Humankind has entered another lithic epoch. Concrete is the modern stone. Since taking its contemporary form nearly two centuries ago, over five hundred billion tons of the gray matter have been deposited on the earth’s crust. If this amount of concrete was used to build a sidewalk that was six feet wide and three inches thick, it could wrap around the equator over thirty-eight thousand times. The scale of production is tremendous, but only part of the story. Due to being fire-resistant, waterproof, plentiful, durable, malleable and relatively cheap, concrete has become the primary material usedto transform the possibilities of human geography. Such megalithic environmental manipulations would be impossible without the sustained mass production of cement, concrete’s essential ingredient. This dissertation explores the origins of the contemporary concrete cornucopia through an environmental history of the cement transitions that manifested it. Abundant fuel and raw materials as well as robust building regimes and demand for large-scale building on land and under water are necessary conditions for such cement transitions—defined as occurring whenever the production process and properties of cement are altered in a way that significantly changes construction possibilities. A central claim of this dissertation is that these requirements were met in southeastern Great Britain at the turn of the nineteenth century with the discovery of the cementitious properties of the natural cement stones in the London Clay at the moment of British imperial consolidation and industrial take-off. Ironically named “Roman cement,” this natural cement substitute differed from its ancient namesake that had determined the building possibilities of western Europe for roughly two millennia. The British cement production system soon spread to other industrial regions with similar raw material deposits, notably the northern United States, in a process of technology transfer that has since transformed the world. It is argued that this method of mass producing durable, quick-setting and waterproof cement with fossil fuels and its worldwide diffusion was foundational to the built environment’s divergence from the organic economy. Thus began the Second Stone Age.

Wildfire is an inescapable feature of Canadian landscapes, burning an average of over two million hectares annually and causing significant repercussions for communities, infrastructure, and resources. Because fire is managed provincially, each jurisdiction has developed a distinctive approach to preparing for, responding to, and recovering from fire on its landscapes. Using a comparative study between seven provinces and four national agencies, this dissertation examines differences in institutional design and policy with respect to the knowledge management systems required to respond to wildfire: How do policies and procedures vary between jurisdictions, how do they affect the practices of each fire management agency, and how can they be improved through a critical analysis of the knowledge management systems in use? And, what is the role of and limits on expertise within these fire management institutions that manage high-risk, highly uncertain socio- environmental challenges?

I begin by introducing the 2016 Fort McMurray/Horse River fire as a lens for exploring these questions. I then use the past one hundred years of fire history in Canada to illustrate the continual presence of fire, its human and social dimensions, and the evolution of differing fire management regimes. Drawing on extended ethnographic observation and interviewing of fire managers across Canada, I examine the varied provincial systems of response through following an active fire day in Alberta. I analyze the decision support and geospatial information systems used to guide fire agency decision-making, as well as the factors that limit their effectiveness in both response and hazard reduction modes. I begin Part Two with a discussion of mutual aid arrangements between the provinces, and critically examine the core strategy – interagency fungibility – used to allow this exchange. I analyze forecasting and predictive models used in firefighting, with an emphasis on comparing advantages and disadvantages of attempts at predicting future firefighter capacity requirements. I review organizational learning approaches, considering both fire research strategies and after action reviews. Finally, I consider the implication of changes in climates, politics, and public behaviours and their impacts on fire management.

Over the last few decades, the western United States has experienced more extreme wildland fire events, remarkable for their size and severity. The frequency, intensity, and size of wildfires is projected to only increase, with severe consequences for biodiversity, ecosystem services, human property, and more broadly, the sustainability of western forests. These trends are the result of a complex suite of factors including, past land-use policies, fire suppression, climate change, and human development. To protect fire-adapted ecosystems from further damage, fuel reduction and fire reintroduction are required over large landscapes, necessitating government agencies, landowners, and other interests to work together. In response, collaborative fire restoration efforts are forming to carry out this much needed work. This research takes a multi-level approach to understanding these new models for fire management and restoration. Collaborative, landscape-level approaches to fire reintroduction are a direct response to a failure in past policies and approaches, which necessitates a discussion of why these policies allowed fires to grow worse and why management failed to effectively prevent this from happening. Thus, a historical analysis of wildland fire policy and management constitutes one layer in this analysis. Collaborative frameworks to wildland fire reintroduction are few and far between, which obliges a discussion of how collaboration works and why it may be necessary. An in-depth case study of FireScape, a collaborative effort in southeastern Arizona to restore wildfire completes this analysis and provides a discussion of the challenges, benefits, and implications of these new approaches. The context for this case study is southeastern Arizona's Sky Islands. The Sky Islands region spans the U.S. Mexico borderlands and is a biodiversity hotspot, making it an ideal place to explore the interactions between humans and natural systems. The more recent emphasis on collaboration in wildfire management has yet to be fully explored in other academic circles. Collaboration is essential in fire restoration and provides one pathway to solve complex natural resource management issues.