Scale-Dependent Coherence of Terrestrial Vertebrate Biodiversity with
Environment
Abstract
Disentangling contributions from environmental variables is crucial for
explaining global biodiversity patterns. We use wavelet power spectra to
separate wavelength-dependent trends across Earth’s surface. Spectra
reveal scale- and location-dependent coherence between species richness
and topography (E), annual precipitation (Pn), temperature
(Tm) and temperature range (ΔT). >97% of
richness of carnivorans, bats, songbirds, hummingbirds and amphibians
resides at wavelengths
>~103 km. 30-69% is
generated at scales >~104
km. At these scales, richness across the Americas is anti-correlated
with E and ΔT, and positively correlated with Pn
and Tm. Carnivoran richness is incoherent with ΔT,
suggesting insensitivity to temperature seasonality. Conversely,
amphibian richness is anti-correlated with ΔT at large scales. At
scales <~103 km, richness is
highest within the tropics. Terrestrial plateaux exhibit coherence
between carnivoran richness and E at scales
~103 km, reflecting contributions of
orogeny/epeirogeny to biodiversity. Similar findings result from
transects across other continents. Scale-dependent sensitivities of
vertebrate populations to climate are revealed.