Lake Titicaca Basin Research Articles

Chapter 4. Locating field systems in the southern Peruvian Andes

AbstractIn this paper, we review current understandings of anthropogenic field systems, focusing on trends and variations in the chronology of field construction, use, and in some cases, abandonment, as well as labor organization of agrarian production across the Lake Titicaca Basin. These trends indicate that agricultural intensification increased both during the political centralization of the Tiwanaku state and during periods of political fragmentation. In contrast to prior work on fields in the region, we argue that there was no single cultural, environmental, or historical impetus that ignited the construction of any particular field type. Additionally, we present the results of pedestrian survey of terraces carried out in 2018 in the northern Lake Titicaca Basin. While there were regional commonalities across survey areas in the masonry design of terrace risers, presence of pathways and radiating walls separating vertical tracts of terraces, and a general absence of irrigation, we found deviations from each of these trends in individual terrace complexes. While preliminary evidence indicates that more terraces were built or cultivated during the Late Intermediate period (1100–1450 CE) than in other time periods in the northern Titicaca basin, some terraces were likely built earlier. Our findings point to the multiplicity of strategies that ancient farmers employed in the varied ecological settings of the Lake Titicaca basin under diverse sociopolitical programs. This contrasts with previous research on agrarian field systems, which is mostly single‐sited and tends to emphasize individual strategies over the quiver of agrarian options available to Andean farmers.

New insights into the biennial-to-multidecadal variability of the water level fluctuation in Lake Titicaca in the 20th century

The water disponibility of Lake Titicaca is important for local ecosystems, domestic water, industry, fishing, agriculture, and tourism in Peru and Bolivia. However, the water level variability in Lake Titicaca (LTWL) still needs to be understood. The fluctuations of LTWL during the 1921–2018 period are investigated using continuous wavelet techniques on high- and low-pass filters of monthly time series, ERA-20C reanalysis, sea surface temperature (SST), and water level. We also built multiple linear regression (MLR) models based on SST indices to identify the main drivers of the LTWL variability. LTWL features annual (12 months), biennial (22–28 months), interannual (80–108 months), decadal (12.75–14.06 years), interdecadal (24.83–26.50 years), and multidecadal (30–65 years) signals. The high- and low-frequency components of the LTWL are triggered by the humidity transport from the lowland toward the Lake Titicaca basin, although different forcings could cause it. The biennial band is associated with SST anomalies over the southeastern tropical Atlantic Ocean that strengthen the Bolivian High-Nordeste Low system. The interannual band is associated with the southern South Atlantic SST anomalies, which modulate the position of the Bolivian High. According to the MLR models, the decadal and interdecadal components of the LTWL can be explained by the linear combination of the decadal and interdecadal variability of the Pacific and Atlantic SST anomalies (r > 0.83, p < 0.05). In contrast, the multidecadal component of the LTWL is driven by the multidecadal component of the North Atlantic SST anomalies (AMO) and the southern South Atlantic SST anomalies. Moreover, the monthly time series of LTWL exhibits four breakpoints. The signs of the first four trends follow the change of phases of the multidecadal component of LTWL, while the fifth trend is zero attributable to the diminished amplitude of the interdecadal component of LTWL.

The origin and dispersion of the bow in the Andes (16–37°S) based on a controlled database of projectile point metrics

We present a discriminant metric study of stone projectile points (n = 422) from 21 archaeological sites in the Andes of South America (16–37°S). We use comparative datasets critically, since darts may have been smaller than previously thought. We assess the use-life of each point and tie them to reliable chronological sequences, in order to increase the reliability of our data. Our results show that in the Lake Titicaca Basin and northwestern Argentina, bows had replaced spearthrowers by 1780–950 cal BP, prior to the development of complex societies such as Wari and Tiwanaku. South of 29°S, the results suggest that bow technology was transmitted from north to south, since the earliest arrow-sized points at 29°S date to 3000 cal BP and at 37°S, 1800–1000 cal BP. North of 34°S, the continental limit of domesticated plants and animals, there is a gradual abandonment of the spearthrower. South of 34°S in northern Patagonia, both weapon systems coexisted. We suggest that bow and arrow technology was not an independent invention in the southern Andes, but instead, it appeared in new groups via macroregional technological borrowing among Andean herders.

