Differential Responses of Soil Prokaryotic and Fungal Communities to Forest Conversion in Two Contrasting Zambian Soils

ABSTRACT

Drylands are crucial for global carbon (C) storage and biodiversity, yet increasing food demands are driving the extensive conversion of natural lands to croplands in Zambia. While soil microbes play key roles in nutrient cycling, the effects of forest conversion to cropland on their community structure and functional potential remain unclear in these oligotrophic ecosystems. We present a case study on the impacts of recent land conversion (< 5 years) on soil prokaryotic and fungal communities in two contrasting soils with different C contents in Zambia. Our results showed that soil chemical properties were primarily site‐specific and not significantly affected by the short‐term (< 5 years) land conversion. Nevertheless, both prokaryotic and fungal abundances decreased significantly and consistently in croplands compared to natural forests. In addition, prokaryotic and fungal communities responded differently to land conversion, with responses influenced by site characteristics. Prokaryotic diversity remained stable following conversion; however, the C‐limited site showed significantly higher predicted abundance of genes for N‐metabolism pathways with reduced functional redundancy, suggesting a predicted shift toward increased dependence on nutrient cycling functions under resource limitation. In contrast, fungal communities were highly sensitive to the conversion, indicating within‐site taxonomic homogenization, despite maintained alpha diversity. This study highlights the vulnerability of microbial communities at these specific study sites and the importance of understanding the long‐term functional consequences of land conversion for sustainable land management in these fragile environments.