Correlation between modern plant δ15N values and activity areas of Medieval Norse farms

Stable nitrogen isotopic examination of Norse sites in the Western settlement of Greenland

“…Given this complexity, the exact source of the very high plant d 15 N values observed on the archaeological sites is not fully understood. Even so, we had found recurring patterns in which the d 15 N values for plants from functionally similar features were approximately the same from farm to farm (Commisso and Nelson, 2008). Further, these values were consistent with the d 15 N of the materials expected to have been deposited at these locales in the past.…”

“…We have previously suggested that the magnitude of plant d 15 N values within the sites reflects both the d 15 N of the introducednitrogen and the amount admixed into the soil (Commisso and Nelson, 2008). Here, the comparatively higher values and greater variation found for the Western Settlement infields may indicate that the source of fertilizer, or the amount applied varied considerably between farms.…”

“…We recently described the results of a series of empirical studies in which we examined the stable nitrogen isotope ratio (d 15 N) of plants now growing on several of the Norse farms in the Eastern settlement (Commisso and Nelson, 2006, 2007, 2008. We postulated that in areas where humans had discarded 15 N enriched organic materials in the past, the impact of this anthropogenicallyintroduced nitrogen might be reflected in the d 15 N of plants now growing there.…”

Diet and society in Poland before the state: stable isotope evidence from a Wielbark population (2nd c. AD)

“…δ 15 N values in collagen can thus be used to estimate the amounts and types of animal products consumed, with higher values in consumers suggesting greater animal protein intake. However, δ 15 N values also vary with respect to local climate (Ambrose 1991;Drucker et al 2003), soil nitrogen composition (Britton et al 2008;Grogan et al 2000), production systems (Bogaard et al 2007;Commisso and Nelson 2008) and consumer physiology (Ambrose 1991;Fuller et al 2005;Hobson et al 1993), complicating their interpretation. Isotopic evidence from animal bones in this region of Poland dating to the medieval period shows a 3.3‰ difference in δ 15 N values and a 1.4‰ difference in δ 13 C values of wild and domestic animals (Reitsema et al 2013).…”

“…As previously discussed, the medieval animals from Kałdus exhibit unusually high δ 15 N values likely due to land management practices (e.g., manuring, ploughing, fire-clearing, etc.). At some point in antiquity, the local baseline δ 15 N in this region of Poland may have been raised by human land management strategies such as burning or fertilizing fields (Bogaard et al 2007;Commisso and Nelson 2008;Grogan et al 2000), and it is possible this occurred as early as the Roman era. A grain of wheat sampled from a nearby modern field yielded a high δ 15 N value of 7.2‰, which could be due to the influence of either modern or past land management strategies on soil nitrogen (c.f., Commisso and Nelson 2008).…”