Architecture and Authority: A Spatial Analysis of Power and Control at Three Spanish Colonial Silver Refineries (Puno, Peru)

This paper examines the spatial layout of three Spanish colonial silver refineries from the western Lake Titicaca Basin of southern Peru. These sites, located approximately 15 km from the city of Puno, Peru, were operated by Indigenous laborers throughout the Middle Colonial period (AD 1600–1800). Space syntax analysis is employed to evaluate the degree of control and access across these sites, examining the location of dormitories, storage buildings, administrative patios, work areas, entrances, and exits. Using both intra- and inter-site comparisons, results indicate the presence of restricted and segregated areas at all three refineries. However, inter-site comparisons highlight the integrated nature of the smaller, more rural refineries, revealing how control of labor manifested in diverse ways at the local scale.

Diversity on the Altiplano: Geochemical perspectives on 3,000 years of potting practices in the Lake Titicaca basin

Potters in the Lake Titicaca basin produced a wide variety of ceramic styles over the last 3000 years. Archaeologists have drawn on this variety across space and time to track processes such as the development of multi-community polities during the Late Formative (200 BC-AD 600), the origins and expansion of Tiwanaku (AD 600–1000), the creation and maintenance of political boundaries during the Late Intermediate period (AD 1000–1400), and the strategies of Inca conquest and consolidation (AD 1400–1534). We report on LA-ICP-MS research into Titicaca ceramics and clays conducted at the Field Museum’s Elemental Analysis Facility (EAF), and present the first review of raw materials and pottery analyzed from across the region. Ceramic samples from the northern basin include samples from Taraco, Pukara, and neighboring sites, and speak to the diversity of intraregional potting practices during the Late Formative Period. Ceramic samples from the southern basin span the Middle Formative through the Inca periods, and index local and regional practices over two millennia. After presenting our specific case studies, we touch on how shifting scales of locality impact the chemical signatures explored here, the potential for comparative analyses across the region, and future directions for research collaborations.

Did archery technology precipitate complexity in the Titicaca Basin? A metric analysis of projectile points, 11–1 ka

The extent to which archery technology affected social organization in the Andes region of South America remains understudied. To identify the timing and consequences of archery technology in the Lake Titicaca Basin, this analysis examines metric data from 1179 projectile points from the region, 11–1.0 cal. ka. We find that the greatest decrease in projectile point size occurred across the Late/Terminal Archaic and Formative/Tiwanaku period boundaries, 5.0 and 1.5 cal. ka, respectively. We do not find a statistically significant decrease in size during any other transition, including the Terminal Archaic/Formative boundary, which was previously hypothesized to have been the time when archery technology first appeared in the region. These results instead favor the hypothesis that archery technology first entered the region during the Terminal Archaic Period, 5.0–3.5 cal ka. We furthermore observe that this technological transition coincided with the growth of settlements, a surge in the use of exotic goods such as obsidian, a low level of inter-group violence, and incipient agropastoralism—a pattern that intensified during the subsequent Formative period when monumental ceremonial centers emerged. These findings lead us to propose a model for South American archery technology in which its appearance after 5000 years ago contributed to the emergence of new cooperative dynamics that expanded regional exchange networks and community aggregation.

