To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
We present a sediment-mixing process model of till genesis based on data from surface tills of the Saginaw lobe terrain in lower Michigan. Our research uses a spatial approach to understanding glacial landsystems and till genesis. We sampled calcareous till at 336 upland sites and at 17 sites in lacustrine sediment of the Saginaw Lake plain. The loamy tills have bimodal grain-size curves, with a fine-texture mode near the silt–clay boundary and a sand mode. Spatial grouping analysis suggests that tills can be divided into six groups, each with different textures and clay mineral compositions that vary systematically down-ice. The similarity among groups with respect to the silt–clay mode and clay mineralogy argues for a common origin for the fines—illite-rich lacustrine sediment of the Saginaw Lake plain. Fine-textured sediments were probably entrained, transported, and deposited down-ice as till, which also becomes sandier and enriched in kaolinite, reflecting increasing mixing with shallow sandstone bedrock with distance from the lacustrine clay source. Clayey tills on the flanks of the Saginaw terrain may reflect proglacial ponding against nearby uplands. A process model of progressive down-ice mixing of preexisting fine lake sediments with crushed/abraded sandstone bedrock helps to better explain till textures compared with a purely crushing/abrasion process model.
As archaeologists expand the accessibility of legacy data, they have an opportunity to use these datasets to design future research. We argue that legacy data can be a critical resource to help predict characteristics of sites and socioeconomic systems. In this article, we present a combined geographic information system (GIS) and network analysis methodology that turns site location data into testable hypotheses about site characteristics and the organization of regional settlement systems. We demonstrate the utility of this approach with a case study: Bronze Age (2700–1100 BC) settlement patterns in the mining region of Hunedoara in southwest Transylvania, Romania. We leverage unsystematically collected site location information in legacy datasets to develop testable predictions about sites, regional networks, and socioeconomic systems that can be evaluated through future systematic surveys and large-scale excavations. Such testable hypotheses can inform archaeological research design by providing a quantitative basis for determining where to focus research efforts and can also help secure funding and fieldwork permits. The method developed here can be applied in diverse archaeological contexts to reinvigorate legacy data as part of future archaeological research design.
The purpose of this article is to discuss the challenges and opportunities for integrating archaeological information in landscape-scale conservation design while aligning archaeological practice with design and planning focused on cultural resources. Targeting this opportunity begins with statewide archaeological databases. Here, we compare the structure and content of Pennsylvania's and Florida's statewide archaeological databases, identifying opportunities for leveraging these data in landscape conservation design and planning. The research discussed here was part of a broader project, which was working through the lens of Landscape Conservation Cooperatives in order to develop processes for integrating broadly conceived cultural resources with natural resources as part of multistate or regional landscape conservation design efforts. Landscape Conservation Cooperatives offer new ways to think about archaeological information in practice and potentially new ways for archaeology to contribute to design and planning. Statewide archaeological databases, in particular, offer transformative potential for integrating cultural resource priorities in landscape conservation design. Targeted coordination across state boundaries along with the development of accessible derivative databases are two priorities to advance their utility.
With generous support from the National Science Foundation, we have spent the past four years developing an archaeological radiocarbon database for the United States. Here, we highlight the importance of spatial data for open-access, national-scale archaeological databases and the development of paleodemography research. We propose a new method for analyzing radiocarbon time series in the context of paleoclimate models. This method forces us to confront one of the central challenges to realizing the full potential of national-scale databases: the quality of the spatial data accompanying radiocarbon dates. We seek to open a national discussion on the use of spatial data in open-source archaeological databases.
We compared systematic and random survey techniques to estimate breeding population sizes of burrow-nesting petrel species on Marion Island. White-chinned (Procellaria aequinoctialis) and blue (Halobaena caerulea) petrel population sizes were estimated in systematic surveys (which attempt to count every colony) in 2009 and 2012, respectively. In 2015, we counted burrows of white-chinned, blue and great-winged (Pterodroma macroptera) petrels within 52 randomized strip transects (25 m wide, total 144 km). Burrow densities were extrapolated by Geographic Information System-derived habitat attributes (geology, vegetation, slope, elevation, aspect) to generate island-wide burrow estimates. Great-winged petrel burrows were found singly or in small groups at low densities (2 burrows ha−1); white-chinned petrel burrows were in loose clusters at moderate densities (3 burrows ha−1); and blue petrel burrows were in tight clusters at high densities (13 burrows ha−1). The random survey estimated 58% more white-chinned petrels but 42% fewer blue petrels than the systematic surveys. The results suggest that random transects are best suited for species that are widely distributed at low densities, but become increasingly poor for estimating population sizes of species with clustered distributions. Repeated fixed transects provide a robust way to monitor changes in colony density and area, but might fail to detect the formation/disappearance of new colonies.
