江苏泗洪韩井遗址水稻驯化的植硅体证据及相关问题

韩井遗址顺山集文化一期由洼地和水沟组成的水稻田,很可能是目前发现的最早与人类驯化水稻相关的遗迹,植硅体分析也在一定程度上对这一论断给予支持。从顺山集文化一期到二期,韩井遗址均以水稻双峰型植硅体居多,而且其百分比和浓度(均值)均呈现增多的态势;水稻扇型和横排哑铃型植硅体表现出相反的规律。与同时期顺山集遗址相比,韩井遗址的水稻扇型植硅体尺寸偏小。水稻扇型植硅体鱼鳞状纹饰个数和水稻双峰型植硅体形态测量用于水稻驯化程度的判定上,表现出非协同性。陶胎中掺入破碎稻壳是韩井遗址水稻栽培与驯化实践的又一反映。     

Locally diagnostic phytoliths of wild rice (Zizania palustris L.) from Minnesota,USA: comparison to other wetland grasses and usefulness for archaeobotany and paleoecological reconstructions

Wild rice (Zizania spp.) is an important native grain of north-central North America, with spiritual and subsistence significance to many native peoples. Due to lack of suitable proxies, its past distribution and pattern of use are poorly known. This study demonstrates the diagnostic value of silica phytoliths from Z. palustris as a proxy tool to detect its past occurrence in a variety of paleoenvironmental and archaeological contexts. Our main findings are: 1) Dominant wetland grass species in Minnesota produce phytoliths distinct from Zizania phytoliths; 2) Closely related Leersia oryzoides produces a few Zizania-like phytolith morphotypes; however, these potential confusers can be identified based on 2-D and 3-D morphologies; 3) Z. palustris produces a wide variety of phytolith morphotypes, many of which are only found in certain parts of the plant (e.g., Inflorescence Type 1 from the spikelet); 4) Z. palustris produces 23 locally diagnostic phytolith morphotypes that can be used to determine the presence and abundance of wild rice in modern and paleo lake sediments; and 5) Wild rice phytolith Inflorescence Type 1 is the morphotype most likely to be observed in archaeological contexts, and may be unequivocally diagnostic for the genera Zizania.     

Phytolith assaying using a micron-scale electrokinetic sorting ring

A particularly useful indicator of past vegetation are phytoliths, glassy products of plant metabolism which have distinctive size and morphology based on the plant taxa which produced them; however, their analysis is a time-consuming task. Building on investigations into mobilizing and sorting of synthetic polystyrene microspheres using a closed loop rectangular microelectromechanical systems (MEMS) electrokinetic array, we investigate these devices’ utility for sorting natural microparticles. Using phytolith samples extracted from archaeological sediment, we show that closed loop MEMS can separate the glassy bodies from both mineral contaminants and each other. Also, small differences in polarization between the phytoliths cause lateral segregation between particles of different sizes and shapes. This process facilitates manual analysis by providing a motive force to the phytoliths that translates and rotates them, showing different configurations as they are propelled by the MEMS array. The organization of the phytoliths into streams also opens the door to automated analysis using image processing. Phytolith assaying is therefore feasible using a MEMS electrokinetic ring and merits additional research to explore the potential of this innovative approach.     

The phytolith archaeological record: strengths and weaknesses evaluated based on a quantitative modern reference collection from Greece

The phytolith record from archaeological strata is a powerful tool for reconstructing aspects of past human behaviour and ecology. Considerable insights into the problems and potentials of this record can be obtained by studying phytoliths in modern plants. We prepared a phytolith reference collection of modern plants mostly from northern Greece that includes quantitative information on phytolith concentrations (number of phytoliths per gram dry organic material) and morphological assemblages. Here we analyse this reference collection with the aim of evaluating the strengths and weaknesses of the archaeological phytolith record. The reference collection comprises 62 different plant taxa. Of them, 28 are trees, 1 conifer, 10 shrubs and 1 herb, 3 domesticated annual legumes and 19 monocotyledons. We demonstrate quantitatively the extent to which woody species, legumes and fruits of dicots contribute only small amounts of phytoliths to the sediments per unit tissue dry weight, while leaves of trees and shrubs produce significant amounts of phytoliths and grasses are prolific phytolith producers. We compare the data of this reference collection with a similar reference collection from another Mediterranean ecosystem (Israel). The comparison indicates that some aspects of phytolith production are probably genetically controlled, whereas others are environmentally controlled. We note that despite the fact that woody species produce few phytoliths per gram of tissue, their record can be most informative when taking into account other properties of the sediments. We also note that jigsaw puzzle-shaped phytoliths normally form in plants that grow in humid conditions, but may form in arid environments when the plants are irrigated. This study clearly shows the extent to which some plants can be under-represented and others over-represented in the phytolith record. Knowing the extent of this bias can greatly improve our interpretation of the phytolith record.     

