Skip to content

Root responses

Project team: Kalhari Gunarathna Yahampath Arachchige (University of Portsmouth), Yolima Carrillo (Western Sydney University), Catriona Macdonald (Western Sydney University), Benjamin Smith (Western Sydney University), Uffe Nielsen (Western Sydney University) and David Wårlind (Lund University)

Project period: 2025 – ongoing

You can find contacts to the Western Sydney University members of the project here

Summary

My PhD research project focuses on the belowground mechanistic responses of Eucalyptus tereticornis to elevated CO₂ (eCO2) and phosphorus (P) enrichment at the EucFACE site. It integrates both empirical and modelling approaches. 

The primary objective of this project is to determine whether eCO₂ stimulates belowground carbon (C) allocation to enhance P acquisition, root biomass, and root net primary productivity (NPP). Given that P is strongly limited at the EucFACE site and that a large proportion of bioavailable P is retained within microbial biomass.

I am also investigating microbial P retention time and turnover to assess whether microbial immobilization constrains plant P availability.

In addition, this project aims to use the empirical data generated to improve the predictive capacity of the LPJ-GUESS model, particularly in relation to belowground C allocation and P cycling processes, in order to better predict nutrient-limited forest responses to rising atmospheric CO₂ concentrations.

I am investigating:
i. Whether increased organic acid exudation enhances plant-available P in EucFACE soils under elevated versus ambient CO₂ conditions, and under P-enriched versus P-limited treatments.
ii. Root morphological development (live root dynamics) of E. tereticornis in response to elevated CO₂ and P enrichment.
iii. Microbial P mean residence time and turnover rates in EucFACE soils.

Publications

The project is still in its early stages. Aside from preliminary soil analyses, full fieldwork has not yet commenced, and therefore no definitive findings are available at this stage. (2025)

Forums

You are welcome to take part in discussions about the research topic below. To start click a desired topic below. To prevent spam we ask you to create an account. You do this by clicking a topic and then hit the Login button. Then an option to create an account will appear. 

Note that you might get a message from the University spam filter to allow notifications from the forum first time you use it. For WSU “You have new held emails”. Click Permit. After that it should not be an issue. 

To get notifications when new messages are sent for a particular topic, click Subscribe in the upper right corner when the topic is open.