Effects of wildfire severity on the soil properties of Mediterranean forests
摘要
Wildfire is the principal cause of forest degradation in the Mediterranean region, affecting ecosystems such as plant growth and soil properties. This study aims to assess the effects of forest fire severity on soil physico-chemical properties and hydrological response in the central Rif in Northern Morocco. Soil samples taken from three sites (unburned, moderate-severity wildfires, and high-severity wildfires) were selected to assess the fire severity on topsoil (0–5 cm). Soil properties analyzed include soil aggregate stability, bulk density, texture, pH, electrical conductivity, nitrate nitrogen, organic carbon, available phosphorus, potassium, calcium, magnesium, sodium. The soil hydrological response was assessed using a manual rainfall simulator with an intensity of 80 mm h⁻1. The results show that severe fires significantly alter soil properties. The main changes observed are an increase in bulk density, a reduction in aggregate stability, a decrease in organic carbon content and an increase in soil acidity (decrease pH). Severe fires increase runoff by 285%, which increases erosion and leaching of exchangeable bases and fine-textured elements. On the other hand, severe fires significantly increase nitrate nitrogen and available phosphorus. Moderate-severity fire cause little change in physico-chemical properties of soil, or soil properties are likely to recover rapidly after burning. Based on these results, the management and restoration of soils affected by severe fires is recommended to preserve soil fertility and maintain plant regrowth.