Environmental legacy of the early modern artillery fortifications: soil alteration recorded by magnetic susceptibility and elemental concentrations

Abstract Purpose Warfare activities have detrimental effects on terrestrial ecosystems, including soil environments. However, there is a significant gap in knowledge regarding the military impact on soils of pre-20th-century sites. Therefore, we propose fast approach to evaluate the magnetic susceptibility and element concentrations of such soils. Method Four artillery fortifications from the War of the Bavarian Succession (1778) located on granite and sandstone bedrock in Czechia were examined. In-situ magnetic susceptibility measurements were conducted to identify spatial variability in soil magnetic properties and determine optimal locations for soil coring. Laboratory-based analyses, including magnetic susceptibility and elemental concentration measurements using portable X-ray fluorescence (pXRF) were performed on soil cores 30 cm long. Concentrations of As, Mn, Zn, Pb, Fe, P and S were validated by the Inductively Coupled Plasma (ICP). Results Anthropogenic contributions and contamination levels were assessed using the enrichment factor and the geoaccumulation index, with the highest levels for As, Mn, and S. Relationships between magnetic susceptibility and 15 key elements were explored through principal component analysis. Historical contamination is showed by associations between S and P; recent contamination can be found in topsoil by associations between magnetic susceptibility, As and Pb. Increased values of magnetic susceptibility and elemental concentrations of As, Ca, Mn and S in specific soil cores were connected to the most probable soldier activities. Conclusion This study provides new insights into the environmental legacy of former warzones and suggests that warfare prior to the 20th century resulted in measurable environmental degradation.