Carbon and Nitrogen Isotopic Survey of Northern Peruvian Plants: Baselines for Paleodietary and Paleoecological Studies

Abstract

The development of isotopic baselines for comparison with paleodietary data is crucial, but often overlooked. We review the factors affecting the carbon (δ13C) and nitrogen (δ15N) isotopic compositions of plants, with a special focus on the carbon and nitrogen isotopic compositions of twelve different species of cultivated plants (n = 91) and 139 wild plant species collected in northern Peru. The cultivated plants were collected from nineteen local markets. The mean δ13C value for maize (grain) was −11.8±0.4 ‰ (n = 27). Leguminous cultigens (beans, Andean lupin) were characterized by significantly lower δ15N values and significantly higher %N than non-leguminous cultigens. Wild plants from thirteen sites were collected in the Moche River Valley area between sea level and ∼4,000 meters above sea level (masl). These sites were associated with mean annual precipitation ranging from 0 to 710 mm. Plants growing at low altitude sites receiving low amounts of precipitation were characterized by higher δ15N values than plants growing at higher altitudes and receiving higher amounts of precipitation, although this trend dissipated when altitude was >2,000 masl and MAP was >400 mm. For C3 plants, foliar δ13C was positively correlated with altitude and precipitation. This suggests that the influence of altitude may overshadow the influence of water availability on foliar δ13C values at this scale.

Isotopic evidence for the trade and production of exotic marine mammal bone artifacts at Chavín de Huántar, Peru

“…Previous studies of archaeological fauna and flora from the Andes have documented the range of carbon isotope data for some flora and fauna, particularly maize, tubers, and camelids (Berryman 2010;Burger and Van der Merwe 1990;DeNiro 1988;DeNiro and Hastorf 1985;Finucane, Maita Agurto, and Hastorf and DeNiro 1985;Izeta 2005;Mengoni Gonalons 2007;Miller 2005;Miller, Capriles, and Hastorf 2010;Szpak et al 2013;Thornton et al 2011;Verano and DeNiro 1993). Most Andean domesticated plants such as tubers, including potatoes, and quinoa have δ 13 C values reflecting C 3 plant physiology, showing more negative values ranging from −27 to −18 ‰, while one critical Andean crop, maize, is a C 4 grass that has much more positive δ 13 C values, around −13 to −10 ‰ (Miller 2005;Szpak et al 2013).…”

“…Most Andean domesticated plants such as tubers, including potatoes, and quinoa have δ 13 C values reflecting C 3 plant physiology, showing more negative values ranging from −27 to −18 ‰, while one critical Andean crop, maize, is a C 4 grass that has much more positive δ 13 C values, around −13 to −10 ‰ (Miller 2005;Szpak et al 2013). Importantly, camelids from archaeological contexts have been found to have diets reliant on both C 3 and C 4 plants, indicating diversity in their foddering, often related to local ecology and archaeological context (see Finucane et al 2006, Izeta et al 2009, and Mengoni Gonalons 2007, but potentially also showing overlap with aquatic δ 13 C values.…”

“…Importantly, camelids from archaeological contexts have been found to have diets reliant on both C 3 and C 4 plants, indicating diversity in their foddering, often related to local ecology and archaeological context (see Finucane et al 2006, Izeta et al 2009, and Mengoni Gonalons 2007, but potentially also showing overlap with aquatic δ 13 C values. Nitrogen stable isotope ratios in plants relate to the nitrogen source and metabolic pathways of the plant, with most terrestrial plants' δ 15 N ranging from 0 ‰ (nitrogen fixing plants such as legumes) to~7 ‰ DeNiro and Hastorf 1985;Miller 2005;Schoeninger and DeNiro 1984;Szpak et al 2013). In animals, δ 15 N values reflect the trophic position of an organism, where consumers have higher nitrogen values by 2 to 6 ‰ more than the foods they consume, with most isotopic studies using a dietary offset factor of about 3 to 4 ‰ (DeNiro and Epstein 1981; Minagawa and Wada 1984).…”

Recursos y Dietas Humanas en Laguna Llancanelo (Mendoza, Nordpatagonia): Una Discusión Isotópica del Registro Arqueológico

“…A su vez, el agua bebida varía de modo regular en relación a la latitud, elevación, patrones de lluvia y otros factores ambientales (Dansgaard 1964;Gat 1996;White et al 1998White et al , 2004. Por ello, si hay variaciones en los isótopos de oxígeno del agua de una región, entonces hay un potencial para explorar aspectos de la movilidad y patrones de residencia humanos (White et al 2000(White et al , 2002(White et al , 2004Dupras y Schwarcz 2001; Para entender las tendencias en las dietas humanas inferidas desde los isótopos se requiere un modelo sobre las cadenas tróficas que contemple la variabilidad isotópica de los recursos de base (Szpak et al 2013). Por ello, para ajustar la ecología isotópica se procesaron 68 muestras óseas de fauna actuales que incluyeron aves (n=38), mamíferos (n=19), reptiles (n=1) y peces (n=10) (Tabla 1).…”

Origins of Prehispanic Camelid Wool Textiles from the North and Central Coasts of Peru Traced by Carbon and Nitrogen Isotopic Analyses

“…As one moves from the coastal desert to the highaltitude grasslands, there are large-scale changes in annual precipitation (increases with altitude), temperature (decreases with altitude), and floral community composition (Molina and Little 1981). These large coastal-highland environmental differences produce three trends in plant carbon and nitrogen isotopic compositions with increasing altitude: on average, (1) plant nitrogen isotopic compositions decrease, (2) the relative abundance of C 4 plants decreases, and (3) the overall isotopic variability in plants decreases (Szpak et al 2013). With respect to camelids in particular, some of these effects may be mediated by the consumption of agricultural products or by-products, which has been observed in modern camelids (e.g., McCorkle 1987) and suggested for archaeological camelids (Dufour et al 2014;Finucane, Agurto, and Isbell 2006;Szpak et al 2014b).…”