The application of light detection and ranging (LiDAR), a laserbased remote-sensing technology that is capable of penetrating overlying vegetation and forest canopies, is generating a fundamental shift in Mesoamerican archaeology and has the potential to transform research in forested areas world-wide. Much as radiocarbon dating that half a century ago moved archaeology forward by grounding archaeological remains in time, LiDAR is proving to be a catalyst for an improved spatial understanding of the past. With LiDAR, ancient societies can be contextualized within a fully defined landscape. Interpretations about the scale and organization of densely forested sites no longer are constrained by sample size, as they were when mapping required laborious on-ground survey. The ability to articulate ancient landscapes fully permits a better understanding of the complexity of ancient Mesoamerican urbanism and also aids in modern conservation efforts. The importance of this geospatial innovation is demonstrated with newly acquired LiDAR data from the archaeological sites of Caracol, Cayo, Belize and Angamuco, Michoacán, Mexico. These data illustrate the potential of technology to act as a catalytic enabler of rapid transformational change in archaeological research and interpretation and also underscore the value of on-the-ground archaeological investigation in validating and contextualizing results.T ransformational changes are rare in archaeology and often are best recognized in hindsight (1). However, there are times when advances in technology are so far reaching that they serve as catalysts in transforming our understanding of both the past and the practice of archaeological research, thus triggering a scientific revolution as conceptualized by Thomas Kuhn (2). We believe that advances in the remote geospatial imaging of cultural landscapes, including ancient communities and their anthropogenic hinterlands, constitute such an archeological paradigm shift. Here we present newly acquired data from two recent archaeological projects in different parts of Mesoamerica showcasing the application of light detection and ranging (LiDAR) technology to ancient urban settlements. In both cases, the nearly 3D data are changing commonly held interpretations of societal development profoundly. The phenomenon described is not limited to archaeology; technical innovations have been noted as spawning advances in other areas of research, such as astrophysics (3). However, the magnitude of change enabled by the use of LiDAR technology is particularly apparent in the archaeology of Mesoamerica.Archaeological research revolves around temporal and spatial data; thus, advances in either parameter can be transformative. Histories of archaeology (1, 4) have noted the change in the discipline from an ancient antiquarian focus on objects to the current scientific enterprise. Great enablers of archaeological research have included various technological enhancements to spatial, temporal, and functional interpretations. Although many technical imp...

This paper presents 2,000 years of settlement and land use within the Lake Pá tzcuaro Basin, Mexico. Three findings challenge the conclusions of previous research. We show (i) that initial land degradation was caused by settlement, not by agriculture; (ii) that population density inversely correlates with erosion; and (iii) that land degradation was associated with European Conquest but not from the introduction of the Euro-agro suite. Instead, demographic collapse caused by European-introduced disease prevented human-generated landscapes from being maintained, resulting in widespread degradation. These findings support the use of indigenous landscape technology for modern conservation if past failings can be resolved.

Land degradation is frequently cited as a factor in the collapse of ancient complex societies. Implicit in these tales of ecological suicide is the assumption that land degradation is an ecological rather than a social problem. Here, I discuss how land degradation can be reconceptualized as a social–environmental dialectic. I then discuss the implications of this perspective using evidence from a recent landscape project exploring diachronic relationships between environmental and social transformations in the development of the Precolumbian Tarascan (Purépecha) empire, centered in the Lake Pátzcuaro Basin, Mexico. Project findings challenge common conceptions regarding the impact of agriculture, urbanism, and state collapse on ancient landscapes, as well as the dating of the most serious episodes of degradation.

There is a growing recognition that modern environmental problems bear striking resemblance to those faced by past societies and that to understand the environmental present we must consider the total sweep of anthropogenic environmental change on specific landscapes. This “In Focus” assembles five articles encompassing diverse time periods and different global regions to make the case that long‐term perspectives on the relationship between people and their environmental contexts are critical for understanding and evaluating contemporary environmental debates, interpretations, and even policies.

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