Change in yield of water following a bushfire in a forest of eucalyptus regnans

Abstract

The hydrological changes following regeneration by fire of forests of Eucalyptus regnans were analysed in detail using non-parametric statistical methods. The streamflow data showed that some three to five years after the fire the flows started declining below the levels prevailing before the fire. The average annual reduction in flow over the 163-km2 study area for a 21-year period was 35,000 Ml or 24% of the average streamflow before the fire. Measurements of fogdrip and canopy interception showed that those processes could not be the sole cause of the reduction in flow. A difference in transpiration is the most likely cause. Since E. regnans is one of the world's tallest hardwood species ..