TAPHONOMIC OBSERVATIONS OF ARCHAEOLOGICAL WHEAT PHYTOLITHS FROM NEOLITHIC ÇATALHÖYÜK,TURKEY, AND THE USE OF CONJOINED PHYTOLITH SIZE AS AN INDICATOR OF WATER AVAILABILITY*

An investigation of wheat husk phytoliths from a midden deposit at Neolithic Çatalhöyük provided the opportunity to investigate the impact of taphonomic processes on conjoined phytolith size. Wheat husk phytoliths from a possible crop processing deposit were examined using three methods. The results indicate that the size of conjoined forms decreases significantly as a result of laboratory extraction and slide preparation. Observations of the phytolith layer in thin section show some of the depositional and post‐depositional processes affecting phytolith size. These results indicate that these taphonomic factors need further investigation before conjoined phytolith size can be used to infer past water availability and agricultural practices.     

Stability of phytoliths in the archaeological record: a dissolution study of modern and fossil phytoliths

Opaline phytoliths are important microfossils used in archaeological and ecological research. Relatively little is known about the stability of phytoliths after burial. Under alkaline pH conditions they can dissolve, and mechanical disturbances can cause a loss of their more delicate appendages. Here we present an experimental study of phytolith stability (combination of solubility and abrasion). Modern and fossil phytoliths were extracted from wheat using new methods to minimize dissolution, and by burning in an oven. These assemblages were placed in a solution buffered to pH 10 and maintained under constant temperature and shaking conditions. The silicon concentrations in the solution were monitored once a week for 5 weeks. The phytolith morphologies in each assemblage were determined at the outset of the experiment and after 5 weeks. The results show that there are differences in stability between various assemblages. Modern inflorescence wheat phytolith assemblages are more unstable than those from leaves/stems. Burnt assemblages are less stable than unburnt assemblages, and a fossil phytolith assemblage about 3000 years old is more stable than the modern wheat assemblages. The results also show that individual phytolith morphotypes have different stabilities, and as a result of dissolution and abrasion, some morphotypes may resemble others. This study further shows that archaeological and/or paleo-environmental interpretation of phytolith assemblages may change with the assemblage’s state of preservation.     

A Comparative Analysis of Wet and Dry Ashing Techniques for the Extraction of Phytoliths from Plant Material

Two methods are commonly used for the extraction of phytoliths from plant material to be used as reference in the analysis of archaeological phytolith samples: (1) spodograms or dry ashings; and (2) acid digestions or wet ashing. It has been suggested that these techniques may modify the resultant samples in different ways. Dry ashing, in particular, has been implicated as a cause of shrinkage and warping in phytolith assemblages when incineration occurs at ≥450°C. The results of a morphometric comparative analysis between the dry ashing and wet ashing methods do not support these claims. This study establishes that differences in patterns of dimension and curvature of short bilobate phytoliths and of elongate phytoliths both subjected to dry and wet ash preparation are not statistically significant. There is, therefore, no detectable evidence of morphological impact as a result of these methods. This finding implies that any differences that do occur in phytolith size and curvature are typical, possibly random permutation within assemblages, or that they are the result of variation in leaf cell structure rather than the consequence of a particular extraction procedure. This suggests that the practice of using different methods of preparation of reference samples for fossil analysis can be reliably continued.     

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.     

Human impact around settlement sites: a phytolith and mineralogical study for assessing site boundaries,phytolith preservation,and implications for spatial reconstructions using plant remains

Defining the extent of human activity around settlement sites is of particular significance in archaeology as it may define peripheral activity areas and thus the site's boundary. In Near Eastern archaeology, site boundaries are usually defined by the presence of architectural and other macroscopic archaeological remains. Here we use the phytolith concentrations and morphotype assemblages, as well as changes in the mineralogical composition of the sediments in and around the small Iron Age site of Izbet Sartah in central Israel to determine the site boundaries. The site has a shallow stratigraphy and highly bioturbated sediments. Coincidental changes in the clay/quartz ratio and phytolith concentrations define the boundary between high and low impact anthropogenic activities. This boundary is generally some 20 m away from the architectural remains. In addition, we note that the phytoliths in the site's core show clear evidence of having been affected by chemical dissolution (i.e., diagenesis), while those in the vicinity of the site's boundary have undergone severe diagenesis. These observations indicate that phytolith diagenesis will affect site boundaries determination, as well as phytolith-based reconstructions of activity areas. We propose that phytolith preservation depends on the initial amount of available silica, the depth of burial with respect to the active root area of modern vegetation, and the presence of fresh phytoliths in the soil.     

