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Lucero LJ. Ancient Maya reservoirs, constructed wetlands, and future water needs. Proc Natl Acad Sci U S A 2023; 120:e2306870120. [PMID: 37812714 PMCID: PMC10589657 DOI: 10.1073/pnas.2306870120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023] Open
Abstract
The Classic Maya (c. 250 to 900 CE) in the tropical southern lowlands of Central America dealt with water scarcity during annual dry seasons and periods of climate instability via sophisticated urban reservoir systems they relied on for over a thousand years. Surface water is limited because typically rain percolates through the karstic terrain. I posit that Maya reservoirs functioned as do constructed wetlands (CWs) at present. Still-water systems like CWs and Maya reservoirs can become stagnant and nonpotable due to the build-up of nutrients that promote algal growth. Stagnant waters also serve as breeding grounds for mosquitoes that spread endemic diseases. CWs keep water clean via certain aquatic plants since all plants uptake nutrients (e.g., nitrogen, phosphorus) and decomposing plant matter supports microbial biofilms that break down nutrients. CWs also support diverse zooplankton that prey on pathogens and bacteria that assist to denitrify water. CWs do not require the use of chemicals or fossil fuels and after the initial labor-intensive output become self-cleaning and self-sufficient with some maintenance. I posit that the Maya used a diverse array of aquatic plants and other biota to keep water clean in the same manner as do CWs, which I demonstrate using evidence from excavations and settlement maps, sediment cores and current wetlands, and the iconographic and hieroglyphic records. The next step is to combine what we know about ancient Maya reservoirs in conjunction with what is currently known about CWs to better address future water needs.
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Affiliation(s)
- Lisa J. Lucero
- Department of Anthropology, University of Illinois at Urbana-Champaign, Urbana, IL61801
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2
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Hou J, Ji K, Zhu E, Dong G, Tong T, Chu G, Liu W, Wu W, Zhang S, Guedes JD, Chen F. Climate change fostered rise and fall of the Tibetan Empire during 600-800 AD. Sci Bull (Beijing) 2023:S2095-9273(23)00294-3. [PMID: 37179230 DOI: 10.1016/j.scib.2023.04.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/09/2023] [Accepted: 04/10/2023] [Indexed: 05/15/2023]
Abstract
During the 7-9th century, the Tibetan Empire constituted a superpower between the Tang Empire and Abbasid Caliphate: one that played significant roles in geopolitics in Asia during the Early Medieval Period. The factors which led to the rise and rapid decline of this powerful Empire, the only united historical regime on the Tibetan Plateau (TP), remain unclear. Sub-annual scale precipitation and decadal-scale temperature records of the central TP are presented, indicating that the height of this Empire coincided with a two-century long interval of uncharacteristically warm and humid climate. The ameliorated climate enabled the expansion of arable land and increased agricultural production. The close relationship between the precipitation records and historical events implied that the Empire implemented flexible strategies to tackle the effects of climate changes. This has implications for agricultural production in alpine regions including the TP, in the context of current global warming.
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Affiliation(s)
- Juzhi Hou
- Group of Alpine Paleoecology and Human Adaptation, State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kejia Ji
- Group of Alpine Paleoecology and Human Adaptation, State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Erlei Zhu
- Group of Alpine Paleoecology and Human Adaptation, State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Guanghui Dong
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Tao Tong
- Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China
| | - Guoqiang Chu
- Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Weiguo Liu
- Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Wenxiang Wu
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Shuilong Zhang
- Key Laboratory of Network Information System Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jade D'Alpoim Guedes
- Scripps Institution of Oceanography, Department of Anthropology, University of California San Diego, San Diego CA 92093, USA
| | - Fahu Chen
- Group of Alpine Paleoecology and Human Adaptation, State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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3
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Feinman GM, Carballo DM, Nicholas LM, Kowalewski SA. Sustainability and duration of early central places in prehispanic Mesoamerica. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1076740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
During the last millennium BCE, central places were founded across many regions of western (non-Maya) Mesoamerica. These early central places differed in environmental location, size, layout, and the nature of their public spaces and monumental architecture. We compare a subset of these regional centers and find marked differences in their sustainability--defined as the duration of time that they remained central places in their respective regions. Early infrastructural investments, high degrees of economic interdependence and collaboration between domestic units, and collective forms of governance are found to be key factors in such sustainability.
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4
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Tally‐Schumacher KJ. Warm Soil, Westerly Wind, and Wet Feet: Feeling and Measuring Ecological Time in the Roman World. GEOHEALTH 2023; 7:e2022GH000720. [PMID: 36636747 PMCID: PMC9830967 DOI: 10.1029/2022gh000720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/15/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
Although climate change, pollution, and environmental degradation are contemporary problems, these are also challenges with deep historic roots in antiquity. 2,000 years ago, during the Roman Climate Optimum, a period of unusually warm, wet, and stable temperatures in the Mediterranean from roughly 200 BCE to 150 CE, the Romans altered the natural environment so greatly that they produced a level of pollution that was unparalleled until the Industrial Revolution. It is precisely in this contradictory time of unusually productive growth and destruction that we discover a blossoming of textual and visual ecological calendars illustrating how the Romans experienced the changing Mediterranean seasons. Roman agricultural treatises instruct us on specific agricultural tasks based on celestial movement, the arrival of particular winds, and on corporeal sensations, such as the warmth of the soil. Literary texts from the period portray kinship and shared corporeality between farmers and plants, with parent farmers listening to and assisting plant-children in achieving their desires. The concept of measuring time by means of the human body and its sensations is most explicit in the agricultural mosaics of the Late Roman period, which depict enslaved workers laboring, sweating, stomping, plowing, and performing seasonal tasks. While much of the conceptualization of indigenous ecological calendars is framed within the context of modern states, juxtaposing ancient predecessors and contemporary practices offers a new perspective on this topic.
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5
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Sullivan RM, van Hengstum PJ, Donnelly JP, Tamalavage AE, Winkler TS, Little SN, Mejia-Ortiz L, Reinhardt EG, Meacham S, Schumacher C, Korty R. Northeast Yucatan hurricane activity during the Maya Classic and Postclassic periods. Sci Rep 2022; 12:20107. [PMID: 36418858 PMCID: PMC9684114 DOI: 10.1038/s41598-022-22756-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/19/2022] [Indexed: 11/24/2022] Open
Abstract
The collapse of the Maya civilization in the late 1st/early 2nd millennium CE has been attributed to multiple internal and external causes including overpopulation, increased warfare, and environmental deterioration. Yet the role hurricanes may have played in the fracturing of Maya socio-political networks, site abandonment, and cultural reconfiguration remains unexplored. Here we present a 2200 yearlong hurricane record developed from sediment recovered from a flooded cenote on the northeastern Yucatan peninsula. The sediment archive contains fine grain autogenic carbonate interspersed with anomalous deposits of coarse carbonate material that we interpret as evidence of local hurricane activity. This interpretation is supported by the correlation between the multi-decadal distribution of recent coarse beds and the temporal distribution of modern regional landfalling storms. In total, this record allows us to reconstruct the variable hurricane conditions impacting the northern lowland Maya during the Late Preclassic, Classic, and Postclassic Periods. Strikingly, persistent above-average hurricane frequency between ~ 700 and 1450 CE encompasses the Maya Terminal Classic Phase, the declines of Chichén Itza, Cobá, and subsequent rise and fall of the Mayapán Confederacy. This suggests that hurricanes may have posed an additional environmental stressor necessary of consideration when examining the Postclassic transformation of northern Maya polities.
