Modelling Woody Plant Tissues5

An electrical impedance spectrum (20 Hz to 1 MHz) was measured in both the bark and wood of current-year and one-year-old Scots pine (Pinus sylvestris L.) shoots. The measured impedance spectra were analysed in reference to two lumped circuits and a distributed circuit. It was found that neither of the two lumped circuits fit the data from bark or wood as well as the distributed model. The lumped (double-shell) model fit fairly well for bark, but poorly for wood. It is proposed that the good fit of the distributed model and the poorer fit of the lumped models are due to a wide range of cell sizes in the bark and wood. The distributed circuit used in the present study may be useful for describing differentiated plant tissues for physiological studies