Use of space in a Neolithic village in Greece (Makri): phytolith analysis and comparison of phytolith assemblages from an ethnographic setting in the same area

Phytolith analyses were conducted in a Pottery Neolithic village (Makri) of Northern Greece in order to reconstruct aspects of past human activities as a function of both space and time. The analyses of phytolith assemblages were based on a reference collection of modern plant phytoliths (Tsartsidou et al., 2007), as well as an ethnographic study in an agropastoral community (Sarakini) in the same area that showed that many phytolith assemblages are characteristic of the activities carried out in different locations within and around the village (Tsartsidou et al., 2008). The same approach was used for studying the phytolith assemblages in the Neolithic village of Makri, namely measuring phytolith concentrations, diversities of phytolith assemblages relative to control samples collected from samples outside the village and detailed analysis of various phytolith morphotypes. At Makri samples from floors and various constructions (i.e. pit, platforms) were analysed, as well as sediments from an open area inside the village. The results show that Neolithic Makri was a society with a mixed agricultural and pastoral economy. Wheat and barley were cultivated for food and fodder and free-range animals were raised in a village inhabited year round. Indoor areas were not clearly differentiated from outdoor areas inside the village. The phytolith assemblages in only one series of floors produced at a specific location over an extended period of time reflected the use of that space for cereal storage or food processing. The phytolith assemblages from all the other floors examined did not reflect the local activities, but rather the constructional materials used for producing the floors.     

Palm reading: a pilot study to discriminate phytoliths of four Arecaceae (Palmae) taxa

A pilot study of an opal phytolith morphotype series diagnostic for palms (Arecaceae), using modern specimens of four economically important palm species (Areca catechu L., Calamus aruensis Becc., Cocos nucifera L., and Metroxylon sagu Rottb.), was undertaken to identify distinctive features of leaf phytoliths from each taxon. Our univariate and multivariate analyses documented that although it was not possible to identify individual palm phytoliths unambiguously to taxon, interspecific differences in phytolith morphology significantly outweighed intraspecific variation, revealing the potential value of further research in this area and the possible utility of assemblage-level analysis to palm phytoliths in archæological assemblages. The methods are applied to archæological phytoliths from Watom Island, East New Britain, Papua New Guinea, and directions for further research outlined.     

Rice archaeological remains and the possibility of DNA archaeology: examples from Yayoi and Heian periods of Northern Japan

Japanese rice cultivation in paddy fields has 2,400∼3,000 years of history. Most of modern Japanese rice varieties are classified as Temperate-japonica (Tm-J). Few landraces are recognized as Tropical-japonica (Tr-J) only in southwestern Japan. However, ancient DNA studies and phytolith analysis suggest that Tr-J strains were more popular in the past than now. Maekawa is a complex archaeological site composed of paddies dated from the Yayoi (2,100 years BP) to the Heian (1,100 years BP) periods. Phytolith analysis indicates that intensive rice cultivation was practiced in both periods, but there was no cultivation in the intervening period. Morphological features of bulliform phytoliths suggest that Tr-J was cultivated during both periods. Locally, rice cultivation during the Heian period was brought to a close by a flood event, in which immature rice plants were pulled down and buried in silt to be preserved in a quasi-carbonized/ waterlogged state. Ancient DNA (aDNA) analysis of the carbonized plant culm from Heian Maekawa recovered chloroplast DNA sequences of the 6C7A plastid subtype, which is common to both Tr-J and Tm-J, whereas two plastid subtypes, such as 6C7A and also 7C6A, were found in aDNA of carbonized grains from the Tareyanagi site of the Yayoi period. The latter plastid subtype was specific only to Tr-J. In order to better characterize the past rice populations, modern landraces collected in the local area were classified with morphophysiological traits. Some of the landraces were found to carry several traits of Tr-J, including bulliform phytolith types, but mixed with Tm-J traits. Based on the discontinuous distribution of rice phytoliths between the Yayoi and the Heian period, the early introduction of rice cultivation may have been discontinuous and locally reintroduced after a ∼1,000-year hiatus, but with a genetically different rice population. Such populations were composed from Tr-J like strains as shown by landraces but with reduced diversity in plastid types. Through such changes, since the Yayoi era, Tr-J was largely replaced by Tm-J, although ancient Tr-J continued to participate in the genetic makeup of later rice populations and may have aided the local adaptation of introduced Tm-J.     