Archaeobotanical Insights into Kañawa (Chenopodium pallidicaule Aellen) Domestication: A Rustic Seed Crop of the Andean Altiplano

Kañawa/Cañihua (Chenopodium pallidicaule Aellen) is the lesser-known cousin of the domesticated Andean pseudocereal quinoa (Chenopodium quinoa Willd.). In 1970, Daniel Gade hypothesized that Andean farmers may have domesticated volunteer wild kañawa plants that occupied quinoa or potato fields after observing that they could survive harsh climatic events such as drought or frost. To revisit this question of kañawa domestication, this paper provides an overview of the current botanical, genetic, and archaeological knowledge of kañawa domestication. It then provides patterns in the presence of wild and domesticated kañawa seeds from archaeological sites in the southern Lake Titicaca Basin of Bolivia, spanning the Formative and Tiwanaku periods from approximately 1500 BCE to 1100 CE. This archaeobotanical evidence supports Gade’s hypothesis that kañawa was a later domesticate, not appearing until after 250 CE. Regional paleoclimatic evidence of frequent climatic fluctuations lends support to the argument that kañawa contributed to a diversified food supply, which could provide a buffer against climate risks.

Evaluation of Satellite Precipitation Products over the Lake Titicaca Basin

Resumen Los productos de precipitación satelital (PPS), proporcionan una fuente alternativa para aplicaciones hidrometeorológicas principalmente en áreas donde los datos de precipitación son limitados. Sin embargo, es necesario evaluar los PPS para cuantificar la incertidumbre en la estimación de la precipitación. Este estudio tuvo como objetivo evaluar el desempeño de los PPS GSMaP-G-NRT, PERSIANN-CCS, PERSIANN-CDR y PERSIANN sobre la cuenca del Lago Titicaca (CLT). Para la evaluación de los PPS se utilizaron tres métricas de desempeño que evaluaron la precisión (coeficiente de correlación, CC), error (raíz del error cuadrático medio, RMSE) y sesgo (sesgo porcentual, PBIAS). Los resultados indican que PERSIANN-CDR y PERSIANN-CCS son los productos que muestran una mayor concordancia con las mediciones de pluviómetros, pero con un gran sesgo para PERSIANN-CCS. Los hallazgos proporcionan una idea del rendimiento de PPS en la CLT que contribuye a posibles direcciones de mejora de los algoritmos para un mejor servicio en aplicaciones hidrometeorológicas.

Burying the Dead at Ayawiri: Mortuary Diversity and Postmortem Manipulation at an Andean Hillfort (AD 1100–1450)

This article presents results from the excavation and analysis of 11 slab-cist tombs associated with the site of Ayawiri, one of the largest hillforts in the western Lake Titicaca Basin during the Late Intermediate period (LIP; AD 1100–1450). These semi-subterranean tombs typically contain commingled human remains. Variation between and within tombs in the number of individuals, the body parts represented, and the degree of skeletal articulation points to a complex burial practice that likely involved tomb reopening, successive burial, and even the deposition of select body parts. Demographic and mortuary profiles suggest that burial practices were decentralized and flexible, structured by shared attitudes toward “the dead” and the dead body but also subject to the prerogatives and preferences of semi-autonomous corporate groups. This study advances our understanding of a lesser-known mortuary tradition in the Lake Titicaca Basin—one long overshadowed by more prominent burial towers (chullpas)—and sheds new light on the complex interactions that took place between the living and the dead during the LIP.

Plants in Transit Communities: Circulating Tubers and Maize in the Lake Titicaca Basin, Bolivia

Archaeologists working in the Late Formative Lake Titicaca Basin have identified several “transit communities”—villages that benefited from long-distance exchange. Some scholars suggest that such places played a key role in the development of the Middle Horizon city of Tiwanaku. In this article, we explore the movement of plant goods into transit communities during both the Late Formative (300 BC–AD 500) and Middle Horizon (AD 600–1100) periods. After presenting the current understanding of transit communities, we summarize previous work on both local plants, including tubers and quinoa, and the presence of maize. We then report on a recent microbotanical study of ceramics recovered from excavations at Late Formative Challapata (in the eastern basin) and a burial from the Middle Horizon occupation at Chiripa (in the southern basin). For the first time we identify lowland tubers in the Lake Titicaca Basin, including yuca, sweet potato, and arrowroot. These findings reveal the critical importance of microbotanical analyses for tracing regional connections and foodways in emergent Middle Horizon worlds, as well as the need for more complex interpretive models for things/plants-in-motion.

