Research Seminar - Hawkesbury Institute for the Environment

Seminar Abstract: Leaves and roots of trees perform complementary roles in resource acquisition – leaves take up carbon (C) and export a portion of it to other plant organs including roots, but they require nitrogen (N) acquired by roots to do so; roots take up N and export a portion of it to aboveground organs, but they require C acquired by leaves to do so. When that symmetry is built into forest growth models and the additional assumption is made that trees maximise their annual wood production, three surprising results emerge. One relates to canopy structure, one to root structure, and the third and prettiest result is an equation linking leaf and root function. That equation provides insight into CO₂ responses of leaf and root traits such as leaf N concentration, photosynthetic rate, leaf-area index and maximum rooting depth. The three results when combined lead to a new method for scaling from leaf and root functional traits to stand productivity, and an approach for modelling C allocation that avoids the need to represent specific C allocation mechanisms.

Ross McMurtrie has spent more than 30 years working with process-based models of forests, and is author of several forest ecosystem models, including BIOMASS, G’DAY and MATE. From 2004 to 2009 he served as lead PI on the Hawkesbury Forest Experiment. He now works mainly on models of optimal plant function and is an Honorary Professor at the University of NSW.

The seminar will be followed by drinks and nibbles available in the foyer of L9 – all are welcome! We hope to see you all there - no RSVP is required.