ANU Research Forests


Overview

This research project focuses on the effects of climate variability, climate change and water use in two different types of eucalypt trees, Corymbia maculata (spotted gum) and Eucalyptus tricarpa (red ironbark).

These two different species were chosen because they cope with low rainfall and drought in different ways; spotted gum is a drought ‘avoider’ and uses an extensive root system to maintain its water intake, whereas red ironbark is a drought ‘tolerator’ and alters its metabolism to stop growing during drought.

Irrigation to these trees is being manipulated to simulate drought in forests 98, 99 and 101 in this long term, detailed study on the adaptability, genetics, physiology and ecology of the Eucalyptus genus.

Chief investigator

Cris Brack, Fenner School, Australian National University (ANU)

Other investigators

Michael Roderick, Tim Brown and Justin Borovitz, RSB, Australian National University

Albert van Dijk, Fenner School, Australian National University

Research aims

Methods

Time frame

Outputs

Further information

Results as of September 2013

Many of the seedlings survived establishment, however, a late and severe frost in October 2012, followed by extreme heat, caused many of the Corymbia maculata (spotted gum) to die or die-back, whereas most of the Eucalyptus tricarpa (red ironbark) survived the extreme temperatures. Water availability was deliberately restricted to both species.

Eucalyptus tricarpa (red ironbark) Sept 2013

Eucalyptus tricarpa (red ironbark) Sept 2013

Corymbia maculata (spotted gum) Sept 2013

Corymbia maculata (spotted gum) Sept 2013.

Key research questions

All data collected will be available online for research, outreach and educational use.

Experimental design

Two eucalypt species were selected for their different responses to low rainfall:

The trees were planted in blocks of single species, with the blocks arranged to allow three watering treatments and replication. Such an arrangement allows researchers to measure the effects of different watering regimes on the growth and survival of the trees, and consequently estimate the effects on many other eucalypt species. The blocks are large enough to allow them to be split to examine other important environmental effects such as competition.