Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Global diversity of marine macroalgae
T2 - environmental conditions explain less variation in the tropics
AU - Keith, Sal
AU - Kerswell, Ailsa S. P.
AU - Connolly, Sean R.
PY - 2014/5
Y1 - 2014/5
N2 - AimMarine macroalgae provide an excellent opportunity to test hypotheses about latitudinal diversity gradients because macroalgal richness decreases towards the tropics, contrary to classic patterns, and because three evolutionarily distinct macroalgal clades (Rhodophyta, Chlorophyta, Phaeophyceae) have converged ecologically. Specifically, we determine the extent to which environmental conditions can predict genus richness in macroalgae. We also evaluate whether the magnitude or direction of the effect of environmental factors, or their ability to explain variation in macroalgal diversity, varies geographically.LocationGlobal oceans.MethodsWe formulated and fitted global spatial regression models and geographically weighted regression (GWR) models to determine the extent to which environmental conditions could predict genus richness in macroalgae. GWR allowed us to determine how the role of environmental conditions varied amongst geographical regions.ResultsThe global regression model showed that sea surface temperature and nutrients were important predictors of macroalgal genus richness at a global scale. However, GWR revealed that environmental factors explained less variability in richness in the tropics than elsewhere.Main conclusionsOur results show that whilst environmental conditions influence marine macroalgal diversity, the strength of this influence shows considerable geographical variation. In particular, environmental conditions explain more of the observed variation in diversity at high latitudes than at low latitudes. This finding is consistent with the hypothesis that environmental tolerances influence species distributions more strongly at high latitudes, whereas other factors, such as biotic interactions, play a more prominent role in the tropics.
AB - AimMarine macroalgae provide an excellent opportunity to test hypotheses about latitudinal diversity gradients because macroalgal richness decreases towards the tropics, contrary to classic patterns, and because three evolutionarily distinct macroalgal clades (Rhodophyta, Chlorophyta, Phaeophyceae) have converged ecologically. Specifically, we determine the extent to which environmental conditions can predict genus richness in macroalgae. We also evaluate whether the magnitude or direction of the effect of environmental factors, or their ability to explain variation in macroalgal diversity, varies geographically.LocationGlobal oceans.MethodsWe formulated and fitted global spatial regression models and geographically weighted regression (GWR) models to determine the extent to which environmental conditions could predict genus richness in macroalgae. GWR allowed us to determine how the role of environmental conditions varied amongst geographical regions.ResultsThe global regression model showed that sea surface temperature and nutrients were important predictors of macroalgal genus richness at a global scale. However, GWR revealed that environmental factors explained less variability in richness in the tropics than elsewhere.Main conclusionsOur results show that whilst environmental conditions influence marine macroalgal diversity, the strength of this influence shows considerable geographical variation. In particular, environmental conditions explain more of the observed variation in diversity at high latitudes than at low latitudes. This finding is consistent with the hypothesis that environmental tolerances influence species distributions more strongly at high latitudes, whereas other factors, such as biotic interactions, play a more prominent role in the tropics.
KW - Biogeography
KW - colonization
KW - competition
KW - geographically weighted regression
KW - herbivory
KW - macroecology
KW - origination
KW - seaweed
KW - species interactions
KW - time-for-speciation
U2 - 10.1111/geb.12132
DO - 10.1111/geb.12132
M3 - Journal article
VL - 23
SP - 517
EP - 529
JO - Global Ecology and Biogeography
JF - Global Ecology and Biogeography
SN - 1466-822X
IS - 5
ER -