Abstract:We tested whether the abundance of C4 vegetation in grasslands of the Mongolian plateau is influenced by grazing conditions. The analysis exploited the politically originated contrast that exists between Mongolia (low stocking rate, transhumant system) and the district of Inner Mongolia, China (high stocking rate, sedentary system). We estimated the proportion of C4 carbon (PC4) in grazed vegetation from the relative carbon isotope ratio (δ13C) of sheep wool sampled from 298 annual shearings originating from 1… Show more
“…4), but Mongolia’s Gobi–Steppe ecosystem still remains one of the largest intact expanses of steppe, desert-steppe and desert habitats in the world 12 . There is also little evidence that C 3 /C 4 plant ratios are influenced by grazing pressure 29 and the fact that diets in historic and extant khulan were almost identical further argues against a habitat-induced diet change in Przewalski’s horses.Figure 4Living conditions of Przewalski’s horses and khulan in the steppe and desert steppe areas of Mongolia in winter past and present. For supporting references see Supplementary Information S5.…”
The Przewalski’s horse (Equus ferus przewalskii), the only remaining wild horse within the equid family, is one of only a handful of species worldwide that went extinct in the wild, was saved by captive breeding, and has been successfully returned to the wild. However, concerns remain that after multiple generations in captivity the ecology of the Przewalski’s horse and / or the ecological conditions in its former range have changed in a way compromising the species’ long term survival. We analyzed stable isotope chronologies from tail hair of pre-extinction and reintroduced Przewalski’s horses from the Dzungarian Gobi and detected a clear difference in the isotopic dietary composition. The direction of the dietary shift from being a mixed feeder in winter and a grazer in summer in the past, to a year-round grazer nowadays, is best explained by a release from human hunting pressure. A changed, positive societal attitude towards the species allows reintroduced Przewalski’s horses to utilize the scarce, grass-dominated pastures of the Gobi alongside local people and their livestock whereas their historic conspecifics were forced into less productive habitats dominated by browse.
“…4), but Mongolia’s Gobi–Steppe ecosystem still remains one of the largest intact expanses of steppe, desert-steppe and desert habitats in the world 12 . There is also little evidence that C 3 /C 4 plant ratios are influenced by grazing pressure 29 and the fact that diets in historic and extant khulan were almost identical further argues against a habitat-induced diet change in Przewalski’s horses.Figure 4Living conditions of Przewalski’s horses and khulan in the steppe and desert steppe areas of Mongolia in winter past and present. For supporting references see Supplementary Information S5.…”
The Przewalski’s horse (Equus ferus przewalskii), the only remaining wild horse within the equid family, is one of only a handful of species worldwide that went extinct in the wild, was saved by captive breeding, and has been successfully returned to the wild. However, concerns remain that after multiple generations in captivity the ecology of the Przewalski’s horse and / or the ecological conditions in its former range have changed in a way compromising the species’ long term survival. We analyzed stable isotope chronologies from tail hair of pre-extinction and reintroduced Przewalski’s horses from the Dzungarian Gobi and detected a clear difference in the isotopic dietary composition. The direction of the dietary shift from being a mixed feeder in winter and a grazer in summer in the past, to a year-round grazer nowadays, is best explained by a release from human hunting pressure. A changed, positive societal attitude towards the species allows reintroduced Przewalski’s horses to utilize the scarce, grass-dominated pastures of the Gobi alongside local people and their livestock whereas their historic conspecifics were forced into less productive habitats dominated by browse.
