5:15 PM - 7:15 PM
[HDS07-P08] Post-fire soil erosion of a subtropical forest is mainly reduced by ground cover vegetation
Keywords:Canopy openness, forest recovery, hemispherical photography, rainfall interception, soil erosion
Forest fires exacerbate soil erosion by removing tree canopies which intercept rainfalls. This study aimed to investigate the decline of post-fire soil erosion and its influencing factors. The study site was located in a lowland evergreen broadleaf forest in central Taiwan, which was affected by a fire in 2021. We established three study plots in both a burned and an adjacent unburned forest stand. Every six months, we conducted hemispherical photography for tree canopies, used cell phone cameras with the Canopeo application to estimate the coverage of ground cover vegetation, and measured soil erosion using erosion pins. By analyzing canopy images, we estimated canopy openness as an indicator of light availability and the leaf area index as a measure of canopy rainfall interception. Results showed that three years after the fire, canopy openness and rainfall interception in the burned stand remained significantly lower than in the unburned stand, indicating the severe impact of the 2021 fire on trees. However, soil erosion in the burned stand was not significantly higher than in the unburned stand. This was because the high canopy openness promoted the development of dense ground cover vegetation, compensating for the loss of canopy rainfall interception. Thus, in humid subtropical regions, ground cover vegetation plays a crucial role in soil conservation during the early stages of forest recovery after fire. When implementing reforestation efforts, ground cover vegetation should be preserved as much as possible.