Reconstructing late Holocene palaeoenvironments in Bangladesh: phytolith analysis of archaeological soils from Somapura Mahavihara site in the Paharpur area,Badalgacchi Upazila,Naogaon District,Bangladesh

Palaeoenvironmental reconstruction based on phytolith analysis of late Holocene-aged soils in and around the Somapura Mahavihara archaeological monastery site in the Paharpur area, Badalgacchi Upazila of Naogaon District in northwestern Bangladesh was undertaken. Results indicate five climate zones marked by alternatively cool and temperate events. The phytolith assemblages of Zones 1, 3 and 5 are clearly characterized by a higher proportion of Pooideae phytoliths. The climate indices for these zones are all greater than 50, indicating cooler climatic conditions. In contrast, the phytolith assemblages of Zones 2 and 4 are typified by a higher proportion of Panicoideae phytoliths; their climate indices are 42 and 44, respectively, indicating the presence of a warmer, more temperate climate. In general, the dominance of grasses over broad- leaved trees throughout the sequences suggests that generally cool to temperate and dry conditions with some cyclical variability persisted around Paharpur and the surrounding region throughout the Pala Dynasty from AD 730 to 1080. The question of whether these shifts in vegetation might be linked with El Niño Southern Oscillation events, and whether these might in turn have cultural responses, is raised.     

One,two, three phytoliths: assessing the minimum phytolith sum for archaeological studies

The number of phytolith studies has increased steadily in the last decades in palaeoecological as well as archaeological research, and phytolith analysis is currently recognised as a proper area of expertise within archaeobotany. This has led towards a strengthening in the standardisation of the different steps involved in analysis; e.g. sampling strategies, laboratory extraction or processing of plant material/soils for the creation of reference collections. In spite of this, counting procedures remain one of the areas that could be further developed. The aim of this paper is to assess representativeness of phytolith count size in archaeological samples and specifically to assess whether an increase in total number of individuals counted influences the number or distribution of morphotypes observed. Two statistical tests are performed to evaluate the representativeness of count size: phytolith sum variability analysis (PSVA) and morphotype accumulation curve (MAC). The analyses show the relationship among the number of counted phytoliths, the variability (that is, the number of different morphotypes identified) and the stabilisations of the MACs. Results allow us to support the standard count size in phytolith studies, which ranges from 250 to 300 particles. Together with a quick scan, this strategy should produce a precise and clear phytolith assemblage for archaeological studies.     

Pervasiveness of phytoliths in prehistoric southwestern diet and implications for regional and temporal trends for dental microwear

Our previous analysis of phytolith content of coprolites showed that calcium oxalate phytoliths from desert food plants caused dental microwear among prehistoric Texas hunter-gatherers. We demonstrated that phytoliths from desert succulents were ubiquitous and abundant in hunter-gatherer coprolites. We found that calcium oxalate phytoliths were harder than human dental enamel. We concluded that phytoliths from desert succulent plants caused dental microwear and hypothesized that such dental microwear would be common in other desert hunter-gatherer and horticultural peoples. Presented here are further analyses of phytoliths from coprolites. Two additional hunter-gatherer sites and three Ancestral Pueblo (Anasazi) horticultural sites are included in this study. Calcium oxalate phytoliths are ubiquitous in coprolites from hunter-gatherer sites in the Mojave Desert and the Colorado Plateau. For the three Ancestral Pueblo sites, calcium oxalate phytoliths from desert succulents (agave family and cactus family) are the most common types of phytoliths encountered. However, silica phytoliths are also present in Ancestral Pueblo coprolites. The data demonstrate that phytoliths from non-cultivated desert plants were a source of dental microwear for the pre-maize Archaic hunter-gatherer bands and maize-reliant Ancestral Pueblo villages.     

