Effects of fire-derived charcoal on soil properties and seedling regeneration in a recently burned Larix gmelinii/Pinus sylvestris forest

Purpose Fire is a primary form of disturbance in boreal ecosystems. Charcoal is an important by-product of forest fire and has been reported to have the potential to influence the plant community establishing after fire. To date, however, no study has effectively tested the relationship between charcoal and plant regeneration in the actual post-fire forests. To determine the contribution of charcoal to soil properties and plant regeneration after forest fires, we conducted in situ investigations concerning the relationship between charcoal and the plant-soil system. Materials and methods We conducted a field investigation in a recently burnt Gmelin larch (Larix gmelinii)/Scots pine (Pinus sylvestris) forest in the Russian Far East to investigate charcoal contents, pH, water contents, and nutrient availability in soil together with the regeneration of larch and pine seedlings. Results and discussion Positive correlations were found between charcoal contents and soil pH, water contents, and available P contents. Additionally, charcoal contents and the number of pine seedlings were positively correlated. There was, however, no significant relationship between charcoal content and extractable NH(4) (+) content or the number of larch seedlings. These results suggest that while charcoal influences are somewhat obscure in the field, charcoal significantly contributes to the amelioration of water and nutrient availability together with the success of regeneration of pine seedling. Conclusions Charcoal produced during fire events in Gmelin larch and Scots pine forests of eastern Russia has a modest influence on soil properties, but has the potential to improve regeneration in these fire-prone ecosystems.