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Affiliation(s)
- Richard M. Sullivan
- grid.264756.40000 0004 4687 2082Department of Oceanography, Texas A&M University, College Station, TX 77843 US
| | - Peter J. van Hengstum
- grid.264756.40000 0004 4687 2082Department of Oceanography, Texas A&M University, College Station, TX 77843 US ,grid.264764.50000 0004 0546 4832Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, 1001 Texas Clipper Road, Galveston, TX 77553 US
| | - Jeffrey P. Donnelly
- grid.56466.370000 0004 0504 7510Geology & Geophysics, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA 02543 US
| | - Anne E. Tamalavage
- grid.264756.40000 0004 4687 2082Department of Oceanography, Texas A&M University, College Station, TX 77843 US ,grid.14848.310000 0001 2292 3357Département de Sciences Biologiques, Université de Montréal, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, QC H2V 0B3 Canada
| | - Tyler S. Winkler
- grid.264756.40000 0004 4687 2082Department of Oceanography, Texas A&M University, College Station, TX 77843 US ,grid.56466.370000 0004 0504 7510Geology & Geophysics, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA 02543 US
| | - Shawna N. Little
- grid.264764.50000 0004 0546 4832Department of Marine Biology, Texas A&M University at Galveston, 1001 Texas Clipper Road, Galveston, TX 77553 US
| | - Luis Mejia-Ortiz
- División de Desarrollo Sustentable, Universidad Autónoma del Estado de Quintana Roo, Av. Andrés Quintana Roo s/n, 77600 Cozumel, Quintana Roo Mexico
| | - Eduard G. Reinhardt
- grid.25073.330000 0004 1936 8227School of Geography and Earth Sciences, McMaster University, Hamilton, ON L8S 4K1 Canada
| | - Sam Meacham
- CINDAQ - El Centro Investigador del Sistema Acuífero de Quintana Roo, A.C., Puerto Aventuras, Quintana Roo Mexico
| | - Courtney Schumacher
- grid.264756.40000 0004 4687 2082Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843 US
| | - Robert Korty
- grid.264756.40000 0004 4687 2082Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843 US
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6
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Ford A. Scrutinizing the paleoecological record of the Maya forest. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.868660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Human expansion into and occupation of the New World coincided with the great transition from the Pleistocene to the Holocene epoch, yet questions remain about how we detect human presence in the paleoecological record. In the Maya area of southern Mesoamerica, archeological evidence of the human imprint is largely invisible until ∼4,000 years ago. How do environmental changes after that time correspond and relate to human impacts? Are the archeological signatures of initial settlements in the Early Preclassic detected? Later, by ∼2,000 years ago when the Maya had fully settled the landscape, how does the evidence of forest compositional changes relate to human intervention? This paper evaluates published paleoecological data in light of the rise of the Maya civilization and reflects on interpretations of how swidden agriculture and the milpa cycle impacted the environment. Evaluating the contrast between the long archeological sequence of successful Maya development and paleoecological interpretations of destructive human-induced environmental impacts requires a concordance among pollen data, archeological evidence, ethnohistoric observations, ethnological studies of traditional Maya land use, and the historical ecology of the Maya forest today.
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7
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Abstract
The influence of climate change on civil conflict and societal instability in the premodern world is a subject of much debate, in part because of the limited temporal or disciplinary scope of case studies. We present a transdisciplinary case study that combines archeological, historical, and paleoclimate datasets to explore the dynamic, shifting relationships among climate change, civil conflict, and political collapse at Mayapan, the largest Postclassic Maya capital of the Yucatán Peninsula in the thirteenth and fourteenth centuries CE. Multiple data sources indicate that civil conflict increased significantly and generalized linear modeling correlates strife in the city with drought conditions between 1400 and 1450 cal. CE. We argue that prolonged drought escalated rival factional tensions, but subsequent adaptations reveal regional-scale resiliency, ensuring that Maya political and economic structures endured until European contact in the early sixteenth century CE. The influence of climate on premodern civil conflict and societal instability is debated. Here, the authors combine archeological, historical, and paleoclimatic datasets to show that drought between 1400-1450 cal. CE escalated civil conflict at Mayapan, the largest Postclassic Maya capital of the Yucatán Peninsula.
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Cruz‐Silva E, Harrison SP, Marinova E, Prentice IC. A new method based on surface-sample pollen data for reconstructing palaeovegetation patterns. JOURNAL OF BIOGEOGRAPHY 2022; 49:1381-1396. [PMID: 35915724 PMCID: PMC9328394 DOI: 10.1111/jbi.14448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 04/02/2022] [Accepted: 04/30/2022] [Indexed: 06/15/2023]
Abstract
AIM Biomisation has been the most widely used technique to reconstruct past regional vegetation patterns because it does not require an extensive modern pollen dataset. However, it has well-known limitations including its dependence on expert judgement for the assignment of pollen taxa to plant functional types (PFTs) and PFTs to biomes. Here we present a new method that combines the strengths of biomisation with those of the alternative dissimilarity-based techniques. LOCATION The Eastern Mediterranean-Black Sea Caspian Corridor (EMBSeCBIO). TAXON Plants. METHODS Modern pollen samples, assigned to biomes based on potential natural vegetation data, are used to characterize the within-biome means and standard deviations of the abundances of each taxon. These values are used to calculate a dissimilarity index between any pollen sample and every biome, and thus assign the sample to the most likely biome. We calculate a threshold value for each modern biome; fossil samples with scores below the threshold for all modern biomes are thus identified as non-analogue vegetation. We applied the new method to the EMBSeCBIO region to compare its performance with existing reconstructions. RESULTS The method captured changes in the importance of individual taxa along environmental gradients. The balanced accuracy obtained for the EMBSeCBIO region using the new method was better than obtained using biomisation (77% vs. 65%). When the method was applied to high-resolution fossil records, 70% of the entities showed more temporally stable biome assignments than obtained using biomisation. The technique also identified likely non-analogue assemblages in a synthetic modern dataset and in fossil records. MAIN CONCLUSIONS The new method yields more accurate and stable reconstructions of vegetation than biomisation. It requires an extensive modern pollen dataset, but is conceptually simple, and avoids subjective choices about taxon allocations to PFTs and PFTs to biomes.
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Affiliation(s)
- Esmeralda Cruz‐Silva
- School of Archaeology, Geography & Environmental ScienceReading UniversityReadingUK
| | - Sandy P. Harrison
- School of Archaeology, Geography & Environmental ScienceReading UniversityReadingUK
| | - Elena Marinova
- Laboratory for ArchaeobotanyBaden‐Württemberg Cultural Heritage State OfficeGeienhofen‐HemmenhofenGermany
| | - I. Colin Prentice
- Georgina Mace Centre for the Living Planet, Department of Life SciencesImperial College LondonAscotUK
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Large variation in availability of Maya food plant sources during ancient droughts. Proc Natl Acad Sci U S A 2022; 119:2115657118. [PMID: 34969847 PMCID: PMC8740729 DOI: 10.1073/pnas.2115657118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2021] [Indexed: 11/24/2022] Open
Abstract
The disruption of Classic Maya society coincided with extended droughts, as suggested by numerous paleoclimatic studies. However, the role of drought in civil upheaval and demographic decline is complicated by the difficulty of linking relatively coarse estimates of meteorological drought with fine-scale plant processes that underpin agriculture. Our analysis of drought resistance across the historically documented, indigenous food plants of ethnographic Maya groups shows a broad range of foods gradually dwindling through droughts of increasing severity. This finding implies that short to moderate droughts could have caused agricultural disruption but not subsistence collapse. However, multiyear extreme drought is consistent with agricultural collapse and the specter of starvation, unless mitigated by food storage or trade from areas less affected by drought. Paleoclimatic evidence indicating a series of droughts in the Yucatan Peninsula during the Terminal Classic period suggests that climate change may have contributed to the disruption or collapse of Classic Maya polities. Although climate change cannot fully account for the multifaceted, political turmoil of the period, it is clear that droughts of strong magnitude could have limited food availability, potentially causing famine, migration, and societal decline. Maize was undoubtedly an important staple food of the ancient Maya, but a complete analysis of other food resources that would have been available during drought remains unresolved. Here, we assess drought resistance of all 497 indigenous food plant species documented in ethnographic, ethnobotanical, and botanical studies as having been used by the lowland Maya and classify the availability of these plant species and their edible components under various drought scenarios. Our analysis indicates availability of 83% of food plant species in short-term drought, but this percentage drops to 22% of food plant species available in moderate drought up to 1 y. During extreme drought, lasting several years, our analysis indicates availability of 11% of food plant species. Our results demonstrate a greater diversity of food sources beyond maize that would have been available to the Maya during climate disruption of the Terminal Classic period than has been previously acknowledged. While drought would have necessitated shifts in dietary patterns, the range of physiological drought responses for the available food plants would have allowed a continuing food supply under all but the most dire conditions.
