Scales of impact: Settlement history and landscape change in the Gordion Region, central Anatolia

Abstract

The expansion of agriculture in the Near East during the middle Holocene significantly altered the physical landscape. However, the relationship between the scale of agriculture and the magnitude and timing of the environmental impacts is not well known. The Gordion Regional Survey provides a novel dataset to compare settlement density during archaeological periods to rates of environmental disruption. Sediment samples from alluvial cores directly date the environmental disruption, which can be matched to period-specific settlement intensities in the watershed as constructed from archaeological survey ceramics. Degradation rates rose sharply within a millennium of the earliest Chalcolithic occupation. Early Bronze Age (EBA) land use induced the greatest rates of environmental degradation, although settlement density was relatively low on the landscape. The degradation rate subsequently decreased to one-third its early peak by the Iron Age, even as settlement intensity climbed. This trajectory reveals how complex interaction effects can amplify or subdue the responses of the landscape–land use system. Prior to settlement, landscape soil reservoirs were highly vulnerable, easily tipped by early agricultural expansion. Subsequent reduced rates of erosion are tied both to changes in sociopolitical organization and to depletion of the vulnerable soil supply.

Modeling Resilience and Sustainability in Ancient Agricultural Systems

“…Two distinct periods of erosion are evident. Initial human occupation of the region resulted in changes in regional forest structure resulting from wood procurement (Marston 2009;Miller 2010) and rapid sedimentation of upland streams, which was likely the result of agricultural practices and animal husbandry in a previously unsettled landscape (Marsh 2005;Marsh and Kealhofer 2014). The Sakarya River, however, shows aggradation during a much later period, with most of its sedimentation dating to the Middle Phrygian (YHSS 5) and later periods (Marsh 1999(Marsh , 2005; Figure 2e).…”

“…A similarly rapid increase in land devoted to pasture without the corresponding reduction of herd sizes in recent years has led to significant environmental degradation in central Anatolia (Fırıncıog lu et al 2007), and we can envision a parallel regional process having occurred during the expansion of the population and urban footprint of Phrygian Gordion. While the ecological nature of this threshold has been discussed previously (Marsh 1999;Marsh and Kealhofer 2014;Marston 2012), attention to the process of crossing that threshold yields new insights into the linked social and environmental factors that led to upland erosion at Gordion. In addition, climate change leading to increased rainfall in Anatolia during the Roman period (Figure 2a), coupled with ongoing regional deforestation (Marston and Miller 2014;Miller 2010), may have then exacerbated the erosion that began in the Middle Phrygian period, resulting in increased aggradation of the Sakarya river from the first century BCE (Figure 2e).…”

“…Increasing densities of trees appear at higher elevations, with open woodlands around 1000 masl and canopy forest above 1200-1400 masl (Miller 2010;Zohary 1973; Figure 1). Geological sections and a reconstruction of the alluvial history of the Sakarya indicate that significant erosion postdates substantial human settlement of Gordion and suggest deforestation and overgrazing as probable causes for this erosion (Marsh 1999(Marsh , 2005Marsh and Kealhofer 2014).…”

“…First, during early human settlement of the Gordion region (the Chalcolithic through Middle Bronze Age, prior to 1600 BCE), anthropogenic landscape disturbance led to highland erosion and stream aggradation (Marsh 2005;Marsh and Kealhofer 2014). A second phase of erosion upstream of Gordion began in the Middle Phrygian period, possibly exacerbated by increased rainfall during the Roman period, and resulted in the aggradation of the Sakarya River (Marsh 1999;Marsh and Kealhofer 2014).…”

“…Years of interdisciplinary investigation into agricultural systems and environmental change at Gordion, using botanical (Marston 2012;Miller 2010) and faunal Zeder and Arter 1994) remains from the site, as well as regional geomorphological and archaeological survey (Kealhofer 2005;Marsh 1999Marsh , 2005Marsh and Kealhofer 2014), provide rich datasets on humanenvironmental interaction to explore from a resilience perspective.…”