Monday, August 6, 2018: 4:00 PM
254, New Orleans Ernest N. Morial Convention Center
Brunno F. Oliveira1,2 and Brett R. Scheffers2, (1)Environmental Science and Policy, University of California Davis, Davis, CA, (2)Wildlife Ecology and Conservation, University of Florida, Gainesville, FL
Background/Question/Methods Species fill the three-dimensional vegetation space of terrestrial ecosystems, resulting in vertically stratified communities. It is presumed that this layering allows for greater species coexistence, so verticality should also influence biogeographical patterns via its interaction with the physical and climatic environments. As environments become more structurally complex, arboreality becomes a beneficial attribute provided by morphological specializations for perching, nesting and foraging on branches of trees. Moreover, vertical movements, either upwards in the canopy (i.e., arboreality) or downwards into the ground (i.e., fossoriality), afford more plastic ecologies and confer advantages over entirely ground-dwelling species due to a greater accessibility to micro- habitats and climates. Using a unique dataset for >4500 amphibian species globally, we show how vertical niche strategies interact with the physical and climatic environments to govern global patterns of species richness and community composition.
Results/Conclusions
We reveal a marked latitudinal shift in strategies of vertical habitat use, from highly arboreal assemblages in the tropics to highly fossorial assemblages in sub-tropical and temperate regions. The most divergent modes of verticality (arboreality vs. fossoriality) are favored in contrasting sets of environments—arboreality is strongly associated with precipitation, vegetation structure and climatic stability, whereas fossoriality is more common in harsh environments with high diurnal temperature range. Our findings demonstrate that global amphibian diversity is structured in vertical niches, such that species-rich regions are typified by high vertical stratification. The strong link between verticality and precipitation suggests that as regions experience drying from climate change, vertically stratified communities, a signature of tropical rainforests, may be flattened as ground-living lifestyles are selected for more frequently.
