A Landscape Perspective on Climate-Driven Risks to Food Security: Exploring the Relationship between Climate and Social Transformation in the Prehispanic U.S. Southwest

Spatially and temporally unpredictable rainfall patterns presented food production challenges to small-scale agricultural communities, requiring multiple risk-mitigating strategies to increase food security. Although site-based investigations of the relationship between climate and agricultural production offer insights into how individual communities may have created long-term adaptations to manage risk, the inherent spatial variability of climate-driven risk makes a landscape-scale perspective valuable. In this article, we model risk by evaluating how the spatial structure of ancient climate conditions may have affected the reliability of three major strategies used to reduce risk: drawing upon social networks in time of need, hunting and gathering of wild resources, and storing surplus food. We then explore how climate-driven changes to this reliability may relate to archaeologically observed social transformations. We demonstrate the utility of this methodology by comparing the Salinas and Cibola regions in the prehispanic U.S. Southwest to understand the complex relationship among climate-driven threats to food security, risk-mitigation strategies, and social transformations. Our results suggest key differences in how communities buffered against risk in the Cibola and Salinas study regions, with the structure of precipitation influencing the range of strategies to which communities had access through time

Climate challenges, vulnerabilities, and food security

This paper identifies rare climate challenges in the long-term history of seven areas, three in the subpolar North Atlantic Islands and four in the arid-to-semiarid deserts of the US Southwest. For each case, the vulnerability to food shortage before the climate challenge is quantified based on eight variables encompassing both environmental and social domains. These data are used to evaluate the relationship between the “weight” of vulnerability before a climate challenge and the nature of social change and food security following a challenge. The outcome of this work is directly applicable to debates about disaster management policy

Footprints- In the Footprints of Squier and Davis: Archeological Fieldwork in Ross County, Ohio

TABLE OF CONTENTS Acknowledgements....................................................................iList of Tables...................................................................vii List of Figures...................................................................ix Contributors .........................................................................xiii Chapter 1 In the Footprints of Squier and Davis : Archeological Fieldwork in Ross County, Ohio Mark J. Lynott................................................................................1 Previous Studies in Ohio ...................................................1 Hopewell Studies Today ................................................................4 Recent Field Research ..........................................................................6 Goal of this Volume ................................................................................12 Chapter 2 In Non-mound Space at the Hopewell Mound Group Jennifer Pederson Weinberger .........................................13 Geophysical Survey .......................................................15Western Village Area.....................................................................16 Near the East Village .....................................................................18 Central Area ............................................................................19 Discussion .......................................................................................19 Chapter 3 Field Studies of the Octagon and Great Circle, High Bank Earthworks Ross County, Ohio N’omi B. Greber and Orrin C. Shane III ..............................................23 Excavations at the Octagon ............................................................25 Geophysics at the Great Circle ............................................................30 Excavations at the Great Circle ..........................................................33 Radiocarbon Assays ...........................................................................41 Comments ....................................................................................44 Addendum ..........................................................................................46 Chapter 4 Spruce Hill Earthworks: The 1995-1996 National Park Service Investigations Bret J. Ruby .............................................................................................49 Background .......................................................................................49 The Spruce Hill Earthworks .......................................................................49 Spruce Hill Revisited ......................................................................53 The 1995-1996 National Park Service Investigations ............................53 Discussion and Conclusions ..............................................................61 Chapter 5 Falling Through a Crack in the Core: The Surprise and Demise of Anderson Earthwork William H. Pickard and Jeffrey W. Weinberger ........................................ 67 History and Setting ..................................................................................68 1993 Excavations ..................................................................................70 Discussion ..............................................................................................72 Conclusion ............................................................................................74 Chapter 6 Middle Woodland and Other Settlement Remains in the Overly Tract Near The Hopeton Earthwork, Ross County, Ohio William S. Dancey .....................................................................................................77 Research Design.............................................................................77 Artifact Categories and their Distributions..............................................80 Discussion............................................................................................92 Chapter 7 Hopewell Occupation at the Hopeton Earthworks: Large Scale Surface Survey Using GPS Technology Jarrod Burks and Dawn Walter Gagliano................................................97 The Survey Area ................................................................................98 Survey Methodology .............................................................................99 Survey Results ...................................................................................99 The Surface Data: A Siteless Approach .................................................103 Discussion and Conclusion .........................................................................106 Notes ...................................................................................................107 Chapter 8 Hopewellian Centers in Context: Investigations In and Around the Hopeton Earthworks Bret J. Ruby And Mark J. Lynott .................................................................109 Surface Survey ......................................................................................110 Redwing Site ...........................................................................................111 Comparisons .........................................................................................118 Conclusions ......................................................................................122 Chapter 9 Searching for Hopewell Settlements: The Triangle Site at the Hopeton Earthworks Mark Lynott ...................................................................................... 125 Field Investigations ............................................................................127 Geophysical Survey ............................................................................128 1998 Season ....................................................................................128 Features, Artifacts and Radiocarbon Dating ........................................130 Animal Remains ...............................................................................137 Plant Remains ................................................................................138 Interpretations ..............................................................................139 Chapter 10 Geophysical Investigations at the Hopeton Earthworks John Weymouth, Bruce Bevan, and Rinita Dalan ...............................145 The Cesium Gradiometer Survey ...........................................................146 Cesium Gradiometer Results ...................................................................146 Geoscan Instrument Surveys ..............................................................148 Comparison of Cesium Magnetic and Resistance Data ........................148 Small Circles...........................................................................................149 Trench Excavations ...................................................................................149 Discussion ................................................................................................152 Conclusions ......................................................................................157 Chapter 11 Archeological and Geoarcheological Study of the Rectangular Enclosure at the Hopeton Works Mark J. Lynott and Rolfe D. Mandel ......................................................159 The Study of the Rectangular Earthwork ................................................161 Geophysical Survey ..............................................................................163 Trench Excavations .............................................................................164 Chronology ........................................................................................170 Geoarcheological Analysis of Trench 1 .................................................172 Interpretations ................................................................................174 Chapter 12 Ohio Hopewell Ritual Craft Production Katherine A. Spielmann ............................................................ 179Raw Material Procurement ....................................................................180 Hopewell Crafting ................................................................................181 Deposition ...........................................................................................186 Conclusions ....................................................................................188 References Cited .....................................................................................................18

Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

The uptake of carbonyl sulfide (COS) by terrestrial plants is linked to photosynthetic uptake of CO2 as these gases partly share the same uptake pathway. Applying COS as a photosynthesis tracer in models requires an accurate representation of biosphere COS fluxes, but these models have not been extensively evaluated against field observations of COS fluxes. In this paper, the COS flux as simulated by the Simple Biosphere Model, version 4 (SiB4), is updated with the latest mechanistic insights and evaluated with site obser- vations from different biomes: one evergreen needleleaf forest, two deciduous broadleaf forests, three grasslands, and two crop fields spread over Europe and North America. We improved SiB4 in several ways to improve its representation of COS. To account for the effect of atmospheric COS mole fractions on COS biosphere uptake, we replaced the fixed atmospheric COS mole fraction boundary condition originally used in SiB4 with spatially and temporally varying COS mole fraction fields. Seasonal amplitudes of COS mole fractions are similar to 50-200 ppt at the investigated sites with a minimum mole fraction in the late growing season. Incorporating seasonal variability into the model reduces COS uptake rates in the late growing season, allowing better agreement with observations. We also replaced the empirical soil COS uptake model in SiB4 with a mechanistic model that represents both uptake and production of COS in soils, which improves the match with observations over agricultural fields and fertilized grassland soils. The improved version of SiB4 was capable of simulating the diurnal and seasonal variation in COS fluxes in the boreal, temperate, and Mediterranean region. Nonetheless, the daytime vegetation COS flux is underestimated on average by 8 +/- 27 %, albeit with large variability across sites. On a global scale, our model modifications decreased the modeled COS terrestrial biosphere sink from 922 Gg S yr(-1) in the original SiB4 to 753 Gg S yr(-1) in the updated version. The largest decrease in fluxes was driven by lower atmospheric COS mole fractions over regions with high productivity, which highlights the importance of accounting for variations in atmospheric COS mole fractions. The change to a different soil model, on the other hand, had a relatively small effect on the global biosphere COS sink. The secondary role of the modeled soil component in the global COS budget supports the use of COS as a global photosynthesis tracer. A more accurate representation of COS uptake in SiB4 should allow for improved application of atmospheric COS as a tracer of local- to global-scale terrestrial photosynthesis.Peer reviewe

Early Warning Signals of Social Transformation: A Case Study from the US Southwest

abstract: Recent research in ecology suggests that generic indicators, referred to as early warning signals (EWS), may occur before significant transformations, both critical and non-critical, in complex systems. Up to this point, research on EWS has largely focused on simple models and controlled experiments in ecology and climate science. When humans are considered in these arenas they are invariably seen as external sources of disturbance or management. In this article we explore ways to include societal components of socio-ecological systems directly in EWS analysis. Given the growing archaeological literature on ‘collapses,’ or transformations, in social systems, we investigate whether any early warning signals are apparent in the archaeological records of the build-up to two contemporaneous cases of social transformation in the prehistoric US Southwest, Mesa Verde and Zuni. The social transformations in these two cases differ in scope and severity, thus allowing us to explore the contexts under which warning signals may (or may not) emerge. In both cases our results show increasing variance in settlement size before the transformation, but increasing variance in social institutions only before the critical transformation in Mesa Verde. In the Zuni case, social institutions appear to have managed the process of significant social change. We conclude that variance is of broad relevance in anticipating social change, and the capacity of social institutions to mitigate transformation is critical to consider in EWS research on socio-ecological systems.The article is published at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.016368

Sustainable Small-Scale Agriculture in Semi-Arid Environments

For at least the past 8000 years, small-scale farmers in semi-arid environments have had to mitigate shortfalls in crop production due to variation in precipitation and stream flow. To reduce their vulnerability to a shortfall in their food supply, small-scale farmers developed short-term strategies, including storage and community-scale sharing, to mitigate inter-annual variation in crop production, and long-term strategies, such as migration, to mitigate the effects of sustained droughts. We use the archaeological and paleoclimatic records from A.D. 900-1600 in two regions of the American Southwest to explore the nature of variation in the availability of water for crops, and the strategies that enhanced the resilience of prehistoric agricultural production to climatic variation. Drawing on information concerning contemporary small-scale farming in semi-arid environments, we then suggest that the risk coping and mitigation strategies that have endured for millennia are relevant to enhancing the resilience of contemporary farmers' livelihoods to environmental and economic perturbations

Frequency of Central Mesa Verde Communal Structure Types.

<p>Frequency of Central Mesa Verde Communal Structure Types.</p