中国北方史前遗址稻作遗存的植物硅酸体判别标准

利用植物硅酸体方法鉴定考古遗址中的栽培稻遗存,关键之一就是确立鉴定标准。通过对野生稻生长的环境背景进行综合分析,提出在中国北方地区,在全新世时期,特别是仰韶时代和龙山时代,不具备野生稻生长的气候条件;在考古遗址中发现的稻属植物硅酸体可以被看成是栽培稻的遗存。     

Investigating crop processing using phytolith analysis: the example of rice and millets

The application of crop processing models to macro-botanical assemblages has traditionally been used to interpret past husbandry practices and organisation of labour involved in crop-processing. Phytoliths offer an alternative method of analysis because they are durable in most environments, regardless of whether plant parts are charred, and the identification of plant types and plant parts allows them to be used in much the same way as macro-botanical remains. Indeed macro-remains and phytoliths are complementary datasets for examining the input of plant parts, such as crop-processing waste, into archaeological deposits. We outline crop-processing models in relation to macro-remains and then develop the framework for their application to archaeological phytolith assemblages. Rice and millet processing models are explored in relation to patterns expected in both macro-remains and phytoliths. The utility of these models is demonstrated with archaeological evidence from the site of Mahagara, an early farming site in North-Central India. The results indicate a way to employ phytoliths in archaeology which complements the fragmentary evidence available from plant macroremains.     

Ethno-geochemical and Phytolith Studies of Activity Related Patterns: A Case Study from Al Ma’tan,Jordan

ABSTRACT

Understanding Neolithic sites in southwest Asia is often difficult because of the lack of preservation of organic remains and the effects of various taphonomic processes that alter the original record. Here, we use an ethnographic approach to test the potential of using plant phytoliths and geochemistry to aid our interpretation of southwest Asian Neolithic sites. Our study of a recently abandoned stone and mud constructed village in Jordan, shows that for certain activity types, phytoliths and geochemistry can help distinguish different construction methods and functions, particularly for burnt areas, animal use areas and where there has been the addition of a specific construction material. For features constructed from the same source materials distinctions are more problematic. Geochemical and phytolith proxies were individually effective in distinguishing activity areas and construction materials, but signals were diminished when the statistical analysis was run on both forms of evidence combined. It is therefore recommended that the data from plant phytolith and geochemical analyses are subject to separate statistical tests and that the two sets of results are used in combination to interpret archaeological sites and their uses.     

Diet,Geography and Drinking Water in Polynesia: Microfossil Research from Archaeological Human Dental Calculus,Rapa Nui (Easter Island)

Microfossil analysis of human dental calculus provides consumption‐specific and archaeologically relevant data for evaluating diet and subsistence in past populations. Calculus was extracted from 114 teeth representing 104 unique individuals from a late 16^th to early 18^th century skeletal series on Rapa Nui (Easter Island) to address questions of human–environment interactions and possible dietary preference. Scanning electron microscopy was used in lieu of optical microscopy for its superior depth of field and resolution of surface detail. The calculus microfossil recovery produced 16,377 total biogenic silica microfossils: 4733 phytoliths and 11,644 diatoms. The majority of phytoliths correspond with the Arecaceae or palm family (n = 4,456) and the minority corresponds to the Poaceae or grass family (n = 277). Because of the relatively large sample size, we were able to test hypotheses related to age cohort, sex, dental element and geographic region. Results indicate no significant difference in phytolith or diatom recovery based on age cohort or sex. The high frequency and proportion of Arecaceae phytoliths found in calculus extracted from the anterior dentition suggests consumption of soft or cooked foods containing palm phytoliths and the high frequency of diatoms recovered from the southern part of the island argue for different sources of drinking water. Copyright © 2012 John Wiley & Sons, Ltd.     

Wild and domesticated forms of rice (Oryza sp.) in early agriculture at Qingpu, lower Yangtze, China: evidence from phytoliths

Rice cultivation in parts of the Yangtze valley, eastern China, is thought to date to at least the early Holocene. Using phytolith analysis, sediments from an exposed profile at Qingpu in the lower Yangtze were examined in detail in order to contribute to the growing body of information relating to the history of rice agriculture in the Yangtze delta area. The presence of phytoliths from domesticated rice, Oryza sativa, indicates that rice agriculture was well developed at Qingpu by ca. 2350 BP and may have increased in intensity from ca. 2100 BP. Rice cultivation at Qingpu was comparatively late in relation to other areas in the Yangtze valley, possibly due to the seasonal intrusion of saline waters, while the cultivation of wild rice remained a prominent feature of food production in the area to at least as late as ca. 1800 BP. Results presented here support the existence of a period of overlap, during which both wild and domesticated forms of rice were cultivated, rather than a linear transition from wild to domesticated rice cultivation and the possible influence of environmental factors over farming in an area subjected to frequent flooding.