Tesis: "Phytoliths"

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Hart, Thomas Chesley. "A stroll through the park evaluating the usefulness of phytolith and starch remains found on medieval sherds from Wicken, Northamptonshire, England /". Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5058.

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Thesis (M.A.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on January 3, 2008) Includes bibliographical references.

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2

Tubb, Helen J. "Anatomical, developmental and physiological aspects of silica in wheat". Thesis, Oxford Brookes University, 1995. https://radar.brookes.ac.uk/radar/items/197165a2-c303-4a80-a9d2-93b8954f4e92/1.

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The major aims of this thesis were to study silica deposits in cereal inflorescences and wheat roots and investigate soluble/deposited silica partitioning and uptake of silica by wheat. The morphology of a particular phytolith (the papilla) from inflorescence bracts of 70 species from Triticum (wheat). Hordeum, Aegilops families and Secale cereale was analyzed. Using papilla pit number and/or diameter it is possible to distinguish between Hordeum sp. and Triticum sp., and between wheats of different ploidy levels. The root growth of T. aestivum was reduced by silica in the nutrient solution (Si+) during the first six days of growth, compared to plants grown in solution not supplemented by silica (Si-), After a further four days Si+ plants had significantly longer roots than Si- plants. At the light microscope level, a time course for silicification of the inner tangential wall of the root endodermis of T. aestivum was elucidated over ten days. Very few walls were silicified after 24 hours exposure to Si+ solution, but by day 10 up to 80% of endodermal cells in the basal area of the root were silicified. The percentage of silicified cells increased from the apex to the base of the root. Silica in T. aestivum was measured quantitatively using a molybdate blue detection method. Typically, 99% of the total silica in the seedlings was in the deposited form. The average concentration of soluble silica within the xylem exudate was 3.6 mM. The uptake of silica was affected by the silica concentration and pH of the nutrient solution. By measuring transpirational water loss and the silica content of the plants, it was concluded that silica uptake was active in T. aestivum. Uptake mechanisms were investigated by growing seedlings in nutrient solutions containing 2 mM Si and an inhibitor for 24 hours. The inhibitors used were ATPase inhibitors ( sodium orthovanadate, diethylstilbestrol, erythrosin B) and ionophores (nigericin, FCCP). The data suggests that functional ATPases and a proton gradient are required for silica uptake. Transport into the xylem and uptake at the root surface may be differentially affected by the inhibitors.

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3

Blinnikov, Mikhail S. "Late-Pleistocene history of the Columbia Basin grassland based on phytolith records in loess /". view abstract or download file of text, 1999. http://wwwlib.umi.com/cr/uoregon/fullcit?p9948017.

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Thesis (Ph. D.)--University of Oregon, 1999.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 202-211). Also available for download from the Internet; free to University of Oregon users. Address: http://wwwlib.umi.com/cr/uoregon/fullcit?p9948017.

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4

Duncan, Neil Andrew. "At the edge of the Puna : archaeological test excavation and sampling for phytolith signatures of ancient corrals at Antibal, Peru /". free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p1418014.

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5

Gallaher, Kirsten S. L. "Reconstruction of late Holocene vegetation and climate of Hluhluwe Mfolozi area using phytoliths". Bachelor's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/26585.

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This study presents a phytolith record from a late Holocene sedimentary core from the Hluhluwe-iMfolozi area in northeastern KwaZulu-Natal. Radiocarbon dating showed the oldest sediments to be from 23 80 ± 40 BP. Phytoliths are present throughout the record. There was a high degree of unclassifiable phytoliths (>79% per sub-sample), but preliminary trends identified include a dominance of C₄ grasses throughout (Chloridoideae and Panicoideae; adapted to higher temperatures and greater insolation), and slightly more C₃ grasses (Pooideae; adapted to cooler temperatures and/or winter rainfall) towards the base. The tree cover density index (D/P) does not reflect increased bush encroachment at this site, but appears to show a closed forest at 36cm depth and relatively densely-wooded savannas throughout, while the humidity-aridity index (lph) and water stress index (Fs) suggest a move towards a xerophytic short grass savanna, and increased water stress at the top of the sequence, which could reflect the climate becoming hotter and drier due to global warming. Future studies should be done to identify phytoliths specific to the vegetation of the study site and to calibrate the indices used to confirm their utility for this area.

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6

Pomerantz, Solomon. "The prehistory of Madagascar : microbotanical and archaeological evidence from coastal and highland sites". Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:a0f536e8-9f1f-451b-b02d-cc9365ed3aba.

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Despite nearly one hundred years of archaeological and palaeoecological research in Madagascar, the human colonisation of the island remains poorly understood. Long- standing narratives of this colonisation described the arrival of Austronesian- speaking peoples by AD 400, eventually reaching the Central Highlands by the 12th century. The recent discovery of microlithic tools at the rockshelter of Lakaton'i Anja has radically disrupted conventional narratives for this colonisation by more than doubling the known period of Madagascar's human history, and questioning the presumed Austronesian origins of these first Malagasy peoples. This discovery also challenges existing models for the late Holocene extinction of the island's megafauna. This thesis constitutes the first systematic review in the last thirty years of literature relating to the colonisation of the island, as well as the first to approach this multidisciplinary material in light of new archaeological evidence from Lakaton'i Anja. This study also represents the first comprehensive and comparative phytolith analysis conducted on Madagascar. Despite the wide application of phytolith analysis across regional archaeological and palaeoecological contexts, it has never before been applied here. This thesis explores the botanical impact of these early colonists in and around sites of occupation, as well as tracing the introduction of Asian rice (Oryza sativa) and domesticated bananas (Musa acuminata). New methods of phytolith analysis were developed, adapted, and applied to sediments collected from two seasons of excavations in 2012 and 2013. The sites of Lakaton'i Anja, Mahilaka, and Ankadivory D'Ralambo were re-excavated, as well as the new site of Ampasimahavelona, near Vohémar. This thesis presents and discusses these excavations as well as the earliest evidence for the cultivation of both Musa acuminata and Oryza sativa on Madagascar, and an ultra-high resolution botanical perspective on the last four millennia of Madagascar's prehistory.

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7

Watling, Jennifer Georgina. "Environmental impact of the pre-Columbian geoglyph builders of Western Amazonia". Thesis, University of Exeter, 2014. http://hdl.handle.net/10871/16386.

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A debate that has received much attention in recent years is the nature and scale of pre-Columbian impact in the Amazon lowlands. While the notion that Amazonia is a “pristine wilderness" has long been debunked, several papers have proposed that human impact in western regions was more sporadic and on a smaller scale than impacts in central and eastern regions, and that western Amazonia supported sparse pre-Columbian populations. The discovery of over 400 geometrically-patterned earthworks (geoglyphs) in the western Brazilian Amazon, which until recently lay under in-tact tropical forest, has raised important questions about the kind of societies that built them and the impact that they had on the terra firme upland landscapes. This study represents the very first investigations into human-environment interactions in the geoglyph region. By analysing phytoliths, charcoal and stable carbon isotopes from a series of soil profiles in the vicinities of two well-dated and excavated geoglyph sites, this study aims to discern the nature of the environment before, during and after the construction and use of the sites, and the spatial and temporal scales of landscape transformations that were effected by the geoglyph cultures. The data call for a re-appraisal of what is meant by “scales" of human impact in Amazonia, and propose that an understanding of the diversity of human-environment interactions must be considered through studies that closely combine regionally-sensitive archaeological and palaeoecological data.

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8

Logan, Amanda Lee. "The application of phytolith and starch grain analysis to understanding formative period subsistence, ritual, and trade on the Taraco Pennisula, Highland Bolivia". Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4596.

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Thesis (M.A.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 21, 2009) Includes bibliographical references.

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9

Taylor, Sam. "Reconstructing Historical Vegetation Cover in Otago, New Zealand, Using Multi-proxy Analysis of Peat Cores". Thesis, University of Canterbury. Geological Sciences, 2010. http://hdl.handle.net/10092/4206.

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This research has examined the historical vegetation of two Eastern Otago sites below the regional treeline, with the aim of addressing questions about the distribution and spread of native tussock grasslands prior to human arrival in New Zealand c. 800 yr BP. Pollen and phytolith (plant opaline silicate) proxies have been extracted from peat cores at Swampy Summit and Clarks Junction to provide a record of vegetation spanning the Holocene. Using multiple proxies and two sample sites has allowed for comparisons of the record of vegetation from within sites and between sites. A record of the modern pollen rain was also gathered from localised moss polsters at Swampy Summit in order to reconcile modern pollen assemblages and transport patterns with historical findings. It became clear from the research that the record of vegetation inferred from phytoliths was not analogous to the pollen-based records, which supported the hypothesis that vegetation reconstructions based solely on pollen may be unreliable. Good pollen preservation in the sediments allowed for the identification of over 50 taxa, although only Chionochloid forms were identifiable to a family level in the phytolith records. Poaceae pollen was abundant throughout the Clarks Junction record, suggesting grassland had persisted at this site during the Holocene, while Poaceae pollen at Swampy Summit was minimal and sporadic. Phytoliths at Swampy Summit show grasses have persisted at the site thoughout the Holocene, at times in much greater proportions than the pollen record would suggest, while Chionochloid phytoliths only become common near the top of the record, possibly reflecting increasing dominance of this taxa after human disturbance. In contrast to Swampy Summit, the Clarks Junction phytolith record reflects a more stable presence of grasses throughout the Holocene, with Chionochloid forms present throughout. Phytoliths appear to be a more reliable proxy for local vegetation, with both sites indicating a Holocene presence of grasses below the regional treeline prior to human arrival in New Zealand. In comparison, the pollen record appears to indicate a more regional pattern of vegetation, with the grassland pollen record complicated by pollen dispersal and deposition factors.

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10

Iriarte, José. "MID-HOLOCENE EMERGENT COMPLEXITY AND LANDSCAPE TRANSFORMATION: THE SOCIAL CONSTRUCTION OF EARLY FORMATIVE COMMUNITIES IN URUGUAY, LA PLATA BASIN". UKnowledge, 2003. http://uknowledge.uky.edu/gradschool_diss/243.

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This dissertation is a multidisciplinary study combining both archaeological andpaleoecological data to examine the rise of early Formative societies in Uruguay, La Plata Basin.It is contextualized within broader anthropological concerns related to the emergence of culturalcomplexity, the significance of ritual and public architecture in intermediate-level societies, andthe role of human-environment interactions during the mid-Holocene. This investigationgenerated the first Late Quaternary paleoclimatic record, based on pollen and phytolith analyses,documenting that the mid-Holocene (ca. 6,620 to ca. 4,040 bp) was a period of environmentalflux and increased aridity. It describes the occupational history of the Los Ajos site from thecreation of a household-based community integrating a centralized communal space during thePreceramic Mound Component (ca. 4,120 – 3,000- 2,500 bp) to the Ceramic Mound Component(ca. 3,000 2,500 bp to the Contact Period), where Los Ajos acquired a strong public ritualcharacter through the formatilization and spatial segregation of its mounded architecture. Duringthe Ceramic Mound Period, the site exhibited both internal stratification (inner versus outerprecincts) and dual asymmetrical architecture in its central sector, which suggest the emergenceof incipient social differentiation. This study also marks the earliest occurrence of at least twodomesticated crops in the region: corn (Zea mays) and squash (Cucurbita spp.), showing that theearly Formative societies adopted a mixed economy shortly after 4,120 bp. Collectively, theseresults challenge the long-standing view that the La Plata Basin was a marginal area byevidencing an early and idiosyncratic emergence of social complexity never before registered inthis region of South America.

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Rocheford, MaryKathryn. "An early to middle Holocene carbon isotope and phytolith record from the Sac Valley Archaeological District, southwest Missouri". Thesis, University of Iowa, 2009. https://ir.uiowa.edu/etd/425.

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New pedologic, carbon isotope and phytolith analyses along with stratigraphic correlations to nearby archaeological sites record the spatial and temporal distribution of past vegetation patterns in the Sac Valley Archaeological District of southwest Missouri. Radiocarbon ages obtained from a soil core along Bear Creek, CB5, are related to those from Hajic et al. (1998, 2000) indicating that the CB5 location contains correlative middle Rodgers Shelter submember deposits. This relationship also indicates that sedimentation was approximately two times greater at the CB5 locality than at the Big Eddy (23CE426) archaeological site providing much higher temporal resolution for the alluvial history as well as the vegetation proxies during the early to middle Holocene. Most midcontinent climate proxy records include indications of an early Holocene warm period when prairie replaced forests, then a cooler period in which trees dominated the landscape, followed by a warmer middle Holocene period when prairie vegetation was dominant. However, the CB5 δ13C profile of mixed C3/C4 vegetation indicates either that the vegetation at this location was not as sensitive to climate change or that this location was buffered from other influences, e.g. fires, which were critical to the expansion of prairie vegetation. On the other hand, the phytolith assemblages at CB5 indicate that there were periods with abundant C4 grasses even though the δ13C values indicate a dominance of C3 vegetation. This indicates that in the mixed forest/prairie ecotone interpretations of past vegetation from either carbon isotopes or phytolith assemblages alone may not accurately reflect patterns of vegetation. A new core, DDY-KR2, was obtained from the Big Eddy (23CE426) archaeological site and a finer resolution of δ13C values at Big Eddy increased the detail about alluvial activity and revealed subtle changes in the vegetation. The vegetation types suggested by the δ13C values for DDY-KR2 are reflected in the phytolith assemblages validating their usefulness in reconstructing local vegetation history.

