Functional plant ecology: can we use long-dead plants to reconstruct what the plants did in life? (28.06.2018)

Functional ecology aims to explain how species’ traits (i.e. their shape, size, structure, metabolism, chemistry etc.) influence how they interact with their environment. For example: do plants with certain types of leaves cope better in certain environments, and why? This approach is very powerful in explaining ecological patterns, but relies heavily on good measurements of the traits of interest (e.g. leaf traits). Thus, the important question is: how can we get good trait data in large quantities?

Often, measurements are derived from living or just dead organisms. For example, plant leaves can be measured while still on the plant, or when they have just been cut. This ensures good data, but requires fieldwork, which is time consuming, costly and sometimes impractical. However, large numbers of specimens are easily available for measurement in natural history collections, such as herbaria (http://bios.au.dk/fileadmin/bioscience/Doede_planter_er_fulde_af_liv.pdf ). Can we use these specimens to obtain meaningful measurements of functional traits? If yes, this would revolutionize our ability to conduct functional ecological analyses.

The challenge is that traits change when specimens are being preserved. For example, leaves shrink when plants are dried. In this project, you will conduct controlled experiments measuring plant functional traits (http://www.publish.csiro.au/BT/bt12225) before and after preservation, to find out if changes are random or systematic. You will also experiment with techniques to reverse these changes at the specimen-level (e.g. rehydrating leaves to undo shrinkage) and statistical approaches aiming to compensate for systematic changes.  

Your study will show under what circumstances preservation bias can be a problem for collections-based functional ecology, and offer some practical solutions.

Contact: supervisors: Wolf L. Eiserhardt (wolf.eiserhardt@bios.au.dk) and Alejandro Ordonez (alejandro.ordonez@bios.au.dk) (supervision in English or Danish)

Photo: Jurriaan de Vos