A review of Botanical Resource Use in the Bronze and Iron Age of the Central Eurasian Mountain/Steppe Interface: Decision Making in Multiresource Pastoral Economies, by Robert N. Spengler III.
Robert N. Spengler’s dissertation provides an important contribution to our understanding of mobile pastoral communities of Central Asia and the role of agricultural, pastoralism, and exchange in regional sociopolitical development during the Bronze Age (ca. 2500-800 B.C.) and Iron Age (ca. 800 B.C. to A.D. 500). Using botanical data obtained from four archaeological sites located in the Semirech’ye region of eastern Kazakhstan, Begash, Mukri, Tasbas, and Tuzusai, Spengler develops a narrative of the diversity and variability present in farming activities, herding strategies, and social interactions reflecting powerful kinship bonds of these mobile Bronze and Iron Age communities. He links major demographic shifts taking place during the Iron Age transition to intensification of agriculture among agropastoral communities and, later, the spread of agriculture throughout Eurasia.
Spengler’s research provides the first comprehensive dataset of botanical remains recovered from Bronze and Iron Age sites in Central Asia. This original data fills a major gap in this important region during a period of rapid agricultural spread and unification of political entities. Earlier models for economic development in Central Asia placed their emphasis on the political agency of sedentary empires in spreading important Iron Age technology through Silk Road trade networks during the first millennium B.C., stereotyping the steppe landscape as a vast expanse of harsh, sterile grasslands. Spengler uses his botanical data to explore the importance of Eurasian steppe pastoralists in growing supraregional interaction; by developing a more complex picture of the steppe biogeography and the culturally and economically diverse peoples who reside there, he expands our interpretive possibilities of causal factors in the increased complexity occurring during the transition to the Iron Age.
In Chapter 1, Spengler addresses the development of prominent political entities in Central Asia, including the Xiongnu Empire and the Han dynasty, which the Silk Road connects to other parts of Eurasia as early as 200 B.C. In Boserupian models of subsistence and demography, agricultural intensification is linked to an input of technological innovation and a subsequent expansion of population and sociopolitical networking. Earlier models of economic development in Central Asia minimize the broader contributions of pastoralist communities, assuming that Bronze and Iron Age pastoralists would not have incorporated even low-investment agriculture in their subsistence regimes and unfavorable climatic conditions on the steppe limited agricultural production. While Spengler agrees that environmental factors play a role in shaping social interaction and economic development, his work demonstrates that mobile pastoralists used varied subsistence regimes, actively shaping rich ecological zones with seasonal mobility of herding and farming practices, and participating in exchange networks to spread agriculture across Eurasia. Spengler suggests the foundation of agricultural practices in Bronze and Iron Age pastoralism groups is linked to adoption of new subsistence technology, shared via supraregional networks, with agricultural intensification and subsequent expansion of Iron Age populations.
Spengler presents his model of economy and ecology interactions in Eurasian steppe pastoralist societies in Chapter 2, drawing from Niche Construction Theory (NCT) to explain the significance of ecologically rich nodes in spreading innovative technologies through networks. Eschewing earlier notions of pastoralist societies as static groups practicing environmentally determined cultural and subsistence practices, he turns to recent literature that emphasizes the heterogeneous nature of these communities (e.g., Barnard and Wendrich). In doing so, Spengler articulates the unique “portable” niche construction used by mobile groups, thus acknowledging the agency of these groups in shaping the landscape to support ongoing technological innovation and in using these rich ecological zones as nodes of regional networks. While we currently lack comprehensive paleoenvironmental reconstructions of Central Asia, palynological records from the western steppe provide empirical evidence of deforestation during the Bronze Age, supporting the idea that mobile herding communities actively interacted with the landscape without “full-time” sedentism.
Archaeological data from a variety of mobile pastoralism settlements is required to fully test the assumptions of these models. Spengler conducted archaeobotanical sampling at four sites in the Semirech’ye region, located in the heart of early Central Asian agriculture. Located strategically along important points of exchange, such as the Dzhungarian Gate, and mountain passes connecting Asia and Europe in the marginal Koksu River Valley, Begash was occupied continuously for 4,000 years. Nearby, the Mukri site was occupied intermittently for 3,000 years. Bronze and Iron Age economies at both sites were based on pastoral products, supplemented by foraging, hunting, and craft production of pottery and textiles. Tasbas is a Bronze Age multi-occupation pastoralist campsite located in the fertile Byan-Zherek valley. Nearby, in the Talgar alluvial fan, Tuzusai is a more sedentary Early Iron Age pastoral site with mud brick architecture and evidence of seasonal occupation for harvesting. The Talgar microregion has irregular rainfall, but the fan is ideal for irrigated agriculture. These sites thus represent a range of economies and ecologies present in Bronze and Iron Age agropastoral communities in Central Asia.