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Rocheford, Mary Kathryn Bettis Elmer A. "An early to middle Holocene carbon isotope and phytolith record from the Sac Valley Archaeological District, southwest Missouri". [Iowa City, Iowa] : University of Iowa, 2009. http://ir.uiowa.edu/etd/425.

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13

Webb, Elizabeth A. "Stable isotopic compositions of silica phytoliths and plant water in grasses, implications for the study of paleoclimate". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/NQ58164.pdf.

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14

Madella, Marco. "Morphological analysis of phytoliths : a botanical tool for the interpretation of archaeological and geological sediments from Eurasia". Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421361.

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15

Buffington, Abigail Francesca. "Using Phytolith Assemblages to Detect a Pastoral Landscape in Neolithic Wādī Sanā, Yemen". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1566227843382311.

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16

Pasturel, Marine. "Pour une meilleure représentation de la diversité des biomes herbacés africains dans les modèles de végétation : apports des traits physionomiques, de l’indice de surface foliaire et des phytolithes de graminées". Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4316.

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Les biomes herbacés africains intertropicaux devraient faire face, dans un proche futur, à des changements drastiques. Les modèles dynamiques de végétation (DGVM) ont des difficultés à simuler les limites actuelles de ces biomes, notamment parce qu’ils ne prennent pas en compte la diversité des couverts herbacés en C4. Il est donc nécessaire de caractériser cette diversité floristique et physionomique afin qu’elle puisse être facilement prise en compte dans les DGVMs, et que les comparaisons modèle/données (phytolithes) soient possibles.Dans cet objectif, les traits physionomiques des graminées en C4 dominantes au Sénégal et en Afrique du Sud ont été répertoriés. Quatre groupes physionomiques ont été statistiquement discriminés. Ils varient avec la distribution spatiale des biomes et les précipitations régionales. Deux groupes sont fortement corrélés à l’indice de surface foliaire (LAI) et à la biomasse herbacée. Au Sénégal ces deux groupes sont bien différenciés par l’indice phytolithique Iph qui est un proxy des couverts herbacés intertropicaux. En Afrique du Sud, les phytolithes n’ont pas permis de tracer l’ensemble de la transition savane/steppe. Ces deux groupes physionomiques remplissent les critères nécessaires à la caractérisation de types fonctionnels de plantes (PFT). L’intégration de ces PFTs dans le modèle LPJ-GUESS améliore la simulation des biomes herbacés actuels et permet de proposer des simulations pour l’horizon 2100. Ces simulations montrent que l’augmentation de la durée de la saison sèche et de la concentration en CO2 atmosphérique devraient favoriser l’expansion simultanée des steppes et des savanes fermées aux dépens des savanes ouvertes
Intertropical african herbaceous biomes are expected to face drastic changes in a near future. However Dynamic Global Vegetation Models (DGVMs) simulate their modern boundaries with poor accuracy, especially at the regional scale. DGVMs fail to consider the diversity of their C4 grass cover. Efforts are thus needed to characterize this floristic and physiognomic diversity in a way that can be used for enhancing DGVMs simulations, and enabling model/data (phytoliths) comparisons. For that purpose, physiognomic traits of dominant C4 grass species settled in Senegal and South Africa were listed. Four grass physiognomic groups were statistically identified. The abundance of four of them significantly varied with biome distributions and regional precipitation. Two grass physiognomic groups were additionally strongly correlated with leaf area index (LAI) and grass biomass. In Senegal, those two groups were also well traced by the Iph phytolith index which is a tropical grass cover proxy. In South Africa the limited set of phytolith data did not allow to observe the full savanna/steppe transition. The two physiognomic groups finally fulfilled the criteria required for creating Plant Functional Types (PFTs). Those new PFTs, parameterized in the LPJ-GUESS DGVM, enhanced the simulation of modern herbaceous biomes distribution in Senegal and South Africa. Simulations were additionally performed for the 2100 horizon. They evidence that the increase of both length of the dry season and atmospheric CO2 concentration should favor the simultaneous spread of steppes and closed savannas at the expense of open savannas

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17

Sjöström, Jenny. "Late Holocene palaeoenvironmental reconstruction on a peat sequence from northeastern South Africa, using grass phytoliths as main proxy". Thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-91882.

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Contemporary a geographical imbalance of where palaeoclimatological studies have been undertaken exists, where the majority of palaeodata is based on studies from the northernhemisphere. Multiproxy analysis was performed on a peat core from Lydenburg, north-eastern Mpumalanga, covering the last 1.600 years. Proxy focus was put on fossil grassphytoliths. A general drying trend can be noted from AD 400 to 1000, followed by moremesic conditions around AD 1200. The increasingly mesic conditions were interrupted by asignificantly drier period between c. AD 1250 to 1350. This part of the Lydenburg sequenceoccurs in the end of a climate event termed “Medieval warm period” (MWP), suggested tohave been warmer and variable but mostly wetter in southern Africa. The results are in lineregarding the increased temperature and suggested variability. However, in contrast withearlier findings, significantly drier conditions seem to have prevailed at the Lydenburg fenat the end of “MWP” as interpreted by multiple proxies. Following AD 1400 increasinglymesic conditions was recorded as interpreted by several of the analysed proxies. Morepalaeoenvironmental studies needs to be performed in the area in order to elaborate on thedriving factors of palaeoenvironmental change in the region, as well as to establish if thesignals from the Lydenburg fen record local or regional changes. The results support earlierphytolith studies suggesting that small rondels should be excluded from phytolithassemblages in tropical and sub-tropical areas in Africa.
People, Land, and Time in Africa (PLATINA)
Bokoni project. This MA thesis is part of a transdisciplinary project involving scholars from Sweden and South Africa aiming to understand traces of pre-colonial terraces found in north-easter Mpumalanga, South Africa.

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Hilbert, Lautaro Maximilian. "Investigating plant management in the Monte Castelo (Rondônia-Brazil) and Tucumã (Pará-Brazil) shell mound using phytoliths analysis". Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/30060.

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Shell mound or sambaqui, as commonly named in Brazil, are anthropic intentional mound constructions made by complex hunter-gatherer fishing communities. Typically distributed along shorelines and inland regions of Brazil, these sites are arguably one of the earliest evidence of human presence in South America, with dates ranging from 910-660 to 10,179-9,708 cal. yr. B.P. As archaeobotanical investigations reported the presence of various plant resources in these sites, a debate that has received much attention in recent years is regarding the scale of which the shell mound builders managed these resources. The Monte Castelo (9,495-9,137 cal. yr. B.P - state of Rondônia) and the Tucumã shell mound (4,425-4245 cal. yr. B.P. - state of Pará) will be the case studies of this research. The aim of this thesis is to use phytolith data from archaeological contexts in order to evaluate and discern the extent to which these mound builders managed plant resources. The outcome of this study provides novel evidence revealing the management and consumption of wild and domesticated plants through the mid-Holocene. The data calls for an evaluation on the potential scale of horticulture practices by Amazonian shell mound builders as well as the relative contribution of each domesticated resources to the indigenous diet.

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Boyadjian, Célia Helena Cezar. "Microfósseis contidos no cálculo dentário como evidência do uso de recursos vegetais nos sambaquis de Jabuticabeira II (SC) e Moraes (SP)". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/41/41131/tde-31012008-161121/.

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A análise de microfósseis vegetais é extremamente útil para a recuperação de informações acerca da utilização de plantas por grupo humanos do passado, especialmente em sítios arqueológicos em que os macro-restos botânicos são raros, como é o caso dos sambaquis. Estes micro-restos podem ser obtidos a partir de sedimento, coprólitos, utensílios de pedra ou cerâmica, assim como de cálculo dentário (tártaro). Durante a mastigação e a utilização dos dentes como ferramentas, micro partículas provenientes do alimento ou da matéria prima utilizada, como grãos de amido, fitólitos, fibras, ficam retidas na matriz do cálculo, podendo ali permanecer protegidas por milhares de anos. O tratamento químico do cálculo permite a recuperação destes microfósseis, que, uma vez quantificados e identificados, fornecem dados valiosos para a reconstrução de hábitos e dieta. Entretanto, existem sítios em que, além da má preservação dos macro-restos vegetais, restam apenas escassas marcas de cálculo dentário aderidos aos dentes, impedindo a obtenção de fragmentos de cálculo e conseqüentemente a recuperação dos microfósseis. A utilização de recursos vegetais pelos grupos construtores de sambaquis constitui uma área do conhecimento ainda pouco explorada. Dentre os sambaquieiros há aqueles com depósitos fartos de cálculo dentário, como é o caso em Jabuticabeira II (SC), mas também há aqueles que apresentam somente reduzidos depósitos de cálculo, como é o caso em Moraes (SP). Assim, os objetivos deste trabalho foram: processar e analisar quantitativamente o conteúdo do cálculo dentário de indivíduos de Jabuticabeira II; desenvolver e testar um método alternativo que permitisse a recuperação de microfósseis a partir de marcas de cálculo dentário (.dental wash.); aplicar este método alternativo nos indivíduos de Moraes e comparar os resultados obtidos entre os dois sítios. Através dos resultados obtidos concluiu-se que: - O método .dental wash. é eficiente para a recuperação de micro partículas a partir de marcas exíguas de cálculo dentário, e seus resultados são comparáveis àqueles obtidos através da técnica tradicional. Contudo, o .dental wash. pode tornar os dentes mais friáveis, prejudicando análises morfológicas e de microdesgaste. - Foram observados grãos de amido em praticamente todas as amostras de Jabuticabeira II e Moraes, enquanto fitólitos somente foram encontrados em poucas delas. Isso indica um importante aporte de alimento amiláceo em ambos os sítios, enquanto que apenas 134 alguns indivíduos consumiam uma dieta mais diversificada, constituída em parte de vegetais ricos em fitólitos. - Grãos de amido modificados (em ambos os sítios) e fragmentos escuros de origem vegetal (somente em Jabuticabeira II) indicam o preparo de alimentos através de cocção, maceração, abrasão. - A concentração média dos grãos de amido significativamente maior nas amostras de Moraes em comparação com Jabuticabeira II sugere que o aporte amiláceo tivesse sido maior em Moraes, o que é confirmado indiretamente através da maior freqüência de cáries. -Não parece ter havido distinção no aporte vegetal da dieta entre os sexos, já que não houve diferença das concentrações de amido e fitólitos entre homens e mulheres de Jabuticabeira II e Moraes.
The analysis of vegetal microfossils is paramount for the recovery of informations about plant use in past human groups, especially in archaeological contexts where macro remains are poorly preserved (as in shellmounds or sambaquis). Micro remains can be recovered from sediments, coprolites, stone artefacts, pottery, as well as from dental calculus. During the mastication and the use of the teeth as tools, micro particles like starch grains, phytoliths and fibers, become trapped in the dental calculus matrix. Chemical processing of dental calculus permits the extraction of microfossils. Quantification and identification allows reconstruction of habits and diet of past human groups. However, there are sites in which the calculus deposits do not preserve well enough to be processed using the traditional method. The plant use by Brazilian shellmound groups is still an underexplored matter. Among these there are groups like Jabuticabeira II (SC) with large deposits of dental calculus, where the traditional method can be applied, as well as others with just faint dental calculus marks, like Moraes (SP). Therefore, the aims of this work are to: process and analyse dental calculus contents from Jabuticabeira II individuals; develop and test a new method for the recovery of microfossils form cryptic dental calculus marks (dental wash); apply the dental wash in Moraes teeth; and, finally, to compare the results between both sites. The data obtained permit the following conclusions: -The dental wash technique is efficient for the recovery of microfossils from faint dental calculus marks and the results are comparable to those obtained by the traditional method. However, dental wash can preclude morphological and microwear analyses. - Starch grains were observed in almost all samples from both sites but the phytoliths were obtained only from few of them. This indicates that the vegetal diet in these sites was based mainly in storage organs of plants where only few individuals had a more diverse food intake, consuming also vegetal parts rich in phytoliths. - Modified starch grains found in both sites and dark plant fragments (charcoal) found only in Jabuticabeira II suggest food preparation. - The significant higher concentrations of starch grains in Moraes than in Jabuticabeira II, suggests that the intake of carbohydrate rich food was higher in Moraes. Indeed, this is corroborated by a much higher caries rates in the latter site. 136 -The absence of differences of starch and phytolith concentrations between men and women suggest that there was no distinction in the plant food consumed between the sexes.

