Study of damage produced by a wildfire in trees, by means of bioelectric methods. I. Radiata pine

S. Bara, J. A. Vega, M. Alonso

Abstract


A plot of P. radiata was burned in the same conditions of a summer wildfire. Close to this site was placed another plot as control. Tree fire damage was followed by phloem conductivity measure, by biocurrents production and the use of square waves. The conductivity permits to distinguish well among damaged trees and controls. Burned trees have a lower conductivity than controls. Biocurrent is little higher in damaged trees; nevertheless its signification is less than conductivity. Square waves, with the 1 probe method, produce very significant results. The output voltage for damaged trees, in the range on frequencies used (50, 1K and 50 KHz) is lower than in controls. The ratio V50/V50k is higher in burned trees. With the 3 probe method, for the first months, the average value of output voltage is higher in burned trees, but this situation is reversed later. The ratio V50/V50k is higher in damaged trees, during all the trial. Several ratios among results, are proposed for damage characterization. With the results of 1S probe measurements, obtained a month after burning, it was possible to predict the tree survival.


Keywords


Bioelectric methods; conductivity; electrical resistence; square waves; Radiata pine; fire damage





Webpage: www.inia.es/Forestsystems