Archaeological narratives of Eurasian nomadic society rely heavily on ethnographic analogy drawn from participant observation of contemporary agropastoral groups in the Central Asian steppe. In Chapters 5 and 6, Spengler combines such observations with an analysis of archaeological material. He discusses the archaeobotanical seeds derived from burning of dung as a proxy for reconstructing landscape alteration, herd diet, grazing patterns, and paleoecology. At sites located in the marginal zone, Begash and Mukri, deposits contain broomcorn millet and wheat, as well as taxa dominant in disturbed landscapes. The presence of these plant taxa suggests either connections with agricultural communities or practice of agriculture by occupants themselves; millet, in particular, would have been a drought tolerant crop for the region and could have been sown and harvested in congruence with herd scheduling. The oldest domesticated grains, wheat, broomcorn millet, and foxtail millet, are present during the Early Bronze Age deposits at Begash. The Iron Age component at Mukri produced a more ephemeral assemblage, comprised of a single wheat grain and 20 broomcorn millet grains. At site located in the fertile zone, Tuzusai and Tasbas, eight major crop domesticates are present, including hulled barley, naked barley, free-threshing compact wheat and free-threshing lax-eared wheat, broomcorn millet, foxtail millet, grapes, and peas. Tuzusai thus represents a mixed agropastoral economy that seasonally moved herds but episodically committed to sedentary lifestyles. Tasbas, the only site with peas present, is evidence of early low-maintenance agricultural pursuits in northern Central Asia. Based on the patterns of seeds appearing at the four sites, Spengler proposes that agropastoral communities centralized around key nodes for intensive, routine social interaction, areas which they enhanced with natural fertilizer (animal dung) to improve productivity of crops for both human and animal consumption. A similar system is observed in contemporary communities, in which rich vegetation zones serve as focal points for communication, exchange, and social interaction.
Spengler’s discussion of his research results is organized around the three economies that drive his model of political development: agriculture, exchange, and pastoralism. In addressing agriculture, the results of Spengler’s archaeobotanical analysis clearly demonstrate the presence of both low-investment cultivation and intensive farming among Bronze and Iron Age agropastoral people in northern Central Asia. Begash is an excellent example of low-investment agriculture; broomcorn and foxtail millets are hardy and withstand harsh winters. The presence of wheat at other sites implies a substantial dedication of occupants’ labor, irrigation, and time. As expected, Tuzusai stands out as an important site; agropastoralists in the Talgar alluvial fan incorporated multiple crops, each requiring different agricultural technologies and cultivation knowledge. This complex subsistence economy would have required a detailed understanding of plant life histories and seasonality. This new information suggests that intensive agriculture was, in fact, an important aspect of some mobile pastoralist communities, and invites new discussion on how these people used kinship relations and regional networks to harness labor for irrigation, planting, and harvesting. Clearly, despite scheduling issues, intensive agriculture was one component of a diverse economy that likely helped buffer against risk.
In addressing pastoralism, Spengler seeks to explain the social processes that promoted long-distance exchange. He turns our attention to plant categories present in the Semirech’ye archaeobotanical samples. Stipa, a drought-tolerant genus of plants is well adapted to the saline surface soils, exposed sandy soils, and rocky outcroppings characteristic of the semi-arid steppe landscape. Their non-native introduction to Begash suggests the seeds were introduced to the area through adherence to sheep hair and dispersed through wool processing activities, an important economic activity at the site. Two large mountain ranges, the Tien Shan and the Dzhungar, dissect the study region, creating a spatial continuum of geographic types. Riparian regions nestled in valleys are dominated by aspen and willows, and shrubby forests are dominated by viburnum in the Dzhungar Mountains and sea buckthorn in the Tien Shan. Patterns of dominant plants present in samples from the four sites show that mobile pastoralists frequently shifted their herds between small patches throughout the year, alternating between wetter lower altitudes and drier higher altitudes. Geographic variability of these foraging resources suggests ancient herders had reliable knowledge of seasonal growth cycles at varying elevations. Spengler interprets this vertical migration as a risk-management strategy, underpinned by extended family systems to support labor pooling, which ultimately facilitated exchange of agricultural resources and cultivation techniques.
Spengler’s discussion of exchange emphasizes the importance of labor pooling to support intensive agricultural production, particularly considering the seasonal demands sowing and harvesting would have placed on pastoralists who simultaneously managed herds. He examines ethnohistoric records documenting the fissioning and fusioning of groups for pastoral and agricultural activities and draws connections between these dynamics and the spread of information and technological innovations during the Iron Age. Increased exchange amongst rising nomadic confederacies during this time culminates in the famous Silk Road that connected Europe to Asia. Spengler notes that, by the second millennium B.C., all mountainous regions of Central Asia had adopted agricultural production of wheat, barley, broomcorn millet, and peas — taxa which he identifies in Early Iron Age deposits at the Semirech’ye sites. Agropastoral groups were most mobile between these important nodes, suggesting they may have been the prime movers in distributing this information.
Archaeological narratives of regional dynamics in the Bronze and Iron Age Eurasian steppe are increasingly based on multi-scalar analyses of sites scattered across varied ecological niches. Prior studies lacked data from critical areas, such as the northern steppe of Central Asia, and data directly documenting the initial appearance and later intensification of agriculture among communities. Spengler’s research provides new data essential to addressing this gap in our knowledge of Early Iron Age political and economic development and establishes an important empirical baseline for assessing plant use during this time. His discussion of recovered botanical remains challenges long-held assumptions that Central Asia was a strictly “pastoral realm” and introduces a more complex account of agropastoralism; especially the peoples’ alteration and use of the rich mosaic of resource pockets embedded in the steppe landscape, and their degree of interaction with outer Asian communities by 1000 B.C. Spengler emphasizes that prehistoric economies were constantly changing in adaptation to environmental and social factors. In doing so, he expands upon stagnant economic parallels previously drawn between archaeological data and ethnographic accounts in the region. In producing such an extensive discussion, Spengler demonstrates the broad intellectual value of archaeobotanical analysis to holistic reconstructions of political, economic, and social interactions in non-state societies around the world.
Lana S. Martin
Department of Anthropology
University of California, Los Angeles
Primary archaeobotanical data
Washington University in St. Louis. 2013. 503 pp. Primary Advisors: Gayle Fritz and Michael Frachetti.
Image: A modern mobile pastoralist seasonal camp in the Dzhungar Mountains not far from the city of Taldy Kurgan in eastern Kazakhstan. Photographed by the author in 2008.