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20

Alves, Daiana Travassos. "Dark Earth plant management in the Lower Tapajos". Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/34077.

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The highly fertile Amazonian Dark Earths (ADE) results from landscape transformations found in association with archaeological sites throughout Amazonia. In the Lower Tapajos region, ADEs are found in ancient Tapajó settlements dated to the Late Pre-Columbian period (AD 1000-1600). This research focuses on plant management associated with the regional formation of ADE. Three ADE sites are analysed for microbotanical remains. Phytolith and microcharcoal (< 125μm) from test pits and excavation profiles reveal diverse plant-use including food and non-food plants. Geochemical data indicated a variety of formations processes intra-site. The inter-site comparison indicated a gradiente of vegetation change related with the formation of ADEs. Aditionally, small changes folloed the adoption of cultigens together with ADE formation. These data suggest the practice of polyculture agroforestry in the investigated sites.

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Novello, Alice. "Les phytolithes, marqueurs des environnements mio-pliocènes du Tchad. Reconstitution à partir du signal environnemental des phytolithes dans l'Afrique subsaharienne actuelle". Thesis, Poitiers, 2012. http://www.theses.fr/2012POIT2303/document.

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Ce mémoire présente l'étude du signal phytolithique de sédiments mio-pliocènes du Tchad(Afrique Centrale) datés entre 7-2 Ma, et contemporains des Homininés anciens Sahelanthropustchadensis et Australopithecus bahrelghazali. Une calibration de la relation plantes-phytolithes-solspour l'Afrique tropicale subsaharienne actuelle a d'abord été réalisée pour apprécier la signatureenvironnementale des phytolithes dans le registre fossile. L'analyse des assemblages phytolithiques de98 espèces de graminées (Poaceae) a permis d'élaborer trois nouveaux indices phytolithiques à partirde 43 types propres aux Poaceae. Testés sur une base de 57 sols/sédiments modernes du Tchad, cesindices permettent de tracer les associations graminéennes aquatiques du Lac Tchad, les associationsmésophytiques des milieux humides soudaniens, et les associations xérophytiques des milieux secssahéliens. L'analyse des assemblages phytolithiques des sols/sédiments actuels considérés dans leurensemble a permis d'évaluer le potentiel de ce proxy à caractériser la physionomie des formationssoudano-sahéliennes modernes. La calibration a été appliquée à l'étude d'un enregistrementsédimentaire discontinu du Lac Tchad (6-2 Ma) (forage de Bol, 13°N/14°E) et à celle de 18 niveauxpaléontologiques du Djourab (7-3.5 Ma) (16°N/17°E). Les résultats indiquent la présence de savanesintermédiaires à fermées et de zones de végétation aquatique dominantes à 7 Ma dans le Djourab, puisde savanes plus ouvertes et sèches à 3.5 Ma. Une phase de bas niveau lacustre est enregistrée entre3.6-2.8 Ma à Bol, et un pic d'aridité à 3.2 Ma. Enfin, les résultats montrent l'existence de graminéesen C4 au Tchad depuis 7 Ma
This thesis dissertation is dedicated to the study of the phytolith signal of Mio-Pliocenesediments from Chad (Central Africa) dated between 7-2 Ma, and contemporary to the early Homininspecies Sahelanthropus tchadensis and Australopithecus bahrelghazali. A calibration work studyingthe relationship plants-phytoliths-soils in modern sub-Saharan tropical Africa was carried out in orderto assess the environmental significance of the phytolith signal in the fossil record. Phytolithassemblages produced by 98 sub-Saharan grass species (Poaceae) were analyzed and the results led tothe development of three new phytolith indices defined from 43 types specific to Poaceae. Tested on adatabase of 57 modern soil/sediment samples from Chad, these indices allow drawing aquatic grassassociations of Lake Chad, mesophytic grass associations of wetlands from the Sudanian domain, andxerophytic grass associations of drylands from the Sahelian domain. The analysis of modern soilphytolith assemblages (total assemblages) was used to assess the potential of this proxy to characterizethe physiognomy of the Sudano-Sahelian vegetation types. The calibration had been applied to thestudy of a discontinuous sedimentary record from Lake Chad (6-2 Ma) (Bol core, 13°N/14°E) and of18 paleontological levels from the Djourab (7-3.5 Ma) (16°N/17°E). The results indicate thedominance of intermediate to closed savannas and areas of aquatic vegetation at 7 Ma in the Djourab,and more open and dry savannas at 3.5 Ma. A limited lacustrine stage is recorded between 3.6-2.8 Maat Bol, and a shift of aridity at 3.2 Ma. Finally, the results show the existence of C4 grasses in Chadsince 7 Ma

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22

Pearce, Madison Natasha. "Laying the Foundation for a Fremont Phytolith Typology Using Select Plant Species Native to Utah County". BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6648.

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Archaeobotanical evidences for the presence of wild plants at Fremont archaeological sites are numerous. However, little can be positively argued for why those plants are present, if they were used by site inhabitants, and how they were used. Additionally, there are likely several wild plants that were used but that do not appear in the archaeobotanical record as pollen or macrobotanicals, the two most commonly identified plant remains. I argue that it is possible to provide better interpretations for how and why the Fremont used plants by researching how their historic counterparts, the Goshute, Shoshone, Ute, and Southern Paiute, used the same plants that are identified at prehistoric sites. I further argue that a phytolith typology for Fremont archaeology can provide more insight into prehistoric plant use. I demonstrate its utility through a phytolith analysis of ground stone tools from Wolf Village, a Fremont site in Utah County.

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23

Rodríguez, Antón David. "Ocupación e impacto humano en la alta montaña durante la prehistoria. Un estudio arqueoambiental de Aigüestortes (8 – 4 ka cal BP) mediante el análisis de fitolitos". Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/669526.

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Aquesta tesi doctoral investiga sobre el poblamiento prehistòric a l’alta muntanya dels Pirineus catalans occidentals, més concretament, al Parc Nacional d’Aigüestortes i Estany de Sant Maurici (Lleida). En particular, aquest treball de recerca es distingeix per presentar una proposta metodològica innovadora, que contribueix a l’estudi de l’ocupació humana de les muntanyes durant el Neolític. La metodologia arqueològica desenvolupada s’adreça a la detecció de les activitats productives realitzades per les comunitats agroramaderes prehistòriques, la seva gestió ambiental i el seu impacte en el medi. Amb aquest objetiu s’han analitzat els fitòlits procedents de diferents tipus de dipòsits sedimentaris. Aquestes microrestes són cossos silicis produïts per les plantes, que ens informen de la composició vegetal dels sediments. Els fitòlits son un bon indicador per a l’estudi de les activitats que les societats feien amb les plantes i la conseqüent generació de paisatges socials. L’anàlisi de fitòlits s’ha integrat en aquesta tesi com una eina per a l’estudi de les ocupacions prehistòriques en zones d’alta muntanya dels Pirineus per primer cop. A més, com a proposta d’investigació bioarqueològica integradora, els resultats obtinguts s’han interpretat tenint en compte altres restes biològiques presents als sediments analitzats, com ara els carbons, el pol·len, les diatomees o la matèria orgànica.
Esta tesis doctoral investiga sobre el poblamiento prehistórico de la alta montaña en los Pirineos catalanes occidentales, concretamente, en el Parque Nacional de Aigüestortes i Estany de Sant Maurici (Lleida). En particular, este trabajo de investigación se distingue por presentar una propuesta metodológica innovadora, que contribuye al estudio de la ocupación humana de las montañas durante el Neolítico. La metodología arqueológica desarrollada se enfoca en la detección de las actividades productivas realizadas por las comunidades agropastorales prehistóricas, su gestión ambiental y su impacto en el medio. Para ello, se han analizado los fitolitos procedentes de diferentes tipos de depósitos sedimentarios. Estos microrestos son cuerpos silíceos producidos por las plantas, que nos informan de la composición vegetal de los sedimentos. Los fitolitos son un indicador de las actividades realizadas por las sociedades con las plantas y su impacto en el paisaje. El análisis de fitolitos se ha integrado como una herramienta para el estudio de las ocupaciones prehistóricas en la alta montaña de los Pirineos por primera vez. Además, como propuesta de investigación bioarqueológica integral, los resultados obtenidos en esta tesis se han interpretado en relación con otros restos biológicos documentados en los sedimentos analizados, como los carbones, el polen, las diatomeas o la materia orgánica.
This Ph.D dissertation focuses on the prehistoric settlement at high mountain areas of the western Catalan Pyrenees, particularly, in Aigüestortes i Estany de Sant Maurici National Park (Lleida). More specifically, this research work distinguished by an innovative methodological approach, which contributes to the study on human mountain occupation during Neolithic. The archaeological method is focused to detect the activities carried out by these agropastoral populations, the natural resources exploited and the impact caused on environment. Different sedimentary deposits were studied, in order to analyse silica phytoliths. They are siliceous bodies produced by plants, used as a proxy for detecting human activities on plants and their impact on landscape. Phytolith analysis is integrated as a tool for studying the prehistoric occupations in the high-altitude areas at the Pyrenees for the first time. In addition, into an integrated bioarchaeological approach, the results obtained are interpreted taken into account other biological remains analysed in sediments, such as charcoal, pollen, diatoms and organic matter.

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Macedo, Rodrigo Santana. "Pedogênese e indicadores pedoarqueológicos em terra preta de índio no município de Iranduba - AM". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-14042014-164952/.