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Hutson SR, Dunning NP, Cook B, Ruhl T, Barth NC, Conley D. Ancient Maya Rural Settlement Patterns, Household Cooperation, and Regional Subsistence Interdependency in the Río Bec Area: Contributions from G-LiHT. JOURNAL OF ANTHROPOLOGICAL RESEARCH 2021. [DOI: 10.1086/716750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Airborne Lidar Survey, Density-Based Clustering, and Ancient Maya Settlement in the Upper Usumacinta River Region of Mexico and Guatemala. REMOTE SENSING 2021. [DOI: 10.3390/rs13204109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
We present results from the archaeological analysis of 331 km2 of high-resolution airborne lidar data collected in the Upper Usumacinta River basin of Mexico and Guatemala. Multiple visualizations of the DEM and multi-spectral data from four lidar transects crossing the Classic period (AD 350–900) Maya kingdoms centered on the sites of Piedras Negras, La Mar, and Lacanja Tzeltal permitted the identification of ancient settlement and associated features of agricultural infrastructure. HDBSCAN (hierarchical density-based clustering of applications with noise) cluster analysis was applied to the distribution of ancient structures to define urban, peri-urban, sub-urban, and rural settlement zones. Interpretations of these remotely sensed data are informed by decades of ground-based archaeological survey and excavations, as well as a rich historical record drawn from inscribed stone monuments. Our results demonstrate that these neighboring kingdoms in three adjacent valleys exhibit divergent patterns of structure clustering and low-density urbanism, distributions of agricultural infrastructure, and economic practices during the Classic period. Beyond meeting basic subsistence needs, agricultural production in multiple areas permitted surpluses likely for the purposes of tribute, taxation, and marketing. More broadly, this research highlights the strengths of HDBSCAN to the archaeological study of settlement distributions when compared to more commonly applied methods of density-based cluster analysis.
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Historical socioecological transformations in the global tropics as an Anthropocene analogue. Proc Natl Acad Sci U S A 2021; 118:2022211118. [PMID: 34580206 DOI: 10.1073/pnas.2022211118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2021] [Indexed: 11/18/2022] Open
Abstract
Large, low-density settlements of the tropical world disintegrated during the first and second millennia of the CE. This phenomenon, which occurred in South Asia, Southeast Asia, and Mesoamerica, is strongly associated with climate variability and extensive landscape transformation. These profound social transformations in the tropical world have been popularized as "collapse," yet archaeological evidence suggests a more complex and nuanced story characterized by persistence, adaptation, and resilience at the local and regional scales. The resulting tension between ideas of climate-driven collapse and evidence for diverse social responses challenges our understanding of long-term resilience and vulnerability to environmental change in the global tropics. Here, we compare the archetypal urban collapse of the Maya, in modern Belize, Guatemala, Honduras, and Mexico, during the 8th to 11th centuries CE, and the Khmer in modern Cambodia, Laos, Thailand, and Vietnam during the 14th to 15th centuries CE. We argue that the social response to environmental stress is spatially and temporally heterogenous, reflecting the generation of large-scale landesque capital surrounding the urban cores. Divergences between vulnerable urban elite and apparently resilient dispersed agricultural settlements sit uncomfortably with simplistic notions of social collapse and raise important questions for humanity as we move deeper into the Anthropocene.
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Geomorphology of the Mirador-Calakmul Karst Basin: A GIS-based approach to hydrogeologic mapping. PLoS One 2021; 16:e0255496. [PMID: 34339460 PMCID: PMC8328328 DOI: 10.1371/journal.pone.0255496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 07/16/2021] [Indexed: 11/19/2022] Open
Abstract
This paper classifies the karst landscapes of the Petén Plateau and defines the Mirador-Calakmul Karst Basin by illustrating the distribution of its karst hydrologic features. Archaeological and spatial research of the Mirador-Calakmul area of Guatemala and Mexico has shown it to be a karst basin with geopolitical implications. Current research characterizes the karst landscapes of the Petén Plateau, maps the distribution of karst hydrologic features, and delineates the basin in geomorphological terms. To further this aim, multiple forms of remote sensing data including orthophotographs, a satellite Digital Elevation Model, satellite multispectral images, and Light Detection and Ranging (LiDAR) data have been integrated to interpret the karst features in the study area. Outcrop study and thin section analysis of the upper Buena Vista Formation document that the dominant lithologies are a shallow water algal boundstone interbedded with terrestrial caliche. Karst landforms have been mapped over the Petén Plateau and we identify five karst landscapes, the largest of which is a fluviokarst landscape dominated by karst valleys. We further map karst hydrologic features including seasonal swamps, dolines, intermittent lakes, intermittent streams, solution-enhanced fractures, and springs all of which are characteristic of drainage basins. Boundaries of the karst basin are mapped from multiple lines of evidence including distribution of the karst valleys, a line of springs along the western boundary of the fluviokarst landscape, and a surface drainage analysis. We capture and classify hydrologic data points and develop a regional groundwater map that indicates subsurface flow from east to west within the basin. A drainage map illustrates the extensive system of karst valleys, boundaries, and inferred groundwater flow paths of the Mirador-Calakmul Karst Basin. It was within this geomorphological setting that the ancient Maya developed an extensive civilization during the Middle and Late Preclassic periods (1000 BCE-150 CE).
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Collard M, Carleton WC, Campbell DA. Rainfall, temperature, and Classic Maya conflict: A comparison of hypotheses using Bayesian time-series analysis. PLoS One 2021; 16:e0253043. [PMID: 34329320 PMCID: PMC8323947 DOI: 10.1371/journal.pone.0253043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 05/27/2021] [Indexed: 11/29/2022] Open
Abstract
Studies published over the last decade have reached contrasting conclusions regarding the impact of climate change on conflict among the Classic Maya (ca. 250-900 CE). Some researchers have argued that rainfall declines exacerbated conflict in this civilisation. However, other researchers have found that the relevant climate variable was increasing summer temperatures and not decreasing rainfall. The goal of the study reported here was to test between these two hypotheses. To do so, we collated annually-resolved conflict and climate data, and then subjected them to a recently developed Bayesian method for analysing count-based times-series. The results indicated that increasing summer temperature exacerbated conflict while annual rainfall variation had no effect. This finding not only has important implications for our understanding of conflict in the Maya region during the Classic Period. It also contributes to the ongoing discussion about the likely impact of contemporary climate change on conflict levels. Specifically, when our finding is placed alongside the results of other studies that have examined temperature and conflict over the long term, it is clear that the impact of climate change on conflict is context dependent.
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Affiliation(s)
- Mark Collard
- Department of Archaeology, Simon Fraser University, Burnaby, Canada
| | - W. Christopher Carleton
- Extreme Events Research Group, The Science of Human History, and Biogeochemistry, Max Planck Institutes for Chemical Ecology, Jena, Germany
| | - David A. Campbell
- School of Mathematics and Statistics, Carleton University, Ottawa, Canada
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15
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Rojo-Garibaldi B, Rangoni C, González DL, Cartwright JHE. Non-power positional number representation systems, bijective numeration, and the Mesoamerican discovery of zero. Heliyon 2021; 7:e06580. [PMID: 33851058 PMCID: PMC8022160 DOI: 10.1016/j.heliyon.2021.e06580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 03/18/2021] [Accepted: 03/18/2021] [Indexed: 11/28/2022] Open
Abstract
Pre-Columbian Mesoamerica was a fertile crescent for the development of number systems. A form of vigesimal system seems to have been present from the first Olmec civilization onwards, to which succeeding peoples made contributions. We discuss the Maya use of the representational redundancy present in their Long Count calendar, a non-power positional number representation system with multipliers 1, 20, 18 × 20, …, 18 × 20n. We demonstrate that the Mesoamericans did not need to invent positional notation and discover zero at the same time because they were not afraid of using a number system in which the same number can be written in different ways. A Long Count number system with digits from 0 to 20 is seen later to pass to one using digits 0 to 19, which leads us to propose that even earlier there may have been an initial zeroless bijective numeration system whose digits ran from 1 to 20. Mesoamerica was able to make this conceptual leap to the concept of a cardinal zero to perform arithmetic owing to a familiarity with multiple and redundant number representation systems.