The Diurnal Cycle of Precipitation over Lake Titicaca Basin Based on CMORPH

This paper examines the diurnal cycle of precipitation (DCP) over Lake Titicaca basin (LTb) during the summertime months based on the high spatial–temporal resolution (8 × 8 km2 and hourly) estimates of the Climate Prediction Center Morphing technique (CMORPH). This analysis was carried out using observations from rain gauges (RgSENAMHI) as a reference for the period 2002 to 2013. The accuracy of the CMORPH product was tested with graphical comparisons and several statistical metrics, such as correlation coefficient, bias, and root mean square error. Spatial maps of these metrics and of the diurnal cycle were developed to assess the spatial dependency in the CMORPH accuracy over the LTb. On average, 43% of the total RgSENAMHI variation was explained by the CMORPH. The correlation between the CMORPH and RgSENAMHI amounts was positive over the southeastern and northern LTb and negative in the central and southern LTb. An underestimation bias was observed over most of the LTb areas, and an overestimation bias was observed at some stations (e.g., Lagunillas, Isla Suana, and Desaguadero stations). The total bias decreased when approaching the lake attaining its minimum value over the mountains consistent with previous studies. Overall, the CMORPH was able to capture the spatial patterns of rainfall over the LTb. Over the surrounding lake area, the plateau, and high mountain areas, precipitation peaks were in the late afternoon, while over low areas, such as the valleys and Lake Titicaca, it peaked around midnight to early morning. This result suggests that the DCP is closely related to the local circulation resulting from a response due to solar radiation and the complex orography. On the other hand, the high resolution CMORPH technique can depict finer regional details, such as the less coherent phase pattern over a few regions.

Land Cover Change and Water Quality: How Remote Sensing Can Help Understand Driver–Impact Relations in the Lake Titicaca Basin

The increase of human interventions and developments are modifying the land use/land cover (LULC) of the global landscape, thus severely affecting the water quality of rivers and lakes. Appropriate management and effective policy developments are required to deal with the problems of surface water contamination around the globe. However, spatiotemporal variations of water quality and its complex relation with land cover (LC) changes, challenge adequate water resources management. In this study, we explored the use of remote sensing to relate LC change in the Katari River Basin (KRB) located in the Bolivian Andes and water quality on the shores of Lake Titicaca, in order to support water management. An unsupervised classification of Landsat 7 satellite images and trajectory analysis was applied to understand the modifications of LC through time. In addition, water-quality indicators at the outlet of the basin were retrieved from remote-sensing images and its temporal behavior was analyzed. The results show that the expansion of urban areas is the predominant environmental driver in the KRB, which has great impact on the water quality of Lake Titicaca. We conclude that there is a strong link between the rapid growth of urban and industrial areas with the detriment of river and lake water quality. This case study shows how remote sensing can help understand driver–impact relations.

Diversity on the Altiplano: Geochemical Perspectives on 3,000 Years of Potting Practices in the Lake Titicaca Basin

Diversity on the Altiplano: Geochemical Perspectives on 3,000 Years of Potting Practices in the Lake Titicaca Basin

Quinoa, potatoes, and llamas fueled emergent social complexity in the Lake Titicaca Basin of the Andes