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Uma evidência contundente da ocupação pré-histórica na Amazônia são os solos de cor escura com material arqueológico, conhecidos regionalmente como Terra Preta de Índio (TPI). Apesar de amplamente estudados, alguns de seus atributos permanecem ainda pouco conhecidos, especialmente os micromorfológicos, mineralógicos e geoquímicos. Esses estudos podem identificar os processos envolvidos na gênese e evolução desses solos, e quando empregados em conjunto com estudos fitolíticos, podem auxiliar na elucidação das suas formas de uso pretéritas. O objetivo desse estudo foi obter uma aproximação da hierarquia dos processos envolvidos na gênese desses solos e as suas prováveis formas de uso em tempos pré-colombianos. A pesquisa foi conduzida no Campo Experimental do Caldeirão, Iranduba - AM. Foram estudados dois perfis com TPI (P1 e P2) e um solo adjacente com horizonte A moderado (P3). Em cada horizonte foram coletadas amostras deformadas para análises físico-químicas, mineralógicas e geoquímicas e a cada 5 cm de profundidade para análise fitolítica e isotópica. Lâminas delgadas de amostras indeformadas de horizontes selecionados foram confeccionadas e descritas em sua micromorfologia, com posterior exame em microscópio eletrônico de varredura com microanálise química. A idade dos solos foi estabelecida com base em datações 14C de carvões. A microestrutura granular das TPI é de origem zoogenética e geoquímica. A gênese dos horizontes antrópicos envolveu: i) a ação do homem descartando e queimando resíduos (antropização); ii) espessamento do horizonte A e escurecimento dos horizontes subsuperficiais por bioturbação (cumulização e melanização); iii) dispersão e translocação de colóides (argiluviação); iv) condições pedoambientais diferentes das atuais (pedorrelíquia - nódulos ferruginosos). Revestimentos de argila com extinção forte, contínua e estriada nas cerâmicas indica que o processo de argiluviação é atual. O processo de elutriação predomina no solo não antrópico. A degradação dos nódulos de ferro na TPI favorece a xantização e atua como fonte de argila (pedoplasmação). Arecaceae e Cyperaceae são mais abundantes nos horizontes antrópicos, notadamente nos níveis com maior quantidade de cerâmica. A ausência de fitólitos de plantas domesticadas indica que a formação das TPI não está relacionada com práticas agrícolas. As evidências fitolíticas demonstram que as atividades antrópicas ocorreram de forma mais intensa no P1. A rápida ciclagem de silício, evidenciada pela presença de fitólitos com silicificação incompleta, favorece a estabilidade da mineralogia caulínitica. VHE, ilita e variscita-estrengita ocorrem somente nos perfis com TPI. P2O5-CaO-K2O-NaO-Cs-Co-Zn-Cu-Ba-Rb-Ni representa a assinatura geoquímica das TPI. A presença de variscita-estrengita, tridimita e maghemita nas TPI, notadamente nas cerâmicas, confirma a formação de minerais em decorrência das práticas antrópicas. As cerâmicas apresentam predominantemente cauixi (Tubella reticulata e Parnula betesil) e cariapé (Licania utilis). A presença comum de micas primárias nesses artefatos sugere material alóctone em seu fabrico. As TPI resultam da adição de artefatos arqueológicos e melanização de horizontes pedogenéticos não antropizados. Tais atividades enriqueceram em nutrientes e alteraram a assinatura geoquímica do solo, assim como promoveram a formação de minerais. Essa antropização acelerou os processos de argiluviação e de degradação de petroplintitas. No decorrer de sua evolução, foram utilizados e adicionados resíduos de plantas, destacadamente de palmeiras e Cyperaceae.
A remarkable evidence of human occupation in Amazonian region is the existence of soils with dark colors and presence of ceramic materials, known as Indigenous Dark Earth (IDE). Despite of widely studied some of their features are still poorly understood, mainly that related to micromorphology, mineralogy and geochemical aspects. Such approach, in combination to phytolytic studies, is able to identify soil genesis processes and unravel the comprehension of occupation mechanisms of human. The aim of this study was to establish the hierarchy of these processes and their association with ancient activities of pre-Columbian populations. The research was carried out in the experimental site of Caldeirão, Iranduba city (Amazon state, Brazil). Two pedons containing surface anthropogenic horizons (P1 and P2) were directly compared to a non-anthropogenic soil (P3). In each soil horizon disturbed soil samples were sampled in order to perform physical, chemical, mineralogical and geochemical analyses. For phytolitic analyses samples were taken each 5 cm of depth. Micromorphological samples were studied in thin sections in the optical microscope and further analyzed in Scanning Electron Microscopy (SEM). The chronology was accomplished after 14C dating. The microaggregates in anthropogenic horizon are related to geochemical and biological processes. The genesis of IDE implicates in the following mechanisms: i) disposal and burning of residues by humans (anthropization); ii) deepening A horizons and darkening subsurface horizons by bioturbation (cumulization and melanization processes); iii) dispersion and migration of colloidal particles leading to argiluviation process; iv) different condictions of environment that not occur nowdays (pedorelict - ferruginous nodules). Clay coatings with extinction bands and continuous orientation in the ceramic artifacts suggest a current argiluviation process. The degradation of Fe nodules enhances the xantization process also providing clay (source of clay). The prevalent soil genesis in non-anthropic soil is the elutriation. The degradation of Fe nodules in the IDE enhances the xantization process also providing clay (pedoplasmation). The number of phytoliths of Arecaceae and Cyperaceae is higher in IDE than non-IDE, mainly in the horizons with more ceramics. The phytolitic evidence demonstrate that activities anthropic was more intense in the P1. The rapid Si cycling, highlighted by the presence of phytoliths without complete silicification, contribute to stability of kaolinitic mineralogy. HIV, illite and variscite-strengite are constrained to IDE pedons. P2O5-CaO-K2O-NaO-Cs-Co-Zn-Cu-Ba-Rb-Ni represents the geochemical signature of IDE. The presence of maghemite, variscite-strengite and tridimite strengthen a mineral forming process linked to human activity. In ceramic materials there is a prevalence of phytoliths from cauixi (Tubella reticulata and Parnula betesil) and cariapé (Licania utilis). The presence of mica suggests an alloctone material for their manufacturing. Hence the anthropic horizons result from the addition of archeological artifacts and melanization of non-anthropic horizons. These activities chemically enriched and modify the geochemical signature of soil, as soon as promoted formation of minerals. The anthropic activities conducted the argiluviation and degradation of Fe nodules. During their evolution there was a clear addition of plant residues, notably related to palm trees and Cyperaceae species.

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Morris, Lesley. "Combining Environmental History and Soil Phytolith Analysis at the City of Rocks National Reserve: Developing New Methods in Historical Ecology". DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/35.

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Historical ecology is an emerging and interdisciplinary field that seeks to explain the changes in ecosystems over time through a synthesis of information derived from human records and biological data. The methods in historical ecology cover a wide range of temporal and spatial scales. However, methods for the more recent past (about 200 years) are largely limited to the human archive and dendrochronological evidence which can be subject to human bias, limited in spatial extent or not appropriate for non-forested systems. There is a need to explore new methods by which biological data can be used to understand historic vegetation and disturbance regimes over the recent past especially in arid ecosystem types. Soil phytolith analysis has the potential to provide much needed information regarding historical conditions in both areas. Phytoliths are structures formed in plants through deposition and accumulation of silica within and around cell walls that are released from plants and preserved in sediments long after death and decay of plant material. The City of Rocks National Reserve in southern Idaho was an excellent place to develop new methods in historical ecology because the human records of historic environmental conditions were so rich. There were two overarching and interconnected objectives for this dissertation research. The first was to reconstruct an ecological history of the City of Rocks National Reserve from the period of overland emigration to present. The second objective was to explore the utility of soil phytolith analysis for inferring vegetation and disturbance regime change over the recent past by testing its sensitivity to record known changes. I employed modern analogue studies, a multi-core approach and detailed core analysis to test for known changes through analysis of extraction weights, relative abundance of phytolith assemblages, microscopic charcoal and burned (darkened) phytoliths. My results showed that this combination of history and soil phytolith analysis would be a useful approach for inferring vegetation changes (e.g. increases in introduced grasses) and disturbances (e.g. fire) in ecological histories.

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Raitz, Edenilson. "Coleção de referência de silicofitólitos da flora do Sudoeste do Paraná: subsídios para estudos paleoambientais". Universidade Estadual do Oeste do Parana, 2012. http://tede.unioeste.br:8080/tede/handle/tede/133.

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Phytoliths bodies are of amorphous silica (SiO2.nH20) produced during the vegetative cycle and plant death after the production can be incorporated into the soil/sediment, and may remain there for extended periods of time. For an analysis consistent fitolítica is necessary to compare the sets of phytoliths found in soil and the collections of references phytoliths extracted from existing plants. The problem is there is no reference collection available for the Southwest region of Paraná and in Brazil, so there is no possibility of comparisons difficult paleoenvironmental reconstructions through this proxy. In order to minimize the lack of information on the production of phytoliths by vegetation of Brazil was made a reference collection of phytoliths from phytophysionomies Mixed Ombrophylous Forest and grassland, both located in the Southwest of Paraná State. This collection consists of 30 families, 57 genera and 75 species. In the floristic survey of FOM Lauraceae, Myrtaceae, Poaceae, and Fabaceae Pteridaceae families have greater representation of species. The vegetation of the grassland had a high representation of Poaceae, Asterceae, Cyperaceae, and Lauraceae. It was found that the production of Late Gray (fraction that contains the phytoliths) decrease of herbaceous to woody phytophysionomies in both. Only two (Araucaria angustifolia and Rapanea gardneriana) of 71 species analyzed did not produce identifiable phytoliths in the leaves. The production of phytoliths in different strata varied in similar proportions in the FOM and the field, especially in stratum A, because the presence of grass species that contributed to high amount of morphotypes short-cells (bilobate, cross and saddle, rondel and conical) in two forest types. While the layers B, C, D and redundancy Epiphytes presented to each other for producing morphotypes blocky, tabular, globular, cylindric and irregular cells by species. The production of phytoliths in the FOM morphological differ in quantity significantly from conjuto produced by species of the grassland, since grasses produce more biomineralizations than eudicotyledonous. The analysis fitolítica the first 40 cm of soil under the FOM revealed a change in vegetation type, evolving from a opened vegetation to more closed forest (current). It was possible to deduce that this change has occurred as a result of past human action. Similar trend was found in the soil analysis of the grassland, that is, moved from grassland to grassland clean of this dirty again to grassland clean, change occurred due to the abandonment of the field and return of site anthropogenic activities. The degradation of two morphotypes differed in physiognomy. The morphotypes found in soil under the FOM showed the lowest degradation compared to the grassland. The set of two soils revealed significant patterns that differentiate the two forest types, showing that different vegetation units can be discriminated by the signatures phytolitic produced by them. These results reinforce the utility of using phytoliths as significant indicators to distinguish vegetation units dominated by field and/or forest, even in a short period of time, thus demonstrating the potential of phytoliths analysis for paleoecological reconstruction in southern Brazil.
Fitólitos são corpos de sílica amorfa (SiO2.nH20), produzidos ao longo do ciclo vegetativo das plantas e após a morte das produtoras podem ser incorporados ao solo/sedimentos, podendo permanecer ali por longos períodos de tempo. Para uma análise fitolítica consistente é necessária a comparação entre os conjuntos de fitólitos encontrados no solo e as coleções de referências de fitólitos extraídos de plantas atuais. O problema consiste em não haver coleção de referência disponível para a região Sudoeste do Paraná e do Brasil, logo, não existem possibilidades de comparações, dificultando a reconstrução paleoambiental por meio deste proxy. Visando minimizar a carência de informações sobre a produção de fitólitos pela vegetação do Brasil foi elaborada uma coleção de referência de fitólitos da fitofisionomias Floresta Ombrófila Mista e do Campo, ambas localizadas no Sudoeste do Estado do Paraná. Esta coleção é composta por 30 famílias, 57 gêneros e 75 espécies. No levantamento florístico da FOM as famílias Lauraceae, Myrtaceae, Poaceae, Pteridaceae e Fabaceae apresentam maior representatividade de espécies. A vegetação do Campo apresentou elevada representatividade de espécies de Poaceae, Asterceae, Cyperaceae e Lauraceae. Constatou-se que a produção de Cinza Final (fração que contém os fitólitos) diminuem do estratos herbáceo para o arbóreo nas duas fitofisionomias. Somente duas (Araucaria angustifolia e Rapanea gardneriana) das 71 espécies analisadas não produziram fitólitos identificáveis nas folhas. A produção de fitólitos nos diferentes estratos variou em proporções similares na FOM e no Campo, principalmente no estrato A, devido presença de espécies de gramíneas que contribuiram com elevada quantidade de morfotipos short-cells (bilobate, cross e saddle, rondel e conical) nas duas fitofisionomias. Enquanto que os estratos B, C, D e Epífitas apresentaram redundância entre si pela produção de morfotipos blocky, tabular, globular, cylindric, irregular cells pelas espécies. A produção morfológica de fitólitos na FOM diferiu em quantidade, significativamente em relação ao conjuto produzido pelas espécies do Campo, pois as gramíneas produzem mais biomineralizações do que as eudicotiledôneas. A análise fitolítica dos primeiros 40 cm de solo sob a FOM revelou mudança no tipo de vegetação, evoluindo de uma vegetação mais aberta para floresta mais fechada (atual). Foi possível elocubrar que esta mudança tenha ocorrido em decorrência da ação antrópica passada. Tendência similar foi encontrada na análise do solo do Campo, isto é, passou de Campo limpo para Campo sujo e deste, novamente para Campo limpo, mudança ocorrida devido ao abandono da área e retorno das atividades antrópicas locais. A degradação dos morfotipos diferenciou nas duas fitofisionomia. Os morfotipos encontrados no solo sob a FOM apresentaram menor índice de degradação se comparado ao do Campo. O conjunto dos dois solos revelaram padrões significativos que diferenciam as duas fitofisionomias, mostrando que diferentes unidades de vegetação podem ser discriminadas pelas assinaturas fitolíticas por elas produzidas. Estes resultados reforçam a utilidade de usar fitólitos como indicadores significativos para diferenciar unidades de vegetação dominada por Campo e/ou Floresta, mesmo em curto período de tempo, demonstrando assim, o potencial da análise de fitólitos para a reconstrução paleoecológica na região Sul do Brasil.

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Silva, Deyvis Willian da. "Caracterização paleoclimática do quaternário tardio em áreas planálticas do Estado do Paraná". Universidade Estadual de Ponta Grossa, 2018. http://tede2.uepg.br/jspui/handle/prefix/2672.

