With National Science Foundation support, Drs. Irina Panyushkina and Claudia Chang will conduct research to examine how climate, landscapes and prehistoric societies have interacted in Central Asia. This project involves expert collaborators and partnerships in the fields of archaeology, dendrochronology, paleoclimatology, palynology, ecology and hydrogeology in order to examine past climate changes and social transformations throughout a 2000-year prehistory of southern Kazakhstan. The research will generate new field-based datasets for modeling population dynamics, land use patterns in the grassland plains and forested mountains. The goal is to determine human response to climatic and environmental changes beginning at the transition from the Middle Bronze Age to the Late Bronze Age (ca. 1600 to 900 BC) and through the Iron Age (ca. 800 BC to AD 500). The research is important because it will test the direct impact of climate change on ancient societies and cultures of the Eurasian Steppe. It will broaden perspectives on the nature of climate-human interactions which influenced the social evolution of the subsequent civilizations and led to the development of the modern world. Archaeological data from Semirechye (the mountain zone of the Aral Basin) suggest that during the Late Bronze Age, small, dispersed populations of mobile pastoralists occupied the upland valleys and mountains near critical pasture and water resources. Later, in the first millennia BC, these marginal upland regions led to the formation of two distinct types of settlement: larger, aggregated populations of agro-pastoralists who utilized the fertile, arable land of alluvial fans and smaller, dispersed populations of transhumant pastoralists who relocated to high elevations. By ca. 100 AD, population density and storage capacity at villages was comparable to that of early sedentary farming villages in other world regions. A marked reduction in the number of Iron Age sites took place after AD 200 probably a result of out-migration or conflict. The research will interrelate the archaeological datasets with sophisticated reconstructions of climate variability. These integrated data shall provide key insights into the adaptive responses of ancient populations to climate and environmental changes. This multi-disciplinary project includes: (1) archaeological survey and site testing; (2) geophysical settlement surveys using a magnetometer; (3) C14 wiggle-match and tree-ring dating; (4) multi-scale climate and environment reconstructions from tree-ring and pollen proxies, and corresponding ice-cores. The assembled lines of evidence will be used to estimate the impact of climate change on population size and landscape productivity in this region. Furthermore, it will document the social and economic factors within Iron Age society that led to possible environmental stress such as the depletion of water sources, wood fuel and soil fertility. The broader impacts include 1) graduate students' field and state-of-art training in the management and interpretation of large and complex data sets, and 2) strong international collaborations between the archaeological and environmental science communities of US, UK, Kazakhstan, Germany, Hungary and Russia.