Faunal changes in farming communities from Basketmaker II to Pueblo III (A.D. 1–1300) in the San Juan Basin of the American Southwest

The San Juan Basin of the American Southwest is home to some of the best known architecture in pre-Columbian North America. Although many faunal assemblages have been reported for individual sites, there has been little synthesis of hunting and husbandry in these farming communities. In an attempt to understand changing animal usage over time in the San Juan Basin, we use three indices to investigate the usage of artiodactyls, lagomorphs and turkeys. These three taxonomic groups formed the bulk of meat diets between Basketmaker II and Pueblo III times (A.D. 1–1300). Our analysis indicates that artiodactyls declined over time in relation to lagomorphs. Turkeys increased in the northern regions when compared to lagomorphs. Cottontails increased when compared to jackrabbits over time. We suggest that as human populations increased in the San Juan Basin, artiodactyls were more intensely hunted. People then began to raise more turkeys in favorable regions, and also hunted more lagomorphs in relation to artiodactyls. Deforestation, also as a result of increased human populations, would have created conditions more favorable for cottontails than jackrabbits in many areas.     

Ancient soil resources of the Usumacinta River Region,Guatemala

In this study we present the results of a combination of methods used to identify possible agricultural activity of the ancient Maya in the Usumacinta River Basin in Guatemala. These methods included stable carbon isotope analysis of bulk soil organic matter, soil profile investigations and a spatial model of gentle slopes and well-drained soils to identify favorable agricultural conditions. Stable carbon isotope analysis of bulk soil organic matter in particular offers potentially direct evidence of agricultural activity. The δ¹³C results suggest that there is a strong signature of C₄ plants, such as maize and tropical grasses, throughout the study area. Further, the current soil conditions and extent of relatively gently sloped areas are favorable to agriculture. Overall, the results are supportive of the hypothesis that the area, located between the polities of Piedras Negras and Yaxchilán, was agriculturally important to surrounding areas.     

Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 2: The Chaco Halo, Mesa Verde, Pajarito Plateau/Bandelier, and Zuni Archaeological Regions

Chemical and nutrient analyses of 471 soil samples from 161 sites within four archaeological regions (Pajarito Plateau/Bandelier, Zuni, Mesa Verde, and the Chaco Halo) were combined with historical climate data in order to evaluate the agricultural productivity of each region. In addition, maize productivity and field-life calculations were performed using organic-nitrogen (N) values from the upper 50 cm of soil in each region and a range (1?C3%/year) of N-mineralization rates. The end-member values of this range were assumed representative of dry and wet climate states. With respect to precipitation and heat, the Pajarito Plateau area has excellent agricultural potential; the agricultural potentials of the Zuni and Mesa Verde regions are good; and the agricultural potential of the Chaco Halo is poor. Calculations of N mineralization and field life indicate that Morfield Valley in Mesa Verde should be able to provide 10 bu/ac of maize for decades (without the addition of N) when organic N-mineralization rates exceed 2%. Productivity and field-life potential decrease in the following order: Zuni, Mesa Verde, Bandelier, Chaco Halo. The Chaco Halo is very unproductive; e.g., 10 bushels per acre can be achieved within the Halo only from soils having the highest organic N concentration (third quartile) and which undergo the highest rate (3%) of N mineralization.     

Genuine Community Engagement in Remote Dryland Regions: Natural Resource Management in Lake Eyre Basin

Remote dryland regions are characterised by sparse populations and socially marginalised voices which pose particular challenges to natural resource management. This paper considers the issue of how to achieve community engagement in regions with these characteristics. In doing so, the paper contributes to an expanding international research agenda focusing on the distinct characteristics of arid and semi‐arid regions under the heading of ‘dryland syndrome’. The paper draws on government liaison officer and local community perspectives of successful engagement in the case‐study region of Lake Eyre Basin, Australia. The results demonstrate that widely recognised characteristics of successful engagement are required but insufficient for genuine engagement in remote dryland regions. In addition to building trust through community ownership, being inclusive, effective communication, and adequate resources, genuine community engagement in drylands also requires respecting the extreme conditions and extraordinary variability of these areas. Residents of dryland regions seek genuine engagement yet engage opportunistically when seasons are conducive and when tangible outcomes are visible.     