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Este trabalho apresenta um estudo em escala de detalhe regional para a compreensão das configurações paleoambientais do Quaternário em três regiões planálticas do estado do Paraná, sul do Brasil (Ponta Grossa, Guarapuava e Palmas). Para tanto utilizou-se como principal objeto de análise assembleias fitolíticas, aliados a dados isotópicos da matéria orgânica do solo e datações 14C, extraídos de testemunhos de Organossolo em altitudes que variaram de 850 a 1.280 metros. Para o reverso da Escarpa Devoniana, em Ponta Grossa, os resultados sugerem que desde 34.550 anos cal. AP até 11.000 anos cal. AP vigorou na região um clima mais frio e seco que o atual, dominado por vegetação campestre. Diferentemente, na Serra da Esperança, em Guarapuava, no período entre 13.660 e 10.000 anos AP, apesar do clima mais frio que o atual, havia umidade suficiente para que vegetação do tipo florestal predominasse. Para ambos os locais, no entanto, o intervalo entre 10-11.000 e 5-6.000 anos AP é marcado por um ambiente de maior aridez, ocupado por um mosaico floresta/campo com prevalência campestre. A partir de 6.000 anos AP inicia-se uma mudança significativa no sentido de um clima mais quente e úmido. Mas, enquanto na Escarpa Devoniana a vegetação assume configuração semelhante a atual, propícia a formação de um mosaico campo/floresta, na Serra da Esperança a vegetação tende a ser bem mais fechada, num mosaico floresta/campo. O testemunho de Palmas abrange apenas os últimos 4.920 anos cal. AP e sugere o estabelecimento de um ambiente característico de mosaico campo/floresta, gradativamente mais aberto. A partir dos últimos 1.500 anos AP, mudanças na configuração de gramíneas sugerem um ambiente mais úmido, sob condições climáticas mais próximas às atuais, uma típica paisagem de campo entremeada por agrupamentos florestais. Os dados apontam possíveis variações na intensidade de mudanças climáticas no Pleistoceno Tardio em função de diferenças no relevo planáltico e sua capacidade de interferência microclimática.
This paper presents a study on a detailed regional scale for understanding the Quaternary paleoenvironmental settings in the Paraná Highlands, Southern Brazil (Ponta Grossa, Guarapuava, and Palmas. The main object of analysis was phytolitc assemblies, combined with isotopic data of soil organic matter and carbon-14 dating, sampled from peat testimonies at altitudes that ranged from 850 to 1,280 m. For the reverse of the Escarpa Devoniana, in Ponta Grossa, the results suggest that since 34,550 yrs. cal BP up to 11,000 yrs. cal BP the region had a colder and dryer climate than the current one, dominated by grassland. In contrast, in Serra da Esperança, in Guarapuava, in the period between 13,660 yrs. cal BP up to 10,000 yrs. cal BP despite the colder climate than the current, there was enough moisture for a kind of forest predominance. For both locations, however, the interval between 10-and 56,000 yrs. 11,000 BP is marked by greater aridity, occupied by a mosaic forest/field with prevalence of grasses. From 6,000 yrs. BP, it begins a significant shift towards a warmer moister climate. Nevertheless, while in the Escarpa Devoniana vegetation takes similar configuration to the current one, favorable to a mosaic field/forest, in Serra da Esperança the vegetation tends to be much more closed, as a mosaic forest/field. The Palmas testimony only comprises the last years 4,920 yrs. cal BP and suggests the establishment of an environment of mosaic field/forest, gradually more open. From the past 1,500 yrs., changes in grassland configuration suggest a moister environment under climatic conditions closer to the present, a typical grassland landscape with forest patches. The data indicate possible variations in the intensity of climate change in the Late Pleistocene due to differences in the Highlands’ relief and its capacity of microclimatic interference.

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Testé, Marc. "Histoire naturelle des phytolithes des basses-terres mayas : implication pour la reconstitution des Paléoenvironnements et des interactions sociétés-environnements". Thesis, Paris 1, 2020. http://www.theses.fr/2020PA01H023.

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Sous les latitudes tropicales, les phytolithes représentent un indicateur clé dans la reconstitution des paléoenvironnements. Pourtant, ils sont encore modestement utilisés dans les études sur les environnements passés des basses-terres mayas, et ce, en dépit du faible potentiel des autres bioindicateurs de la végétation. C’est dans ce contexte et au travers des riches archives sédimentaires du site archéologique de Naachtun et de ses alentours, que nous proposons une nouvelle approche permettant d’exploiter les avantages inhérents à ces microfossiles siliceux, pour l’étude des environnements passés. Situé à l’extrême nord du Guatemala dans la forêt subtropicale du Petén, le territoire de Naachtun fait l’objet de recherches archéologiques et géoarchéologiques depuis 2010. Par sa localisation géographique au sein des basses-terres et sa proximité aux grands centres politiques mayas, ce site représente un espace clé dans l’évaluation des interactions entre les sociétés mayas et l’environnement au cours des 4 derniers millénaires, problématique principale de ce travail doctoral. Afin d’y répondre, deux axes méthodologiques ont été privilégiés. Le premier axe concerne une démarche actualiste et a pour but de calibrer les assemblages modernes de phytolithes par rapport aux écosystèmes actuels, ‘’naturels’’ et anthropiques, de Naachtun et de sa région. Le second axe, paléoenvironnemental, vise à utiliser les assemblages de phytolithes fossiles, enregistrés en contextes hors-site, dans les sédiments palustres de bajo, et intrasite, afin de proposer une reconstitution de l’histoire socioenvironnementale de Naachtun. Ce travail de thèse démontre le potentiel de ce nouvel outil pour l’approche des paléoenvironnements dans les basses-terres mayas mais il apporte aussi de nouvelles connaissances sur l’utilisation des zones humides par les populations mayas. Plus largement, ce travail s’insère dans la construction actuelle d’un imaginaire des sociétés mayas conscientes de leur environnement et adaptées à ses changements, contre-exemple de nos problématiques et crises modernes
In tropical latitudes, phytoliths represent an important indicator of the paleoenvironmental reconstitutions. Yet, they are still modestly used in past environments studies of Mayan Lowlands, despite the low potential of other vegetation bioindicators. It is in this context, and through the rich sedimentary archives of the Naachtun archaeological site and its surroundings, that we propose a new approach to exploit the inherent advantages of these siliceous microfossils for the study of past environments. Located in the extreme north of Guatemala in the subtropical Petén forest, the territory of Naachtun has been the subject of archaeological and geoarchaeological research since 2010. With its geographical location in the middle of the major Mayan political centers, this site represents a crucial space in the evaluation of the interactions between Mayan societies and the environment over the last 4 millennia, the main issue of this doctoral dissertation. To answer this question, two methodological axes have been privileged. The first axis concerns an actualist approach and aims to calibrate modern phytolith assemblages about the current natural and anthropogenic ecosystems of Naachtun and its region. The second axis, palaeoenvironmental, aims to use fossil phytolith assemblages recorded in off-site contexts, in the bajo palustrine sediments, and intra-site, to propose a reconstruction of the socio-environmental history of Naachtun. This thesis research demonstrates the potential of this new tool for the approach of palaeoenvironments in the Mayan lowlands, but it also provides new knowledge on the use of wetlands by Mayan populations. More broadly, this work is part of the current construction of an imaginary of Mayan societies conscious of their environment and adapted to its changes, a counter-example to our modern problems and crises
En las latitudes tropicales, los fitolitos representan un indicador esencial en la reconstitución de paleoambientes. Sin embargo, todavía se utilizan modestamente en estudios de ambientes pasados en las Tierras Bajas Mayas, a pesar del bajo potencial de otros bioindicadores de vegetación. Es en este contexto, y a través de los ricos archivos sedimentarios del sitio arqueológico de Naachtun y sus alrededores, que proponemos un nuevo enfoque para explotar las ventajas inherentes de estos microfósiles silíceos para el estudio de los ambientes del pasado. Ubicado en el extremo norte de Guatemala en el bosque subtropical del Petén, el territorio de Naachtun ha sido objeto de investigaciones arqueológicas y geoarqueológicas desde 2010. Por su situación geográfica en las tierras bajas y su proximidad a los principales centros políticos mayas, este sitio representa un espacio crucial en la evaluación de las interacciones entre las sociedades mayas y el medio ambiente durante los últimos 4 milenios, el tema principal de este trabajo de doctorado. Para responder a esta pregunta se han privilegiado dos ejes metodológicos. El primer eje se refiere a un enfoque de actualismo y tiene como objetivo calibrar los ensamblajes de fitolitos modernos en relación con los actuales ecosistemas naturales y antropogénicos de Naachtun y su región. El segundo eje, paleoambiental, tiene como objetivo utilizar los ensamblajes de fitolitos fósiles registrados en contextos fuera del sitio, en los sedimentos palustres de bajo, y dentro del sitio, para proponer una reconstrucción de la historia socio-ambiental de Naachtun. Este trabajo de tesis demuestra el potencial de esta nueva herramienta para el abordaje de paleoambientes en las tierras bajas mayas, pero también aporta nuevos conocimientos sobre el uso de los humedales por parte de las poblaciones mayas. En términos más generales, este trabajo se inscribe en la construcción actual de un imaginario de sociedades mayas conscientes de su entorno y adaptadas a sus cambios, un contraejemplo a nuestros problemas y crisis actuales

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Alexandre, Anne. "Phytolithes, interactions sol-plante et paléoenvironnements". Aix-Marseille 3, 1996. http://www.theses.fr/1996AIX30122.

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Les phytolithes sont des particules d'opale-a (sio#2 nh#2o) micrometriques qui precipitent dans et entre les cellules des tissus vegetaux vivants. Le but de ce travail a ete de developper l'etude des phytolithes afin de mieux contraindre la dynamique des sols et les reconstitutions paleoenvironnementales dans la zone intertropicale. Trois etudes sont presentees: 1) le cycle biogeochimique du silicium en foret dense (dimonika, congo) est estime. On montre que entre 2 et 7. 5% de l'apport au sol en silicium biogenique alimentent un pole phytolithique stable. Pour que le systeme soit maintenu a l'equilibre, la vegetation doit absorber du silicium dissous provenant de l'alteration, autrement disponible pour des neoformations ou une exportation hors du systeme, dans les eaux de lessivage. La vegetation augmente donc le taux d'alteration sans augmenter le taux de denudation dans cet environnement. 2) l'analyse morphologique d'assemblages phytolithiques issus de sediments lacustres (lac sinnda, congo et lac de guiers, senegal), montre que les phytolithes sont des traceurs precis de la dynamique des differentes formations herbacees en c4 qui ne sont discriminables ni par analyse pollinique ni par analyse isotopique du carbone. Ce resultat est de premiere importance pour l'etude de la dynamique des zones biogeographiques intertropicales et des phases climatiques ou anthropiques associees. 3) les etudes morphologique, quantitative et en microspectroscopie infrarouge de phytolithes de sol permettent de tracer les processus de translocation, de dissolution et de melange particulaire au sein du profil. On montre que malgre ces perturbations, les assemblages phytolithiques du sol peuvent etre interpretes en terme paleoenvironnemental

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Fraysse, Fabrice. "Cycle biogéochimique du silicium dans les environnements superficiels continentaux : Impact des plantes terrestres". Phd thesis, Université Paul Sabatier - Toulouse III, 2007. http://tel.archives-ouvertes.fr/tel-00179740.

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Cette étude expérimentale a consisté dans un premier temps en la caractérisation de la réactivité et des propriétés physico-chimiques de microparticules d'opales biogènes appelées phytolithes, pour plusieurs espèces de plantes terrestres provenant de milieux différents. Pour ce faire, une approche combinant plusieurs techniques complémentaires telles que, mesures de solubilité, cinétiques de dissolution, mesures électrophorétiques et titrages acido-basiques, a été menée sur ces phytolithes ce qui a permis de mieux quantifier le cycle biogéochimique du silicium (Si) à travers les plantes terrestres. Dans un second temps et afin de mieux contraindre ce cycle biogéochimique, cette étude a aussi porté sur les interactions de litières de plantes terrestres avec les solutions aqueuses en combinant cette fois des expériences de dégradation de litières dans des réacteurs fermés et dans des réacteurs à circulation. Les résultats démontrent une très forte réactivité des phytolithes et des litières de plantes vis-à-vis du relargage de Si, qui sont au minimum de un à deux ordres de grandeur plus élevés que les minéraux. La quantification du contrôle des phytolithes et des litières de plantes sur le relargage de Si à partir de ces réservoirs solides, démontre la possibilité d'un fort impact des plantes sur le cycle biogéochimique du silicium dans la plupart des environnements terrestres.

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Esteban, Alamá Irene. "Reconstructing past vegetation and modern human foraging strategies on the south coast of South Africa". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/401426.

