After incubation (20 °C, for up to 4 h depending on the substrate), fluorescence was measured using 365 nm excitation and 450 nm emission filters. Phenol oxidase and peroxidase activities were measured spectrophotometrically (450 nm) using L-3,4-dihydroxyphenylalanine. The data of soil respiration and soil factors (e.g. pH and soil extractable cations) in the present study were derived from Chen et al. (2015)