(2016) Ramos-Scharrón, C. and LaFevor, M. C., The Role of Unpaved Roads as Active Source Areas of Precipitation Excess in Small Watersheds Drained by Ephemeral Streams. Journal of Hydrology 533: 168-79.
Abstract. Quantitative understanding of the impacts of land development on runoff generation is vital for managing aquatic habitats. Although unpaved roads are broadly recognized as significant sources of sediment within managed forested landscapes, their role in altering runoff response is characteristically dependent on rainstorm and watershed size. Here we evaluate the role of unpaved roads in the development of Horton overland flow and their potential to influence the delivery of runoff from small watersheds (~ 1s km2) drained by ephemeral streams flowing towards coral reef bearing waters of the Northeastern Caribbean. Infiltration capacity curves for undisturbed forest soils and unpaved roads were developed based on hydrologic characterization performed with a Guelph permeameter. Results demonstrate that infiltration capacities from unpaved roads are roughly a quarter of those for forest soils. Consequently, localized precipitation excess is about four times greater on unpaved roads than on forest soils. Analyses indicate that unpaved roads generate precipitation excess roughly ten times more frequently than watershed-scale storm flow generated by the combined effects of precipitation excess and saturation overland flow. Comparison of unpaved road precipitation excess with observed watershed discharge suggests that road networks may produce localized surface runoff equal to 62% of total watershed discharge for rainstorms up to 3.0 cm, and this holds even for watersheds with low and moderate road densities (0.8 to 2.3 km km-2). For watersheds with high road densities (~7.6 km km-2), roads may contribute about one - quarter of storm flow for rain events up to 10 cm. Our results stress the high sensitivity of runoff response in dry tropical watersheds to land disturbance, even when this disturbance occurs on only about 1% of the land surface. In this particular case study, unpaved roads prove capable of altering the time distribution of runoff and, by extension, sediment delivery, from one that is naturally infrequent and sporadic to one that is potentially chronic.
(2015) Suding, K., Higgs, E., Palmer, M., Callicott, J. B., Anderson, C. B., Baker, M., Gutrich, J. J., Hondula, K. L., LaFevor, M. C., Larson, B. M., Randall, A., Ruhl, J. B., Schwartz, K. Z., Committing to Ecological Restoration: Efforts Around the Globe Need Legal and Policy Clarification. Science 350(6235): 638-640.
Summary. This paper proposes four principles for planning comprehensive ecological restoration. These are meant to give legal and policy clarification to the practice of ecological restoration and to improve the structural and functional diversity of ecosystems. Diverse ecosystems are more likely to be durable and capable of adapting to future challenges of climate change, introduced species, and land-use change and can be sustained with a declining investment of human and financial capital over time.
(2015) LaFevor, M. C., Environmental Concerns Facing the U.S. and Latin America: An International Perspective. In Neighborly Adversaries: Readings in U.S.-Latin American Relations, 3rd Edition. Michael J. LaRosa and Frank O. Mora, eds. (Roman and Littlefield): 265-276.
Abstract. This chapter traces the historic "geographic" challenges faced between the United States and Latin America, with an emphasis on the relationship between the United States and Mexico. Given that the two nations share a two-thousand-mile border, water and air quality, population growth, and the health of plants, animals, and humans are all of vital concern. Professor LaFevor, a geographer, addresses these issues from a historic and thematic framework. He points to the importance of human exigency in an evolving international dynamic.
(2014) Hudson, P. F., LaFevor, M. C., Introduction: Managing and Monitoring Human Impacts on Landscapes for Environmental Change and Sustainability, In P. F. Hudson and M. C. LaFevor (guest eds) special issue of the Journal of Environmental Management 138: 1-3.
Excerpt. Understanding the impacts of human activities on landscapes has long been important to environmental scientists and managers (Marsh, 1864; Goudie, 1981), but has never been more pressing than today. Broad scientific engagement with the subject of climate change since the early 1990s has resulted in a new appreciation for understanding landscape sensitivity to environmental change (Turner et al., 1990). This is essential, for against forecasted average changes in climate at a global scale is great variability in temperature and precipitation at regional and seasonal scales (e.g., IPCC, 2007). Additionally, the past couple of decades have witnessed a paradigm change in landscape contextualization. Scientists no longer singularly uphold the idea of a pristine environmental base-line for restoration purposes, as natural landscapes untouched by human presence are unlikely to have existed (Turner et al., 1990; Vitousik et al., Zalasiewicz, 2011). The coupling of these two concepts implies that decision makers and land managers must understand the historic environmental context and inherent sensitivity of landscapes to implement effective strategies to defend and mitigate against anticipated climate change. These topics steered the direction of this special issue, which examines human impacts on landscapes from two perspective, specifically: i) managing the environmental impacts of human actions, and ii) monitoring and assessing the effectiveness of these efforts. The first seeks to better understand the historic controls and processes that led to environmental change in order to develop appropriate responses or remedial measures. The second explores processes of environmental monitoring and assessment that are, ideally, guided by previous analyses and cumulative understanding of environmental cause and effect. Analysis and response to degradation are synergistic in their effects -- better understanding of root causes informs management strategies. Subsequently, periodic review and reassessment of these strategies serves to strengthen future efforts and the empirical foundations upon which sound decision making in based. The latter approach is increasingly included within new "integrated" approaches to environmental management...