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The importance of South Africa lies in the many caves and rock shelters containing well preserved evidence of human activity, cultural material complexity and a growing number of early modern human fossils dating to the Middle Stone Age (MSA). South Africa also hosts the world's smallest floral kingdom, now called the Greater Cape Floristic Region (GCFR), with high species richness and endemism. We use phytoliths –amorphous silica particles that formed in epidermal cells of plants–in order to study the evolution of plant exploitation strategies by first modern humans and to understand the response of GCFR environments to glacial-interglacial cycles and rainfall shifts and its implication with the evolution of first modern humans that inhabited the south coast of South Africa during the Upper Pleistocene. In paleoanthropological research, improving our capacity to reconstruct past climatic and environmental conditions can help us to shed light on survival strategies of hunter- gatherers. To do this, one must use actualistic studies of modern assemblages from extant habitats to develop analogies for the past and improve paleoenvironmental reconstructions. Accordingly, this thesis contemplates fossil and modern material: i) archaeological sediment samples from Pinnacle Point 5-6 site (PP5-6) located on the south coast of South Africa; ii) modern plants from the GCFR and susceptible to have been exploited by first modern humans inhabiting the south coast; iii) modern surface soil samples from different GCFR vegetation types of the south coast of South Africa. The modern plant reference collection is the first quantitative and morphological study conducted with wood and leaves of trees and shrubs, leaves, bulb scale leaves and edible part of the bulb of geophytes, restios–Restionaceae and grasses–Poaceae from the GCFR on the south coast of South Africa. We observed that grasses are the highest phytolith producers among plant types. We reported through thin sections and SEM that the characteristic restio phytoliths belong to and characterize the Restionaceae family and have been detected in the parenchyma sheath of the culms. Geophytes did not produce diagnostic phytolith morphotypes that can be used for taxonomic identification what might make difficult their identification in the fossil record. The results of the modern surface soil samples showed that phytolith concentration relates mostly to vegetation types and the dominant vegetation rather than to the type of soils. More abundant phytoliths from Restionaceae and woody/shrubby vegetation are also noted from fynbos vegetation and grass phytoliths are a recurrent component in all the vegetation types in spite of being a minor component in the modern vegetation. The grass silica short cells (GSSCs) from these plants, however, suggest a mix of C3 and C4 grasses in most of the vegetation types with a major presence of the rondels ascribed to C3 grasses. The exceptions are riparian, coastal thicket and coastal forest vegetation, which are characterized by the dominance of C4 grass phytoliths. The study of the modern plants and soils from the surrounding areas of Pinnacle Point were used as proxy for the reconstruction of past human foraging strategies and paleoenvironmental reconstruction through the phytolith record from PP5-6 site. The study of the archaeological sediment samples from this site indicated a wide range of plants used by first modern humans inhabiting the area including wood, leaves and fruits of trees and shrubs, grasses and restios. We reported for the first time the presence of restios in the South African archaeological record through the study of phytoliths. From an environmental perspective, the changes observed in the phytolith record from Pinnacle Point deposits are indicative of vegetation movements accordingly to climate changes and sea level fluctuations, in a continuous regional mosaic of habitats.
Este trabajo de tesis tiene el objetivo último de conocer las estrategias de explotación de recursos vegetales de las poblaciones de primeros humanos modernos, así como la reconstrucción de la vegetación y el clima existente durante el Pleistoceno Medio y el Pleistoceno Final a través del estudio de fitolitos de los depósitos arqueológicos del abrigo rocoso de Pinnacle Point 5-6 (PP5-6). Para ello realizamos u Realiamos estudios actualísticos de plantas y suelos modernos como base análoga de nuestro estudio. Del estudio de plantas modernos dos son los principales resultados que se obtuvieron: i) a través de secciones delgadas y microscopio electrónico de barrido se caracterizó fitolitos diagnósticos de la familia Restionaceae (restios) en la vaina del parénquima de los tallos y ii) los geófitos no producen morfotipos diagnósticos que pudieran ser utilizados para su identificación taxonómica. Los resultados de los suelos mostraron que la concentración de fitolitos se relaciona principalmente con el tipo de vegetación y las plantan que ellos dominan. Los fitolitos característicos de restios dominan en la vegetación de tipo fynbos. Las células cortas de gramíneas (GSSC) sugieren una mezcla de gramíneas de tipo C3 y C4 en la mayoría de los tipos de vegetación. Las excepciones son la vegetación riparia y de coastal thicket donde gramíneas C4 dominan. El estudio de las muestras de sedimentos arqueológicos de PP5-6 indicó una amplia gama de plantas utilizadas por los habitantes de PP5-6. Identificamos por primera vez la presencia de restios en el registro arqueológico sudafricano a través del estudio de fitolitos. Desde una perspectiva ambiental, los cambios observados en el registro de fitolitos de los depósitos de Pinnacle Point son indicativos de los movimientos de vegetación en consecuencia a los cambios climáticos y las fluctuaciones del nivel del mar, en un mosaico regional continuo de hábitats.

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Wilbur, Cricket C. "A History of Place: Using Phytolith Analysis to Discern Holocene Vegetation Change on Sanak Island, Western Gulf of Alaska". Antioch University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1395927847.

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Hughes, Matthew William. "Late Quaternary Landscape Evolution and Environmental Change in Charwell Basin, South Island, New Zealand". Phd thesis, Lincoln University. Agriculture and Life Sciences Division, 2008. http://theses.lincoln.ac.nz/public/adt-NZLIU20080214.132530/.

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Charwell Basin is a 6 km-wide structural depression situated at the boundary between the axial ranges and faulted and folded Marlborough Fault Zone of north-eastern South Island, New Zealand. The basin contains the piedmont reach of the Charwell River, and a series of late Quaternary loess-mantled alluvial terraces and terrace remnants that have been uplifted and translocated from their sediment source due to strike-slip motion along the Hope Fault which bounds the basin to its immediate north. The aim of this study was to provide an interdisciplinary, integrated and holistic analysis of late Quaternary landscape evolution and environmental change in Charwell Basin using terrain analysis, loess stratigraphy, soil chemistry and paleoecological data. The study contributes new understanding of New Zealand landscape and ecosystem responses to regional and global climatic change extending to Marine Isotope Stage (MIS) 6, and shows that climatically-forced shifts in biogeomorphic processes play a significant role in lowland landscape evolution. Morphometric analysis of alluvial terraces and terrace remnants of increasing age demonstrated geomorphic evolution through time, with a decrease in extent of original planar terrace tread morphology and an increase in frequency of steeper slopes and convexo-concave land elements. Paleotopographic analysis of a >150 ka terrace mantled by up to three loess sheets revealed multiple episodes of alluvial aggradation and degradation and, subsequent to river abandonment, gully incision prior to and coeval with loess accumulation. Spatial heterogeneity in loess sheet preservation showed a complex history of loess accumulation and erosion. A critical profile curvature range of -0.005 to -0.014 (d2z/dx2, m-1) for loess erosion derived from a model parameterised in different ways successfully predicted loess occurrence on adjacent slope elements, but incorrectly predicted loess occurrence on an older terrace remnant from which all loess has been eroded. Future analyses incorporating planform curvature, regolith erosivity and other landform parameters may improve identification of thresholds controlling loess occurrence in Charwell Basin and in other South Island landscapes. A loess chronostratigraphic framework was developed for, and pedogenic phases identified in, the three loess sheets mantling the >150 ka terrace. Except for one age, infrared-stimulated luminescence dates from both an upbuilding interfluve loess exposure and colluvial gully infill underestimated loess age with respect to the widespread Kawakawa/Oruanui Tephra (KOT; 27,097 ± 957 cal. yr BP), highlighting the need for improvements in the methodology. Onset of loess sheet 1 accumulation started at ca. 50 ka, with a break at ca. 27 ka corresponding to the extended Last Glacial Maximum (eLGM) interstadial identified elsewhere in New Zealand. Loess accumulation through MIS 3 indicates a regional loess flux, and that glaciation was not a necessary condition for loess generation in South Island. Loess accumulation and local alluvial aggradation are decoupled: the youngest aggradation event only covers ~12 kyr of the period of loess sheet 1 accumulation. Older local aggradation episodes could not be the source because their associated terraces are mantled by loess sheet 1. In the absence of numerical ages, the timing of L2 and L3 accumulation is inferred on the basis of an offshore clastic sediment record. The upbuilding phase of loess sheet 2 occurred in late MIS 5a/MIS 4, and loess sheet 3 accumulated in two phases in MIS 5b and late MIS 6. Biogenic silica data were used to reconstruct broad shifts in vegetation and changes in gully soil saturation status. During interglacial/interstadial periods (MIS 1, early MIS 3, MIS 5) Nothofagus¬-dominated forest covered the area in association with Microlaena spp grasses. Lowering of treeline altitude during glacial/stadial periods (MIS 2, MIS 3, MIS 5b, late MIS 6) led to reduction in forest cover and a mosaic of shrubs and Chionochloa spp, Festuca spp and Poa spp tussock grasses. Comparison of interfluve and gully records showed spatial heterogeneity in vegetation cover possibly related to environmental gradients of exposure or soil moisture. A post-KOT peak in gully tree phytoliths corresponds to the eLGM interstadial, and a shift to grass-dominated vegetation occurred during the LGM sensu stricto. Diatoms indicated the site became considerably wetter from ca. 36 ka, with peak wetness at ca. 30, 25 and 21 ka, possibly due to reduced evapotranspiration and/or increased precipitation from a combination of strengthened westerly winds and increased cloudiness, or strengthened southerly flow and increased precipitation. Human influence after ca. 750 yr BP led to re-establishment of grassland in the area, which deposited phytoliths mixed to 30 cm depth in the soil. A coupled gully colluvial infilling/vegetation record showed that sediment flux during the late Pleistocene was ~0.0019 m3 m-1 yr-1 under a shrubland/grassland mosaic, and Holocene sediment flux was ~0.0034 m3 m-1 yr-1 under forest. This increase of 60% through the last glacial-interglacial transition resulted from increased bioturbation and down-slope soil transport via root growth and treethrow, which formed a biomantle as evidenced by slope redistribution of the KOT. These results contrast with sediment transport rates and processes hypothesised to occur contemporaneously in adjacent mountain catchments. This suggests that intraregional biogeomorphic processes can differ significantly depending on topography and geological substrate, with different landscapes responding in unique ways to the same climate shifts. Analysis of Quaternary terrestrial landscape evolution in non-glaciated mountainous and lowland areas must therefore consider spatial and temporal heterogeneity in sediment fluxes and underlying transport processes.

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Calegari, Márcia Regina. "Ocorrência e significado paleoambiental do Horizonte A húmico em Latossolos". Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-11032009-093135/.

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A ocorrência de solos com horizonte A húmico (Ah) hiperdesenvolvido ainda é pouco entendida. Nos Latossolos com esse horizonte (Lh) ele freqüentemente é muito espesso, com baixa saturação por bases e cor escura advinda do relativamente grande acúmulo de matéria orgânica até profundidades superiores a 100 cm. Exceto para a região Sul, tais atributos estão em desconformidade com as atuais condições de clima e vegetação em que esses Lh se encontram. Objetivou-se definir variáveis ambientais que teriam influenciado na gênese desse horizonte em Latossolos, investigando-se dados de morfologia, textura, geoquímica, geomorfologia e evidências de paleoambientes. Realizou-se primeiro um estudo bibliográfico das principais características dos Lh no Brasil, em um conjunto de 39 perfis. Destes, 11 variáveis, representando atributos ambientais, químicos e granulométricos do solo foram submetidas a análises estatísticas multivariadas, para agrupá-los segundo similaridades. Três grupos foram definidos: G1 - Latossolos Brunos e Vermelhos em superfícies de cimeira da região Sul, com os mais altos teores de carbono orgânico e de Fe2O3, Ah menos espesso e mineralogia mais oxídica que os demais; G2- Latossolos Vermelho-Amarelos e Amarelos em antigas superfícies geomorfológicas da região Sudeste, associados à vegetação e clima de altitude, com valores intermediários de carbono e de mineralogia; G3 - Latossolos Vermelho-Amarelos e Amarelos com Ah mais espessos, encontrados nos níveis mais elevados de superfícies intermediárias (Depressão Periférica Paulista e Tabuleiros do Nordeste),com os menores teores de carbono e mineralogia caulinítica. Baseados nesses agrupamentos amostraram-se 30 pedons para fins de caracterização detalhada: análise total de Zr e Ti para identificar descontinuidades e técnicas isotópicas (13C,14C) aliadas a análises de fitólitos para inferir paleoambientes. Para esta análise procedimentos de extração de fitólitos foram adaptados. Nas regiões Sudeste e Nordeste o Ah teria se formado sob vegetação menos densa que a atual, como indicado pelos fitólitos e valor 13C que indicou mistura de plantas de ciclo C3 e C4 (~-22), que revelaram predomínio de plantas C3 e, na região Sul, vegetação mais aberta com predomínio de plantas C4 (~-16), indicando clima mais seco entre o Holoceno inferior e médio. A partir das datações 14C e dos valores 13C inferiu-se um empobrecimento isotópico (~-25) no Holoceno superior, sugerindo expansão da vegetação de floresta para todas as regiões, associada à clima mais úmido e quente, semelhante ao atual, nas regiões Sudeste e Nordeste e mais úmido e frio, na região Sul. Esses resultados indicaram que vegetação e climas pretéritos, associados aos materiais de origem e estabilidade do relevo, têm participação importante na geografia e nos processos de formação do material de origem e dos horizontes Ah. As relações Ti/Zr indicaram descontinuidades litológicas, fato que sugere a ação de processos de coluvionamento no espessamento dos Ah que, com isso, podem ser considerados como poligenéticos. O Ah constitui um importante registro das variações climáticas ocorridas durante o Quaternário sendo considerado como um paleossolo relictual. A integração da análise isotópica, de fitólitos, análise total de Zr e Ti, com a morfologia e análises de rotina foram bastante úteis para esclarecer a origem dos Ah desses Lh.
Thick humic A horizons (umbric epipedons) may be found in several Brazilian Latosols (well drained Oxisols - Lh). This dark colored horizon (Ah) is frequently more than 1m thick and has a large stock of soil organic matter (SOM) and differ from nearby Latosols without an Ah and on younger surfaces and do not conform with present climate and vegetation. Several hypothesis about their genesis had been raised but without a good pedogenetic understanding. This thesis aims to define environmental variables responsible for their formation. Several pedons were examined through their morphology and landscape position, and their soil materials were studied by geochemistry methods and paleoenviromental evidence by C isotope and phytolith assemblages. First, a bibliographic survey was performed to choose a set of 39 profiles were chosen to be studied on a data set where 11 noted chemical and granulometric attributes and one environmental variable were submitted to multivariate statistic analysis in order to group then according to similarities. Three groups were defined: G1 - Brown and Red Latosols from summit surfaces of the Brazilian Southern uplands (with the highest clay, organic carbon and iron oxide values, but with thinner epipedons than the others groups). G2 - Yellow-Red and Yellow Latosols, predominantly found in summit positions, remnant ancient geomorphic surfaces from the Southeast region and associated with the vegetation adapted to high altitudinal tropical climate. G3 - Red Yellow and Yellow Latosols from the Brazilian Southeastern piedmont upland surfaces and Northeastern coastal tablelands (with the thickest umbric epipedons, loamy to clayey textures, lower carbon contents, and a kaolinitic mineralogy). From this analysis 30 Lh representative pedons were field sampled to be characterized, including total Zr and Ti contents, stable carbon isotopes (13C, 14C) and phytolith analysis, in order to better understand paleo-environmental conditions they were subjected. For the phytolith extraction laboratory procedure were adapted in order to better separate and clean then from oxidic coatings. The SOM isotope data and phytolith assemblages indicated that these Ah were formed under a less dense vegetation than the present one: a probably mixture of C3 and C4 (~-22) plants, with more contribution of the C3 in the Southeast and Northeast regions, a more open (~-16, grassy), vegetation (with contribution of C4 plants) in the middle to medium Holocene indicating the presence of a drier climate in the Southern region. From the Late Holocene a more 13C depleted values (~-25) was observed, suggesting the expansion of the tropical and subtropical forests in this region, probably associate to a humid and warm climate in the Southeast and Northeast regions, and humid and cold in the Southern region. The combination of climate and vegetation late, parent material, and stability relief have played a major role in the geographic and formation of the parent material and pedogenetic horizons of these Lh, and thus they should be considered as polygenetic soils. The humic horizons constitute an important register of Holocene climate change and that they should be considered as relic paleosoils.

