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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. 

For the last seven years, PlanetScope satellites have started near-daily imaging of parts of the Earth’s surface, making high-density multitemporal, multispectral, 3-m pixel imagery accessible to researchers. Multitemporal satellite data enables landscape archaeologists to examine changes in environmental conditions at time scales ranging from daily to decadal. This kind of temporal resolution can accentuate landscape features on the ground by de-emphasizing non-permanent signatures caused by seasonal or even daily changes in vegetation. We argue that the availability of high spatial and temporal resolution multispectral imagery from Planet Inc. will enable new approaches to studying archaeological visibility in landscapes. While palimpsests are discrete overlapping layers of material accumulation, multitemporal composites capture cyclical and seasonal time and can be used to interpret past landscape histories at multiple scales. To illustrate this perspective, we present three case studies using PlanetScope imagery in tropical environments on the Indian Ocean islands of Madagascar, Mauritius, and Zanzibar. 

Communities in resource-poor areas face health, food production, sustainability, and overall survival challenges. Consequently, they are commonly featured in global debates surrounding societal collapse. Rapa Nui (Easter Island) is often used as an example of how overexploitation of limited resources resulted in a catastrophic population collapse. A vital component of this narrative is that the rapid rise and fall of pre-contact Rapanui population growth rates was driven by the construction and overexploitation of once extensive rock gardens. However, the extent of island-wide rock gardening, while key for understanding food systems and demography, must be better understood. Here, we use shortwave infrared (SWIR) satellite imagery and machine learning to generate an island-wide estimate of rock gardening and reevaluate previous population size models for Rapa Nui. We show that the extent of this agricultural infrastructure is substantially less than previously claimed and likely could not have supported the large population sizes that have been assumed 

Throughout the history of archaeology, researchers have evaluated human societies in terms of systems and systems interactions. Complex systems theory (CST), which emerged in the 1980s, is a framework that can explain the emergence of new organizational forms. Its ability to capture nonlinear dynamics and account for human agency make CST a powerful analytical framework for archaeologists. While CST has been present within archaeology for several decades (most notably through the use of concepts like resilience and complex adaptive systems), recent increases in the use of methods like network analysis and agent-based modeling are accelerating the use of CST among archaeologists. This article reviews complex systems approaches and their relationship to past and present archaeological thought. In particular, CST has made important advancements in studies of adaptation and resilience, cycles of social and political development, and the identification of scaling relationships in human systems. Ultimately, CST helps reveal important patterns and relationships that are pivotal for understanding human systems and the relationships that define different societies. 

This study presents preliminary results from recent bathymetric LiDAR-guided surveys of submerged archaeological landscapes in the Apalachee Bay off the coast of Florida. We show how bathymetric LiDAR can re-identify previously recorded archaeological sites and identify new cultural deposits at shallow depths and help aid SCUBA surveys of submerged environments. While most prior archaeological applications of bathymetric LiDAR have focused on shipwrecks and historic era sites, our case study demonstrates that bathymetric LiDAR is capable of detecting Holocene and Pleistocene era archaeological sites as well. Detecting and eventually characterizing these ancient deposits will greatly expand our understanding of settlement trends when sea levels were lower and may provide insights into how some of the earliest coastal populations adapted to this novel and changing environment. Our SCUBA surveys also elucidate the impact of local environmental conditions of the applicability of deploying bathymetric LiDAR; specifically, eel grass cover does not hinder LiDAR capabilities, while high rates of sedimentation greatly reduce success in identifying archaeological deposits. Overall, our results show promise in the future of applying remote sensing to study shallow submerged archaeological landscapes, which can help improve our understanding of human–environment dynamics prior to and during periods of sea level change. 

Archaeologists interested in the evolution of anthropogenic landscapes have productively adopted Niche Construction Theory (NCT), in order to assess long-term legacies of human-environment interactions. Applications of NCT have especially been used to elucidate co-evolutionary dynamics in agricultural and pastoral systems. Meanwhile, foraging and/or highly mobile small-scale communities, often thought of as less intensive in terms of land-use than agropastoral economies, have received less theoretical and analytical attention from a landscape perspective. Here we address this lacuna by contributing a novel remote sensing approach for investigating legacies of human-environment interaction on landscapes that have a long history of co-evolution with highly mobile foraging communities. Our study is centered on coastal southwest Madagascar, a region inhabited by foraging and fishing communities for close to two millennia. Despite significant environmental changes in southwest Madagascar’s environment following human settlement, including a wave of faunal extinctions, little is known about the scale, pace and nature of anthropogenic landscape modification. Archaeological deposits in this area generally bear ephemeral traces of past human activity and do not exhibit readily visible signatures of intensive land-use and landscape modification (e.g., agricultural modifications, monumental architecture, etc.). In this paper we use high-resolution satellite imagery and vegetative indices to reveal a legacy of human-landscape co-evolution by comparing the characteristics – vegetative productivity and geochemical properties – of archaeological sites to those of locations with no documented archaeological materials. Then, we use a random forest (RF) algorithm and spatial statistics to quantify the extent of archaeological activity and use this analysis to contextualize modern-day human-environment dynamics. Our results demonstrate that coastal foraging communities in southwest Madagascar over the past 1,000 years have extensively altered the landscape. Our study thus expands the temporal and spatial scales at which we can evaluate human-environment dynamics on Madagascar, providing new opportunities to study early periods of the island’s human history when mobile foraging communities were the dominant drivers of landscape change. 

ABSTRACT Critical data concerning key developments in global human history now lie submerged on continental shelves where investigations confront significant challenges. Whereas underwater excavations and surveys are expensive and weather dependent and require specialized training and equipment, remote sensing methods can improve chances for success offshore. A refinement in one method, a semi‐automated analysis protocol that can help to identify Pleistocene and Holocene era archaeological deposits in bathymetric LiDAR datasets, is presented here. This method employs contour mapping to identify potential archaeological features in shallow water environments in Apalachee Bay, Florida. This method successfully re‐identified multiple previously recorded archaeological sites in the study region and detected at least four previously undocumented archaeological sites. These results suggest that this procedure can expand on methods to identify and record submerged archaeological deposits in sediment‐starved, shallow‐water environments. 

This rapid communication describes a lithic blade that was recently recovered during excavations in the Velondriake Marine Protected Area in southwest Madagascar. This represents the only recorded archaeological lithic blade recovered from southwest Madagascar. The blade was recovered in situ at a depth of 1.66 m, a deposit dating to between 750 and 1200 BP at site G134, adjacent to the modern village of Antsaragnasoa. While similar in material choice (translucent-brown chert) and morphology (parallel-sided blade) to other lithics recovered at the northern sites of Ambohiposa and Lakaton’i Anja, it is significantly larger than other recorded lithics on Madagascar. More research is required but this finding suggests that lithic technology may have been more widespread on the island, particularly among coastal communities, than previously thought. 

Palaeoenvironmental data indicate that the climate of south-western Madagascar has changed repeatedly over the past millennium. Combined with socio-political challenges such as warfare and slave raiding, communities continually had to mitigate against risk. Here, the authors apply social network analysis to pottery assemblages from sites on the Velondriake coast to identify intercommunity connectivity and changes over time. The results indicate both continuity of densely connected networks and change in their spatial extent and structure. These network shifts coincided with periods of socio-political and environmental perturbation attested in palaeoclimate data and oral histories. Communities responded to socio-political and environmental risk by reconfiguring social connections and migrating to areas of greater resource availability or political security.