“…While C 4 plants make up a relatively limited portion of the biotic community today, we established local isotopic baselines for Mongolia in the past using archaeological fauna in order to determine if shifts in δ 13 C values through time are the product of environmental variations or social and economic choices. Isotopic studies of modern and archaeological herd animals have shown differences in δ 13 C values between more and less arid regions [43][44][45] , and that there is variation in the availability of C 3 and C 4 plants across the country 46,47 . While there were no fauna associated with the human remains collected for this study, we were able to use previously published faunal stable isotope data from the Minusinsk Basin of Siberia (just north of Mongolia)(MNSK, AD, AM; n = 21) 20,29 , the Gobi (BGC; n = 14) 30,48 , Gobi-Altai (SBR; n = 5) 30 , and north central Mongolia (EG; n = 13) 30 areas to show that regional herbivores generally consumed C 3 plants, with some having higher stable carbon isotope values, indicative of C 4 plant consumption, in the hyper-arid desert regions 30,48 .…”
Populations in Mongolia from the late second millennium B.C.E. through the Mongol Empire are traditionally assumed, by archaeologists and historians, to have maintained a highly specialized horsefacilitated form of mobile pastoralism. Until recently, a dearth of direct evidence for prehistoric human diet and subsistence economies in Mongolia has rendered systematic testing of this view impossible. Here, we present stable carbon and nitrogen isotope measurements of human bone collagen, and stable carbon isotope analysis of human enamel bioapatite, from 137 well-dated ancient Mongolian individuals spanning the period c. 4400 B.C.E. to 1300 C.E. Our results demonstrate an increase in consumption of C 4 plants beginning at c. 800 B.C.E., almost certainly indicative of millet consumption, an interpretation supported by archaeological evidence. The escalating scale of millet consumption on the eastern Eurasian steppe over time, and an expansion of isotopic niche widths, indicate that historic Mongolian empires were supported by a diversification of economic strategies rather than uniform, specialized pastoralism. Mongolian empires, such as the Xiongnu and Mongols, are some of the most renowned imperial entities in public and academic thought. This is, in part, due to their historical portrayal as highly mobile, predatory horseback polities with a specialized dairy and meat-based economy 1-4 , an image that is perpetuated in cinema, novels, and documentaries alike. While such stereotypes likely arose from the hyperbolized accounts of neighboring adversaries, starting with the Han, who fought against the Xiongnu 5 , they have persisted and now pervade academic evaluations of the economic basis of these ancient peoples. The modern economic focus on pastoralism in rural areas of Mongolia today is frequently viewed as a relic of the past and has been drawn upon to interpret the often-fragmentary archaeological record of this region 6,7 , although ethnoarchaeological approaches often ignore the role of urban markets and motorized transport in modern mobile pastoralism. The view of uniformly specialized pastoral economies has also furthered the scholarly fascination with historical Mongolian populations, resurrecting the long-standing question of whether an empire can meet the costs and challenges of long-term political and economic organization in the absence of grain surpluses 6,7. Empires are, however, inherently complex and, by definition, extend their control over multiple societies, cultures, and economies, as well as heterogeneous landscapes 8-10. Crop surplus has traditionally been viewed as an essential component of stable political entities and complex imperial food production and procurement systems are often oversimplified by historians and archaeologists, leading to their characterization as single-resource systems (such as maize for the pre-Columbian empires of South America). Refined analyses generally reveal diverse and dynamic economies supporting imperial expansions, which draw together a variety of food sou...
“…After harvest of maize, roe deer must feed from plants using the C3 photosynthetic pathway. The large contrast in carbon isotopes between C4 and C3 plants (about 14‰ [23]) is recorded in the animal tissue [5,8]. δ 13 C in keratinous tissue thus increases from about −26‰ with pure C3 diet to −12‰ with pure maize diet, which includes enrichment by 2.7‰ due to the diet-keratin shift [21].…”
Section: Introductionmentioning
confidence: 99%
“…Such heterogeneities can especially be expected for herbaceous species or young trees occupying niches. Stored animal tissues like wool products or hunting trophies provide long-term time series [8] but may also be used to resolve within growing periods [9].…”
Abstract:Hooves preserve the isotopic information laid down during their growth and may be used for reconstruction of animal feeding history. To assign certain positions along hooves to corresponding times, growth rates are required. Hoof growth rates are known for domestic animals; however, they cannot be obtained easily in wild animals. We estimated the hoof growth rate of the European roe deer (Capreolus capreolus L.) by using the immediate drop in δ 13 C along the hoof as a tag that is assigned to the date of maize (Zea mays L.) harvest. Keratin samples were taken each mm along 17 hooves and analyzed for their δ 13 C. A linear regression between (1) time differences of expected maize harvest to animal death and (2) distances between the points of the δ 13 C drop to the periople yielded the growth rate. Mean hoof growth rate was 0.122 mm/day (95% CI 0.014 mm/day) and 0.365%/day (±0.026%/day) of the hoof length and within the range of domestic animals. The method may be applied to determine growth rates of other incrementally growing tissues. Our estimated growth rate fosters dating isotopic information in hooves, facilitating research on feed resources and space use of roe deer.
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