Neanderthal use of plants and past vegetation reconstruction at the Middle Paleolithic site of Abrigo de la Quebrada (Chelva,Valencia, Spain)

Despite phytoliths having been used to understand past human use of plants and palaeoenvironment in Middle Paleolithic sites, little is known on this aspect in the well-documented central region of Mediterranean Iberia. This paper presents the first phytolith and mineralogical study conducted at Abrigo de la Quebrada (Chelva, Valencia). Forty-one samples were analyzed through phytoliths and Fourier transform infrared spectroscopy (FTIR) from different areas, stratigraphic levels, and archeological contexts (hearth, hearth-related, and non-hearth-related sediments) of the shelter. The results obtained point towards a different pattern of preservation in the site depending firstly on the stratigraphy and secondly on the area where the samples were collected. Postdepositional processes that may have chemically affected phytolith preservation are discussed. Grasses are the main plant component identified in all the samples while woody plants are scarce. The abundance of grasses in the non-hearth-related sediments might be related, at least partially, to the dispersion of ashes from hearths, as indicated by the FTIR results. The results are indicative of an occupation of the site during the spring-autumn season. At this time, the area would be dominated by a semi-open environment with supramediterranean vegetation.     

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.     

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.     

Sweet potato (Ipomoea batatas) and banana (Musa sp.) microfossils in deposits from the Kona Field System,Island of Hawaii

Analysis of plant microfossils (pollen, phytoliths, starch grains and xylem cells) was carried out on 12 soil samples from a variety of pre-contact archaeological features in South Kona within a portion of what has been termed the Kona Field System, on the Island of Hawaii. The oldest radiocarbon ages of the sampled deposits are 1300–1625 AD and 1310–1470 AD. The pollen and phytolith evidence suggests a change from more to less trees and shrubs in the area as a result of human activity. We found phytoliths of banana (Musa sp.) leaves in most and starch grains and xylem cells of tuberous roots of c.f. sweet potato (Ipomoea batatas) in all of the samples, suggesting that the sampled features were associated with these crops and that both crops were cultivated intensively within the study area. Higher concentrations (volumetric) of starch and xylem in samples from older deposits suggest that cultivation was more intensive then. The apparent absence of starch and xylem remains of other tuberous crops archaeologically identified elsewhere in Polynesia suggests that tuberous cropping within the study area was mono-specific.     

Rapid phytolith extraction for analysis of phytolith concentrations and assemblages during an excavation: an application at Tell es-Safi/Gath,Israel

A rapid phytolith extraction procedure is described, that allows phytolith concentrations and morphotype assemblages to be analyzed within hours. This procedure enables the results of these analyses to be used during an archaeological excavation, in order to better understand how plants were used. The new procedure was tested using a standard phytolith extract and two experimental phytolith-sediment blends and found to be both accurate and precise. The reliability of partial slide counting was evaluated and found to be as accurate and precise as existing phytolith quantification methods. The new extraction and counting procedures were applied to an archaeological site, Tell es-Safi/Gath, Israel. The results demonstrate how information on phytolith concentrations in sediments that are available from one day to the next, can be used during an excavation to more effectively document the local features of interest and obtain better information.     

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.     

The potential of paleoethnobotanical evidence for the study of Teotihuacan foodways

Macro- and microscopic plant remains recovered from excavations at Teotihuacan over several decades contribute to an understanding of the subsistence resources available to the city’s inhabitants. However, associated contextual evidence may be inconclusive regarding the specific uses of the plants in question and, particularly, whether their presence or relative abundance indicates processing and consumption or the consequence of depositional processes. While the analysis of archeological plant remains is necessarily an interdisciplinary endeavor, involving aspects of botany, ecology, ethnography and history among other disciplines, contextual archeological evidence provides the matrix for interpretation. In this paper, we explore direct archeological evidence for plant use, considering the significance of appropriate contextual evidence (e.g., activity areas, associated ceramics, lithics, etc.) and the potential complementary role of analytical techniques such as residue analyses, and carbon isotope signatures in faunal and human osteological remains as well as stratigraphic sediments.     

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.     

Microarchaeology of a collective burial: cova des Pas (Minorca)

FTIR and phytolith analyses have been used to understand the exceptional preservation of the organic remains at the burial cave of Cova des Pas (Minorca), and to obtain high-resolution data of the plant remains present in the sediments. The presence of sodium nitrate and gypsum suggests a relatively dry environment that has enabled the preservation of the organic material, and contributed to the natural mummification. The dry conditions also favored phytolith preservation. Grass inflorescence phytoliths are abundant all over the site suggesting that phytolith accumulations might have an anthropogenic origin and are related to the burial ritual.     

The status of phytolith analysis in the American tropics

Phytolith analysis is now sufficiently mature to provide an independent source of data in tropical paleoethnobotany and paleoecology. At the same time, ongoing studies of phytoliths from tropical plants and sediments are discovering new applications. There are, to be sure, problems in interpreting prehistoric plant use and paleoecology which cannot be addressed through phytolith analysis; some of the more important ones are listed. Through a review of recent studies in the New World tropics, this paper presents some contributions to, problems of, and prospects for phytolith analysis to inform the archaeological community about such issues as (1) the origins and dispersals of domesticated plants, (2) the development of tropical forest agriculture, (3) the uses of tropical plants in prehistory, and (4) the distribution and composition of past plant communities.     

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.     

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.     

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.     