The Lake Titicaca basin was one of the major centers for cultural development in the ancient world. This lacustrine environment is unique in the high, dry Andean altiplano, and its aquatic and terrestrial resources are thought to have contributed to the florescence of complex societies in this region. Nevertheless, it remains unclear to what extent local aquatic resources, particularly fish, and the introduced crop, maize, which can be grown in regions along the lakeshores, contributed to facilitating sustained food production and population growth, which underpinned increasing social political complexity starting in the Formative Period (1400 BCE to 500 CE) and culminating with the Tiwanaku state (500 to 1100 CE). Here, we present direct dietary evidence from stable isotope analysis of human skeletal remains spanning over two millennia, together with faunal and floral reference materials, to reconstruct foodways and ecological interactions in southern Lake Titicaca over time. Bulk stable isotope analysis, coupled with compound-specific amino acid stable isotope analysis, allows better discrimination between resources consumed across aquatic and terrestrial environments. Together, this evidence demonstrates that human diets predominantly relied on C3 plants, particularly quinoa and tubers, along with terrestrial animals, notably domestic camelids. Surprisingly, fish were not a significant source of animal protein, but a slight increase in C4 plant consumption verifies the increasing importance of maize in the Middle Horizon. These results underscore the primary role of local terrestrial food resources in securing a nutritious diet that allowed for sustained population growth, even in the face of documented climate and political change across these periods.

Diet, Mobility, Technology, and Lithics: Neolithization on the Andean Altiplano, 7.0–3.5 ka

Neolithization was a complex, protracted process of domestication, sedentarization, and technology change that occurred in various combinations in various times and places around the world. Understanding the causal relationships among those and other important human behaviors remains an analytical challenge. This study examines Neolithization through the lens of lithic artifact variation in the Lake Titicaca Basin, Peru. Drawing on previous lithics research, we outline a synthetic model linking changing diet, mobility, and projectile technology to predicted trends in lithic assemblages. The expectations are then compared to two large, well-dated lithic assemblages from the Titicaca Basin—one from the Middle/Late Archaic forager site of Soro Mik’aya Patjxa (8.0–6.5 cal. ka) and the other from the Terminal Archaic horticultural site of Jiskairumoko (5.2–3.4 cal. ka). We find that the strongest signal in lithic technology change is related to the introduction of archery technology. Signals for subsistence change and declining mobility are relatively weak. The results suggest an early but unconfirmed adoption of archery technology in the Terminal Archaic Period with major transitions in mobility and diet likely to have occurred subsequently in the Terminal Archaic or Formative periods. The findings are consistent with a behavioral model in which changes in projectile technology played a prominent role in the evolution of resource intensification and residential sedentism as well as resource privatization and sexual division of labor in the high Andes.

Heavy Metals in Archaeological Soils

AbstractPortable X-ray fluorescence (pXRF) spectroscopy is commonly used for testing toxic levels of heavy metals in modern industrial waste sites, and it has seen growing applicability in the context of archaeological survey and soils. In this study, we present the results of our pXRF analysis of surface soils at a historic silver refinery located near Puno, Peru, in the western Lake Titicaca Basin. The results of our analysis identified hazardous levels of antimony (Sb), arsenic (As), mercury (Hg), and lead (Pb) in excavation soils, necessitating the relocation of planned excavation units and the use of personal protective equipment. This study highlights the advantages of rapid, in situ pXRF analysis of surface soils in contaminated industrial archaeology sites to assess potential harm to human health.

The Rise and Fall of Wiñaymarka: Rethinking Cultural and Environmental Interactions in the Southern Basin of Lake Titicaca

Investigations of how past human societies managed during times of major climate change can inform our understanding of potential human responses to ongoing environmental change. In this study, we evaluate the impact of environmental variation on human communities over the last four millennia in the southern Lake Titicaca basin of the Andes, known as Lake Winaymarka. Refined paleoenvironmental reconstructions from new diatom-based reconstructions of lake level together with archaeological evidence of animal and plant resource use from sites on the Taraco Peninsula, Bolivia, reveal frequent climate and lake-level changes within major cultural phases. We posit that climate fluctuations alone do not explain major past social and political transformations but instead that a highly dynamic environment contributed to the development of flexible and diverse subsistence practices by the communities in the Titicaca Basin.

