Ancient settlement activities as important sources of nutrients (P, K, S, Zn and Cu) in Eastern Mediterranean ecosystems – The case of biblical Tel Burna, Israel

Human settlement activities are connected with the accumulation of nutrients in archaeological soils. We address the question of whether the large-scale mapping of the elemental composition of the topsoil in contemporary rangeland can be used for the detection of ancient settlement activities. Using portable X-ray fluorescence (pXRF), we mapped the elemental composition of contemporary soils over an area of 67 ha in and around the Bronze and Iron Age settlement of Tel Burna (identified as probably corresponding with biblical Libnah). Ancient settlement activities substantially increased concentrations of nutrients (P, K, S, Zn and Cu) in the contemporary topsoil owing to the deposition of biomass ashes and organic wastes. Increased concentrations of elements were detected 2500 years after the site was abandoned and we can therefore suppose that changes in the elemental composition of the soil caused by ancient settlement activities are irreversible on a timescale in which human societies operate. Ancient settlement activities increased concentrations of nutrients in contemporary soil to the same level as recent intensive fertiliser application on an adjacent arable field used for vegetable production. Concentrations of nutrients higher than those on the tell summit were recorded only in recent cattle resting areas with intensive deposition of cattle faeces. Changes in the elemental composition of the soil caused by ancient settlement activities consequently result in differential nutrient availability for contemporary vegetation, affecting ecosystem functions for thousands of years. Using pXRF, large-scale mapping of the elemental composition of the topsoil layer at archaeological sites can help to identify the extent and provide basic information on the character of past human activities in the affected landscape units.