A field study of the nutritional dynamics of black box (Eucalyptus largiflorens) throughout a major flooding event
Dr Denise Fernando
La Trobe University
This field study investigated interactions between environmental water levels and mineral nutrition in black box, a key floodplain eucalypt of the Murray Darling Basin. It addressed several knowledge gaps, including an understanding of black box nutrition in situ, the nutritional dynamics associated with water-level fluctuation, and changes to soils that drive black box nutrient uptake. The data gathered is likely to enable new ecophysiological insight into the species.
Paper 1 found that … “variation in whole-leaf elemental levels across flooded and dry trees aligned with known nutritional fluctuations in this drought-tolerant species reliant on occasional infrequent flooding. The microprobe data provide evidence of drought tolerance by demonstrating that extended conditions of lack of water to trees do not elicit leaf anatomical changes nor changes to leaf cellular storage of these elements. Foliar Na concentrations of ~2000–6000 mg kg–1 DW were found co-localised with Cl in mesophyll and dermal cells of young and mature leaves, suggesting vacuolar salt disposal as a detoxification strategy.”
Paper 2 found that… “flooding induced mostly temporary soil chemical changes in the surface horizon, which enhanced trace-nutrient access to trees. Results suggest that the short-term flooding of Black Box on drained loamy sands likely provides nutritional advantage by generating soil chemical fluxes. They also raise questions about flooding-induced movement of nutrients through the soil profile, and about the combined effects of pedology and duration of flooding on the nutritional health of Black Box.”