Climatic drivers of hemispheric asymmetry in global patterns of ant species richness.
Although many taxa show a latitudinal gradient in richness, the relationship between latitude and species richness is often asymmetrical between the northern and southern hemispheres. Here we examine the latitudinal pattern of species richness across 1003 local ant assemblages. We find latitudinal asymmetry, with southern hemisphere sites being more diverse than northern hemisphere sites. Most of this asymmetry could be explained statistically by differences in contemporary climate. Local ant species richness was positively associated with temperature, but negatively (although weakly) associated with temperature range and precipitation. After contemporary climate was accounted for, a modest difference in diversity between hemispheres persisted, suggesting that factors other than contemporary climate contributed to the hemispherical asymmetry. The most parsimonious explanation for this remaining asymmetry is that greater climate change since the Eocene in the northern than in the southern hemisphere has led to more extinctions in the northern hemisphere with consequent effects on local ant species richness.
Dunn
Robert R
RR
Department of Biology, North Carolina State University, Raleigh, NC 27695, USA. rob_dunn@ncsu.edu
Agosti
Donat
D
Andersen
Alan N
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Arnan
Xavier
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Bruhl
Carsten A
CA
Cerdá
Xim
X
Ellison
Aaron M
AM
Fisher
Brian L
BL
Fitzpatrick
Matthew C
MC
Gibb
Heloise
H
Gotelli
Nicholas J
NJ
Gove
Aaron D
AD
Guenard
Benoit
B
Janda
Milan
M
Kaspari
Michael
M
Laurent
Edward J
EJ
Lessard
Jean-Philippe
JP
Longino
John T
JT
Majer
Jonathan D
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Menke
Sean B
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McGlynn
Terrence P
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Parr
Catherine L
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Philpott
Stacy M
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Pfeiffer
Martin
M
Retana
Javier
J
Suarez
Andrew V
AV
Vasconcelos
Heraldo L
HL
Weiser
Michael D
MD
Sanders
Nathan J
NJ
D000818:Animals; D001000:Ants / Q000235:genetics / Q000502:physiology*; D044822:Biodiversity; D005075:Biological Evolution; D002980:Climate