MODELING WOODY PLANT-TISSUES USING A DISTRIBUTED ELECTRICAL CIRCUIT

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 fo und 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 th e good fit of the distributed model and the poorer fit of the lumped m odels 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 descri bing differentiated plant tissues for physiological studies.