1. Scientist, Dept. of Natural Resources and Water, Meiers Rd., Indooroopilly, Queensland 4068, Australia (corresponding author). E-mail: cara.beal@nrw.qld.gov.au
2. Senior Scientist, CSIRO Land and Water, Indooroopilly, Queensland 4068, Australia. E-mail: david.rassam@csiro.au
3. Principal Scientist, Dept. of Natural Resources and Water, Meiers Rd., Indooroopilly, Queensland 4068, Australia. E-mail: ted.gardner@nrw.qld.gov.au
4. Honorary Research Fellow, School of Land, Crop and Food Sciences, Univ. of Queensland, St. Lucia, Queensland 4073, Australia. E-mail: g.kirchhof1@uq.edu.au
5. Professor, School of Land, Crop and Food Sciences, Univ. of Queensland, St. Lucia, Queensland 4073, Australia. E-mail: n.menzies@uq.edu.au