(2014) LaFevor, M. C., Restoration of Degraded Agricultural Terraces: Rebuilding Landscape Structure and Process. Journal of Environmental Management 138: 32-42.
Abstract. The restoration of severely degraded cropland to productive agricultural capacity increases food supply,improves soil and water conservation, and enhances environmental and ecological services. This article examines the key roles that long-term maintenance plays in the processes of repairing degraded agricultural land. Field measurements from Tlaxcala, Mexico stress that restoring agricultural structures (the arrangements of landforms and vegetation) is alone insufficient. Instead, an effective monitoring and maintenance regime of agricultural structures is also crucial if the efforts are to be successful. Consequently, methods of wildland restoration and agricultural restoration may differ in the degree to which the latter must plan for and facilitate a sustained human involvement. An improved understanding of these distinctions is critical for environmental management as restoration programs that employ the technologies of intensive agriculture continue to grow in number and scope.
(2014) Hudson, P.F. and LaFevor, M.C., (guest editors) Management and Monitoring of Land Degradation and Environmental Change. Journal of Environmental Management 138: 1-96.
Summary. The papers published in this special issue were presented at sessions organized by the Commission of Land Degradation and Desertification (COMLAND) for the International Geographical Union's Congress in Santiago, Chile in November 2011, and in the IGU's Main Congress in Cologne, Germany in August 2012.
(2014) LaFevor, M. C., Review of Estudio Costero del Suroccidente de México (CIGA-UNAM, 2013) by Donald D. Brand. In The AAG Review of Books 2(3): 113-115.
Excerpt. Donald D. Brand's Estudio Costero del Suroccidente de México is a highly detailed account of the Pacific coast of the state of Michoacán during the 1950s. El Centro de Investigaciones en Geografía Ambiental (CIGA; UNAM Morelia campus) recently published the work in Spanish, some fifty years after Brand and his collaborators compiled it. The Spanish translation is easily readable by those proficient in the language, although dictionaries of geomorphological and historical nautical terms might be helpful...
(2014) LaFevor, M. C., Review of Environmental Histories of Modern Mexico (University of Arizona Press, 2013) edited by Christopher R. Boyer. In Journal of Historical Geography 43: 187.
Excerpt. A Land Between Waters is a diverse collection of case studies on human-environment interactions in nineteenth- and twentieth-century Mexico that should be of broad interest to environmental historians, historical geographers, and specialists on Mexico alike. The chapters explore such varied topics as agricultural soil and water management, pearl aquaculture in the Gulf of California, the production of knowledge in Mexico’s Royal Botanical Gardens, water infrastructure in urban environments, the inter-play of class and nature in northern Veracruz’s petroleum landscapes, the boom and bust of the Yucatán henequen trade, deforestation on the slopes of Tlaxcala’s La Malintzín volcano, and the conflicts and contradictions inherent in the very existence of Mexico City’s Chapultepec Park. Each contributor’s discoveries further the existing literature and open new paths to research, but these cannot be adequately summarized here.Instead, I recommend the book’s concluding chapter, which dis-tills each earlier chapter’s arguments and highlights their most salient points.This book illustrates why environmental history is at its best when it is an integrative field. Its chapters are, for the most part,individual case studies of local and regional level interactions be-tween humans and their distinctive environments. In Mexico, the diversity of biophysical environments, natural and built land-forms, altitudinal zones and latitudes, and indigenous and exotic species make generalization across space difficult. The human element adds additional layers of complexity and meaning. What happened in one alluvial floodplain or national park may not have played out in the same sequence or with the same results in another. There were ‘good' farmers, as the Florentine Codex informs us, but there were also ‘bad’ farmers, both before the arrival of the Spaniards and after. The book implicitly recognizes that where human-environment interactions occurred was often as important as the sequencing or the social construction or context of those events.The result is a thoughtful collection of studies on historical human-environment interaction labeled‘environmental histories. Some may interpret the book more as a collection of historical geographies -- thematic distinctions among the chapters relate more to issues of space and place and the mechanics of environmental stewardship than to the search for meaning in social interaction over time. But the broader point is that historians are venturing into exciting areas that remain relatively new to the field...
(2013) Hudson, P. F., Sounny-Slitine, A., LaFevor, M. C., A New Longitudinal Approach to Assess Hydrologic Connectivity: Embanked Floodplain Inundation along the Lower Mississippi River. Hydrological Processes 27: 2187-2196.