We conducted unmanned aerial vehicle lidar missions in the Maya Lowlands between June 2017 and June 2018 to develop appropriate methods, procedures, and standards for drone lidar surveys of ancient Maya settlements and landscapes. Three site locations were tested within upper Usumacinta River region using Phoenix Lidar Systems: Piedras Negras, Guatemala, was tested in 2017, and Budsilha and El Infiernito, both in Mexico, were tested in 2018. These sites represent a range of natural and cultural contexts, which make them ideal to evaluate the usefulness of the technology in the field. Results from standard digital elevation and surface models demonstrate the utility of deploying drone lidar in the Maya Lowlands and throughout Latin America. Drone survey can be used to target and efficiently document ancient landscapes and settlement. Such an approach is adaptive to fieldwork and is cost effective but still requires planning and thoughtful evaluation of samples. Future studies will test and evaluate the methods and techniques for filtering and processing these data.
Archaeologists are using spatial data in increasingly sophisticated analyses and invoking more explicit considerations of space in their interpretations. Geographic information systems (GIS) have become standard technology for professional archaeologists in the collection and management of spatial data. Many calls have been made to develop and adapt digital geospatial technologies for interpretation and understanding past social dynamics, but this has been limited to some extent by the static nature of map-oriented GIS approaches. Here, we illustrate how coupling GIS with agent-based modeling (ABM) can assist with more dynamic explorations of past uses of space and geospatial phenomena.
Cereal crops are one of the most widely consumed and most valuable crops for humankind. The species have been domesticated for over 10,000 years and as such have lost much of the genetic diversity that is present within their wild relatives. Future breeding efforts will require the use of genetic diversity from crop wild relatives (CWRs) to help improve our cereal crops. This study aims to identify an in situ conservation network within the Mediterranean Basin and west Asia for the four cereal crops, barley (Hordeum L.), oat (Avena L.), rye (Secale L.) and wheat (Aegilops L., Amblyopyrum L., Triticum L.). This region is a centre of diversity for these taxa and an area of potentially high genetic diversity, which if left unprotected will not be available for plant breeders to utilize in the future. Presence point data for a total of 90 taxa were collected from GBIF and resulted in 76,343 individual presence points across the 44 countries in the study region. Geographic Information System (GIS) software was used to identify potential in situ reserve networks per crop genepool and for all crops combined. Results indicate a network of 10 locations across the region which would protect over 80% of the taxa. The number one priority reserve is found within the Fertile Crescent region on the border of Israel, Syria and Jordan. This proposed reserve location contains 93 currently protected areas (i.e. National Parks) and as such, it may only be necessary to alter management plans to effectively protect CWR populations. For taxa not found within protected areas ex situ conservation may be more appropriate and should be implemented as a backup to the in situ reserve network.
Crop wild relatives (CWR) are wild plant taxa relatively closely related to crops that can contribute beneficial traits for crop improvement, such as biotic and abiotic stress resistance. Turkey has a rich flora of approximately 11,000 higher plant taxa, has two Vavilov centres of crop diversity (i.e. the Mediterranean and the Near East), is recognized as the cradle of agriculture providing the northern boundary of the Fertile Crescent, and has recently been identified as the country with the highest concentration of CWR diversity. The objective of this paper is to present the results of a gap analysis of CWR genetic diversity in Turkey using existing data sources of 458 of the 764 priority CWR taxa with available georeferenced data. In total, 27,597 presence points were obtained from the Global Biodiversity Information Facility, Aegean Agricultural Research Institute in Menemen and Field Crops Central Research Institute, Ankara. Geographic Information System (GIS) software was used to identify taxon richness, sampling bias, future ex situ population collection and location where existing protected sites could form the basis of national network of in situ genetic reserves. CWR taxon richness was located along the Aegean Coast, Syrian border and southern Mediterranean coast. Current ex situ representation of CWR taxa is inadequate and further collection across the entire country is required. The highest priority in situ reserve location is found in Izmir, Sanliurfa and Antalya province, which reflects overall CWR richness.
Reducing emissions from deforestation and forest degradation plus the conservation of forest carbon stocks, sustainable management of forests and enhancement of forest carbon stocks in developing countries (REDD+) requires information on land-use and land-cover changes (LULCCs) and carbon emission trends from the past to the present and into the future. Here, we use the results of participatory scenario development in Tanzania to assess the potential interacting impacts on carbon stock, biodiversity and water yield of alternative scenarios where REDD+ is or is not effectively implemented by 2025, a green economy (GE) scenario and a business as usual (BAU) scenario, respectively. Under the BAU scenario, LULCCs will cause 296 million tonnes of carbon (MtC) national stock loss by 2025, reduce the extent of suitable habitats for endemic and rare species (mainly in encroached protected mountain forests) and change water yields. In the GE scenario, national stock loss decreases to 133 MtC. In this scenario, consistent LULCC impacts occur within small forest patches with high carbon density, water catchment capacity and biodiversity richness. Opportunities for maximizing carbon emission reductions nationally are largely related to sustainable woodland management, but also contain trade-offs with biodiversity conservation and changes in water availability.