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35

Roshan, Paladugu. "Interdisciplinary study of the dental calculus in skeleton remains from the cemetery of Santa Maria do Olival (Tomar, Portugal) 15th to 16th century A.D". Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/25590.

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14 humans and 6 faunal dental calculus samples from the medieval necropolis of Santa Maria do Olival, Tomar were selected for microdebris, isotopes, trace elements and organic residues analyses. The major aim of the study was to setup methods for analysis of dental calculus to complement information from bones and teeth. The isotopic values from dental calculi of humans and fauna were comparable to those from bone collagen and led to similar conclusions on dietary practices. Trace element values from human and faunal calculi followed similar trends to their respective bones. Microscopy yielded stray phytoliths from the Poaceae family and no silica skeletons or starch grains. Organic residues analysis indicated a diet based on protein and carbohydrates. Evidences of poor air quality due to char substances from incomplete combustion of wood and biomass were found. Since this is a pilot study, sample size is restricted. The direction of future research on dental calculus is to analyse a large quantity of samples to generate standard range of values for isotopes and trace element concentrations; Resumo: O estudo interdisciplinar do cálculo dentário no esqueleto é feito no cemitério de Santa Maria do Olival (Tomar, Portugal) - 15th to 16th século A.D. Foram selecionadas 14 amostras de humanos e 6 amostras de cálculo dentário da fauna da necrópole medieval de Santa Maria do Olival, Tomar, para análises de microdíbris, isótopos, oligoelementos e resíduos orgânicos. O principal objetivo do estudo foi configurar métodos para análise de cálculo dentário para complementar informações de ossos e dentes. Os valores isotópicos dos cálculos dentários de humanos e fauna foram comparáveis aos do colágeno ósseo e levaram a conclusões semelhantes sobre práticas alimentares. Os valores dos elementos de traço dos cálculos humanos e faunísticos seguiram tendências semelhantes aos seus respectivos ossos. A microscopia produziu fitólitos dispersos da família Poaceae e nenhum esqueleto de sílica ou grãos de amido. A análise de resíduos orgânicos indicou uma dieta baseada em proteínas e carboidratos. Evidências de baixa qualidade do ar devido a substâncias carbonatadas de combustão incompleta de madeira e biomassa foram encontradas. Como este é um estudo piloto, o tamanho da amostra é restrito. A direção de pesquisas futuras sobre cálculo dentário é analisar uma grande quantidade de amostras para gerar uma faixa padrão de valores para isótopos e concentrações de elementos traços.

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Raúl, Sitoe Sandra. "Environmental history in southern Mozambique : Reconstruction of flooding events, hydroclimate and sea-level dynamics since mid-Holocene". Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-148465.

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The aim of this thesis has been to reconstruct paleoenvironment, paleohydrology and paleoclimate in coastal southern Mozambique, with emphasis on tracing past flooding events on the lower Limpopo River floodplain. In order to extend flood chronologies beyond periods covered by instrumental data, sediments from lakes on the floodplain were studied (Lake Lungué, Coassane Oxbow, Lake Magandane and Lake Soane). Past sea-level variations and climate changes were deduced by analyzing sediments from coastal sites north of the floodplain area (Lake Chilau, Lake Nhauhache and Macassa Bay). To achieve the established objectives, a multi-proxy approach was applied on most of the retrieved sediment cores, involving analysis of mineral magnetic parameters, grain-size and organic carbon in combination with analysis of microfossils such as diatoms and/or phytoliths. Chronologies for the constructed time-series analysis were obtained by radiocarbon dating and age-depth modelling. The synthesized data from the sampled sites on the Limpopo River floodplain suggest that the area was affected by at least 16 flooding events of variable magnitudes during the studied period. These are dated to c. AD 940, 980, 1040, 1100, 1250, 1300, 1370, 1580, 1665, 1730, 1755, 1855, 1920, 1945, 1970 and 2000. In calibrated years BP these ages correspond to 1010, 970, 910, 850, 700, 650, 580, 370, 285, 220, 195, 95, 30, and 5 cal yrs BP. The two youngest are dated to 20 and 50 years AP (After Present being 1950). Proxy data further suggest that southern Africa was subject to two periods of sea-level highstands, at c. 5000–4200 BC (6950–6150 cal yrs BP) and AD 300–950 (1650–1000 cal yrs BP). The former represents the middle part of the postglacial climatic optimum. The wettest period in the Limpopo River floodplain was reported between AD 1360 and 1560 (590 and 390 cal yrs BP) in the Lake Lungué record, while Lake Chilau experienced wet conditions between AD 1200 and 1400 (750 and 550 cal yrs BP), then returning to drier conditions that prevailed until c. AD 1600. In Lake Nhauhache, however, drier conditions prevailed from c. AD 1200–1700 (750–250 cal yrs BP), shifting towards wetter at c. AD 1900 (50 cal yrs BP). The deviating signals between records can partly be explained by Lake Lungué basin being located on the Limpopo River floodplain, responding to flooding events associated with precipitation upstream the drainage area. Therefore, wet and dry periods in floodplain lakes (e.g. Lake Lungué) are not expected to correlate with precipitation changes on a local scale, as indicated by e.g. Lake Nhauhache. This is supported by a relatively weak agreement between Lake Lungué record and other nearby records (outside the floodplain), but a better correlation with records from the upper catchment, where a more regional climate signal is provided of the southern African summer rainfall region.
Denna avhandling behandlar studier av paleomiljöer i södra Mozambique med fokus på översvämningshistorik i Limpopo-flodens nedre lopp. Tidsspannet är mitt- och sen-holocen och inkluderar även klimat och havsnivåvariationer. Följande analysmetoder har applicerats på ett flertal sedimentkärnor för att belysa ovanstående frågeställningar: mineralmagnetiska parameterar, kornstorlek, organiskt kol samt kiselmikrofossil (diatoméeter och fytoliter). Åldrar har bestämts med 14C-metoden. Analyserna visar att mineralmagnetiska parametrar är lämpliga för att identifiera översvämningar, speciellt magnetisk susceptibilitet och SIRM. Dessa parametrar visar på ett sediments magnetiska kornstorlerkar och koncentrationen av finkorniga magnetiska mineral. Även kornstorleksanalyser fungerade som ett bra komplement till dessa metoder. Sammantaget har ett minimum av 16 översvämningar registrerats i Limpopo/flodens nedre lopp under de senaste 1100 åren. Särskilt stora översvämningar har daterats till AD 1250 (700 kal år BP), AD 1370 (580 kal år BP), AD 1580 (370 kal år BP), AD 1855 (95 kal år BP), AD 1920 (30 kal år BP), AD 1970 (20 kal år AP) och AD 2000 (50 kal år AP), där AP betyder ”after present”, vilket är 1950. Mindre kraftiga översvämningar har daterats till AD 940 (1010 kal år BP), AD 980 (970 kal år BP), AD 1040 (910 kal år BP), AD 1100 (850 kal år BP), AD 1300 (650 kal år BP), AD 1665 (285 kal år BP), AD 1730 (220 kal år BP), AD 1755 (195 kal år BP) och AD 1945 (5 kal år BP). Skriftliga källor visar på att åtminstone åtta översvämningar har ägt rum under de senaste 62 åren. Under samma period har denna undersökning registrerat två händelser, vilket indikerar att endast ett fåtal har registrerats med ovan nämnda metoder. Det är sannolikt att sedimentationsmönstret under en översvämning är komplicerat och inte heller likartad från gång till gång. Detta innebär att ett flertal sedimentkärnor behöver analyseras och dateras väl. Ytterligare en försvårande faktor är flodens mycket aktiva meandringsaktivitet. Analys av diatoméer har visats vara värdefulla när det gäller översvämningshistorik, klimatförändringar och havsytevariationer. Sedimenten i den något till flodslättens nedre lopp perifert belägna sjön Lungué indikerar fuktiga förhållanden mellan AD 1360 och 1560 (590 till 390 kal år BP). Kombinerade fytolit- och diatoméanalyser av sedimenten i sjön Chilau indikerar fuktiga förhållanden från AD 1200 till 1400 (750 till 550 kal år BP), varefter torrare förhållanden rådde till ca AD 1600 (350 kal år BP). Diatoméanalys av sedimenten i sjön Nhauhache indikerar generellt sett torrare förhållanden mellan AD 1200 och AD 1700 (750 till 250 kal år BP) då klimatet blev fuktigare. De fuktiga och torra förhållanden som dokumenterats i sjön Lungué och översvämningshistoriken korrelerar inte helt med lokala nederbördsförhållanden. Däremot stämmer erhållna data bättre med förhållanden i den övre delen av Limpopoflodens dräneringsområde. Även sjöar och fyllda meanderbågar på själva flodslätten verkar reagera tydligare på översvämningar orsakade av nederbörd i den övre delen av flodloppet. Undersökningen indikerar två faser av en förhöjd havsyta längs kusten i södra Mozambique. En äldre fas är daterad till ca 5000–4200 f.Kr. (6950–6150 kal år BP), vilken representerar den mellersta delen av det postglaciala värmeoptimet. Denna tolkning stöds även av andra undersökningar. En yngre fas har daterats till AD 300–950 (1650–1000 kal år BP), vilken korresponderar till en period med något förhöjda temperaturer i ett globalt perspektiv.
O presente projecto teve como objectivo a reconstrução do paleoambiente, paleohidrologia e paleoclima da costa Sul de Moçambique, com ênfase na identificação de vestígios de eventos de cheias que tenham, no passado, afectado a planície de inundação do Rio Limpopo, com vista a fazer a extensão das datações de cheias para o período anterior aos instrumentos de medição. Deste modo, foram estudados sedimentos recuperados através de testemunhos de sondagem em lagos dentro da planície de inundação (Lago Magandane, Lago Lungué, Lago Soane e o canal abandonado Coassane). As variações do nível do mar e mudanças climáticas do passado foram deduzidas a partir da análise de sedimentos de áreas costeiras a norte da planície de inundação (Lago Chilau, Lago Nhauhache e a Baía de Macassa). Para o alcance destes objectivos, os sedimentos dos testemunhos de sondagem recuperados foram submetidos a várias análises laboratoriais que incluem propriedades de minerais magnéticos, granulometria, teor de matéria orgânica e de microfósseis (diatomáceas e fitólitos). Para o estabelecimento do modelo cronológico foram usadas datações pelo método 14C feitas em matéria orgânica, assim como conchas de gastrópodes e bivalves. A combinação dos resultados obtidos para os pontos de amostragem localizados dentro da planície de inundação do Rio Limpopo, sugerem que esta área foi afectada por um mínimo de 16 eventos de cheias de variada magnitude nos últimos 1100 anos. As cheias de alta magnitude tiveram lugar nos anos 1250, 1370, 1580, 1855, 1920, 1970 e 2000. Por seu turno, as cheias de magnitude moderada ocorrerram nos anos 940, 980, 1040, 1100, 1300, 1665, 1730, 1755 e 1945.. Os anos a negrito são indicativos de eventos de cheias de alta magnitude. O número total de eventos identificados no presente estudo é um mínimo que poderá ter afectado a planície de inundação, tendo em consideração que fontes escritas reportam a ocorrência de pelo menos oito eventos nos últimos 62 anos, tendo o presente estudo revelado somente dois. Isto indica que apenas eventos de cheias intensos podem ser revelados pelos métodos aplicados nesta investigação. Adicionalmente, este estudo mostra a necessidade de aumentar o número de pontos de amostragem para permitir a identificação de mais eventos de cheias ocorridos no passado, devido à diferenciada resposta sedimentológica e geomagnética às cheias, a qual se encontra directamente relacionada à distância do rio meandrante. As análises de microfósseis de diatomáceas permitiram reconstruir o paleoclima e as influências do nível do mar nas áreas de estudo deste projecto. Os registros de diatomáceas do Lago Lungué indicam um período húmido entre AD 1360 e 1560. No Lago Chilau, dados de diatomáceas e fitólitos sugerem condições de humidade entre AD 1200 e 1400. Por seu turno, no Lago Nhauhache, condições de seca dominam entre AD 1200 e 1700. As condições de seca e humidade documentadas no Lago Lungué e os eventos de cheias revelados pelos sedimentos analisados da planície de inundação do Rio Limpopo não mostram total correlação com períodos de baixa e alta precipitação a nível local, mas apresentam boa correlação com evidências a montante na área de drenagem do Rio Limpopo. Em geral, lagos activos ou preenchidos por sedimentos mostrarão ser mais susceptíveis a cheias com origem a montante do que a nível local. As investigações conduzidas permitiram identificar dois períodos de alto nível do mar na região sul de Moçambique. A fase mais antiga teve lugar há cerca de 5000–4200 BC (6950–6150 anos do calendário BP), representando a fase mais recente do pós-glaciar climático óptimo (postglacial climatic optimum, PCA). A fase recente é datada de AD 300–950 (1650–1000 anos do calendário BP), correspondendo a um período de temperaturas relativamente altas a nível global.
Climate and Environmental Research

