Robert N. Spengler

Ecotopes and Herd Foraging Practices In the Steppe/Mountain Ecotone of Central Asia During the Bronze and Iron Ages

Abstract Eurasian mobile pastoralists living in semiarid environments focus on specific locations on the landscape where pasture resources and water are available. Ecotones –or intermediary zones between the mountain and steppe environments– create mosaic landscapes composed of forage-rich patches and other discrete enclaves of useful biota for pastoralist communities. Ecotopes (ecological patches) provide vital resources for the herding systems used in Central Asia today as well as in the past. We document and discuss wild seed composition of archaeobotanical samples from the Bronze and Iron Age site of Begash in southeastern Kazakhstan noting that much of the archaeobotanical assemblage represents carbonized animal dung, which is currently and historically used as fuel in this region by mobile pastoralists. The seeds offer a window into prehistoric herding patterns and provide a nuanced view of prehistoric land use, social interaction, and community formation across discrete ecological nodes in the Bronze and Iron Ages.

Millet cultivation across Eurasia: Origins, spread, and the influence of seasonal climate

The two East Asian millets, broomcorn (Panicum miliaceum) and foxtail millet (Setaria italica), spread across Eurasia and became important crops by the second millennium BC. The earliest indisputable archaeobotanical remains of broomcorn millet outside of East Asia identified thus far date to the end of the third millennium BC in eastern Kazakhstan. By the end of the second millennium BC, broomcorn millet cultivation had spread to the rest of Central Eurasia and to Eastern Europe. Both millets are well suited to an arid ecology where the dominant portion of the annual precipitation falls during the warm summer months. Indeed, the earliest sites with millet remains outside of East Asia are restricted to a narrow foothill ecocline between 800 and 2000 m a.s.l., where summer precipitation is relatively high (about 125 mm or more, from May through October). Ethnohistorically, millets, as fast-growing, warm-season crops, were commonly cultivated as a way to reduce agricultural risk and were grown as a low-investment rain-fed summer crop. In Eurasian regions with moist winters and very low summer precipitation, the prevailing agricultural regime had long depended on winter wheat (Triticum aestivum) and barley (Hordeum vulgare) cultivated with supplemental irrigation. We propose that the secondary wave of millet cultivation that spread into the summer-dry regions of southern Central Asia is associated with an intensification of productive economies in general, and specifically with the expansion of centrally organized irrigation works.

The spread of agriculture into northern Central Asia: Timing, pathways, and environmental feedbacks

Over the past decade, researchers have directed greater focus toward understanding Bronze (3200–800 BC) and Iron Age (800 BC–AD 400) economies of Central Asia. In this article, we synthesize paleobotanical data from across this broad region and discuss the piecemeal archaeological evidence for agriculture in relation to environmental records of vegetation and climate change. The synthesis shows that agricultural products were present in northern Central Asia by the mid-3rd millennium BC; however, solid evidence for their spread even further north into the Altai Mountains and southern Siberia only comes from the late 2nd and early 1st millennia BC. The earliest crops introduced into Central Asia likely came as a mixed package of free-threshing wheat, naked barley, and broomcorn millet, an assemblage pioneered further south along the northern foothills of the Central Asian mountains. Further east, in Mongolia, and debatably to the west of Central Asia, in the steppe of northern Kazakhstan and the southern Ural region of Russia, the earliest evidence of agriculture (with a similar mixed assemblage) is considerably later, roughly late 1st millennium BC. The lack of clear-cut early evidence for agricultural goods either east or west of the Central Asian mountain belt suggests that agriculture spread northward along these mountains, based on an agropastoral system pioneered millennia earlier at higher elevations of lower latitudes. Additionally, moister regional environmental conditions in the northern mountains after 3000 cal. BC may have increased the favorability of adopting an agricultural component in the economy.

Agricultural origins from the ground up: Archaeological approaches to plant domestication

The timing, geographical locations, causes, and consequences of crop domestication have long been major concerns of archaeologists, and agricultural origins and dispersals are currently more relevant than ever to scientists seeking solutions to elusive problems involving food insecurity and global health disparities. Perennial research issues that archaeologists continue to tackle include (1) thinking outside centers of origin that were based on limited and insufficient past knowledge; (2) distinguishing between single and multiple domestications of specific crops; (3) measuring the pace of domestication; and (4) decoupling domestication from agricultural economies. Paleoethnobotanists have expanded their toolkits to include analysis of ancient and modern DNA and have added increasingly sophisticated techniques in the field and the laboratory to derive precise chronological sequences to assess morphological changes in ancient and often fragmentary archaeobotanical remains and to correctly interpret taphonomy and context. Multiple lines of archaeological evidence are ideally brought together, and whenever possible, these are integrated with information from complementary sources. We discuss current perspectives and anthropological approaches to research that have as their goals the fuller and broader understanding of ancient farming societies, the plants that were domesticated, the landscapes that were created, and the culinary legacies that were passed on.

