Spatial scale and opportunities for choice influence browsing and associational refuges of focal plants.

1. Foraging decisions by herbivores depend on variation in food types, the scale(s) at which this variation occurs and the opportunity and capacity for herbivores to respond to such variation. These decisions affect not only the herbivores themselves, but also the vulnerability of individual plants to being eaten.

Kinetics of ammonium and nitrate uptake by eucalypt roots and associated proton fluxes measured using ion selective microelectrodes.

Ion-selective microelectrodes were used non-invasively to measure the concentration dependence of NH and NO fluxes around the roots of intact solution-cultured Eucalyptus nitens (Deane & Maiden) Maiden. In addition, NH and H fluxes were measured simultaneously at a range of NH concentrations, and NO and H fluxes were measured simultaneously at a range of NO concentrations. Nitrogen concentrations ranged from 10-250 μM, i.