Investigation of post-fire natural regeneration in forest plantations of Pinus sylvestris and Larix decidua on the Northern slopes of Rila mountain

Wildfires alter both the vegetation and the soil properties, thus changing the conditions of their regeneration. Each year, forest fires impact significant areas within the lower forest zone, where the coniferous plantations, especially Scots pine plantations are deteriorated. The natural forest recovery processes in fire-affected areas are still insufficiently studied in Bulgaria. Therefore, the aim of the present study was to investigate the possibility of a natural post-fire regeneration of forest vegetation and the conditions, under which it was limited. The natural regeneration of coniferous plantations in the area of Dolna Banya (The Northern slopes of Rila Mt) with dominant tree species of Scots pine (Pinus sylvestris L.) (Object 1) and European larch (Larix decidua Mill.) (Object 2) was studied four years after fire and was found to depend on the slope aspect, the micro-relief and soil humidity. It was found that on the South-western slopes, the diversity of broadleaves tree species recovery (birch, oak, sallow, aspen) was higher in comparison with the coniferous (Scotch pine) ones. On the Eastern slope, the regeneration of coniferous prevailed over that of broadleaves. On the ridges, the regeneration was the lowest one, while on the foot of the slopes was higher.