Hydrochemical Variability in Hydrologically Isolated Semi‐Arid Savanna Water Bodies: Associations With Seasonality, Soils and Historical Wildfire Exposure

ABSTRACT Hydrologically isolated water bodies are important features of semi‐arid savannas, yet their seasonal hydrochemical variability and associations with local environmental conditions remain poorly understood. This study examined water temperature, pH, electrical conductivity (EC) and salinity in eight isolated water bodies in Atherstone Nature Reserve, South Africa, alongside soil classification and historical wildfire exposure. Measurements were obtained at eight sites during the dry period and seven during the wet period. Differences between sampling periods were assessed using paired Wilcoxon signed‐rank tests, hydrochemical gradients using principal component analysis (PCA) and associations with soils and historical wildfire exposure using exploratory multiple factor analysis (MFA). Water temperature differed significantly between sampling periods ( p = 0.016), with higher values during the dry period, whereas pH, EC and salinity showed no significant paired differences. EC exhibited substantial variation among individual water bodies. PCA identified major gradients associated with EC, pH and temperature, whereas exploratory MFA identified associations among dry‐period hydrochemical characteristics, soil classification and historical wildfire exposure. These findings highlight spatial hydrochemical heterogeneity among the sampled bodies and demonstrate the value of integrating measurements from contrasting sampling periods with spatial environmental information. The study provides a basis for site‐specific monitoring of isolated water resources in semi‐arid protected areas.