Environmentally transformative human use of land accelerated with the emergence of agriculture, but the extent, trajectory, and implications of these early changes are not well understood. An empirical global assessment of land use from 10,000 BP to 1850 CE reveals a planet largely transformed by hunter-gatherers, farmers and pastoralists by 3,000 years ago, significantly earlier than land-use reconstructions commonly used by Earth scientists. Synthesis of knowledge contributed by over 250 archaeologists highlighted gaps in archaeological expertise and data quality, which peaked at 2000 BP and in traditionally studied and wealthier regions. Archaeological reconstruction of global land-use history illuminates the deep roots of Earth's transformation and challenges the emerging Anthropocene paradigm that large-scale anthropogenic global environmental change is mostly a recent phenomenon.One Sentence Summary: A map of synthesized archaeological knowledge on land use reveals a planet largely transformed by hunter-gatherers, farmers and pastoralists by 3,000 years ago.

and colleges worldwide have quickly moved campus-based classes to virtual spaces due to the COVID-19 pandemic. This article explores the impact of this sudden transition of learning and teaching based on experiences and evidence from six institutions across three countries. Our findings suggest that although online and remote learning was a satisfactory experience for some students, various inequities were involved. Many students lacked appropriate devices for practical work and encountered difficulties in securing suitable housing and workspace. Students were stressed, and faculty were, too, especially those in precarious employment. The lack of fieldwork and access to laboratories created special challenges. We are concerned that the lack of hands-on experience could cause a decline in enrollments and the number of majors in geography over the next few years. This issue must be addressed by making introductory courses as engaging as possible. It is too early to determine the extent to which online and remote learning can replace campus-based, face-toface geography education once the pandemic ends, but the new academic year of 2020-2021 will be revealing. Nevertheless, the COVID-19 crisis has revealed preexisting problems and inequalities that will need our collective effort to address, regardless of the pandemic's trajectory.

Analyses of agricultural growth in subsistence economies may be facilitated if agricultural intensity is viewed in terms of the concentration of production or yield per unit area and time. This view of agricultural intensity is implicit in many growth arguments and is consistent with their purpose. Limited production data from various subsistence economies necessitate the use of a surrogate measure of intensity that is based on a variety of input factors.

Despite countless archaeological excavations at prehistoric agricultural sites, understanding of the cultivation practices of native North Americans ca. 1492 remains imperfect, and regional syntheses of agricultural patterning elusive. The problem remains that excavations and surveys focus more on site function than on food production; more on the remains of plants than on cultivation practices; more on socioeconomic hypotheses than on human-environmental or spatial implications. This paper uses extensive ethnohistorical accounts of early European explorers that help to identify five different types of agricultural methods in use during the Contact period. I argue that the agroecological landscapes of both the Southwest and Eastern Woodlands were quite complex, in response to mosaic environments, and that labor-intensive agriculture was as common in the East as in the Southwest. Subtleties in irrigation strategies were of equal if not greater importance than the obvious function of simply providing water in arid environments. Pre-European cultivators built terraces in the mountainous Southwest, in part to halt environmental degradation. I question the dominance of shifting cultivation in the Eastern Woodlands. large, permanently cultivated cleared areas, raised fields, and mounding indicate that intensive practices were common and widespread here. Lastly, I argue that house-lot gardens across the continent may have been critical, rather than merely supplemental, in the overall scheme of indigenous food production. Much work remains to be done before the many residual questions about native agriculture can be resolved.

At least two major views of agro-ecosystem change can be recognized-systematic and incremental. Systematic change involves the addition of new fields and associated features that are constructed completely prior to cultivation; incremental change involves gradual transformation of fields and features in conjunction with cultivation. The systematic view has been the more dominant of the two, particularly as applied to interpretations of past agro-ecosystems. Using present-day data on temporales or runoff-dependent fields in eastern Sonora, Mexico, this study describes one case of incremental agro-ecosystem change. Small, individual fields are developed into a more complex system by progressive modification resulting from the cumulative actions of individual farmers. In this case, the resulting constructional form of the agro-ecosystem alone does not allow assessment of the process of its development. Interpretations of past agro-ecosystems should recognize that both change processes are possible.