and Conservation of a Tropical Cloud Forest(eds Nadkarni, N. M.&Wheelwright, N. T.) (Oxford University Press, New York, in press).

  9. Pounds, J. A., Fogden, M. P. L. & Campbell, J. H. in Meeting Report, Bird Life International/WWF Workshop on the Impacts of Climate Change on Flora and Fauna(ed. Briggs, B.) (Royal Society for Protection of Birds, Bedfordshire, UK, 1997).

    Google Scholar 

  10. Still, C. J., Foster, P. N. & Schneider, S. H. Simulating the effects of climate change on tropical montane cloud forests. Nature 398, 608–610 (1999).

    Article  ADS  CAS  Google Scholar 

  11. Diaz, H. F. & Graham, N. E. Recent changes in tropical freezing heights and the role of sea-surface temperature. Nature 383, 152–155 (1996).

    Article  ADS  CAS  Google Scholar 

  12. Beniston, M., Diaz, H. F. & Bradley, R. S. Climatic change at high elevation sites: an overview. Clim. Change 36, 233–251 (1997).

    Article  Google Scholar 

  13. Diaz, H. F. & Bradley, R. S. Temperature variations during the last century at high elevation sites. Clim. Change 36, 253–279 (1997).

    Article  Google Scholar 

  14. Thompson, L. G. et al. Late glacial stage and holocene tropical ice core records from Huascarán, Peru. Science 269, 46–50 (1995).

    Article  ADS  CAS  Google Scholar 

  15. Cavalier, J., Solis, D. & Jaramillo, M. A. Fog interception in montane forests across the Central Cordillera of Panamá. J. Trop. Ecol. 12, 357–369 (1996).

    Article  Google Scholar 

  16. Clark, K. L., Nadkarni, N. M., Schaefer, D. & Gholz, H. Atmospheric deposition and net retention of ions by the canopy in a tropical montane forest, Monteverde, Costa Rica. J. Trop. Ecol. 14, 27–45 (1998).

    Article  Google Scholar 

  17. Karl, T. R. et al. Anew perspective on recent global warming: asymmetric trends of daily maximum and minimum temperatures. Bull. Am. Meteorol. Soc. 74, 1007–1023 (1993).

    Article  ADS  Google Scholar 

  18. Gómez, I. E. & Fernandez, W. Variación interannual de la temperatura en Costa Rica. Top. Meteor. Oceanogr. 3, 27–44 (1996).

    Google Scholar 

  19. Karr, J. R. & Freemark, K. E. Habitat selection and environmental gradients: dynamics in the ‘stable’ tropics. Ecology 64, 1481–1494 (1983).

    Article  Google Scholar 

  20. Fogden, M. P. L. An Annotated Checklist of the Birds of Monteverde and Peñas Blancas(Green Mountain, Monteverde, Costa Rica, 1993).

    Google Scholar 

  21. Andrews, R. M. Population stability of a tropical lizard. Ecology 72, 1204–1217 (1991).

    Article  Google Scholar 

  22. Pounds, J. A. Ecomorphology, locomotion, and microhabitat structure: patterns in a tropical mainland Anolis community. Ecol. Monogr. 58, 299–320 (1988).

    Article  Google Scholar 

  23. Laurance, W. F. Catastrophic declines of Australian rainforest frogs: is unusual weather responsible? Biol. Cons. 77, 203–212 (1996).

    Article  Google Scholar 

  24. Crump, M. L. & Pounds, J. A. Lethal parasitism of an aposematic anuran (Atelopus varius) by Notochaeta bufonivora (Diptera: Sarcophagidac). J. Parasitol. 71, 588–591 (1985).

    Article  Google Scholar 

  25. Pounds, J. A. & Crump, M. L. Harlequin frogs along a tropical montane stream: aggregation and the risk of predation by frog-eating flies. Biotropica 19, 306–309 (1987).

    Article  Google Scholar 

  26. Crump, M. L. & Pounds, J. A. Temporal variation in the dispersion of a tropical anuran. Copeia 1989, 209–211 (1989).

    Article  Google Scholar 

  27. Dobson, A. & Carper, R. in Global Warming and Biological Diversity(eds Peters, R. L.&Lovejoy, T. E.) 201–217 (Yale Univ. Press, New Haven, Connecticut, 1992).

    Google Scholar 

  28. Beebee, T. J. C. Amphibian breeding and climate. Nature 374, 219–220 (1995).

    Article  ADS  CAS  Google Scholar 

  29. Stewart, M. M. Climate driven population fluctuations in rain forest frogs. J. Herpetology 29, 437–446 (1995).

    Article  Google Scholar 

  30. Berger, L. et al. Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America. Proc. Natl Acad. Sci. 95, 9031–9036 (1998).

    Article  ADS  CAS  Google Scholar 

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We thank C. J. Still, P. N. Foster and S. H. Schneider for sharing their GCM simulations and for their comments on the manuscript; we also thank M. Brenes, R. W. Carlson, P.M.Fogden, G. R. Graves, J. F. Jackson, F. J. Joyce, K. L. Masters, J. M. Savage and N. T. Wheelwright for comments that improved the final version. J.A.P. acknowledges partial support from the MacArthur Foundation, Stanford University's Center for Conservation Biology, the Brookfield Zoo, the University of Miami, the US NSF, the Jessie Smith Noyes Foundation, the Organization for Tropical Studies, the Tropical Science Center and the University of Florida.

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Correspondence to J. Alan Pounds.

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Pounds, J., Fogden, M. & Campbell, J. Biological response to climate change on a tropical mountain. Nature 398, 611–615 (1999).

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