Maize,beans and the floral isotopic diversity of highland Oaxaca,Mexico

Oaxaca, Mexico has been inhabited by humans for over 10,000 years. From the time of earliest habitation, this environment provided a wide floral subsistence to its human inhabitants, notably documented at the cave site of Guila Naquitz. Light stable isotopes, primarily carbon and nitrogen, have been used in dietary and environmental reconstructions throughout Mexico and Central America. We report a large isotopic study of wild and market plants from Oaxaca that demonstrates 1) overlapping δ¹³C values of C4 plants, including maize, and plants that utilize the Crassulacean Acid Metabolism (CAM) pathway for biosynthesis, 2) the existence of a significant C4 grass biomass, 3) the lack of isotopic separation in the δ¹⁵N of legumes and non-leguminous plants and 4) the increase in the nitrogen isotopic composition of crop plants relative to wild plant averages. These four observations are potential complicating factors in interpretations involving the origins and spread of maize agriculture, the relative amount of maize in the diet and assessments of trophic level or meat contributions to the human diet.     

Assessing the resilience of irrigation agriculture: applying a social-ecological model for understanding the mitigation of salinization

This paper creates and applies a computational model of irrigation agriculture in order to study the effects of salinization in Mesopotamia, with the model developed applicable to cases beyond that studied here. Scholars have long suspected that central and southern Mesopotamia present environments which limited agricultural production over the long-term. In regions such as central Mesopotamia, where salinization likely affected settlement and agriculture in different periods but was more manageable than in more southern regions, fallowing regimes, natural and engineered leaching, and decisions made on when to crop were strategies applied in order to limit the effects of salinization. In this paper, we assess the effectiveness of these coping strategies by incorporating projected climate, soil, and landscape conditions with agricultural practices. The simulation results not only demonstrate the effectiveness and limitations of inhibiting progressive salinization, but they can be compared with the archaeological record in order to determine if the results could reasonably be matched with past events and help to interpret settlement history.     

Crop marks and soils at two archaeological sites in Britain

The factors which create crop marks at two archaeological sites, at Glenlochar, Kirkcudbrightshire and at Fisherwick, Staffordshire, are examined in some detail. Marks are best recorded at these places in cereals and show earliest over the shallowest soils. They appear when the potential soil moisture deficit, which occurs when water transpired by a crop exceeds rainfall, is greater than the amount of water in the soil available to the plant. Marks only show in grassland when the deficit is about 40 mm more than that calculated for cereals. Marks also appear in very wet years, but are fainter than those caused by a moisture deficit, and are probably caused by waterlogging in the soil. At both sites the soils are moderately stony and shallow over terrace sands and gravels, except for soils in infilled ditches over which crop growth is better.     

Assessing the feasibility of identifying maize through the analysis of cross-shaped size and three-dimensional morphology of phytoliths in the grasslands of southeastern South America

This paper tests the feasibility of applying a technique developed by Piperno and Pearsall (Am. Antiquity 49 (1984) 361; Phytolith Analysis: An Archaelolgical and Geological Perspective, 1988, Academic Press: San Diego; Paleoethnobotany, 2000, Academic Press: San Diego) based on size and three-dimensional morphology criteria of cross-shaped phytoliths to identify maize in a previously unexplored region outside of the Neotropics; the grasslands of southeastern Uruguay. Because the area is dominated by subtropical Panicoid grasses that produce abundant cross-shaped phytoliths, intensive studies of the regional Panicoid grasses are needed to ensure that no wild taxa have phytoliths that are potentially confusable with maize. With this in mind, I carried out analysis of cross-shaped phytoliths in 35 Panicoid, 5 Oryzoid and 1 Bambusoid grasses, as well as on nine modern soil samples that belong to the most representative vegetation formations of the area. This study demonstrates that an application of multivariate (linear discriminant function) analysis together with qualitative and other assessments of cross-shaped phytolith assemblages as originally described by Piperno and Pearsall can be successfully used to distinguish the presence of maize in the grasslands of southeastern Uruguay. The technique provides a useful tool to trace the dispersal of maize into the southern cone of South America.     

