Soils, Climate and Society: Archaeological Investigations in Ancient America

By John D. Wingard and Sue Eileen Hayes

Much recent archaeological research focuses on social forces as the impetus for cultural change. Soils, Climate and Society, however, focuses on the complex relationship between human populations and the physical environment, particularly the land--the foundation of agricultural production and, by extension, of agricultural peoples.

The volume traces the origins of agriculture, the transition to agrarian societies, the sociocultural implications of agriculture, agriculture's effects on population, and the theory of carrying capacity, considering the relation of agriculture to the profound social changes that it wrought in the New World. Soil science plays a significant, though varied, role in each case study, and is the common component of each analysis. Soil chemistry is also of particular importance to several of the studies, as it determines the amount of food that can be produced in a particular soil and the effects of occupation or cultivation on that soil, thus having consequences for future cultivators.

Soils, Climate and Society demonstrates that renewed investigation of agricultural production and demography can answer questions about the past, as well as stimulate further research. It will be of interest to scholars of archaeology, historical ecology and geography, and agricultural history.

• Language: English
• Publisher: University Press of Colorado
• Release date: Mar 15, 2013
• ISBN: 9781607322139

Book preview

Index

Figures

1.1. Study area

2.1. Northwest Honduras, showing the locations of the Naco Valley and the Palmarejo region

2.2. Locations of pre-Hispanic settlement in the Palmarejo region

2.3. Geomorphological map of the Palmarejo region

2.4. Geoarchaeological Section 1

2.5. Geoarchaeological Sections 2, 3, and 4

2.6. Geoarchaeological Sections 5 and 6

3.1. Map of the Vacant Quarter illustrating the locations of the five regions examined in this study: American Bottom, Ohio-Mississippi confluence, Tennessee-Cumberland-Ohio confluence, Ohio-Green confluence, Middle Cumberland basin

3.2. Instrumental Palmer Drought Severity Index (PDSI) grid used for reconstructing potential agricultural food reserves and shortfalls, along with the location of the Vacant Quarter

3.3. Palmer Drought Severity Index (PDSI) reconstruction and reconstructed potential agricultural food reserves and shortfalls for the Vacant Quarter region

3.4. Reconstructions of the number of moderate/severe food stress years for four intense droughts encompassing the southeastern United States in the thirteenth, fourteenth, and fifteenth centuries, along with the locations of the Vacant Quarter and grid point 210

