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Department of Plant Sciences

 
Trait evolution underlies biodiversity patterns

A new paper by Tanentzap & Lee published in New Phytologist 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.

The work finds that 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, Tanentzap and Lee 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 communities to become more closely-related and erode the diversity of the Tree of Life present in nature.

Tanentzap, A. J. and Lee, W. G. (2016), Evolutionary conservatism explains increasing relatedness of plant communities along a flooding gradient. New Phytol. doi:10.1111/nph.14167

Image

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.