High δ15N values in Predynastic Egyptian archeological remains: A potential indicator for localised soil fertilisation practices in extreme conditions

Poulallion, E.; Perraud, A.; Besson, D.; Berthet, D.; Richardin, P.; Vincon-Laugier, A.; Fourel, F.; Flandrois, J.-P.; Maureille, B.; Lecuyer, C.

doi:10.1101/2024.11.18.624066

bioRxiv · 10.1101/2024.11.18.624066

High δ15N values in Predynastic Egyptian archeological remains: A potential indicator for localised soil fertilisation practices in extreme conditions

Poulallion, E.·Perraud, A.·Besson, D.·Berthet, D.·Richardin, P.·Vincon-Laugier, A.·Fourel, F.·Flandrois, J.-P.·Maureille, B.·Lecuyer, C.

View original source ↗Export metadata ↓

Abstract

Predynastic Egypt arose around 5700 BC when nomadic people settled in the Nile Valley. Without voluntary practice related to anthropic mummification, as will be seen with the Egyptian Dynastic empires, human remains from this period were naturally mummified because of the natural environmental conditions, possibly enveloped in plant mats and animal skins. This study focuses on four mummies from the Natural History Museum of Musee des Confluences in Lyon (France). The geographic origin of the mummies and climatic conditions at that time were deduced from o18O measurements on teeth and bones. These measurements confirm that the primary source of drinking water was the Nile, and that one mummy of unknown origin also originated from Upper Egypt like the other three. The diet and life habits of these individuals were inferred from carbon (o13C), nitrogen (o15N) and sulfur (o34S) isotope compositions of their skins and bone collagens. Our study is of particular interest as we were able to analyse the animal skins and plant material enveloping the mummies using the same isotopic systems. The mean o15N values obtained in human skins (17.9{+/-}2.4{per thousand}, AIR) were found to be high, and consistent with the values measured in animal skins (16.0{+/-}2.9{per thousand}, AIR). The analysed plants have even higher values, with an average of 22.1{+/-}2.2{per thousand}, AIR. The most probable explanation for the markedly elevated {delta}15N values observed in all the materials investigated is localised soil amendment practices. This is corroborated by the consistent nitrogen isotopic signatures across all the examined tissues, with a notable prevalence in plant tissues.

Explore related subjects

ecology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Poulallion, E., Perraud, A., Besson, D., Berthet, D., Richardin, P., Vincon-Laugier, A., Fourel, F., Flandrois, J.-P., Maureille, B., Lecuyer, C.. 2024-11-22. High δ15N values in Predynastic Egyptian archeological remains: A potential indicator for localised soil fertilisation practices in extreme conditions. https://doi.org/10.1101/2024.11.18.624066

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

A leaf-carbon economy model to explain the adaptive value of low vs. high leaf mass per area as a function of habitat productivity

Plant traits interact with environmental conditions to determine plant fitness. In particular, plant species with low leaf mass per area (LMA) are more common in high fertility soils and forest gaps, while plant species with high LMA are more common in low fertility soils and in shaded forest understories. It is not yet known why the adaptive value of LMA changes as a function of environmental productivity. We present a model for plant growth as a function of LMA and productivity. Our model relies on an empirically derived relationship between LMA and leaf lifespan. We are able to explain why species with lower LMA are successful in high productivity environments including environments with high availability of either light or soil nutrients, by showing that the LMA which maximizes growth rate decreases with increasing rate of carbon assimilation. We show that low LMA species are better at taking advantage of the 'high interest' environment of high productivity habitats by reinvesting assimilated carbon in new leaves and earning compound interest, while high LMA species grow more efficiently in the 'low interest' environment of low productivity habitats. This tradeoff sheds light on the adaptive value of LMA as it relates to environmental productivity.

ecology↗

bioRxiv2026

Species differentiate water uptake depths within a narrow vertical zone in temperate grasslands

Whether and under which conditions coexisting species in temperate grasslands differentiate their water uptake within the shallow soil layer they share is central to understanding hydrological niche differentiation in these ecosystems. In this field study, we quantified water uptake depth of 28 coexisting herbaceous species across 74 temperate grassland plots in three regions of Germany using oxygen stable isotopes and soil water content measured at multiple depths. Species consistently differed in water uptake depth across all regions, consistent with hydrological niche differentiation. This differentiation was largely confined to the upper 30 cm of soil and became stronger as overall soil moisture declined, with plants accessing water at greater depths in drier plots. In contrast, the vertical distribution of soil moisture was unrelated to either uptake depth or species differentiation. Despite pronounced species level variation, broad herbaceous functional classifications, including grasses versus forbs and fibrous versus taprooted species, showed substantial overlap in water uptake depth. Together, our results show that hydrological niche differentiation in temperate grasslands is expressed through fine scale differences among species within a shared shallow soil domain, becomes more pronounced under drier conditions, and is poorly captured by broad herbaceous functional classifications.

ecology↗

bioRxiv2026

Fungal-bacterial interactions enhance bacterial but constrain fungal resistance and recovery to extreme heat across soil moisture levels

Soil fungi and bacteria are key drivers of nutrient cycling and plant productivity in terrestrial ecosystems, yet their responses to climate extremes are rarely studied as interacting partners rather than in isolation. Moreover, it remains largely unknown how fungal-bacterial interactions regulate fungal and bacterial stability under climate extremes, particularly resistance (immediate responses to climate extremes) and recovery (responses after climate extremes cease). Here, we conducted a soil microcosm experiment with a bacterial species (Pseudomonas putida KT2440) paired with one of four Trichoderma species (T. hamatum, T. atroviride, T. koningiopsis, and T. harzianum). These fungal-bacterial pairs were then exposed to a 5-day heat event (40 {degrees}C/32 {degrees}C, day/night) followed by a 14-day recovery period (25 {degrees}C/17 {degrees}C, day/night), at two soil moisture levels (30% and 5% gravimetric water content). Our results show that fungal-bacterial interactions asymmetrically affect fungal and bacterial responses to extreme heat. Trichoderma species facilitated the resistance and recovery of P. putida density (CFUs) to extreme heat, whereas P. putida constrained the resistance and recovery of fungal biomass (ergosterol) to extreme heat, regardless of soil moisture conditions. Moreover, faster-growing Trichoderma species were associated with greater facilitation of bacterial resistance and recovery. Bacterial density also covaried positively with fungal biomass during heat stress under both soil moisture conditions, suggesting that net fungal facilitation enhances bacterial persistence under extreme heat. Together, our findings reveal that fungal-bacterial interactions can stabilize one microbial partner while increasing the vulnerability of the other, highlighting the contrasting consequences of biotic interactions under climate extremes.

ecology↗