Impact of fire-burn on soil geochemical, microbial biomass and carbon stocks in a dry tropical forest ecosystem

Abstract

Tropical forests are prone to fires, and the severity of burns modulates a crucial function in evaluating the influence of fires on soils. Yet, information about the consequences of wildfires on soil geochemical attributes, carbon stocks, and microbial biomass carbon is limited in Ghana. Therefore, this study was conducted to elucidate the short-term dynamic of soil physico-chemical properties, carbon stocks and microbial biomass carbon to varying fire burn and identify and map sensitive soil quality indicators affected by wildfires in Ghana’s Tain II Forest Reserve. Forty (40) soils were sampled from a 0–15 cm mineral horizon under four forest fire classes (unburnt, low-burnt, moderate-burnt, and high-burnt) in the Tain II Forest Reserve in the 2023 dry season. Concentrations of macronutrients, soil organic matter, total organic carbon, and carbon stocks were higher in the low burn than in the unburnt, moderate, and high burn. Soil microbial biomass carbon was significantly higher in the unburnt (19.88 Mg C kg⁻¹) than in the low burn (16.43 Mg C kg⁻¹), moderate burn (13.90 Mg C kg⁻¹) and high burn (9.88 Mg C kg⁻¹) areas. From the PCA, ten (10) soil sensitive quality indicators to wildfires, including organic carbon, total organic carbon, organic matter, microbial biomass carbon, microbial biomass quotient, clay, available phosphorus, exchangeable calcium, magnesium, and aluminium. Thus, the consequences of wildfires on quality indicators in the Tain II FR are demonstrated and could serve as a database for forest soil quality management after wildfires in the tropical climate of Ghana.

Graphical abstract