3.5. Summed probability plots of calibrated 14C-dates for each of the five regions in the Vacant Quarter

3.6. Comparison of summed probability plots of calibrated 14C-dates for the American Bottom and Cahokia

4.1. Study area

4.2. Estimation of sustainable population units using the multiple regression equation

4.3. Annual consumption units

4.4. Surplus annual consumption units after a one-year storage requirement

5.1. Soil areas at Baking Pot, showing residential mound locations

6.1. Maya region of Mesoamerica

6.2. Major topographic zones and subregions of the Copán Valley

6.3. Models A and B derived populations

6.4. Models C, D, and E derived populations

6.5. Model F derived population

6.6. Land productivity

7.1. Center of Pampatá, view across valley

7.2. Site map of Pampatá, Peru

7.3. House compound constructed of riverside vegetation

7.4. Maize cobs, gourd, and textiles, Camaná Valley

7.5. Seven of over three dozen skeins of cotton thread discarded at looted burial, Camaná Valley

8.1. Excavated milpa from within the Cerén site center

8.2. Map of household and agricultural organization at Cerén

8.3. Maize stalk and cob casts, showing preservation of remarkable detail

8.4. Author with manioc beds located in 2007 season

8.5. Payson Sheets holding a modern manioc tuber and a 2007 manioc plant cast from Cerén

Tables

1.1. Selected population estimates for South America and subregions

1.2. Elements for calculating the Hatahara site population

2.1. Field descriptions and laboratory data for deep auger probes

2.2. Soil chemical data summary for shallow auger probes

2.3. MANOVA and post-hoc test results for soil fertility analysis

3.1. Assignment of Palmer Drought Severity Indices (PDSI) to estimated crop yield production

3.2. Summary data of 14C-dates from the Vacant Quarter, by region

4.1. Estimating the number of small-site rooms in the study area

4.2. Estimate of all Classic Mimbres period rooms

4.3. Usable soil series and their agroecology

4.4. Sustainable population estimate in study area based on 1966 production

4.5. Results of stepwise multiple regression analysis

5.1. Reclassified soils in Classes I–IV

5.2. Baking Pot soil productivity

5.3. Hectares of each soil class at Baking Pot

5.4. Sustainable population estimates for Baking Pot

6.1. Parameters for simulation runs—Adult Equivalents

6.2. Target population levels—Adult Equivalents

6.3. Target-generated population levels—Adult Equivalents

6.4. Model results—Adult Equivalents

6.5. Target-generated population levels—headcount

6.6. Model results—headcount

6.7. Elite labor requirements

6.8. Labor needs and availability (days)

7.1. Maize production and soil depth

7.2. Maize production and temperature

7.3. Camaná maize productivity

7.4. Sustainable population estimates for Camaná Valley sites

8.1. EPIC simulation results for Cerén, El Salvador

Acknowledgments

SUE EILEEN HAYES AND JOHN D. WINGARD

WE ARE GRATEFUL TO THE MANY INDIVIDUALS WHO have contributed to this volume. Most of the chapters were first presented at a symposium we organized for the 72nd Annual Meeting of the Society for American Archaeology in Austin, Texas. The inspiration for this symposium emerged from discussions between us. Both of us have worked primarily in Mesoamerica but have had field experience outside this region as well. We knew that while similar methodological approaches to analyzing relationships among soils, climate, and society were being applied elsewhere in the Americas, most discussions about this subject were conducted among researchers based within specific regions. We felt that bringing together researchers working in various regions of the Americas would allow us to broaden our perspective on the applications of these approaches and provide an opportunity to share ideas.

Darrin Pratt from University Press of Colorado invited us to develop the symposium papers into a book proposal. Almost all of the original presenters agreed to revise their presentations into formal book chapters. Sissel Schroeder had been invited to participate in the original symposium but lacked the time to do so. Her work, however, makes an important contribution to research in the field, so she was persuaded to write the culminating chapter.

In addition to Darrin Pratt, we are deeply indebted to numerous others. First and foremost, we want to recognize the effort and dedication of the contributors, who responded to our many requests with patience and promptness despite the multitude of other demands on their time. At University Press of Colorado we thank Jessica d’Arbonne for her helpful advice and comments. The chapters were greatly improved thanks to the feedback we received from two anonymous reviewers. We thank our copy editors, Jane Mackay and Cheryl Carnahan, for providing consistency in structure and citations throughout the manuscript. Finally, we would like to thank everyone else at University Press of Colorado for their assistance in helping put this volume together.

Introduction

A User’s Guide to Soils, Climate, and Society

SUE EILEEN HAYES AND JOHN D. WINGARD

FROM THEIR EMERGENCE between 3,000 and 8,000 years ago until the Industrial Revolution, agricultural societies were the most culturally complex and advanced societies in the world. Despite the rise of industrial sectors in many countries, agriculture continues to be the primary livelihood for the majority of the global population. Agricultural societies have persisted for nearly a dozen millennia, eventually occupying virtually every tropical and temperate zone in the world. Much remains to be learned about agricultural societies, both past and present, in their seemingly limitless diversity. The chapters in this volume contribute to our understanding of ancient agricultural societies in the New World. All are based on the premise that to understand agricultural societies, you must understand the complex relationship between human populations and the physical environment, in particular the land—the foundation of agricultural production and, by extension, of agricultural peoples.

The emergence of agricultural societies involved much greater transformations than the development of new techniques and strategies for acquiring food. Profound social changes coincided with the emergence of agriculture, including larger sedentary populations, increased population densities, more complex sociopolitical organization, increased material culture, and occupational specialization. Though the causal relationship between agriculture and these social changes continues to be the focus of considerable debate, the fact that they are correlated is clear.

There is no question that pre-agricultural peoples modified the landscape to enhance the production of plant and animal resources, but the magnitude and frequency of this modification increased dramatically with the advent of agriculture. Understanding the relationship between agricultural societies and the environment is a subset of the broader endeavor to understand the relationships between humans and the physical environment.

The studies in this volume straddle the line between processual and postprocessual archaeology. Relationships between human populations and the physical environment are not unidirectional. On the processual side, humans, like any living organisms, must meet certain biological needs, especially nutritional needs. In agricultural societies, a significant portion of these needs are met through the cultivation of plants. Consequently, the ability of these peoples to meet their biological needs is directly linked to the characteristics of the local environment, including characteristics of soils and climate. On the post-processual side, it is clear that cultural beliefs and values create needs beyond those of basic nutrition. For example, among the Classic Maya (Wingard, this volume), significant effort and resources were expended on the construction of elaborate temples and palaces. Consequently, it is essential to understand the culture of the peoples living in a particular location or region at a particular time in order to understand their relationship with the local environment and, conversely, to understand the reciprocal impacts of changes in either the sociocultural or physical environment. Consequently, rather than fitting neatly under either label, the studies in this volume demonstrate the complementarity of processual and postprocessual theoretical perspectives.

