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The environmental impacts of human societies are generally assumed to correlate with factors such as population size, whether they are industrialized, and the intensity of their landscape modifications (e.g., agriculture, urban development). As a result, small-scale communities with subsistence economies are often not the focus of long-term studies of environmental impact. However, comparing human-environment dynamics and their lasting ecological legacies across societies of different scales and forms of organization and production is important for understanding landscape change at regional to global scales. On Madagascar, ecological and cultural diversity, coupled with climatic variability, provide an important case study to examine the role of smaller-scale socioeconomic practices (e.g., fishing, foraging, and herding) on long-term ecological stability. Here, we use multispectral satellite imagery to compare long-term ecological impacts of different human livelihood strategies in SW Madagascar. Our results indicate that the nature of human-environmental dynamics between different socioeconomic communities are similar. Although some activities leave more subtle traces than others, geophysics highlight similar signatures across a landscape inhabited by communities practicing a range of subsistence strategies. Our results further demonstrate how Indigenous land stewardship is integrated into the very fabric of ecological systems in SW Madagascar with implications for conservation and sustainability. 

The Late-Holocene history of hydroclimatic variability in the Atacama Desert offers insights into the effects of precipitation and humans on ecosystems in one of the most extremely arid regions of the world. However, understanding the effects of regional precipitation variability in relation to local ecological stressors remains to be fully resolved. Here, we present a pollen-based qualitative precipitation reconstruction derived from fossil rodent middens recovered from two sites near Laguna Roja (LRO; n = 25) and Isluga (ISL; n = 15) in the Atacama highlands (19°S) of northern Chile. At LRO, the fossil pollen record shows multi-centennial hydroclimatic anomalies during the last millennium, with wetter than present phases at 1155–1130, 865–670, and 215–80 cal yrs BP, and similar to present conditions between 1005 and 880 cal yrs BP. In contrast, the ISL record shows a wet phase during 1115–840 cal yrs BP, suggesting that meso-ecological processes were as important in vegetation turnover as regional hydroclimate anomalies. Wetter conditions derived from LRO partially overlap with the Medieval Climate Anomaly (865–670 cal yrs BP) and with the latest part of the Little Ice Age (215–80 cal yrs BP). Furthermore, no strong anthropogenic signal was identified possibly related to the remote location of the records. Palynological diversity analyses evidence increasing diversification of plant communities during wet events at both sites. In correlation to existing regional hydroclimatic records from the Western Andes, our precipitation reconstruction verifies that centennial-scale changes in the strength of the South American Summer Monsoon (SASM) and partial influence of El Niño-like (ENSO) conditions drove vegetation turnover in the Atacama Desert during the last millennium. 

Research at the Selin Farm site in northeastern Honduras examined changing cultural landscapes in a region whose prehistory is poorly understood. Low-impact field methods and radiocarbon dates reveal how this cultural landscape changed in response to shifting priorities among its inhabitants from a.d. 300–1000. We found evidence for rapid accumulation of deposits beginning around a.d. 600, when the site nearly doubled in size over the span of just decades, before retracting again within a few centuries. Although it was caught up in some of the broader social and political changes that began around a.d. 600 throughout northern Honduras and southern Mesoamerica, the longevity of this site suggests stability of the cultural and ecological systems in which it was embedded until the final centuries of occupation. Well-preserved, long-term deposits make Selin Farm an ideal location in which to explore entangled processes of environmental and social change in the little-known small-scale societies of Central America. 

South America is a megadiverse continent that witnessed the domestication, translocation and cultivation of various plant species from seemingly contrasting ecosystems. It was the recipient and supplier of crops brought to and from Mesoamerica (such as maize and cacao, respectively), and Polynesia to where the key staple crop sweet potato was exported. Not every instance of the trans -ecological expansion of cultivated plants (both domesticated and wild), however, resulted in successful farming. Here, we review the transregional circulation and introduction of five food tropical crops originated in the tropical and humid valleys of the eastern Andes—achira, cassava, ahipa , sweet potato, and pacay—to the hyper-arid coastal valleys of the Atacama Desert of northern Chile, where they have been found in early archeological sites. By means of an evaluation of the contexts of their deposition and supported by direct radiocarbon dating, stable isotopes analyses, and starch grain analysis, we evaluate different hypotheses for explaining their introduction and adaptation to the hyper-arid soils of northern Chile, by societal groups that after the introduction of cultigens still retained a strong dependence on marine hunting, gathering and fishing ways of life based on wide variety of marine coast resources. Many of the studied plants were part of a broader package of introduced goods and technological devices and procedures, linked to food, therapeutic medicine, social and ritual purposes that transformed previous hunter-gatherer social, economic, and ideological institutions. Based on archeological data, we discuss some of the possible socio-ecological processes involved in the development of agricultural landscapes including the adoption of tropical crops originated several hundred kilometers away from the Atacama Desert during the Late Holocene. 

Abstract People could have hunted Madagascar’s megafauna to extinction, particularly when introduced taxa and drought exacerbated the effects of predation. However, such explanations are difficult to test due to the scarcity of individual sites with unambiguous traces of humans, introduced taxa, and endemic megaherbivores. We excavated three coastal ponds in arid SW Madagascar and present a unique combination of traces of human activity (modified pygmy hippo bone, processed estuarine shell and fish bone, and charcoal), along with bones of extinct megafauna (giant tortoises, pygmy hippos, and elephant birds), extirpated fauna (e.g., crocodiles), and introduced vertebrates (e.g., zebu cattle). The disappearance of megafauna from the study sites at ~ 1000 years ago followed a relatively arid interval and closely coincides with increasingly frequent traces of human foraging, fire, and pastoralism. Our analyses fail to document drought-associated extirpation or multiple millennia of megafauna hunting and suggest that a late combination of hunting, forest clearance, and pastoralism drove extirpations.