Concentrations of available and total nitrogen, formylated phloroglucinol compounds and unsubstituted B-ring flavanones in eucalypt foliage (mature phase and epicormic growth) and how it changes over time, 2020 - 2021

This data looks at how eucalypt leaf chemistry changes over time in a burnt and unburnt landscape, observing changes in different leaf types, including adult phase foliage in a burnt area, adult phase foliage in an unburnt area and epicormic growth in a burnt area. Total and available nitrogen and two plant secondary metabolites known to deter marsupial folivore feeding behaviour were also measured, including formylated phloroglucinol compounds (FPCs) and unsubstituted B-ring flavanones (UBFs). This study was undertaken to look at how fire can impact leaf chemistry, the changes in chemistry over time and what this may mean for marsupial folivores living in a burnt landscape, i.e., how the quality of the food source changes after fire and as a landscape recovers. To obtain this data, we randomly sampled 10 trees from each of the six eucalypt species present at both the burnt and unburnt sites. Leaf collection commenced in November 2020 and ended in November 2021, with sampling occurring every 4-6 weeks, with a total of seven samplings rounds being completed. At the start of the first collection round, the GPS location of each tree was recorded and we measured the diameter breast height (DBH). Epicormic growth was collected in the burnt landscape (and we opportunistically collected adult phase foliage where it was available) and adult phase foliage in the unburnt landscape was collected. Adult phase foliage was collected using an arborist throw-line launcher. We collected approximately 100g of leaf per tree by removing them from the stems. They were frozen at -20°C at the end of each day. all samples were freeze dried and ground and then we collected reflectance spectrum using a lab-based near-infrared reflectance spectrometer. We could then calculate total and available nitrogen using a Leco Truspec C/N analyser. UBFs and FPCs were quantified using High-Performance Liquid Chromatography.