Methodologically, the chapters in this volume represent innovative attempts to understand and explain the complex social and ecological dynamics that characterized agricultural societies in various parts of the pre-Columbian Americas. These studies build on research dating back to the early decades of the twentieth century (see Cook 1909, 1921; Cooke 1931, 1933; Emerson and Kempton 1935; Steggerda 1941), as well as research from more recent decades.

Archaeologists have not worked in isolation. Expertise from fields as diverse as astronomy and zoology has contributed to our understanding of ancient agriculturalists. Archaeologists have also benefited from technologies and tools initially developed by practitioners in other professions. From surveying, masonry, and dentistry come important components of mapping and excavation. Knowledge from historical and modern textile and ceramic production has provided insight into the nature of artifacts and the processes that created them. Osteology and linguistics have assisted in the reconstruction of ancient lifeways. Remote sensing, from aerial photography to satellite infrared images, has augmented the identification of sites and aided the analysis of relationships among them. Advances in climatology and ecology allow archaeologists to address new questions. New innovations will certainly continue to add to the archaeologist’s toolkit.

This volume represents another level of application of borrowed analytical tools to archaeological purposes, in this case to interpret the relationships of pre-Columbian populations in the New World with their natural environment, to examine the impact of their environment on the ways people organized their lives and social relationships, and to analyze people’s impacts on the environment. The technologies utilized are varied, from some in common use to others rarely applied in archaeology.

As in present times, people in the past interacted with their environment on many levels, from the household through the village to entire regional ecosystems. Therefore, in studying past populations it is essential to approach each analysis at the appropriate organizational level. In some cases the relationship between humans and their resource base is immediate; they are literally living on the land. Other circumstances, such as wide-ranging climate change, require a broader analytical perspective. Before discussing the sources and uses of the data sets and simulation tools used by the authors of each study in this volume, it should be noted that all of them utilize a common component in their analysis: soil science. There are two branches of soil science, edaphology and pedology. Edaphology studies the influence of soil on organisms, particularly plants. Pedology includes soil chemistry, genesis, morphology, and soil classification. Of these, soil chemistry—which plays a major role in determining the amount of food that can be produced on a given area of a particular soil, how the occupation or cultivation of that particular soil will change it, and the consequences that change may have for future cultivators—is of particular importance to several of the studies in this volume.

Soil science is not merely a technical or chemical process but also requires a knowledge of the history of the human and geologic interactions that have produced the soil being analyzed. Initially, soils were analyzed in efforts to classify them by potential productivity. Pedology has now expanded to examine the origins and modification history of soils. Indeed, archaeology, although a beneficiary of soil science, is now credited as a major contributor to understanding long-term anthropogenic effects.

The role soils play varies in each of these chapters. For Woods and his coauthors the terra preta is the end product of human habitation, not only prized by current cultivators for its productivity but also an indicator of the extent of population in Amazonia before the advent of European diseases and depopulation. For Wells and his coauthors, the soil preserves the history of human use and predicts the outcomes of future utilization. Meeks and Anderson, Pool, Hayes, and Wingard use soil to predict food resources; for Dixon, the soil has preserved evidence of the actual crops cultivated at Cerén.

What is particularly notable in Woods’s and his coauthors’ studies in Amazonia is the degree to which research-based knowledge of the effect of human occupation on soil productivity yields a means for determining the extent of that occupation. Thus, the existence of anthropogenically enriched soils—terra preta—validates the existence of widespread, substantial human populations in a part of the New World once thought to have been sparsely inhabited. The extent of these soils and the degree of modification are cited as evidence of long-term occupation, refuting models of shifting, transitory cultivation by isolated groups.

Wells and his colleagues, working in eastern Honduras, combine archaeological, geoarchaeological, and pedological approaches to determine whether ancient farming practices caused erosion and other degradation in the soilscape and what implications this will have for the success of economic growth through contemporary cultivation in the study area. Their study of past and persisting patterns of land use in the ecosystem and the consequent transformation of the resource informs interpretations of the impact of the environment on the potential quality of life of today’s cultivators.