Fasciola hepatica is a helminth parasite that causes huge economic losses to the livestock industry worldwide. Fasciolosis is an emerging foodborne zoonotic disease that affects both humans and grazing animals. This study investigated the associations between climatic/environmental factors (derived from satellite data) and management factors affecting the spatial distribution of this liver fluke in cattle herds across different climate zones in three Mexican states. A bulk-tank milk (BTM) IgG1 enzyme-linked immunosorbent assay (ELISA) test was used to detect F. hepatica infection levels of 717 cattle herds between January and April 2015. Management data were collected from the farms by questionnaire. The parasite's overall herd prevalence and mean optical density ratio (ODR) were 62.76% and 0.67, respectively. The presence of clustered F. hepatica infections was studied using the spatial scan statistic. Three marked clusters in the spatial distribution of the parasite were observed. Logistic regression was used to test three models of potential statistical association from the ELISA results using climatic, environmental and management variables. The final model based on climatic/environmental and management variables included the following factors: rainfall, elevation, proportion of grazed grass in the diet, contact with other herds, herd size, parasite control use and education level as significant predictors. Geostatistical kriging was applied to generate a risk map for the presence of parasites in dairy herds in Mexico. In conclusion, the spatial distribution of F. hepatica in Mexican cattle herds is influenced by multifactorial effects and should be considered in developing regionally adapted control measures.
A detailed, quantitative, multitemporal analysis of historical maps, aerial photos, and satellite images was performed to investigate the channel planform changes that occurred along the Scrivia River floodplain from 1878 to 2016. Various channel planform features, including channel length, area, width, braiding, sinuosity, lateral migration, activity, and stability, were computed through an innovative geographic information system–based procedure, starting from manually digitized active-channel polygons. Three active-channel morphological evolution stages are evident from: (1) 1878 to the 1950s; (2) the 1950s to the end of 1990s; and (3) the end of 1990s onward. In the first period, the river was generally able to migrate in its floodplain, shaping the riverscape. Active-channel narrowing and increasing channel stability characterize the second period. The most recent phase shows an inversion of the morphological evolutionary trend. This last phase is characterized by a slight generalized widening related to the reactivation of stabilized surfaces and to bank-erosion processes. Particularly from the 1950s to the 1990s, in-channel sediment mining and channelization with consequent occupation of riverine areas strongly affected the Scrivia River. These factors, together with floods, are thought to be the most likely causes of such consistent and fast morphological changes.
The Chacoan great houses and great kivas of the U.S. Southwest are monumental, both in their scale and in conveying meaning. Visibility is key to understanding how and by whom that meaning was experienced. Although often discussed in Chaco studies, visibility has been infrequently tested. Here, the authors consider 430 great house and great kiva locations, and evaluate their visibility within their local landscapes. Using a total viewshed approach, they provide new evidence to suggest that great houses, but not great kivas, were often placed to be highly visible to individuals in the surrounding landscape. These patterns may speak to the social and physical properties of the structures.
Palaeogeography is the representation of the past surface of the Earth. It provides the spatial context for investigating how the Earth evolves through time, how complex processes interact and the juxtaposition of spatial information. In hydrocarbon exploration, palaeogeographies have been used to map and investigate the juxtaposition, distribution and quality of play elements (source, reservoir, seal and trap), as boundary conditions for source-to-sink analysis, climate modelling and lithofacies retrodiction, but most commonly as the backdrop for presentations and montages. This paper demonstrates how palaeogeography has been and can be used within an exploration workflow to help mitigate exploration risk. A comprehensive workflow for building palaeogeographies is described which is designed to provide a standard approach that can be applied to a range of tasks in exploration and academia. This is drawn from an analysis of the history of palaeogeography and how it has been applied to exploration in the past and why. Map applications, resolution and content depend on where in the exploration and production (E&P) cycle the map is used. This is illustrated here through three case studies, from the strategic decisions of global new ventures exploration to the more detailed basin and petroleum analyses of regional asset teams evaluating basins and plays. Through this, the paper also addresses three commonly asked questions: (1) How can I use palaeogeography in my workflow? (2) How reliable are the maps? (3) How do I build a palaeogeography?