Abstract. Hydrologic connectivity is fundamental to understanding floodplain processes along meandering river corridors. This study contributes to understanding hydrologic connectivity by utilizing a high resolution Light Detection and Ranging DEM with anew GIS-based approach for identifying the precise elevation of flood stage. The method created a high-resolution longitudinal channel bank profile, enabling a detailed examination of embanked floodplain hydrologic connectivity. A simple channel cross-section approach is likely to result in a large underestimation of floodplain inundation and hydrologic connectivity along meandering river floodplains because of differences in the elevation of the natural levee surface relative to floodplain bottoms and the considerable variability in the elevation of the channel bank profile. There is a large disparity in discharge duration associated with floodplain inundation in comparison to river channel bank inundation. A discharge duration of 10% is associated with inundation of 87% of the floodplain surface whereas only 53% of the channel bank profile is overtopped. An apparent threshold in inundation occurs as the discharge duration decreases below about 35%. While a duration of 25% results in very little of the channel bank being overtopped, it inundates 50% of the floodplain surface. Floodplain borrow pits, which are created in association with dike construction, represent a constant anthropogenic influence on the lower Mississippi embanked floodplain morphology, and are inundated by low discharge magnitudes. The results of the investigation shed new light on the topic of hydrologic connectivity for an important embanked fluvial system that has previously received little attention concerning its physical floodplain processes.
(2012) LaFevor, M. C., Building a Colonial Resource Monopoly: The Expansion of Sulphur Mining in New Spain (1600-1820). Geographical Review 102(2): 202-224.
Abstract. The discovery, extraction, and monopolistic control of key natural resources was a priority of New Spain’s colonial administration. Managing the region’s abundant resources,however, often proved difficult for the Spanish Crown. Human and environmental challenges impeded proto-industrial growth and development, and monopolistic control of resources often met resistance. In this article I examine these processes in the context of New Spain’s little-known monopoly on sulphura yellow, powdery mineral the Crown jealously guarded as its own. Sulphur was critical for gunpowder and explosives production, yet the Crown often failed to produce enough of it to meet the growing demand by its military and the silver blast-mining industry. Colonial documents reveal administrators’ attempts to improve sulphur production through reform measures, which included advising sulphur miners on how to discover sulphur deposits and, eventually, how to develop their mines. Efforts to improve sulphur production were moderately successful, although the process was messy and inefficient.
(2012) LaFevor, M. C., Sulphur Mining on Mexico's Popocatépetl Volcano (1820-1920): Origins, Development, and Human-Environmental Challenges. Journal of Latin American Geography 11(1): 79-98.
Abstract. This paper traces the origins and development of a little-known extractive industry in nineteenth-century Mexico: volcanic sulphur mining. Unpublished documents from Mexican archives, nineteenth-century travel literature, reports from early scientific expeditions, and historical newspapers provide the bulk of data. Documents show how both Mexican and United States interests – indigenous sulphur miners (azufreros) and venture capitalists – confronted the challenges of mining sulphur from the crater of Mexico’s Popocatépetl volcano, at 5,426 meters (17,802 feet) elevation.
(2010) LaFevor, M. C., Review of Cartographic Encounters: Indigenous People and the Mapping of the New World (Reaktion Books, 2009) by John Rennie Short. In Journal of Latin American Geography 9(2): 183-185.
Excerpt. In his latest book john Short explores the roles of indigenous peoples in the exploration and mapping of the New World. In doing so, eh interprets "cartographic encounters" more broadly than do previous works, such as Malcolm Lewis' Cartographic encounters: perspectives on Native American map making and map use (1998). Instead of focusing on the specific role of map-making or cartographic interpretation, Short analyzes the encounter narratives themselves for evidence of indigenous cartographic contributions to exploration. He proposes that a closer (postmodern) re-reading of these narratives reveals that the explorers were more dependent on information gained form indigenous peoples than has been popularly recognized. By highlighting their contributions, Short attempts to dispel what he calls the myths of discovery and exploration, which tend to glorify the 'discovery' of the New World by the Europeans. He writes, "The image of the lone, western hero exploring virgin territory is so far off the mark as to be laughable" (p.127)...
(2010) LaFevor, M. C., Mountains and Creative Mexican Maps: From Seminar to Survey. Portal: LLILAS Annual Review 5: 28-31.
Excerpt. In the mountain community of San Nicolás de los Ranchos, Puebla, citizens use maps in creative ways. Every year, families gather on the town plaza to engage in artistic map-making rituals as part of a local government campaign to strengthen a sense of community and regional identity. The small town’s ministry of culture provides the materials and refreshments while school kids and their parents draw representations of their surroundings. Parents begin by tracing the municipal boundaries and surrounding mountains, filling in empty spaces with roadways. With these outlines in place, children map their schools, athletic fields, and other, more abstract images that perhaps only they under-stand. Perceptions of space and place are depicted artistically while geographical knowledge is passed between generations. Families, however, seem to consider the event more for enjoyment and less as a serious educational experience. Regional music plays loudly over the plaza speakers as the children proudly display their creations on the walls of municipal buildings for the entire community to view and enjoy...