TY - JOUR
T1 - Latitudinal Gradients of Biodiversity
T2 - Pattern, Process, Scale, and Synthesis
AU - Willig, M. R.
AU - Kaufman, D. M.
AU - Stevens, R. D.
PY - 2003
Y1 - 2003
N2 - The latitudinal gradient of decreasing richness from tropical to extratropical areas is ecology's longest recognized pattern. Nonetheless, notable exceptions to the general pattern exist, and it is well recognized that patterns may be dependent on characteristics of spatial scale and taxonomic hierarchy. We conducted an extensive survey of the literature and provide a synthetic assessment of the degree to which variation in patterns (positive linear, negative linear, modal, or nonsignificant) is a consequence of characteristics of scale (extent or focus) or taxon. In addition, we considered latitudinal gradients with respect to generic and familial richness, as well as species evenness and diversity. We provide a classification of the over 30 hypotheses advanced to account for the latitudinal gradient, and we discuss seven hypotheses with most promise for advancing ecological, biogeographic, and evolutionary understanding. We conclude with a forward-looking synthesis and list of fertile areas for future research.
AB - The latitudinal gradient of decreasing richness from tropical to extratropical areas is ecology's longest recognized pattern. Nonetheless, notable exceptions to the general pattern exist, and it is well recognized that patterns may be dependent on characteristics of spatial scale and taxonomic hierarchy. We conducted an extensive survey of the literature and provide a synthetic assessment of the degree to which variation in patterns (positive linear, negative linear, modal, or nonsignificant) is a consequence of characteristics of scale (extent or focus) or taxon. In addition, we considered latitudinal gradients with respect to generic and familial richness, as well as species evenness and diversity. We provide a classification of the over 30 hypotheses advanced to account for the latitudinal gradient, and we discuss seven hypotheses with most promise for advancing ecological, biogeographic, and evolutionary understanding. We conclude with a forward-looking synthesis and list of fertile areas for future research.
KW - Biogeography
KW - Geographic ecology
KW - Macroecology
KW - Species diversity
KW - Species richness
UR - http://www.scopus.com/inward/record.url?scp=0347473523&partnerID=8YFLogxK
U2 - 10.1146/annurev.ecolsys.34.012103.144032
DO - 10.1146/annurev.ecolsys.34.012103.144032
M3 - Review article
AN - SCOPUS:0347473523
SN - 0066-4162
VL - 34
SP - 273
EP - 309
JO - Annual Review of Ecology, Evolution, and Systematics
JF - Annual Review of Ecology, Evolution, and Systematics
ER -