Mapping at a scale of 1:5000 identified 395 rock glaciers in the Uinta Mountains, Utah. The majority of these have areas<20 ha, although the largest covers 97 ha. Rock glaciers have a mean elevation of 3285 m above sea level (range of 2820 to 3744 m above sea level) and exhibit a preference for northerly aspects. Sixty (15%) have a tongue-shaped morphology, whereas 335 (85%) are lobate features protruding from talus along valley walls. Tongue-shaped rock glaciers are found at significantly higher elevations and receive considerably less direct solar radiation each year than lobate rock glaciers. Winter ground temperatures atop representative rock glaciers drop to between −3°C and −5°C. This result, combined with ~0°C water discharging in the summer and water ages >1 year, suggests that at least some of these landforms contain buried ice. Late summer water discharge from two rock glaciers exhibits higher pH and significantly elevated concentrations of some ions compared with lake water, consistent with ablation of internal ice after melting of winter snowpack is complete. Although the amount of water discharging from individual rock glaciers may be small, the aggregate discharge from all rock glaciers and talus could constitute a significant component of streamflow in late summer and fall.
National protected areas (NPAs) often exhibit biodiversity representation bias, do not adequately protect priority conservation areas (PCAs), and fail to meet conservation goals. Protected area (PA) discourse assumes private PAs (PPAs) are more systematically established than NPAs. The Chilean conservation community has proposed an integrated national–private PA network (IPAN) so PPA benefits can remedy NPA shortcomings. However, there has been no recent assessment of Chilean PPA ecoregion representation or data to support the usefulness of spending valuable resources creating an IPAN. Using the most recent Chilean private and national PA data, this study conducted a terrestrial ecoregion gap analysis under two scenarios. Scenario 1 assessed NPAs and nature sanctuaries. Scenario 2 assessed the IPAN. Both scenarios showed representation bias and failure to adequately protect PCAs or meet conservation goals. The IPAN fell short of expectations because PPAs exhibited bias similar to NPAs. The findings refute PA discourse by upending traditional beliefs regarding PPA effectiveness, and they identify a need to more critically assess the benefits of PPAs and IPANs on a country-by-country basis.
Archaeologists have long examined how the emergence of core polities prompts changes in the settlement patterns of peripheral regions through various processes like warfare, patronage claims, control of ritual rites, and unequal balances of trade. According to historical records, there were 54 small Mahan polities in southwestern Korea, and one of these polities, Baekje, grew to become an ancient state by unifying other polities in the 4th century AD. It is assumed that subsequent changes in the settlement patterns of southwestern Korea were caused directly or indirectly by the expansion of Baekje, but the nature of this presumed influence is not fully explained due to difficulties in establishing chronologies and the limited application of spatial analyses. In this paper, radiocarbon (14C) dates, kernel density estimates, and spatial autocorrelation analyses are used to compare Mahan settlement distributions before and after the rise of the Baekje kingdom. The results demonstrate that the spatial distribution of Mahan settlements changed over time, correlating with the emergence of Baekje statehood, but detailed aspects of the settlement patterns observed in each region were not uniform. Baekje applied various expansion strategies and exerted asymmetrical hegemony based on the conditions and responses of peripheral communities.
We performed a spatial-temporal analysis to assess household risk factors for Ebola virus disease (Ebola) in a remote, severely-affected village. We defined a household as a family's shared living space and a case-household as a household with at least one resident who became a suspect, probable, or confirmed Ebola case from 1 August 2014 to 10 October 2014. We used Geographic Information System (GIS) software to calculate inter-household distances, performed space-time cluster analyses, and developed Generalized Estimating Equations (GEE). Village X consisted of 64 households; 42% of households became case-households over the observation period. Two significant space-time clusters occurred among households in the village; temporal effects outweighed spatial effects. GEE demonstrated that the odds of becoming a case-household increased by 4·0% for each additional person per household (P < 0·02) and 2·6% per day (P < 0·07). An increasing number of persons per household, and to a lesser extent, the passage of time after onset of the outbreak were risk factors for household Ebola acquisition, emphasizing the importance of prompt public health interventions that prioritize the most populated households. Using GIS with GEE can reveal complex spatial-temporal risk factors, which can inform prioritization of response activities in future outbreaks.
The Classic Maya village of Joya de Cerén is extraordinary in that it was preserved by volcanic ash following the Loma Caldera volcanic eruption. The excellent preservation conditions offer a unique opportunity to understand plants in their primary use contexts, and to examine geospatial relationships between plants—both living and curated—in gardens, fields and households. The geospatial analysis of ‘plantscapes’ at Cerén presented here provides a template for interpreting botanical resource use and management at other contemporaneous Maya sites, and can contribute to a broader understanding of the use of space, plants and agriculture in the past.