Barley (Hordeum vulgare) in the Okhotsk culture (5th–10th century AD) of northern Japan and the role of cultivated plants in hunter–gatherer economies

This paper discusses archaeobotanical remains of naked barley recovered from the Okhotsk cultural layers of the Hamanaka 2 archaeological site on Rebun Island, northern Japan. Calibrated ages (68% confidence interval) of the directly dated barley remains suggest that the crop was used at the site ca. 440–890 cal yr AD. Together with the finds from the Oumu site (north-eastern Hokkaido Island), the recovered seed assemblage marks the oldest well-documented evidence for the use of barley in the Hokkaido Region. The archaeobotanical data together with the results of a detailed pollen analysis of contemporaneous sediment layers from the bottom of nearby Lake Kushu point to low-level food production, including cultivation of barley and possible management of wild plants that complemented a wide range of foods derived from hunting, fishing, and gathering. This qualifies the people of the Okhotsk culture as one element of the long-term and spatially broader Holocene hunter–gatherer cultural complex (including also Jomon, Epi-Jomon, Satsumon, and Ainu cultures) of the Japanese archipelago, which may be placed somewhere between the traditionally accepted boundaries between foraging and agriculture. To our knowledge, the archaeobotanical assemblages from the Hokkaido Okhotsk culture sites highlight the north-eastern limit of prehistoric barley dispersal. Seed morphological characteristics identify two different barley phenotypes in the Hokkaido Region. One compact type (naked barley) associated with the Okhotsk culture and a less compact type (hulled barley) associated with Early–Middle Satsumon culture sites. This supports earlier suggestions that the “Satsumon type” barley was likely propagated by the expansion of the Yayoi culture via south-western Japan, while the “Okhotsk type” spread from the continental Russian Far East region, across the Sea of Japan. After the two phenotypes were independently introduced to Hokkaido, the boundary between both barley domains possibly existed ca. 600–1000 cal yr AD across the island region. Despite a large body of studies and numerous theoretical and conceptual debates, the question of how to differentiate between hunter–gatherer and farming economies persists reflecting the wide range of dynamic subsistence strategies used by humans through the Holocene. Our current study contributes to the ongoing discussion of this important issue.

Arboreal crops on the medieval Silk Road: Archaeobotanical studies at Tashbulak

During the first millennium A.D., Central Asia was marked by broad networks of exchange and interaction, what many historians collectively refer to as the “Silk Road”. Much of this contact relied on high-elevation mountain valleys, often linking towns and caravanserais through alpine territories. This cultural exchange is thought to have reached a peak in the late first millennium A.D., and these exchange networks fostered the spread of domesticated plants and animals across Eurasia. However, few systematic studies have investigated the cultivated plants that spread along the trans-Eurasian exchange during this time. New archaeobotanical data from the archaeological site of Tashbulak (800–1100 A.D.) in the mountains of Uzbekistan is shedding some light on what crops were being grown and consumed in Central Asia during the medieval period. The archaeobotanical assemblage contains grains and legumes, as well as a wide variety of fruits and nuts, which were likely cultivated at lower elevations and transported to the site. In addition, a number of arboreal fruits may have been collected from the wild or represent cultivated version of species that once grew in the wild shrubby forests of the foothills of southern Central Asia in prehistory. This study examines the spread of crops, notably arboreal crops, across Eurasia and ties together several data sets in order to add to discussions of what plant cultivation looked like in the central region of the Silk Road.

Introduction to the Special Issue: ‘Introduction and intensification of agriculture in Central Eurasia and adjacent regions’

For well over a century, scholars from across the social and biological sciences have been trying to understand the origins and spread of agriculture. This debate is often intertwined with discussions of climate change and human environmental impact. Over the past decade, this debate has spread into Central Eurasia, from western China to Ukraine and southern Russia to Turkmenistan, a part of the world often thought to have been largely dominated by pastoralists. A growing interest in the prehistory of Central Eurasia has spurred a new chapter in the origins of agriculture debate; archaeobotanical research is showing how important farming practices in this region were in regard to the spread of crops across the Old World. While early people living in Central Eurasia played an influential role in shaping human history, there is still limited understanding of the trajectories of social evolution among these populations. In March 2015, 30 leading scholars from around the globe came together in Berlin, Germany, to discuss the introduction and intensification of agriculture in Central Eurasia and adjacent regions. At the German Archaeological Institute in Berlin (Deutsches Archäologisches Institut, DAI), these scholars presented novel data on topics covering East, South, and Central Asia, spanning a wide realm of methodological approaches. The present special edition volume deals with a selection of the papers given at this conference, and it marks a significant step toward recognizing the contribution of Central Eurasian populations in the spread and development of agricultural systems over the course of the Holocene.

Correction: Arboreal crops on the medieval Silk Road: Archaeobotanical studies at Tashbulak

[This corrects the article DOI: 10.1371/journal.pone.0201409.].