Comparative Analysis of Climate Change Impacts on Meteorological, Hydrological, and Agricultural Droughts in the Lake Titicaca Basin

The impact of climate change on droughts in the Lake Titicaca, Desaguadero River, and Lake Poopo basins (TDPS system) within the Altiplano region was evaluated by comparing projected 2034–2064 and observed 1984–2014 hydroclimate time series. The study used bias-corrected monthly climate projections from the fifth phase of the Coupled Model Intercomparison Project (CMIP5), under the Representative Concentration Pathway 8.5 (RCP8.5) emission scenarios. Meteorological, agricultural, and hydrological droughts were analyzed from the standardized precipitation, standardized soil moisture, and standardized runoff indices, respectively, the latter two estimated from a hydrological model. Under scenarios of mean temperature increases up to 3 °C and spatially diverse precipitation changes, our results indicate that meteorological, agricultural, and hydrological droughts will become more intense, frequent, and prolonged in most of the TDPS. A significant increase in the frequency of short-term agricultural and hydrological droughts (duration of 1–2 months) is also projected. The expected decline in annual rainfall and the larger evapotranspiration increase in the southern TDPS combine to yield larger projected rises in the frequency and intensity of agricultural and hydrological droughts in this region.

Distribution shifts in habitat suitability and hotspot refugia of Andean tree species from the last glacial maximum to the Anthropocene

ABSTRACT Forecasting the effects of climate change on the distribution of Andean trees (Polylepis, Rosaceae) is important to understand how species respond to climate variability and to assess their resilience to the ongoing climate crisis. Here, paleodistribution modelling is used to assess distribution shifts of 17 Polylepis species during the Last Glacial Maximum (LGM), mid-Holocene (MH), and the Anthropocene in the central Andes. Species distribution models (SDMs) were computed by combining presence records and current climatic conditions using Maxent and projected onto three climatic scenarios for the LGM (~22,000 yr BP), the MH (~6,000 yr BP), and the Anthropocene (1,970–2,000). Subsequently, current refugia hotspots were identified by intersecting suitable habitat over the LGM, MH, and anthropogenic conditions for all the studied species. SDMs for the LGM and MH showed a contraction of climate suitable habitat for most of the species in comparison to the Anthropocene. Four current refugia hotspots were identified: central Cordillera of Peru, Lake Titicaca basin, western Cordillera of Bolivia, and northern Chile. In general, SDMs were consistent with patterns proposed with pollen records, and partially with available phylogeographic studies. Current hotspots are highly important areas for the conservation of Polylepis and associated biota. This study assists in understanding distribution shifts over millennia of Andean tree species in response to climate change and identifying key conservation areas for the delineation of future conservation strategies.

Genealogies and Juxtapositions: Traces of Potting Communities and Firing Facilities in Lake Titicaca Basin

In this paper, we develop a genealogy of practice approach for the historical analysis and comparison of Andean ceramic firing. This effort was set in motion by the similarity of two sets of ash mounds observed in the Lake Titicaca Basin of Bolivia, one modern and one from the Late Intermediate Period (A.D. 1100–1450). We eschew an ethnoarchaeological perspective in favor of considering their position within a longer genealogy of potting practice. We argue that a genealogical perspective foregrounds ephemeral evidence that is often ignored in dominant narratives, highlights the emergent nature of practices, and draws attention to subject formation across generations. We examine the extant data for pottery firing in the region, drawing out the genealogy of practices involved in firing facilities and subject formation from the Formative Period (1500 B.C. –A.D. 450) through the present. We then return to the ash mounds, juxtaposing the practices and archaeological traces to consider their historical emergences. These two approaches allow us to begin to map out the particularities of Lake Titicaca Basin production locales and to pose new questions of the social relations associated with ceramic firing contexts.