NCEAS Project 7680

Elevational trends in biodiversity: Examining theoretical predictions across taxa

  • Christy M. McCain

ActivityDatesFurther Information
Postdoctoral Fellow13th January 2004—12th January 2007Participant List  
Graduate Student1st April—30th June 2006Participant List  

Documenting patterns and understanding factors producing and maintaining global biodiversity have been fundamental goals of ecological research since the first expeditions of Darwin and Wallace. After a century and a half of research on biodiversity patterns and processes, Brown asserted that a general explanation for patterns of biodiversity would emerge in the next few years, particularly for elevational and latitudinal patterns. Elevational gradients hold enormous potential for understanding general properties of biodiversity since variable topography is global, and predictable climatic patterns with large concomitant changes in biodiversity occur over small spatial scales. Additionally, biodiversity studies along elevational gradients have been amassed for many taxa on mountain ranges across the globe. Lomolino outlined some testable diversity hypotheses in a research agenda, which would lead to a general explanation for elevational patterns, including climatic hypotheses, species-area effects, community overlap patterns, and historical factors. In the first quantitative synthesis, I tested some of the predictions for elevational diversity patterns of non-volant small mammals (n = 51) with intriguing results. Peak alpha diversity occurred at higher elevations on taller mountains, evidence supporting a combination of climatic factors influencing diversity patterns. In contrast, gamma diversity patterns supported the predictions of the mid-domain effect, displayed a positive, linear trend with latitude, and showed trends consistent with species-area effects. To further examine these preliminary trends, I propose addressing the following questions: (1) Is there a latitudinal trend in elevation of peaks in diversity on mountainsides? (2) Does the species-area relationship inherent to elevational gradients mask other mechanisms producing and maintaining biodiversity? (3) Is there general support for the community overlap hypothesis on elevational gradients? (4) Are there general mechanisms producing elevational diversity patterns across taxa?

TypeProducts of NCEAS Research
Journal Article Dunn, Robert; McCain, Christy M.; Sanders, Nathan J. 2007. When does diversity fit null model predictions? Scale and range size mediate the mid-domain effect. Global Ecology and Biogeography. Vol: 16. Pages 305-312.
Book Chapter Grytnes, John A.; McCain, Christy M. 2007. Elevational patterns in species richness. Edited by S. Levin Encyclopedia of Biodiversity. Elsevier, Inc.. Pages 1-8.
Journal Article McCain, Christy M. 2005. Elevational gradients in diversity of small mammals. Ecology. Vol: 86(2). Pages 366-372.
Journal Article McCain, Christy M. 2006. Do elevational range size, abundance, and body size patterns mirror those documented for geographic ranges? A case study using Costa Rican rodents. Evolutionary Ecology Research. Vol: 8. Pages 435-454.
Journal Article McCain, Christy M. 2007. Area and mammalian elevational diversity. Ecology . Vol: 88 (1). Pages 76-86.
Journal Article McCain, Christy M. 2007. Could temperature and water availability drive elevational species richness patterns? a global case study for bats. Global Ecology and Biogeography. Vol: 16. Pages 1-13.
Journal Article McCain, Christy M. 2009. Global analysis of bird elevational diversity. Global Ecology and Biogeography. Vol: 18. Pages 346-360.
Journal Article McCain, Christy M. 2010. Global analysis of reptile elevational diversity. Global Ecology and Biogeography. Vol: 19(4). Pages 541-553. (Online version)
Journal Article Mittelbach, Gary G.; Schemske, Douglas W.; Cornell, Howard V.; Allen, Andrew P.; Brown, Jonathan; Bush, Mark; Harrison, Susan P.; Hurlbert, Allen H.; Knowlton, Nancy; Lessios, Harilaos A.; McCain, Christy M.; McCune, Amy R.; McDade, Lucinda A.; McPeek, Mark A.; Near, Thomas J.; Price, Trevor; Ricklefs, Robert E.; Roy, Kaustuv; Sax, Dov F.; Schluter, Dolph; Sobel, James M.; Turelli, Michael. 2007. Evolution and the latitudinal diversity gradient: Speciation, extinction and biogeography. Ecology Letters. Vol: 10. Pages 315-331.