Meeks and Anderson and Pool separately address a different issue: the interaction of the soil resource and climate in determining changes in occupation in a region. Utilizing dendroclimatological data along with the Palmer Drought Severity Index, which uses temperature and precipitation to predict soil moisture and thus agricultural production, Meeks and Anderson address the issue of population variations in the Vacant Quarter and the potential impact of drought on Mississippian chief-doms. Pool, examining the Mimbres Mogollon area, utilizes dendroclimatological and soil productivity simulations to investigate assertions that the Classic Mimbres period ended as a result of drought, overpopulation, or overexploitation of resources.

Both Hayes and Wingard apply the EPIC simulation program, which combines soil, climate, and cultivation technology to study the interaction between population and the soil resource in Mesoamerica, although in different ways. EPIC is tested at Baking Pot, a data-rich, thoroughly mapped site, to determine whether agricultural productivity simulations can be used to develop credible estimates of sustainable site populations. At the site of Copán, Wingard utilizes EPIC to model productivity and soil erosion impacts of intensifying cultivation and the sociopolitical implications of different intensities of land use.

In the Camaná Valley study, Hayes again utilizes EPIC, applying the simulation program to estimate potential populations that could be sustained by the irrigated agriculture necessary in the extremely arid conditions of south coastal Peru. This illustrates the use of simulations with limited data, which requires testing and modifying known data from other locations, combined with specific local information to reach reasonable conclusions.

Dixon demonstrates that the investigations at Joya de Cerén are a technical tour de force, involving a broad range of approaches to develop important contributions to understanding this archaeological site sealed deep under volcanic ash. The combination of fiber-optic investigation of ash cavities, the injection of dental plaster to preserve plant forms, and the use of ground-penetrating radar to locate features in the village and surrounding fields has permitted the most precise reconstruction of Mesoamerican lifeways.

Sissel Schroeder raises the most important issue in interpreting the past. No matter the analytical or simulation technique, reliability of the data is paramount. How to determine and adjust for the expectations and biases of those collecting and reporting data so those data can be used to study the past is a crucial question. No sophisticated simulation can compensate for inaccurate data; it is imperative that the investigator understand the limitations for the analysis to succeed.

The studies in this volume clearly show that examination of the complex questions regarding the relationship between ancient peoples and their environments requires an equally complex combination of analytical tools, applied at a scale appropriate to the questions investigated. It is our hope that Soils, Climate, and Society will not only provide answers to some readers’ questions about the past but will also stimulate further research into those questions that remain to be answered.

REFERENCES

Cook, Orator F. 1909. Vegetation Affected by Agriculture in Central America. Bureau of Plant Industry Bulletin 145. Washington, DC: US Department of Agriculture.

Cook, Orator F. 1921. Milpa Agriculture: A Primitive Tropical System. Annual Report of the Smithsonian Institution. Washington, DC: Smithsonian Institution.

Cooke, C. Wythe. 1931. Why the Maya Cities of the Petén District, Guatemala, Were Abandoned. Journal of the Washington Academy of Sciences 21: 283–87.

Cooke, C. Wythe. 1933. A Possible Solution to the Maya Mystery. Science Service Radio Talks presented over the Columbia Broadcasting Service.

Emerson, R. A., and J. H. Kempton. 1935. Agronomic Investigations in Yucatán. Carnegie Institution of Washington Yearbook 34: 138–42.

Steggerda, Morris. 1941. Maya Indians of Yucatan. Publication 531. Washington, DC: Carnegie Institution of Washington.

SOILS, CLIMATE, AND SOCIETY

1

Population Estimates for Anthropogenically Enriched Soils

(Amazonian Dark Earths)

WILLIAM I. WOODS, WILLIAM M. DENEVAN, AND LILIAN REBELLATO

HOW MANY YEARS DO YOU GET FOR COUNTERFEITING A PARADISE?

Until fairly recently, there were two opposing models of the density, size, shape, and duration of Amazonian pre-Columbian settlements. One group of scientists believed environmental conditions in the Amazonian region inhibited the social and cultural development of its populations and posited soil exhaustion and low available protein as principal limiting factors (Gross 1975; Meggers 1954, 1971, 1991, 1995; Steward 1949a). Betty J. Meggers interpreted the archaeological data as indicative of cultural conservatism, with the present situation among native peoples serving as a model for the past (small villages, little societal complexity, subsistence patterns based on shifting cultivation and residence, and low population densities) and with mega–El Niño droughts serving as an explanation for culture change. Where the record demonstrates large archaeological sites or monumental architecture in the form of mounds, these were dismissed, respectively, as the result of recurrent small groups settling in the same place over time or intrusions of more advanced cultures that ultimately failed in a harsh Amazonian environment.

