Rainfall interception recovery in a subtropical forest damaged by the great 2008 ice and snow storm in southern China

Abstract

Canopy interception is an important component of the hydrological cycle of forested catchments, and is influenced by variations in the canopy structure. Extreme meteorological events can have a destructive impact on forest density and structure, and affect the rainfall partitioning by the canopies. Despite extensive investigation of throughfall and stemflow, the response of rainfall interception loss to post-disturbance vegetation recovery is still poorly understood. In this work, we examined the variations in the canopy structure and rainfall interception recovery after a destructive ice and snow storm that occurred in southern China in 2008. Rainfall partitioning into throughfall and stemflow were measured for multiple years at two damaged sites on Nanling Mountain, while the interception loss was modeled using the revised Gash model. The results showed that the vegetation leaf area index (LAI) doubled from 2010 to 2014. This recovery caused the throughfall rate to decrease and the interception rate to increase. The application of the revised Gash model indicates that the vegetation canopy storage capacity (S) and vegetation cover factor (c) increased with the LAI, resulting in an increase in the interception loss and variations in its components. The interception recovery at the study plots provide a biophysical explanation for the threshold behaviors of runoff generation at catchment scale. Comparisons with canopy interception measurements from nearby undamaged secondary forests suggest that interception capacity in the study plots was not fully recovered for the first 5–7 years after the disturbance, indicating that measurements for a longer duration are needed to evaluate the interception recovery from that great disturbance.