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Affiliation(s)
- Berenice Rojo-Garibaldi
- Posgrado en Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Av. Universidad 3000, Col. Copilco, Del. Coyoacán, Cd.Mx. 04510, Mexico
| | - Costanza Rangoni
- Istituto per la Microelettronica e i Microsistemi, Area della Ricerca CNR di Bologna, 40129 Bologna, Italy
| | - Diego L González
- Istituto per la Microelettronica e i Microsistemi, Area della Ricerca CNR di Bologna, 40129 Bologna, Italy.,Dipartimento di Scienze Statistiche "Paolo Fortunati", Università di Bologna, 40126 Bologna, Italy
| | - Julyan H E Cartwright
- Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, 18100 Armilla, Granada, Spain.,Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, 18071 Granada, Spain
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Evaluating the Global State of Ecosystems and Natural Resources: Within and Beyond the SDGs. SUSTAINABILITY 2020. [DOI: 10.3390/su12187381] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Sustainable Development Goals (SDGs) purport to report holistically on progress towards sustainability and do so using more than 231 discrete indicators, with a primary objective to achieve a balance between the environment, social and economic aspects of development. The research question underpinning the analyses presented in this paper is: are the indicators in the SDGs sufficient and fit for purpose to assess the trajectory of natural resources towards sustainability? We extracted the SDG indicators that monitor the state of natural resources, or alternately support policy or governance for their protection, and determined whether these are adequate to provide the essential data on natural resources to achieve the aims of the SDGs. The indicators are clustered into four natural resource categories—land, water (both marine and freshwater), air and biodiversity. Indicators for monitoring land resources show that the most comprehensive land resource indicator for degraded land is not fully implemented and that missing from land monitoring is an evaluation of vegetation health outside of forests and mountains, the condition of soils, and most importantly the overall health of terrestrial ecosystems. Indicators for monitoring water resources have substantial gaps, unable to properly monitor water quality, water stress, many aspects of marine resources and, most significantly, the health of fresh and salt water ecosystems. Indicators for monitoring of air have recently become more comprehensive, but linkage to IPCC results would benefit both programs. Monitoring of biodiversity is perhaps the greatest weakness of the SDG Agenda, having no comprehensive assessment even though narrow aspects are monitored. Again, deliberate linkages to other global biodiversity programs (e.g., CBD and the Post-2020 Biodiversity Framework, IPBES, and Living Planet) are recommended on condition that data can be defined at a country level. While the SDG list of indicators in support of natural resource is moderately comprehensive, it lacks holistic monitoring in relation to evaluation of ecosystems and biodiversity to the extent that these missing but vital measures of sustainability threaten the entire SDG Agenda. In addition, an emerging issue is that even where there are appropriate indicators, the amount of country-level data remains inadequate to fully evaluate sustainability. This signals the delicate balance between the extent and complexity of the SDG Agenda and uptake at a country level.
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Lentz DL, Hamilton TL, Dunning NP, Scarborough VL, Luxton TP, Vonderheide A, Tepe EJ, Perfetta CJ, Brunemann J, Grazioso L, Valdez F, Tankersley KB, Weiss AA. Molecular genetic and geochemical assays reveal severe contamination of drinking water reservoirs at the ancient Maya city of Tikal. Sci Rep 2020; 10:10316. [PMID: 32587274 PMCID: PMC7316703 DOI: 10.1038/s41598-020-67044-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/02/2020] [Indexed: 11/09/2022] Open
Abstract
Understanding civilizations of the past and how they emerge and eventually falter is a primary research focus of archaeological investigations because these provocative data sets offer critical insights into long-term human behavior patterns, especially in regard to land use practices and sustainable environmental interactions. The ancient Maya serve as an intriguing example of this research focus, yet the details of their spectacular emergence in a tropical forest environment followed by their eventual demise have remained enigmatic. Tikal, one of the foremost of the ancient Maya cities, plays a central role in this discussion because of its sharp population decline followed by abandonment during the late 9th century CE. Our results, based on geochemical and molecular genetic assays on sediments from four of the main reservoirs, reveal that two of the largest reservoirs at Tikal, essential for the survival of the city during the dry seasons, were contaminated with high levels of mercury, phosphate and cyanobacteria known to produce deadly toxins. Our observations demonstrate severe pollution problems at a time when episodes of climatic aridity were prevalent. This combination of catastrophic events clearly threatened the sustainability of the city and likely contributed to its abandonment.
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Affiliation(s)
- David L Lentz
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA.
| | - Trinity L Hamilton
- Department of Plant and Microbial Biology and the BioTechnology Institute, University of Minnesota, St. Paul, MN, 55108, USA
| | - Nicholas P Dunning
- Department of Geography, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Vernon L Scarborough
- Department of Anthropology, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Todd P Luxton
- National Risk Management Research Laboratory, US Environmental Protection Agency, Cincinnati, OH, 45224, USA
| | - Anne Vonderheide
- Department of Chemistry, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Eric J Tepe
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Cory J Perfetta
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - James Brunemann
- Department of Chemistry, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Liwy Grazioso
- Museo Miraflores, 7 Calle 21-55, Guatemala City, Guatemala
| | - Fred Valdez
- Department of Anthropology, University of Texas, Austin, TX, 78212, USA
| | - Kenneth B Tankersley
- Department of Anthropology, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Alison A Weiss
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, OH, 45267, USA
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Beach T, Luzzadder-Beach S, Krause S, Guderjan T, Valdez F, Fernandez-Diaz JC, Eshleman S, Doyle C. Ancient Maya wetland fields revealed under tropical forest canopy from laser scanning and multiproxy evidence. Proc Natl Acad Sci U S A 2019; 116:21469-21477. [PMID: 31591202 PMCID: PMC6815109 DOI: 10.1073/pnas.1910553116] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We report on a large area of ancient Maya wetland field systems in Belize, Central America, based on airborne lidar survey coupled with multiple proxies and radiocarbon dates that reveal ancient field uses and chronology. The lidar survey indicated four main areas of wetland complexes, including the Birds of Paradise wetland field complex that is five times larger than earlier remote and ground survey had indicated, and revealed a previously unknown wetland field complex that is even larger. The field systems date mainly to the Maya Late and Terminal Classic (∼1,400-1,000 y ago), but with evidence from as early as the Late Preclassic (∼1,800 y ago) and as late as the Early Postclassic (∼900 y ago). Previous study showed that these were polycultural systems that grew typical ancient Maya crops including maize, arrowroot, squash, avocado, and other fruits and harvested fauna. The wetland fields were active at a time of population expansion, landscape alteration, and droughts and could have been adaptations to all of these major shifts in Maya civilization. These wetland-farming systems add to the evidence for early and extensive human impacts on the global tropics. Broader evidence suggests a wide distribution of wetland agroecosystems across the Maya Lowlands and Americas, and we hypothesize the increase of atmospheric carbon dioxide and methane from burning, preparing, and maintaining these field systems contributed to the Early Anthropocene.
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Affiliation(s)
- Timothy Beach
- Department of Geography and the Environment, The University of Texas at Austin, Austin, TX 78712;
| | - Sheryl Luzzadder-Beach
- Department of Geography and the Environment, The University of Texas at Austin, Austin, TX 78712
| | - Samantha Krause
- Department of Geography and the Environment, The University of Texas at Austin, Austin, TX 78712
| | - Tom Guderjan
- Department of Social Sciences, University of Texas at Tyler, Tyler, TX 75799
| | - Fred Valdez
- Department of Anthropology, The University of Texas at Austin, Austin, TX 78712
| | | | - Sara Eshleman
- Department of Geography and the Environment, The University of Texas at Austin, Austin, TX 78712
| | - Colin Doyle
- Department of Geography and the Environment, The University of Texas at Austin, Austin, TX 78712
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Sabloff JA. How Maya Archaeologists Discovered the 99% Through the Study of Settlement Patterns. ANNUAL REVIEW OF ANTHROPOLOGY 2019. [DOI: 10.1146/annurev-anthro-102218-011044] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This article presents an autobiographical perspective on the changing nature of Maya archaeology, focusing on the role of settlement pattern studies in illuminating the lives of commoners as well as on the traditional emphasis on the ruling elite. Advances in understanding the nature of nonelite peoples in ancient Maya society are discussed, as are the many current gaps in scholarly understandings of pre-Columbian Maya civilization, especially with regard to the diversity of ancient “commoners” and the difficulty in analyzing them as a single group.
