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

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

The human experience of social transformation: Insights from comparative archaeology.

Archaeologists and other scholars have long studied the causes of collapse and other major social transformations and debated how they can be understood. This article instead focuses on the human experience of living through those transformations, analyzing 18 transformation cases from the US Southwest and the North Atlantic. The transformations, including changes in human securities, were coded based on expert knowledge and data analyzed using Qualitative Comparative Analysis techniques. Results point to the following conclusions: Major transformations, including collapses, generally have a strong and negative impact on human security; flexible strategies that facilitate smaller scale changes may ameliorate those difficulties. Community security is strongly implicated in these changes; strong community security may minimize other negative changes. The relationships among the variables are complex and multi-causal; while social transformation may lead to declines in human securities, declining conditions of life can also push people to transform their societies in negative ways. Results show that some societies are better able to deal with difficulties than others. One important policy implication is that community security and local conditions can be instrumental both in helping people to cope with difficulties and in staving off some of those difficulties. A multi-scalar approach is essential as we face the increasing problems of climate change in the decades ahead

Resilience Lost: Intersecting Land Use and Landscape Dynamics in the Prehistoric Southwestern United States

The interdisciplinary framework known as resilience theory used by ecologists, social scientists, as well as policy makers, is primarily concerned with the sources of transformation and stability in complex socioecological systems. The laboratory of the long and diverse archaeological record is uniquely suited to testing some of the implications of this theoretical perspective. In this paper, we consider the history of land use and landscape change across the transition from foraging to agricultural subsistence economies in the Middle Chevelon Creek region of northern Arizona. Through this discussion, we highlight the potential roles of diversity and flexibility at multiple spatial and temporal scales in the resilience of human land use practices from the prehistoric past. Expressing the long-term history of this region in a more general theoretical language that bridges the social and natural sciences promotes the collaboration of scientists with expertise deriving from different traditional disciplines. Such a broad perspective is necessary to characterize changes and stabilities in complex socioecological systems

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