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Accurately reconstructing past human population dynamics is critical for explain- ing major patterns in the human past. Demand for demographic proxies has driven hopeful interest in the “dates-as-data” approach, which models past demography by assuming a relationship between population size, the production of dateable mate- rial, and the corpus of radiocarbon dates produced by archaeological research. How- ever, several biases can affect assemblages of dates, complicating inferences about population size. One serious but potentially addressable issue centers on landscape taphonomy — the ways in which geologic processes structure the preservation and recovery of archaeological sites and/or materials at landscape scales. Here, we explore the influence of landscape taphonomy on demographic proxies. More specif- ically, we evaluate how well demographic proxies may be corrected for taphonomic effects with either a common generalized approach or an empirically based tailored approach. We demonstrate that frequency distributions of landforms of varying ages can be used to develop local corrections that are more accurate than either global corrections or uncorrected estimates. Using generalized scenarios and a simulated case study based on empirical data on landform ages from the Coso Basin in the western Great Basin region, we illustrate the way in which landscape taphonomy predictably complicates “dates-as-data” approaches, propose and demonstrate a new method of empirically based correction, and explore the interpretive ramifications of ignoring or correcting for taphonomic bias. 

South American arid lands present unique constellations of climatic risk to their human inhabitants, due to volatile events that can create markedly different hydroclimate conditions over interannual–centennial scales. However, a main driver of such volatility – the El Niño/Southern Oscillation (ENSO) – occurs with semiregular periodicity. Paleoclimatic and archeological evidence indicate not only that the strength and periodicity of ENSO patterns have changed over the late-Holocene, but their impacts were likely recognized, adapted to, and perhaps capitalized upon by agriculturalists employing adaptive risk strategies. We examine relationships over the last 1.3 kyr between ENSO periodicity, ecological transitions, and archeological settlement in Peru’s Chicama Valley through a coupled paleohydroclimate and agroecology model. We reconstruct periods when ENSO-like conditions dominated past hydroclimates and present a quantitative, spatially-explicit analysis of ecological productivity during modern ENSO-positive hydroclimate conditions. We show that archeological settlement patterns are sensitive to these transformations and reflect efforts to capitalize on expanded agroecological niches. Such expanded niches potentially offset the adverse impacts and risks associated with abrupt ENSO climate events. These results suggest archeological communities were aware of ENSO risk and managed productive strategies accordingly, highlighting the importance of a risk calculus that considers the net ecological effects of climate events.