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Affiliation(s)
- Jeremy A. Sabloff
- Department of Anthropology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Santa Fe Institute, Santa Fe, New Mexico 87501, USA
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21
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Fukasawa K, Akasaka T. Long-lasting effects of historical land use on the current distribution of mammals revealed by ecological and archaeological patterns. Sci Rep 2019; 9:10697. [PMID: 31337778 PMCID: PMC6650404 DOI: 10.1038/s41598-019-46809-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 07/05/2019] [Indexed: 11/16/2022] Open
Abstract
Past land-use activity has massively altered the environment and vegetation over centuries, resulting in range contractions and expansions of species. When habitat recovery and species recolonization require a long time, the fingerprint of past land use can remain on the current distribution of species. To evaluate millennial-scale effects of land use in Japan, we explained the current ranges of 29 mammalian genera based on three types of archaeological land-use patterns (settlement, ironwork and kiln) considering potential confounding factors. The results indicate that archaeological human activity associated with ironwork and pottery production had severe negative effects on many genera of small and medium-sized mammals. Despite positive effects on some genera, the magnitudes were less than those of the negative effects. The relative importance of archaeological factors on small mammals was greater than those for medium- to-large mammals. The persistent imprint of past land-use patterns was non-negligible, explaining current mammalian diversity. Spatial ecological and archaeological information can provide meaningful insights into long-term socio-ecological processes, which are crucial for the development of sustainable societies in the Anthropocene.
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Affiliation(s)
- Keita Fukasawa
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
| | - Takumi Akasaka
- Conservation Ecology Lab., Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-sen 11, Inadacho, Obihiro, Hokkaido, 080-8555, Japan
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22
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Ross NJ, Stevens MHH. Placing human landscape legacies in a dynamic systems framework. AMERICAN JOURNAL OF BOTANY 2019; 106:517-519. [PMID: 30965385 DOI: 10.1002/ajb2.1269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 02/26/2019] [Indexed: 06/09/2023]
Affiliation(s)
- Nanci J Ross
- Drake University, 2507 University Avenue, Des Moines, IA, 50311, USA
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23
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Hegmon M, Peeples MA. The human experience of social transformation: Insights from comparative archaeology. PLoS One 2018; 13:e0208060. [PMID: 30496250 PMCID: PMC6264852 DOI: 10.1371/journal.pone.0208060] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 11/09/2018] [Indexed: 11/22/2022] Open
Abstract
Archaeologists and other scholars have long studied the causes of collapse and other major social transformations and debated how they can be understood. This article instead focuses on the human experience of living through those transformations, analyzing 18 transformation cases from the US Southwest and the North Atlantic. The transformations, including changes in human securities, were coded based on expert knowledge and data analyzed using Qualitative Comparative Analysis techniques. Results point to the following conclusions: Major transformations, including collapses, generally have a strong and negative impact on human security; flexible strategies that facilitate smaller scale changes may ameliorate those difficulties. Community security is strongly implicated in these changes; strong community security may minimize other negative changes. The relationships among the variables are complex and multi-causal; while social transformation may lead to declines in human securities, declining conditions of life can also push people to transform their societies in negative ways. Results show that some societies are better able to deal with difficulties than others. One important policy implication is that community security and local conditions can be instrumental both in helping people to cope with difficulties and in staving off some of those difficulties. A multi-scalar approach is essential as we face the increasing problems of climate change in the decades ahead.
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Affiliation(s)
- Michelle Hegmon
- School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, United States of America
| | - Matthew A. Peeples
- School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, United States of America
- Center for Archaeology and Society, Arizona State University, Tempe, Arizona, United States of America
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24
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Canuto MA, Estrada-Belli F, Garrison TG, Houston SD, Acuña MJ, Kováč M, Marken D, Nondédéo P, Auld-Thomas L, Castanet C, Chatelain D, Chiriboga CR, Drápela T, Lieskovský T, Tokovinine A, Velasquez A, Fernández-Díaz JC, Shrestha R. Ancient lowland Maya complexity as revealed by airborne laser scanning of northern Guatemala. Science 2018; 361:361/6409/eaau0137. [DOI: 10.1126/science.aau0137] [Citation(s) in RCA: 170] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/15/2018] [Indexed: 11/02/2022]
Affiliation(s)
- Marcello A. Canuto
- Middle American Research Institute, Tulane University, New Orleans, LA, USA
| | | | | | | | - Mary Jane Acuña
- Department of Anthropology, Washington University, St. Louis, MO, USA
| | - Milan Kováč
- Center for Mesoamerican Studies, Comenius University, Bratislava, Slovakia
| | - Damien Marken
- Department of Anthropology, Bloomsburg University, Bloomsburg, PA, USA
| | - Philippe Nondédéo
- CNRS–ARCHAM UMR 8096, Université Paris 1–Panthéon-Sorbonne, Paris, France
| | - Luke Auld-Thomas
- Department of Anthropology, Tulane University, New Orleans, LA, USA
| | - Cyril Castanet
- Laboratoire de Géographie Physique–CNRS UMR 8591, Université Paris 8, Paris, France
| | - David Chatelain
- Department of Anthropology, Tulane University, New Orleans, LA, USA
| | | | - Tomáš Drápela
- Center for Mesoamerican Studies, Comenius University, Bratislava, Slovakia
| | - Tibor Lieskovský
- Department of Theoretical Geodesy, Slovak University of Technology, Bratislava, Slovakia
| | | | | | | | - Ramesh Shrestha
- National Center for Airborne Laser Mapping, University of Houston, Houston, TX, USA
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25
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Affiliation(s)
- Anabel Ford
- ISBER/MesoAmerican Research Center, University of California, Santa Barbara, CA 93106, USA.
| | - Sherman Horn
- Department of Anthropology, Grand Valley State University, Allendale, MI 49401, USA
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26
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Lucero LJ. A Cosmology of Conservation in the Ancient Maya World. JOURNAL OF ANTHROPOLOGICAL RESEARCH 2018. [DOI: 10.1086/698698] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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27
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History meets palaeoscience: Consilience and collaboration in studying past societal responses to environmental change. Proc Natl Acad Sci U S A 2018. [PMID: 29531084 DOI: 10.1073/pnas.1716912115] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
History and archaeology have a well-established engagement with issues of premodern societal development and the interaction between physical and cultural environments; together, they offer a holistic view that can generate insights into the nature of cultural resilience and adaptation, as well as responses to catastrophe. Grasping the challenges that climate change presents and evolving appropriate policies that promote and support mitigation and adaptation requires not only an understanding of the science and the contemporary politics, but also an understanding of the history of the societies affected and in particular of their cultural logic. But whereas archaeologists have developed productive links with the paleosciences, historians have, on the whole, remained muted voices in the debate until recently. Here, we suggest several ways in which a consilience between the historical sciences and the natural sciences, including attention to even distant historical pasts, can deepen contemporary understanding of environmental change and its effects on human societies.
