Trait evolution underlies biodiversity patterns

Last updated: 8 Nov, 2016

A new paper by Tanentzap & Lee shows how traits that influence the responses of species to abiotic conditions can help predict the amount of evolutionary history that will be retained in ecological communities under future environmental change.

Study site in South Island, New Zealand showing difference between July (top) and August (bottom) water levels.  The wetlands have three distinct vegetation zones starting on the wetland bottom with short prostrate perennials and moving up slope to taller graminoids and then onto dryland scrub.

The paper describes how species-specific responses to flooding explain most of the variation in the community composition of wetlands, and that these responses are driven by variation in root aerenchyma volume.  By developing a new statistical approach that accounts for the shared evolutionary history among species, the authors go on to show that species with a large root aerenchyma volume are more likely to occur in natural communities when flooding lasts for longer time periods.  This increase arises because large root aerenchyma volume reduces above-ground biomass loss.  As large root aerenchyma was found to be highly conserved in the evolution of their wetland flora, longer flooding can lead to communities becoming more closely-related over time.

This is an edited version of the original press release.