Data from: Contrasting diversity patterns of breeding Anatidae in the Northern and Southern Hemispheres

For sustaining ecosystem functions and services, environmental
conservation strategies increasingly target to maintain the multiple
facets of biodiversity, such as functional diversity (FD) and phylogenetic
diversity (PD), not just taxonomic diversity (TD). However, spatial
mismatches among these components of biodiversity can impose challenges
for conservation decisions. Hence, understanding the drivers of
biodiversity is critical. Here, we investigated the global distribution
patterns of TD, FD and PD of breeding Anatidae. Using null models, we
clarified the relative importance of mechanisms that influence Anatidae
community. We also developed Random Forest models to evaluate the effects
of environmental variables on the Anatidae TD, FD and PD. Our results
showed that geographic variation in Anatidae diversity is hemispheric
rather than latitudinal. In the species-rich Northern Hemisphere (NH), the
three diversity indices decreased with latitude within the tropical zone
of the NH, but increased in the temperate zone reaching a peak at
44.5–70.0° N, where functional and phylogenetic clustering was a
predominant feature. In the Southern Hemisphere (SH), Anatidae diversity
increased poleward and a tendency to over-dispersion was common. In NH,
productivity seasonality and temperature in the coldest quarter were the
most important variables. Productivity seasonality was also the most
influential predictor of SH Anatidae diversity, along with peak
productivity. These findings suggested that seasonality and productivity,
both consistent with the energy-diversity hypothesis, interact with the
varying histories to shape the contrasting hemispheric patterns of
Anatidae diversity. PD and FD under-dispersion, widespread across the
species-rich, seasonally productive mid to high latitudes of the NH,
reflects a rapid evolutionary radiation and resorting associated with
Pleistocene cycles of glaciation. The SH continents (and southern Asia)
are characterised by a widespread tendency towards PD and FD
over-dispersion, with their generally species-poor communities comprising
proportionately more older lineages in thermally more stable but less
predictably productive environments.