Mr Darren Grant

 

This postgraduate research project is undertaken within Programme One of the CRC for Forestry: Managing and Monitoring for Growth and Health.

The project investigates how the characteristics of soil affect the productivity of a forest plantation, and how to better represent these soil characteristics and root growth and soil occupancy in growth and yield models.

Particularly, I will study predictions of plant-available water from soil properties such as sand, silt, loam, and clay fractions, soil aggregation, and soil density in relation to how tree roots grow and which soil layers they occupy.

I want to know what effect these variables have on tree growth in a process model, including what level of sophistication is needed in the model for it to capture the range and sensitivity in the relationship between plant available water and tree growth.

I will use existing data, where soils have been well described in permanent Eucalyptus globulus plantation growth monitoring plots in south-eastern Australia, for model calibration and validation.

I study full-time at the University of Melbourne, after having completed a Bachelor of Applied Science (Environmental Management) with Honours, at the University of Ballarat. I have worked with government and university forest institutions in Victoria in soil and water, and plantation research. The CRC for Forestry offers a great opportunity to develop my skills and interest in soils and forest plantations.

a. duplex soil

b. cracking clay soil

c. gradational soil

Duplex soil has sandy loam top soil, changing to light medium clay in the subsoil below after about 40 cm. As clay is difficult for tree roots to penetrate, it restricts root growth and the volume of water available to the roots.

Cracking clay soil shrinks and cracks when dry and swells when wet, and this movement can damage roots. As with duplex soil, the clay is difficult to penetrate.

Gradational soil has sandy loam in the top soil, sandy clay loam in the subsoil below 60 cm and no restrictive layer to root growth. As this is a relatively deep soil type, and combined with its loamy characteristic, gradational soil has more plant-available water compared to the duplex and cracking clay soil types.

Eucalyptus globulus age 13 years, growing in duplex soil in south-eastern Victoria.

My supervisors are Drs Thomas Baker and Paul Feikema, School of Forest and Ecosystem Science, Dr Craig Beverly, Department of Sustainability and Environment, Victoria, and Dr Neil McKenzie, CSIRO Land and Water.

To browse other PhD projects available with Research Programme One click here

*Edaphic: of the soil; produced or influenced by the soil (The New Shorter Oxford English Dictionary, 1993)