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28
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The Role of Climate in the Collapse of the Maya Civilization: A Bibliometric Analysis of the Scientific Discourse. CLIMATE 2017. [DOI: 10.3390/cli5040088] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Rand DG, Tomlin D, Bear A, Ludvig EA, Cohen JD. Cyclical population dynamics of automatic versus controlled processing: An evolutionary pendulum. Psychol Rev 2017; 124:626-642. [PMID: 28703606 PMCID: PMC5916776 DOI: 10.1037/rev0000079] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Psychologists, neuroscientists, and economists often conceptualize decisions as arising from processes that lie along a continuum from automatic (i.e., "hardwired" or overlearned, but relatively inflexible) to controlled (less efficient and effortful, but more flexible). Control is central to human cognition, and plays a key role in our ability to modify the world to suit our needs. Given its advantages, reliance on controlled processing may seem predestined to increase within the population over time. Here, we examine whether this is so by introducing an evolutionary game theoretic model of agents that vary in their use of automatic versus controlled processes, and in which cognitive processing modifies the environment in which the agents interact. We find that, under a wide range of parameters and model assumptions, cycles emerge in which the prevalence of each type of processing in the population oscillates between 2 extremes. Rather than inexorably increasing, the emergence of control often creates conditions that lead to its own demise by allowing automaticity to also flourish, thereby undermining the progress made by the initial emergence of controlled processing. We speculate that this observation may have relevance for understanding similar cycles across human history, and may lend insight into some of the circumstances and challenges currently faced by our species. (PsycINFO Database Record
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Affiliation(s)
- David G. Rand
- Department of Psychology, Yale University, New Haven, CT 06520 USA
- Department of Economics, Yale University, New Haven, CT 06520 USA
- School of Management, Yale University, New Haven, CT 06520 USA
| | - Damon Tomlin
- Department of Psychology, University of Colorado, Colorado Springs Colorado Springs, CO 80918 USA
| | - Adam Bear
- Department of Psychology, Yale University, New Haven, CT 06520 USA
| | - Elliot A. Ludvig
- Department of Psychology, University of Warwick, Coventry, CV4 7AL, UK
- Princeton Neuroscience Institute, Princeton, NJ 08540 USA
| | - Jonathan D. Cohen
- Princeton Neuroscience Institute, Princeton, NJ 08540 USA
- Department of Psychology, Princeton, NJ 08540 USA
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High-precision radiocarbon dating of political collapse and dynastic origins at the Maya site of Ceibal, Guatemala. Proc Natl Acad Sci U S A 2017; 114:1293-1298. [PMID: 28115691 DOI: 10.1073/pnas.1618022114] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The lowland Maya site of Ceibal, Guatemala, had a long history of occupation, spanning from the Middle Preclassic Period through the Terminal Classic (1000 BC to AD 950). The Ceibal-Petexbatun Archaeological Project has been conducting archaeological investigations at this site since 2005 and has obtained 154 radiocarbon dates, which represent the largest collection of radiocarbon assays from a single Maya site. The Bayesian analysis of these dates, combined with a detailed study of ceramics, allowed us to develop a high-precision chronology for Ceibal. Through this chronology, we traced the trajectories of the Preclassic collapse around AD 150-300 and the Classic collapse around AD 800-950, revealing similar patterns in the two cases. Social instability started with the intensification of warfare around 75 BC and AD 735, respectively, followed by the fall of multiple centers across the Maya lowlands around AD 150 and 810. The population of Ceibal persisted for some time in both cases, but the center eventually experienced major decline around AD 300 and 900. Despite these similarities in their diachronic trajectories, the outcomes of these collapses were different, with the former associated with the development of dynasties centered on divine rulership and the latter leading to their downfalls. The Ceibal dynasty emerged during the period of low population after the Preclassic collapse, suggesting that this dynasty was placed under the influence from, or by the direct intervention of, an external power.
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Hoggarth JA, Restall M, Wood JW, Kennett DJ. Drought and Its Demographic Effects in the Maya Lowlands. CURRENT ANTHROPOLOGY 2017. [DOI: 10.1086/690046] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Spielmann KA, Peeples MA, Glowacki DM, Dugmore A. Early Warning Signals of Social Transformation: A Case Study from the US Southwest. PLoS One 2016; 11:e0163685. [PMID: 27706200 PMCID: PMC5051805 DOI: 10.1371/journal.pone.0163685] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 09/11/2016] [Indexed: 11/19/2022] Open
Abstract
Recent research in ecology suggests that generic indicators, referred to as early warning signals (EWS), may occur before significant transformations, both critical and non-critical, in complex systems. Up to this point, research on EWS has largely focused on simple models and controlled experiments in ecology and climate science. When humans are considered in these arenas they are invariably seen as external sources of disturbance or management. In this article we explore ways to include societal components of socio-ecological systems directly in EWS analysis. Given the growing archaeological literature on 'collapses,' or transformations, in social systems, we investigate whether any early warning signals are apparent in the archaeological records of the build-up to two contemporaneous cases of social transformation in the prehistoric US Southwest, Mesa Verde and Zuni. The social transformations in these two cases differ in scope and severity, thus allowing us to explore the contexts under which warning signals may (or may not) emerge. In both cases our results show increasing variance in settlement size before the transformation, but increasing variance in social institutions only before the critical transformation in Mesa Verde. In the Zuni case, social institutions appear to have managed the process of significant social change. We conclude that variance is of broad relevance in anticipating social change, and the capacity of social institutions to mitigate transformation is critical to consider in EWS research on socio-ecological systems.
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Affiliation(s)
- Katherine A. Spielmann
- School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, United States of America
| | - Matthew A. Peeples
- School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, United States of America
| | - Donna M. Glowacki
- Department of Anthropology, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Andrew Dugmore
- Institute of Geography and the Lived Environment, School of Geosciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
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Fisher CT, Fernández-Diaz JC, Cohen AS, Neil Cruz O, Gonzáles AM, Leisz SJ, Pezzutti F, Shrestha R, Carter W. Identifying Ancient Settlement Patterns through LiDAR in the Mosquitia Region of Honduras. PLoS One 2016; 11:e0159890. [PMID: 27560962 PMCID: PMC4999160 DOI: 10.1371/journal.pone.0159890] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/08/2016] [Indexed: 11/18/2022] Open
Abstract
The Mosquitia ecosystem of Honduras occupies the fulcrum between the American continents and as such constitutes a critical region for understanding past patterns of socio-political development and interaction. Heavy vegetation, rugged topography, and remoteness have limited scientific investigation. This paper presents prehistoric patterns of settlement and landuse for a critical valley within the Mosquitia derived from airborne LiDAR scanning and field investigation. We show that (i) though today the valley is a wilderness it was densely inhabited in the past; (ii) that this population was organized into a three-tiered system composed of 19 settlements dominated by a city; and, (iii) that this occupation was embedded within a human engineered landscape. We also add to a growing body of literature that demonstrates the utility of LiDAR as means for rapid cultural assessments in undocumented regions for analysis and conservation. Our ultimate hope is for our work to promote protections to safeguard the unique and critically endangered Mosquitia ecosystem and other similar areas in need of preservation.
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Affiliation(s)
- Christopher T. Fisher
- Department of Anthropology, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
| | - Juan Carlos Fernández-Diaz
- National Center for Airborne Laser Mapping, University of Houston, Houston, Texas, United States of America
| | - Anna S. Cohen
- Department of Anthropology, University of Washington, Seattle, Washington, United States of America
| | - Oscar Neil Cruz
- Instituto Hondureño de Antropología e Historia, Tegucigalpa, Honduras
| | | | - Stephen J. Leisz
- Department of Anthropology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Florencia Pezzutti
- Department of Anthropology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Ramesh Shrestha
- National Center for Airborne Laser Mapping, University of Houston, Houston, Texas, United States of America
| | - William Carter
- National Center for Airborne Laser Mapping, University of Houston, Houston, Texas, United States of America
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34
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Lima M, Christie DA, Santoro MC, Latorre C. Coupled Socio-Environmental Changes Triggered Indigenous Aymara Depopulation of the Semiarid Andes of Tarapacá-Chile during the Late 19th-20th Centuries. PLoS One 2016; 11:e0160580. [PMID: 27560499 PMCID: PMC4999284 DOI: 10.1371/journal.pone.0160580] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 07/21/2016] [Indexed: 11/25/2022] Open
Abstract
Socio-economic and environmental changes are well known causes of demographic collapse of agrarian cultures. The collapse of human societies is a complex phenomenon where historical and cultural dimensions play a key role, and they may interact with the environmental context. However, the importance of the interaction between socio-economic and climatic factors in explaining possible breakdowns in Native American societies has been poorly explored. The aim of this study is to test the role of socio-economic causes and rainfall variability in the collapse suffered by the Aymara people of the semiarid Andean region of Tarapacá during the period 1820–1970. Our motivation is to demonstrate that simple population dynamic models can be helpful in understanding the causes and relative importance of population changes in Andean agro-pastoral societies in responses to socio-environmental variability. Simple logistic models that combine the effects of external socio-economic causes and past rainfall variability (inferred from Gross Domestic Product [GDP] and tree-rings, respectively) were quite accurate in predicting the sustained population decline of the Aymara people. Our results suggest that the depopulation in the semiarid Tarapacá province was caused by the interaction among external socio-economic pressures given by the economic growth of the lowlands and demands for labor coupled with a persistent decline in rainfall. This study constitutes an example of how applied ecological knowledge, in particular the application of the logistic equation and theories pertaining to nonlinear population dynamics and exogenous perturbations, can be used to better understand major demographic changes in human societies.
