Fine root distribution and soil physicochemical properties variations in four contrasting urban land use types in South Korea

Abstract Fine root distribution patterns across land use types and their relationships with soil physicochemical properties are crucial for sustainable management of vegetated urban land uses amid urbanization and increasing demands for green spaces. Thus, we investigated soil properties and spatial distribution of fine roots mass in two diameter classes of fine roots (0–2 and 2–5 mm) at six soil depths across different land use types in urban areas, including grassland (ZJ), apple orchards (MP), pine forest (PD) and oak forest (QA). Soil pH, organic matter (OM), potassium, calcium varied significantly across land use types. Available P, Ca2+, Mg2+, pH, and NO3-N were higher in ZJ and MP, while CEC, C/N ratio, and OM were higher in PD and QA. Total fine root biomass and necromass (0-5cm) across the 0–30 cm soil profile in ZJ, MP, PD, QA were 440.09, 98.30, 487.21, 700.30 g m− 2 and 88.49, 1.06, 34.33, 64.49 g m− 2, respectively. Results revealed that fine root vertical distribution varied among land use types and most of fine roots were found in the topsoil layers (0–10 cm), except for MP. Fine root biomass in the upper soil layer (0–10 cm) across land use types followed the order ZJ > QA > PD > MP. In conclusion, fine root biomass/necromass differed significantly, primarily explained by variations in soil physicochemical properties and depth. Findings of the study can enhance understanding of the factors influencing spatial distribution of fine roots of various plants and provide implications for sustainable management of different vegetated land uses in urban areas.