Poaceae phytoliths from the Niassa Rift,Mozambique

The most common grass phytoliths from “Zambezian” miombos are described here for the first time. Their potential for long term preservation in sediments makes them a useful tool in the reconstruction of ancient plant communities and plant/human interactions. We processed 60 plant samples (26 identified genera and species), with an average of 300 phytoliths counted per sample to a total of 18,586. Forty-seven morphotypes were described as per the International Code for Phytolith Nomenclature, with exceptions, including forty-five discreet shapes and two articulated forms, which can be used as comparative reference materials. We conducted three forms of statistical analyses: Discriminant Analysis, Cluster Analysis, and Principal Component Analysis. The highest biomineral content was recorded among the Bambuseae and Paniceae, while the lowest silica production is detected in the Cynodonteae tribe. Typologically, the subfamily Panicoideae yielded 50% of the types reported here, 32% are from the Chloridoideae, 12% from the Bambusoideae, and 8% from the Arundinoideae sensu lato. Overall, the idealized Zambezian Poaceae phytolith spectrum is dominated by a small subset of Poaceae short cells, which include five morphotypes conventionally associated with Panicoid grasses (Bilobate concave outer margin long shaft, Bilobate concave outer margin short shaft, Bilobate convex outer margin long shaft, Bilobate convex outer margin short shaft, Cross), one morphotype commonly seen in Chloridoid taxa (saddle), and two types that appear across subfamily boundaries (tower, tower horned). The next logical step to take in regional phytolith research is the account of phytoliths deposited in soils underneath living plants, for they represent the interface between existing vegetation communities and the inevitably distorted fossil assemblages that the paleobotanist uses for environmental reconstruction.     

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.     

Identifying past agricultural activity through soil phytolith analysis: a case study from the Hawaiian islands

Soil samples from documented archaeological sites and adjacent fields were analyzed for phytolith assemblage in an effort to identify and reconstruct prehistoric and early historic agricultural systems on the Island of Hawaii. The removal of indigenous tree and shrub vegetation, subsequent agricultural activity, and eventual abandonment of the fields can be identified in the areas tested. The applicability of phytolith analysis to archaeological problems is advanced and areas of strength and weakness identified.     

Ethnoarchaeological study of phytolith assemblages from an agro-pastoral village in Northern Greece (Sarakini): development and application of a Phytolith Difference Index

Phytolith assemblages are analysed in an ethnographic agro-pastoral community in Northern Greece. A new method for analyzing the data, combined with the concentrations of phytoliths per gram sediment, helps to differentiate diverse uses of space in the village. The Phytolith Difference Index (PDI) contrasts the phytolith assemblages in sediment samples from the region around the village least affected by human activities with those in the village and its immediate surroundings. The PDI reveals that many of the samples are dominated by the input of the stalks of the domestic cereal, rye, which is used for food, animal fodder and roof thatching. The PDI also differentiates between dung from mules or donkeys with dung from free ranging cows and goats. Activity areas analysed include storage areas, stabling areas, animal enclosures, floors from living areas that were repeatedly swept, hearths and open areas between structures. The combined use of the PDI, together with phytolith concentrations and phytolith morphotype analyses, may prove to be useful for deciphering activity areas in archaeological sites of not only agro-pastoralists, but also pastoralists and hunter–gatherers.     

Husbandry practices and livestock dung at the Numidian site of Althiburos (el Médéina,Kef Governorate,northern Tunisia): the phytolith and spherulite evidence

Recent excavations at Althiburos, northern Tunisia, have shown the existence of permanent pre-roman occupations in the central area of the urban settlement. Significantly, the site has been found to contain one of the most complete Numidian sequences, spanning from the Early Numidian (at least from the 10th–9th century BC) to its final stage. Research at the site addresses questions related to the identification of settlement patterns at this time.The combined study of phytoliths and spherulites recovered from well defined archeological contexts at the site have provided new data for identifying husbandry activities carried out by the ancient Numidian populations. The results show that there is abundant evidence for both cooking and processing cereals, primarily from common or bread wheat (Triticum aestivum). Also significantly, was the abundance of faecal spherulites in certain areas of the site, indicative of dung accumulation. The correlation between large amounts of spherulites and rich phytolith sediments in specific contexts, suggested that grasses were brought to the site or consumed offsite and deposited onsite as livestock dung or dung-products. The identification of dung accumulations in the site raises questions about the diversity of economic practices developed by Protohistoric communities in northern Africa. Future research questions regarding such dung rich layers will also be examined.     

Paleoenvironment and plant cultivation on terraces at La Quemada,Zacatecas, Mexico: the pollen,phytolith and diatom evidence

This paper reports the results of pollen, phytolith and diatom analyses conducted on a series of soil samples collected from a large, possibly communal, system of terraces associated with La Quemada in the Malpaso Valley, Zacatecas, Mexico. These analyses rendered data related to both paleoenvironmental and plant cultivation in the area. Preliminary pollen analyses of soil sediments suggest Agave sp. and Opuntia spp. cultivation played an important role on the terraces. The phytolith analyses recovered abundant, well preserved grass phytoliths, including Zea mays. The composition of the grass community suggests that paleoenvironmental conditions in this area were warm and dry, similar to those of today. The presence of three fresh water diatom taxa and sponge spicules in several archaeological soil samples suggests the possibility that water was carried to the terraces for irrigation from the nearby Rio Malpaso on a regular basis.