Long-term frequent fires do not decrease topsoil carbon and nitrogen in an Afromontane grassland

Fire has been an integral evolutionary force shaping and maintaining grassy biomes, such as the Afromontane grasslands of South Africa. represent a large carbon reservoir, but it is uncertain how fire affects their long-term C storage. We investigated effect regime on soil organic N (SOC; SON) in (39-year) burning experiment Maloti-Drakensberg Park, compared SOC SON sampled 2004 2019 from six treatments differing frequency (annual, biennial, five-year, infrequent) season (spring, autumn). Average increased significantly between 2019. slightly, resulting significant increase C:N ratio, indicating that matter becoming less N-eutrophic. Importantly, annually spring SON. This unexpected response attributed to aluandic (acidic, high matter) properties Drakensberg soils. Burning autumn did not The lowest stocks were observed infrequently burnt plots. sequestration across all was 0.30 Mg ha?1 y?1. under frequent fires contrary many findings other studies ecosystems notably driven by season.