The second view presented the Amazonian region as a cultural innovation center where the oldest pottery was created and early plant domestication in South America occurred (Brochado 1984, 1989; Roosevelt 1989, 113). Donald W. Lathrap (1970, 1977) believed that in the Central Amazon region, the ecosystem and associated resource differences among the uplands (terra firme) and the floodplains (várzea) helped create social and economic differences between cultural groups that led to increased interaction and innovation. The enhanced fertility of the flood-plains of whitewater rivers (e.g., the Amazon/Solimões and the Madeira) provided high agricultural productivity that promoted population growth and the creation of large settlements. The demographic pressures consequently spread human populations and associated ceramic styles, languages, and agricultural systems to different areas of South America. Lathrap also suggested that there was settlement continuity in the Central Amazon for millennia before European contact. His hypotheses have recently been reviewed, and archaeological data for the Central Amazon include ceramics associated with early radiocarbon dates and long periods of settlement stability (Neves and Petersen 2006; Neves et al. 2004; Petersen, Neves, and Heckenberger 2001). However, during the last 500 years of the pre-Columbian period, major changes in the cultural groups inhabiting the region and associated settlement-subsistence patterns occurred (Rebellato, Woods, and Neves 2009).

Now, many view the Amazonian environment as a social construction and not as a culturally defining element (Balée 1989; Erickson 2006, 2008; Heckenberger, Petersen, and Neves 1999; Myers 1992; Petersen, Neves, and Woods 2005; Woods and McCann 1999). This perspective is a vision that goes beyond the dichotomy between human societies and nature; the human being is not considered a passive agent who simply reacts to stimuli (environmental determinism) (Balée 1989, 2). This shift in focus presents humans as agents who transform the landscape through the use and manipulation of resources and takes into consideration the inventive character of the human being (Balée 1989; Carneiro 1995; Denevan 1966, 2001; Erickson 2008; Heckenberger, Petersen, and Neves 1999; Woods 1995; Woods and McCann 1999). This perspective in Amazonia has put forward the genesis of fertile anthropogenic soils (discussed in the next sections) as the mark of cultural changes associated with intensive environmental management, including agriculture. The debate on the human articulation with the environment is ongoing, and the implications for pre-Colonial population numbers in Amazonia are considerable (DeBoer, Kintigh, and Rostoker 2001; Heckenberger, Petersen, and Neves 2001; Meggers 2004; Stahl 2002). Previous population estimates are presented in table 1.1.

These population estimates were based on the productive capacities of the various habitats, historical accounts and mission records, retrogressive extrapolations of epidemic vectors, ethnographic data, and archaeological interpretations. However, faced with the increasing depth of our knowledge about the complexity of population distributions at the time of contact and knowing that we still have such questionable and scattered data sources, William M. Denevan concluded that too much variation existed in population densities within habitats to be able to formulate meaningful average densities on the basis of a few sample densities. He concluded that there were large areas with fewer people, but there were also locations with many, many more, both riverine and in the interior (Denevan 2003, 186–7). We clearly need to rethink pre-European settlement-subsistence systems and their distributions with the goal of determining their associated populations.

TABLE 1.1. Selected population estimates for South America and subregions (areas: Amazonia 6.64 million km², Greater Amazonia 9.77 million km²; Denevan 1976)

ARCHAEOLOGICAL EVIDENCE FOR LARGE POPULATIONS

Archaeological and historical evidence exists for large settlements numbering in the thousands in many locations, especially in the upper Amazon, the Central Amazon near the juncture of the Solimões and Negro Rivers (Neves et al. 2004; Petersen, Neves, and Heckenberger 2001), the lower Tapajós River and adjacent uplands (Roosevelt 1987; Woods and McCann 1999), Marajó Island (Meggers and Evans 1957; Roosevelt 1991; Schaan 2008), the Upper Xingu (Heckenberger 1998, 2005; Heckenberger, Petersen, and Neves 1999), and the Mojos savanna of the Bolivian Amazon (Denevan 1966; Erickson 2006). Associated anthropogenic earthworks include mounds, ditches, causeways, canals, raised fields, and complexes of huge geometrically shaped ditch and earthen berms termed geoglyphs (Erickson 2008). These latter in Acre are being exposed by the hundreds as mature tropical forest is being removed for cattle grazing (Schaan et al. 2007; Schaan, Ranzi, and Pärssinen 2008); the clear implication is that the forest was not present there 500 or more years ago. Another widespread alteration of the Amazonian surface is the phenomenon called terra preta de índio (Indian black earth), or Amazonian Dark