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Affiliation(s)
- Mauricio Lima
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
- Laboratorio Internacional de Cambio Global (CSIC-PUC), Santiago, Chile
- * E-mail:
| | - Duncan A. Christie
- Laboratorio de Dendrocronología y Cambio Global, Instituto de Conservación, Biodiversidad y Territorio, Universidad Austral de Chile, Valdivia, Chile
- Center for Climate and Resilience Research (CR)2, Santiago, Chile
| | - M. Calogero Santoro
- Laboratorio de Arqueología y Paleoambiente, Instituto de Alta de Investigación, Universidad de Tarapacá, Arica, Chile
| | - Claudio Latorre
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Laboratorio Internacional de Cambio Global (CSIC-PUC), Santiago, Chile
- Centro del Desierto de Atacama, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute of Ecology & Biodiversity (IEB), Santiago, Chile
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Schwindt DM, Bocinsky RK, Ortman S, Glowacki DM, Varien MD, Kohler TA. THE SOCIAL CONSEQUENCES OF CLIMATE CHANGE IN THE CENTRAL MESA VERDE REGION. AMERICAN ANTIQUITY 2016; 81:74-96. [PMID: 33001060 PMCID: PMC7523884 DOI: 10.7183/0002-7316.81.1.74] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The consequences of climate change vary over space and time. Effective studies of human responses to climatically induced environmental change must therefore sample the environmental diversity experienced by specific societies. We reconstruct population histories from A.D. 600 to 1280 in six environmentally distinct portions of the central Mesa Verde region in southwestern Colorado, relating these to climate-driven changes in agricultural potential. In all but one subregion, increases in maize-niche size led to increases in population size. Maize-niche size is also positively correlated with regional estimates of birth rates. High birth rates continued to accompany high population levels even as productive conditions declined in the A.D. 1200s. We reconstruct prominent imbalances between the maize-niche size and population densities in two subregions from A.D. 1140 to 1180 and from A.D. 1225-1260. We propose that human responses in those subregions, beginning by the mid-A.D. 1200s, contributed to violence and social collapse across the entire society. Our findings are relevant to discussions of how climate change will affect contemporary societies.
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Affiliation(s)
- Dylan M Schwindt
- Crow Canyon Archaeological Center, 23390 Road K, Cortez, CO 81321
| | - R Kyle Bocinsky
- Department of Anthropology, Washington State University, Pullman, WA 99164-4910, and Crow Canyon Archaeological Center
| | - Scott Ortman
- Department of Anthropology, University of Colorado Boulder, 233 UCB, Boulder, CO 80303 and Santa Fe Institute
| | - Donna M Glowacki
- Department of Anthropology, University of Notre Dame, South Bend, IN 46556
| | - Mark D Varien
- Crow Canyon Archaeological Center, 23390 Road K, Cortez, CO 81321
| | - Timothy A Kohler
- Department of Anthropology, Washington State University, Pullman, WA 99164-4910, Santa Fe Institute, and Crow Canyon Archaeological Center
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Abstract
This paper identifies rare climate challenges in the long-term history of seven areas, three in the subpolar North Atlantic Islands and four in the arid-to-semiarid deserts of the US Southwest. For each case, the vulnerability to food shortage before the climate challenge is quantified based on eight variables encompassing both environmental and social domains. These data are used to evaluate the relationship between the "weight" of vulnerability before a climate challenge and the nature of social change and food security following a challenge. The outcome of this work is directly applicable to debates about disaster management policy.
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Endurance and Adaptation of Community Forest Management in Quintana Roo, Mexico. FORESTS 2015. [DOI: 10.3390/f6114295] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Modeling Historical Land Cover and Land Use: A Review fromContemporary Modeling. ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION 2015. [DOI: 10.3390/ijgi4041791] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Singh M, Evans D, Tan BS, Nin CS. Mapping and characterizing selected canopy tree species at the Angkor World Heritage site in Cambodia using aerial data. PLoS One 2015; 10:e0121558. [PMID: 25902148 PMCID: PMC4406680 DOI: 10.1371/journal.pone.0121558] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 02/15/2015] [Indexed: 11/30/2022] Open
Abstract
At present, there is very limited information on the ecology, distribution, and structure of Cambodia's tree species to warrant suitable conservation measures. The aim of this study was to assess various methods of analysis of aerial imagery for characterization of the forest mensuration variables (i.e., tree height and crown width) of selected tree species found in the forested region around the temples of Angkor Thom, Cambodia. Object-based image analysis (OBIA) was used (using multiresolution segmentation) to delineate individual tree crowns from very-high-resolution (VHR) aerial imagery and light detection and ranging (LiDAR) data. Crown width and tree height values that were extracted using multiresolution segmentation showed a high level of congruence with field-measured values of the trees (Spearman's rho 0.782 and 0.589, respectively). Individual tree crowns that were delineated from aerial imagery using multiresolution segmentation had a high level of segmentation accuracy (69.22%), whereas tree crowns delineated using watershed segmentation underestimated the field-measured tree crown widths. Both spectral angle mapper (SAM) and maximum likelihood (ML) classifications were applied to the aerial imagery for mapping of selected tree species. The latter was found to be more suitable for tree species classification. Individual tree species were identified with high accuracy. Inclusion of textural information further improved species identification, albeit marginally. Our findings suggest that VHR aerial imagery, in conjunction with OBIA-based segmentation methods (such as multiresolution segmentation) and supervised classification techniques are useful for tree species mapping and for studies of the forest mensuration variables.
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Affiliation(s)
- Minerva Singh
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Damian Evans
- Departments of Asian Studies and Archaeology, University of Sydney, Sydney, Australia
| | - Boun Suy Tan
- Angkor International Research and Documentation Center, Siem Reap, Cambodia
| | - Chan Samean Nin
- Department of Forestry Management, Cultural Landscape and Environment, APSARA National Authority, Siem Reap, Cambodia
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Drought, agricultural adaptation, and sociopolitical collapse in the Maya Lowlands. Proc Natl Acad Sci U S A 2015; 112:5607-12. [PMID: 25902508 DOI: 10.1073/pnas.1419133112] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (∼800-950 C.E.). Evidence for drought largely derives from the drier, less populated northern Maya Lowlands but does not explain more pronounced and earlier societal disruption in the relatively humid southern Maya Lowlands. Here we apply hydrogen and carbon isotope compositions of plant wax lipids in two lake sediment cores to assess changes in water availability and land use in both the northern and southern Maya lowlands. We show that relatively more intense drying occurred in the southern lowlands than in the northern lowlands during the Terminal Classic period, consistent with earlier and more persistent societal decline in the south. Our results also indicate a period of substantial drying in the southern Maya Lowlands from ∼200 C.E. to 500 C.E., during the Terminal Preclassic and Early Classic periods. Plant wax carbon isotope records indicate a decline in C4 plants in both lake catchments during the Early Classic period, interpreted to reflect a shift from extensive agriculture to intensive, water-conservative maize cultivation that was motivated by a drying climate. Our results imply that agricultural adaptations developed in response to earlier droughts were initially successful, but failed under the more severe droughts of the Terminal Classic period.
