Effects of fire on interception loss in a coniferous and broadleaved mixed forest

Abstract

Interception loss is a crucial part of the hydrological cycle and can influence the water and energy balance between the soil surface and atmosphere. Fire alters forest structure and then can immediately modify hydrological factors that influence interception loss. We monitored and simulated canopy rainfall partitioning responses to fire were monitored in a coniferous and broadleaved mixed forest. The results showed that fire had significant impacts on the process of gross rainfall partitioning. Fire enhanced throughfall rate from 71.1% to 77.9%, but reduced interception loss rate from 22.3% to 19.8% and reduced stemflow rate from 6.6% to 2.3%. Our analysis showed that the revised Gash model can accurately predict interception loss and other rainfall fractions in the burned forest. The fire altered the proportions of interception loss components and their sensitivity to model parameters. However, the dominant components of interception loss were still attributed to evaporation from the water-saturated canopy during and after storms. Moreover, the predicted interception loss was still highly sensitive to changes in canopy cover, rain intensity, and evaporation rate. These findings provide useful information for evaluating post-fire changes in forest canopy water budgets and for predicting rainfall partitioning in response to climate change.