Iluka formed a partnership in 2011 with the University of Adelaide to research plant-soil-water relations at the Jacinth-Ambrosia mine site, with the funding support of the Australian Research Council Linkage Program.
The primary objective has been to provide information to assist rehabilitation at Jacinth-Ambrosia to enable the return of affected areas to ecosystem and landscape functions that will be both resilient and sustainable.
The research has three main aims at Jacinth-Ambrosia:
- to investigate the spatial distribution of roots and how this relates to soil characteristics for key plant species;
- to examine soil-water relations for key plant species; and
- to examine the responses of key plant species to water availability and increased salinity in natural and reconstructed soil profiles.
The Australian Research Council Linkage Program comprises the following programs.
Spatial distribution of roots and soil characteristics.
Root mapping work at Jacinth-Ambrosia has shown a discrepancy between the pre-disturbance soil profile depth utilised by western myall trees and the proposed post-mining soil depth. This study will assess the vertical and horizontal root distribution of key plant species and correlate the root density and distribution to determine the suitability of the post-mining soil profile for different vegetation types.
Hydraulic redistribution by western myall.
Hydraulic redistribution is a process that some deep-rooted plant species employ to redistribute water via their root systems into deeper soil layers during seasons of high rainfall or during large summer rainfall events. In dry seasons or periods of drought, the water stored deep in the soil moves upwards through the root system via hydraulic lift, and can therefore be used by the plant to sustain its surface roots. This study will investigate the hydraulic redistribution process in the two most abundant deep-rooted species at Jacinth-Ambrosia, the western myall and red mallee.
This information will potentially assist with the assessment of the potential growth success of the deep-rooted plant species in modified soils and tailings that may have different water storage capacities when compared with those of undisturbed soil.
Cell 1 Trial.
The Cell 1 Trial has been designed as a larger, long-term study with plant structural, morphological and physiological measurements being collected alongside soil chemistry and soil-water properties to examine the following:
- whether western myall, red mallee and yorrell species of trees are able to produce sustainable populations on shallow soil profiles over saline tailings;
- whether each species is capable of extracting and using moisture from saline tailings and if so, determine where the salt accumulates, that is, exclusion at root zone or uptake, tissue accumulation and loss with subsequent salt accumulation in surface soil; and
- changes in soil chemical and physical characteristics as a result of disturbance.
In addition, Iluka is working with the University of Queensland and University of New South Wales to study biological crusts, specifically in suppressing weed outbreaks and incursions in semi arid environments.
The information gained is expected to have wider application to arid environments requiring restoration, including for example salinity-affected soils.
Researchers collecting soil samples at Jacinth-Ambrosia.
Sap flow meter and deep root species identification
Cell 1 Trial