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Schwartz NB, Corzo M. AR. Swidden Counts: A Petén, Guatemala, Milpa System. JOURNAL OF ANTHROPOLOGICAL RESEARCH 2015. [DOI: 10.3998/jar.0521004.0071.104] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Forests, fields, and the edge of sustainability at the ancient Maya city of Tikal. Proc Natl Acad Sci U S A 2014; 111:18513-8. [PMID: 25512500 DOI: 10.1073/pnas.1408631111] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tikal has long been viewed as one of the leading polities of the ancient Maya realm, yet how the city was able to maintain its substantial population in the midst of a tropical forest environment has been a topic of unresolved debate among researchers for decades. We present ecological, paleoethnobotanical, hydraulic, remote sensing, edaphic, and isotopic evidence that reveals how the Late Classic Maya at Tikal practiced intensive forms of agriculture (including irrigation, terrace construction, arboriculture, household gardens, and short fallow swidden) coupled with carefully controlled agroforestry and a complex system of water retention and redistribution. Empirical evidence is presented to demonstrate that this assiduously managed anthropogenic ecosystem of the Classic period Maya was a landscape optimized in a way that provided sustenance to a relatively large population in a preindustrial, low-density urban community. This landscape productivity optimization, however, came with a heavy cost of reduced environmental resiliency and a complete reliance on consistent annual rainfall. Recent speleothem data collected from regional caves showed that persistent episodes of unusually low rainfall were prevalent in the mid-9th century A.D., a time period that coincides strikingly with the abandonment of Tikal and the erection of its last dated monument in A.D. 869. The intensified resource management strategy used at Tikal-already operating at the landscape's carrying capacity-ceased to provide adequate food, fuel, and drinking water for the Late Classic populace in the face of extended periods of drought. As a result, social disorder and abandonment ensued.
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Cole LES, Bhagwat SA, Willis KJ. Recovery and resilience of tropical forests after disturbance. Nat Commun 2014; 5:3906. [PMID: 24844297 PMCID: PMC4354292 DOI: 10.1038/ncomms4906] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 04/17/2014] [Indexed: 11/09/2022] Open
Abstract
The time taken for forested tropical ecosystems to re-establish post-disturbance is of widespread interest. Yet to date there has been no comparative study across tropical biomes to determine rates of forest re-growth, and how they vary through space and time. Here we present results from a meta-analysis of palaeoecological records that use fossil pollen as a proxy for vegetation change over the past 20,000 years. A total of 283 forest disturbance and recovery events, reported in 71 studies, are identified across four tropical regions. Results indicate that forests in Central America and Africa generally recover faster from past disturbances than those in South America and Asia, as do forests exposed to natural large infrequent disturbances compared with post-climatic and human impacts. Results also demonstrate that increasing frequency of disturbance events at a site through time elevates recovery rates, indicating a degree of resilience in forests exposed to recurrent past disturbance.
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Affiliation(s)
- Lydia E S Cole
- 1] Department of Zoology, Oxford Long-term Ecology Laboratory, University of Oxford, South Parks Road, Oxford OX1 3PS, UK [2] Department of Zoology, Biodiversity Institute, Oxford Martin School, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | - Shonil A Bhagwat
- 1] Department of Zoology, Oxford Long-term Ecology Laboratory, University of Oxford, South Parks Road, Oxford OX1 3PS, UK [2] Department of Zoology, Biodiversity Institute, Oxford Martin School, University of Oxford, South Parks Road, Oxford OX1 3PS, UK [3] Department of Geography, Faculty of Social Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
| | - Katherine J Willis
- 1] Department of Zoology, Oxford Long-term Ecology Laboratory, University of Oxford, South Parks Road, Oxford OX1 3PS, UK [2] Department of Zoology, Biodiversity Institute, Oxford Martin School, University of Oxford, South Parks Road, Oxford OX1 3PS, UK [3] Department of Biology, University of Bergen, P.O. Box 7803, N-5020 Bergen, Norway [4] Royal Botanical Gardens, Kew, Richmond, Surrey TW9 3AB, UK
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Puleston C, Tuljapurkar S, Winterhalder B. The invisible cliff: abrupt imposition of Malthusian equilibrium in a natural-fertility, agrarian society. PLoS One 2014; 9:e87541. [PMID: 24498131 PMCID: PMC3909123 DOI: 10.1371/journal.pone.0087541] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 12/30/2013] [Indexed: 11/18/2022] Open
Abstract
Analysis of a natural fertility agrarian society with a multi-variate model of population ecology isolates three distinct phases of population growth following settlement of a new habitat: (1) a sometimes lengthy copial phase of surplus food production and constant vital rates; (2) a brief transition phase in which food shortages rapidly cause increased mortality and lessened fertility; and (3) a Malthusian phase of indefinite length in which vital rates and quality of life are depressed, sometimes strikingly so. Copial phase duration declines with increases in the size of the founding group, maximum life expectancy and fertility; it increases with habitat area and yield per hectare; and, it is unaffected by the sensitivity of vital rates to hunger. Transition phase duration is unaffected by size of founding population and area of settlement; it declines with yield, life expectancy, fertility and the sensitivity of vital rates to hunger. We characterize the transition phase as the Malthusian transition interval (MTI), in order to highlight how little time populations generally have to adjust. Under food-limited density dependence, the copial phase passes quickly to an equilibrium of grim Malthusian constraints, in the manner of a runner dashing over an invisible cliff. The three-phase pattern diverges from widely held intuitions based on standard Lotka-Verhulst approaches to population regulation, with implications for the analysis of socio-cultural evolution, agricultural intensification, bioarchaeological interpretation of food stress in prehistoric societies, and state-level collapse.
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Affiliation(s)
- Cedric Puleston
- Department of Anthropology, University of California Davis, Davis, California, United States of America
| | - Shripad Tuljapurkar
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Bruce Winterhalder
- Department of Anthropology, University of California Davis, Davis, California, United States of America
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Abstract
Previous archaeological mapping work on the successive medieval capitals of the Khmer Empire located at Angkor, in northwest Cambodia (∼9th to 15th centuries in the Common Era, C.E.), has identified it as the largest settlement complex of the preindustrial world, and yet crucial areas have remained unmapped, in particular the ceremonial centers and their surroundings, where dense forest obscures the traces of the civilization that typically remain in evidence in surface topography. Here we describe the use of airborne laser scanning (lidar) technology to create high-precision digital elevation models of the ground surface beneath the vegetation cover. We identify an entire, previously undocumented, formally planned urban landscape into which the major temples such as Angkor Wat were integrated. Beyond these newly identified urban landscapes, the lidar data reveal anthropogenic changes to the landscape on a vast scale and lend further weight to an emerging consensus that infrastructural complexity, unsustainable modes of subsistence, and climate variation were crucial factors in the decline of the classical Khmer civilization.
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Kahn JG. Anthropological Archaeology in 2012: Mobility, Economy, and Transformation. AMERICAN ANTHROPOLOGIST 2013. [DOI: 10.1111/aman.12007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Jennifer G. Kahn
- Department of Anthropology; College of William and Mary; Williamsburg; VA 23185-8795
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Kennett DJ, Hajdas I, Culleton BJ, Belmecheri S, Martin S, Neff H, Awe J, Graham HV, Freeman KH, Newsom L, Lentz DL, Anselmetti FS, Robinson M, Marwan N, Southon J, Hodell DA, Haug GH. Correlating the ancient Maya and modern European calendars with high-precision AMS 14C dating. Sci Rep 2013; 3:1597. [PMID: 23579869 PMCID: PMC3623374 DOI: 10.1038/srep01597] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 03/14/2013] [Indexed: 11/09/2022] Open
Abstract
The reasons for the development and collapse of Maya civilization remain controversial and historical events carved on stone monuments throughout this region provide a remarkable source of data about the rise and fall of these complex polities. Use of these records depends on correlating the Maya and European calendars so that they can be compared with climate and environmental datasets. Correlation constants can vary up to 1000 years and remain controversial. We report a series of high-resolution AMS (14)C dates on a wooden lintel collected from the Classic Period city of Tikal bearing Maya calendar dates. The radiocarbon dates were calibrated using a Bayesian statistical model and indicate that the dates were carved on the lintel between AD 658-696. This strongly supports the Goodman-Martínez-Thompson (GMT) correlation and the hypothesis that climate change played an important role in the development and demise of this complex civilization.
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Affiliation(s)
- Douglas J Kennett
- Department of Anthropology, The Pennsylvania State University, University Park, PA 16802, USA.
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Ford A. Ancient Maya Landscapes: A Community of Prosperous Farmers Chan: An Ancient Maya Farming Community. Edited by Cynthia Robin. Gainesville: University Press of Florida, 2012. CURRENT ANTHROPOLOGY 2013. [DOI: 10.1086/669119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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