Heads or Tails? Modified Ceramic Gaming Pieces from Colonial California

Modified ceramic disks have been recovered from historic-era sites across the Americas. Small unperforated disks are commonly interpreted as gaming pieces and larger perforated disks are often classified as spindle whorls. Here, we examine these interpretations in light of collections from three colonial-era sites in central California: Mission San Antonio de Padua, Mission San José, and the Rancho San Andrés Castro Adobe. We argue that the small unperforated disks from our study sites were two-sided dice. These gaming pieces facilitated the social cohesion of Native people living in the large, multiethnic Indigenous communities that formed around Spanish colonial missions and later Mexican-era ranchos.     

Excavations at Prehistoric Sites on the Navajo Indian Irrigation Project,Northwestern New Mexico

Abstract

The results of a large excavation project in the San Juan Basin of NW New Mexico are summarized in this article. Discussion is limited to prehistoric and protohistoric sites, 22 of which were excavated. The majority of the remains are small, surface aceramic sites that are believed to relate to the Archaic Cultural Complex. These sites reflect a specialized adaptive strategy focusing on seasonal mobility and the exploitation of resources occurring at or adjacent to sand dunes. The lithic assemblages from these sites generally are homogeneous and reflect opportunistic usage. Occupation of the project area during the Anasazi phases was limited. A considerable protohistoric Navajo occupation is apparent, with one excavated site suggesting a very specialized economic orientation emphasizing antelope procurement. The research focus of the project was on comprehensive lithic analysis and on paleoeconomy. Several methodological considerations are discussed, as is the necessity for developing a unified research perspective that will produce comparable data for the region.     

Sensitivity of bulk sedimentary stable carbon isotopes to prehistoric forest clearance and maize agriculture

The stable carbon isotope compositions (δ¹³C) of tropical lake sediments and soils have been used to reconstruct the occurrence of prehistoric maize cultivation and its relative importance through time. This study assesses some of the possible variables affecting the response of lake sediment bulk organic carbon isotope (δ¹³C_TOC) values to variations in the scale of prehistoric maize cultivation and the potential of this proxy to yield quantitative estimates of the scale of prehistoric maize agriculture in small tropical watersheds. High resolution analyses of δ¹³C_TOC values, maize pollen concentrations, and mineral influx were conducted on sediments deposited during a ∼220 year period of prehistoric maize agriculture in the watershed of Laguna Castilla, a small lake in the mid-elevations of the Cordillera Central, Dominican Republic. Close correspondence between δ¹³C_TOC values and maize pollen concentrations in the Laguna Castilla sediment record indicates a close relationship between the isotopic values and the scale of prehistoric maize cultivation. Correlations between the δ¹³C_TOC signature and mineral influx indicate that the isotope record is also sensitive to variations in allochthonous carbon delivery. This study establishes that sedimentary δ¹³C_TOC values can provide a highly sensitive proxy of the spatial scale of prehistoric maize agriculture in small tropical watersheds, but emphasizes the need for a better understanding of sediment dynamics and carbon cycling in anthropogenically modified landscapes before this proxy can be widely employed in diverse archaeological settings.     

Differentiating Aspen and Cottonwood in Prehistoric Wood from Chacoan Great House Ruins

Accurate taxonomic identification is an essential part of archaeological wood analysis. However, making identifications more precise than the genus level is usually not possible since species within the same genus typically possess very similar cellular morphology. This paper describes a method for distinguishing aspen (Populus tremuloides) from cottonwood (Populus fremontii, Populus angustifolia, Populus acuminata) in samples of wood collected from the San Juan Basin in northwestern New Mexico and southwestern Colorado. This method is then applied to archaeological wood samples from the Anasazi great house at Aztec Ruins National Monument in Aztec, New Mexico. The results of this study demonstrate that quantifiable differences do exist between aspen and cottonwood species and that the technique can be used to separate archaeological specimens of Populus wood.     

