Vertical stratification influences global patterns of terrestrial biodiversity and their vulnerability to climate change

Dr Brett Scheffers¹, Dr.  Brunno Oliveira¹

¹University Of Florida, Gainesville, United States

Background – Species distributions in terrestrial ecosystems are three-dimensional, spanning both the horizontal landscape and the vertical space provided by the physical environment. Classical hypotheses suggest that communities become more vertically stratified with increasing species richness, owing to reduced competition or finer niche subdivision. However, this assertion remains untested in the context of the broader realm of biogeography.

Objective – Here, integrating traits and distribution data for vertebrates globally, we show how vertical niche strategies interact with the physical and climatic environments to govern global patterns of species richness and community composition.

Methods – We created the first ever global dataset on the vertical niches of over 16,000 mammal, bird and amphibian species, and compare patterns of verticality to topography, forest complexity and bioclimatic variables such as precipitation and temperature variability.

Results – Our results 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—a pattern that holds across taxa. Arboreality is strongly associated with precipitation, vegetation structure and climatic stability, whereas fossoriality in select taxa is more common in dry environments with high diurnal temperature range and low vegetation structure.

Conclusion – We will discuss how these analyses shed light on the importance of vertical stratification for species coexistence in species-rich regions. Further we will discuss how drying from climate change can drive tropical diversity from vertically stratified to “flattened”, with future communities living mostly on or beneath the ground.

Biography:

Brett Scheffers runs an international research program at the University of Florida. As an assistant professor in the Department of Wildlife Ecology and Conservation, Brett’s research focuses on how human disturbances such as habitat loss and climate change impacts the ecology of a diversity of animals such as birds, frogs, lizards, ants, and butterflies and spans tropical ecosystems in Central and South America, East Africa, and Australasia. Brett has been published in leading academic journals such as Science, Nature Climate Change, Proceedings of the Royal Society, and Trends in Ecology and Evolution and his work has been covered by dozens of news outlets such as The Economist, Huffington Post, and Bloomberg News. He is an advisory member of the Climate Change Specialist group under the International Union for Conservation of Nature, which provides guidelines for assessing species vulnerability to climate change. He proudly serves as Florida Climate Institute’s 2018 Faculty Fellow and served as an organizing committee member for “Species on the Move” in 2016. His outreach efforts include popular writing in online news outlets such as The Conversation, merging art with science to improve learning, and communicating climate and conservation science to public audiences.