Spatial and temporal variation in vulnerability of crop production to drought in southern Alberta

Growing evidence of global climate change has led to global concerns over the vulnerability of agriculture to drought. Located in a semiarid environment, southern Alberta has suffered significant losses of agricultural productivity due to drought hazards in recent decades. Understanding the relationship between crop production and drought conditions is essential for coping with increasingly uncertain climate conditions. This study attempts to quantify the magnitude of crop production vulnerability to drought in southern Alberta. The standard precipitation index is used to measure drought stress in the region. The empirical results provide a detailed picture of the spatial variation in crop production vulnerability to varying drought conditions. Vulnerability maps from this study reveal that pockets in the study area may experience significant productivity loss given the existing level of adaptive capacity. While the irrigation districts have been associated with a lower level of vulnerability than dryland outside the irrigated region, uncertain water supply under varying climatic conditions coupled with increasing water allocation for non‐agricultural uses may increase the vulnerability in these districts.     

Incorporating Soil Associations into Linear Programming Models for Development of Irrigation Scenarios

An inadequate streamflow supply in Saginaw Bay, Michigan, affects the irrigation development in the region. Linear programming (LP) models are developed in this paper to help irrigation planners determine optimal irrigation scenarios. To incorporate the spatial variations of the soil and climate into the optimization models, soil associations are used as the basic analysis unit for estimating crop yields, irrigation requirements, and expected economic returns. The yields and irrigation requirements of corn, drybeans, and soybeans are simulated by the CERES-MAIZE, BEANGRO, and SOYGRO models at each of the twelve soil associations in the study area over the period of 1951–1980. The yield and irrigation requirement of sugarbeets are simulated by the YIELD model for all the soils in the study area over the period of 1956–1987. The crop prices, simulated crop yields and irrigation requirements, and variable costs are used to compute the expected gross margins and other coefficients in the LP models. The optimization results provide irrigation scenarios that are linked to specific soil associations, which are more useful to decision makers for identifying and targeting individual soils for irrigation development than are the spatially lumped optimal solutions. This study demonstrates that through integration of GIS and simulation models, spatial variations of the climate, soil, and water resources can be better represented in the optimization models to produce more realistic irrigation scenarios.     

The Key Role of Water Resources Management in Ecological Restoration in Western China

The interactions of nature and society are intimately reflected in the degradation of the vast, yet diverse, landscapes and ecosystems of arid western China. The development of agriculture, especially irrigation, has altered rivers, soils and ecosystems so much that major ecological rehabilitation and restoration efforts have been needed since 1950. The catchments of the Tarim River in southern Xinjiang (the Tarim Basin) and of the Black River (Hei He) in Gansu Province and western Inner Mongolia provide examples of the benefits, difficulties and conflicts involved in dryland water management. In the early stages of the human development of these catchments, agriculture depending on irrigation using water from these inland rivers was encouraged. The over‐exploitation of these water resources led to such ecological problems as desiccation of lakes, drying out of rivers, degradation of soils and vegetation and lowering of groundwater levels, with consequent environmental and economic impacts. Since 1990 several high‐cost, national projects to re‐establish ecosystems have been initiated. Water is now released from dams in the headwaters of the rivers in order to restore water flows to the dried out lake basins. Such schemes have inevitably led to social problems and difficulties for the people who depended on the water from the dams for local irrigation. The contrasts in adjustments and attitudes over the use of water for agriculture and other economic activities, as opposed to schemes of restoration of ecosystems and ecological engineering, stem largely from two issues; inconsistent provision of information from the scientific community, and differing ideologies, namely environmental protection versus economic development.     

Settlement and subsistence among the Early Formative Gulf Olmec

Mounting archaeological evidence suggests that floodplain resources, not maize (Zea mays) agriculture, were instrumental in the emergence of Early Formative (ca. 1500–900 uncal BC) complexity across Mesoamerica’s isthmian lowlands. The lion’s share of these data derives from the Pacific side of the isthmus; discussions of the Early Formative Olmec along Mexico’s southern Gulf lowlands have not kept pace. This paper presents settlement and subsistence data that highlight the role of floodplain resources in the development of Gulf Olmec politico-economic complexity. These data support a non-agricultural alternative to traditional models of Gulf Olmec emergence at San Lorenzo, the premier Early Formative Gulf lowlands center. Increased productivity of maize toward the end of the Early Formative period challenged San Lorenzo’s extant politico-economic basis, bringing about a short-term, hyper-acceleration of elite competitive displays. Ultimately, the adoption of maize agriculture generated a reorganized Middle Formative period (ca. 900–400 uncal BC) landscape in and around San Lorenzo. This agrarian adjustment saw occupation move out of the floodplain and into the upland areas, a process sometimes characterized as a cataclysmic system collapse in the Coatzacoalcos basin.     

Nitrates,water and salt: maintaining the fertility of agriculture

Abstract

The fertility of the soil depends on an ample supply of nitrogen compounds and on a variety of other nutrients and trace elements. The supply of nitrates by natural means has posed a limit to productivity since the inception of agriculture, and the avoidance of soil salination has been a necessity in many environments. Since the invention of an industrial process for fixing atmospheric nitrogen (the Haber process), there has been an ample supply of nitrates in the form of chemical fertilisers, capable of sustaining agriculture worldwide, and enabling it to feed the burgeoning human population. The growth in agricultural supply has been attributable, in the second half of the twentieth century, to the combined agency of hybrid crop species, chemical fertilisers and irrigation. Now, at the beginning of the twenty-first century, the problem of soil salination is limiting this growth and threatening to reverse it.     

Maize Agriculture Evolution in the Eastern Woodlands of North America: A Darwinian Perspective

David Rindos' coevolution theory remains the most comprehensive application of Darwinian theory to issues of prehistoric agriculture evolution. While his theory has drawn attention, there has been a lack of subsequent development of the application of Darwinian theory to prehistoric agricultural evolution. Combining Sewall Wright's shifting balance theory of evolution with aspects of Rindos' coevolution theory provides important new insights into the processes of crop transmission between regions. Using these theories, a model is developed for the adoption and subsequent evolution of maize agriculture in the Eastern Woodlands of North America.     

The Use of Old Russian Land Survey Data in Geographic Research for Agricultural Purposes

Estate maps dating from the Russian general land survey of 1770–1781 are used to compile a historical map of land types, including cropland, forest, meadow, swamps, etc. The historical map is then compared with a modern soil map and a map of soil-forming parent materials to establish what effect, if any, past land types have had on present soil qualities. It is suggested that the better soils, in terms of drainage characteristics, were selected by man in the earliest stages of cultivation, and that poorer soils were put under the plow only subsequently as the crop area expanded. Some of these poorer soils have reverted, in the meantime, to grazing land. Soils long cleared of forest are found to have a higher carbonate horizon (effervescing with HCI) than soils more recently cleared of forest. The study area is Sapozhok Rayon of Ryazan' Oblast, southeast of Moscow.     

Some thoughts on the factors that controlled prehistoric maize production in the American Southwest with application to southwestern Colorado

In this paper, we present a model of prehistoric southwestern Colorado maize productivity. The model is based on a tree-ring reconstruction of water-year precipitation for Mesa Verde for the period A.D. 480 to 2011. Correlation of historic Mesa Verde precipitation with historic precipitation at 11 other weather stations enabled the construction of an elevation-dependent precipitation function. Prehistoric water-year precipitation values for Mesa Verde together with the elevation-dependent precipitation function allowed construction of the elevation of southwest Colorado precipitation contours for each year since A.D. 480, including the 30-cm contour, which represents the minimum amount of precipitation necessary for the production of maize and the 50-cm contour, which represents the optimum amount of precipitation necessary for the production of maize. In this paper, calculations of prehistoric maize productivity and field life for any specific elevation are also demonstrated. These calculations were performed using organic nitrogen measurements made on seven southwestern Colorado soil groups together with values of reconstructed water-year precipitation and estimations of the organic nitrogen mineralization rate.