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37

Hughes, Matthew W. "Late Quaternary landscape evolution and environmental change in Charwell Basin, South Island, New Zealand". Lincoln University, 2008. http://hdl.handle.net/10182/305.

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Charwell Basin is a 6 km-wide structural depression situated at the boundary between the axial ranges and faulted and folded Marlborough Fault Zone of north-eastern South Island, New Zealand. The basin contains the piedmont reach of the Charwell River, and a series of late Quaternary loess-mantled alluvial terraces and terrace remnants that have been uplifted and translocated from their sediment source due to strike-slip motion along the Hope Fault which bounds the basin to its immediate north. The aim of this study was to provide an interdisciplinary, integrated and holistic analysis of late Quaternary landscape evolution and environmental change in Charwell Basin using terrain analysis, loess stratigraphy, soil chemistry and paleoecological data. The study contributes new understanding of New Zealand landscape and ecosystem responses to regional and global climatic change extending to Marine Isotope Stage (MIS) 6, and shows that climatically-forced shifts in biogeomorphic processes play a significant role in lowland landscape evolution. Morphometric analysis of alluvial terraces and terrace remnants of increasing age demonstrated geomorphic evolution through time, with a decrease in extent of original planar terrace tread morphology and an increase in frequency of steeper slopes and convexo-concave land elements. Paleotopographic analysis of a >150 ka terrace mantled by up to three loess sheets revealed multiple episodes of alluvial aggradation and degradation and, subsequent to river abandonment, gully incision prior to and coeval with loess accumulation. Spatial heterogeneity in loess sheet preservation showed a complex history of loess accumulation and erosion. A critical profile curvature range of -0.005 to -0.014 (d²z/dx², m⁻¹) for loess erosion derived from a model parameterised in different ways successfully predicted loess occurrence on adjacent slope elements, but incorrectly predicted loess occurrence on an older terrace remnant from which all loess has been eroded. Future analyses incorporating planform curvature, regolith erosivity and other landform parameters may improve identification of thresholds controlling loess occurrence in Charwell Basin and in other South Island landscapes. A loess chronostratigraphic framework was developed for, and pedogenic phases identified in, the three loess sheets mantling the >150 ka terrace. Except for one age, infrared-stimulated luminescence dates from both an upbuilding interfluve loess exposure and colluvial gully infill underestimated loess age with respect to the widespread Kawakawa/Oruanui Tephra (KOT; 27,097 ± 957 cal. yr BP), highlighting the need for improvements in the methodology. Onset of loess sheet 1 accumulation started at ca. 50 ka, with a break at ca. 27 ka corresponding to the extended Last Glacial Maximum (eLGM) interstadial identified elsewhere in New Zealand. Loess accumulation through MIS 3 indicates a regional loess flux, and that glaciation was not a necessary condition for loess generation in South Island. Loess accumulation and local alluvial aggradation are decoupled: the youngest aggradation event only covers ~12 kyr of the period of loess sheet 1 accumulation. Older local aggradation episodes could not be the source because their associated terraces are mantled by loess sheet 1. In the absence of numerical ages, the timing of L2 and L3 accumulation is inferred on the basis of an offshore clastic sediment record. The upbuilding phase of loess sheet 2 occurred in late MIS 5a/MIS 4, and loess sheet 3 accumulated in two phases in MIS 5b and late MIS 6. Biogenic silica data were used to reconstruct broad shifts in vegetation and changes in gully soil saturation status. During interglacial/interstadial periods (MIS 1, early MIS 3, MIS 5) Nothofagus-dominated forest covered the area in association with Microlaena spp grasses. Lowering of treeline altitude during glacial/stadial periods (MIS 2, MIS 3, MIS 5b, late MIS 6) led to reduction in forest cover and a mosaic of shrubs and Chionochloa spp, Festuca spp and Poa spp tussock grasses. Comparison of interfluve and gully records showed spatial heterogeneity in vegetation cover possibly related to environmental gradients of exposure or soil moisture. A post-KOT peak in gully tree phytoliths corresponds to the eLGM interstadial, and a shift to grass-dominated vegetation occurred during the LGM sensu stricto. Diatoms indicated the site became considerably wetter from ca. 36 ka, with peak wetness at ca. 30, 25 and 21 ka, possibly due to reduced evapotranspiration and/or increased precipitation from a combination of strengthened westerly winds and increased cloudiness, or strengthened southerly flow and increased precipitation. Human influence after ca. 750 yr BP led to re-establishment of grassland in the area, which deposited phytoliths mixed to 30 cm depth in the soil. A coupled gully colluvial infilling/vegetation record showed that sediment flux during the late Pleistocene was ~0.0019 m³ m⁻¹ yr⁻¹ under a shrubland/grassland mosaic, and Holocene sediment flux was ~0.0034 m³ m⁻¹ yr⁻¹ under forest. This increase of 60% through the last glacial-interglacial transition resulted from increased bioturbation and down-slope soil transport via root growth and treethrow, which formed a biomantle as evidenced by slope redistribution of the KOT. These results contrast with sediment transport rates and processes hypothesised to occur contemporaneously in adjacent mountain catchments. This suggests that intraregional biogeomorphic processes can differ significantly depending on topography and geological substrate, with different landscapes responding in unique ways to the same climate shifts. Analysis of Quaternary terrestrial landscape evolution in non-glaciated mountainous and lowland areas must therefore consider spatial and temporal heterogeneity in sediment fluxes and underlying transport processes.

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38

Weisskopf, A. R. "Vegetation, agriculture and social change in late Neolithic China : a phytolith study". Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/20313/.

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Late Neolithic and Early Bronze Age Central China was the scene of important cultural developments, which impacted on agricultural practices and local vegetation. Using phytolith data from 4 archaeological -sites and a survey of a further 11 sites in Henan this project investigates changing crop choices, developments in crop processing and, to a lesser extent, differing local environments both temporally and spatially. Comparisons of relative levels of phytoliths from crop husks, Panicum, Setaria and Oryza, from each site and period were compared to provide evidence of changes in crop repertoire. Results from these investigations show crop variation both over time and in different parts of the region. Millet farming predominated in the more Northern sites in the Yellow River Valley, while rice was clearly the main crop at Baligang, the southernmost site within the Yangtze catchment. However, rice became more important in the Yellow River valley during the late Neolithic and interestingly despite a changing climate making rice farming more challenging in the Early Bronze Age farmers continued rice cultivation. Crop processing stages were interpreted by examination of differing proportions of phytoliths from crop husks, weed husks and crop and weed leaves which can illustrate differing cultivation systems, harvesting and processing practices. These can be seen especially clearly in the rice data from Baligang suggesting more successful agricultural practices and possible change in social organisation in the Late Neolithic. Evidence of local environmental variation was more challenging to unpick as all the phytolith samples available were from cultural contexts. However, the results of the investigation into the changing local environment reflect other proxy data. Differences in occurrence of specific key phytolith short cell morphotypes and changes in the levels of bulliforms, and cone shaped phytolith morphotypes from Cyperaceae indicating wetland were used to interpret local vegetational change, again both spatially and temporally. Rondel and bilobe shaped short cells represent Pooid and Panicoid grasses respectively and short cell morphotypes, such as rondels, bilobes, saddles, can also be used to track variation in levels of C3 and C4 grasses, so changes in proportions of these morphotypes can indicate larger vegetational change. A comparison between the dataset from Neolithic Central China and one from Neolithic India highlighted possible variations in arable systems with millet and wet rice farming in China contrasting with dry rice in India.

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Chabot, Yohan. "Approche géomorphologique de la vallée de Deli et étude géoarchéologique du site historique de Kota Cina (Sumatra Nord, Indonésie)". Thesis, Paris 1, 2017. http://www.theses.fr/2017PA01H058/document.

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La reconstitution des paléoenvironnements et la compréhension des dynamiques géomorphologiques sont de plus en plus appréhendées au regard des recherches archéologiques. Toutefois, en Indonésie, cette approche est encore peu usitée. L’étude du site de Kota Cina (Sumatra Nord, Indonésie) entreprise dans le cadre de cette thèse, est un travail pionnier qui vise à comprendre les changements environnementaux à l’interface Homme/Nature, dans le but d’une reconstitution paléogéographique. Cet ancien comptoir commercial portuaire du Détroit de Malacca, actif entre les XIème et XIVème siècles AD, se trouve aujourd’hui à 7 km du rivage. Afin de s’interroger sur les variables de contrôle naturelles et anthropiques de l’évolution paysagère de la région, des investigations ont été menées à Kota Cina et dans la vallée de Deli. Deux approches ont été privilégiées : (1) une approche géomorphologique qui permet de reconstituer les dynamiques hydro-sédimentaires du site et de sa vallée ; (2) une approche biogéographique à travers une analyse du contenu phytolithiques des dépôts de Kota Cina, afin de renseigner l’évolution de la végétation du site. Cette étude met en exergue des évolutions paléoenvironnementales notables, en réponse à des forçages singuliers. Le volcanisme pré-holocène de la région a engendré par son détritisme un remplissage majeur de la vallée. La réponse hydro-sédimentaire holocène a modifié la géomorphologie de la région par une forte incision et un important transfert sédimentaire. Enfin, à l’époque historique, une nouvelle transformation paysagère a eu lieu avec l’anthropisation du milieu, notamment à partir du XIXème siècle avec l’essor des plantations coloniales
Paleoenvironment reconstructions and geomorphological dynamics understanding are increasingly being considered with regards to archaeological research. However, in Indonesia, this approach remains unusual. The present study of Kota Cina site (North Sumatra, Indonesia) is a pioneering work that aims to understand environmental changes dynamics at the human/nature interface for the purpose of paleogeographic reconstruction. Kota Cina is an ancient trade harbour of the Strait of Malacca. It was active between the XIth and the XIVth centuries AD. Nowadays, the site is located at 7 km from the coast. In order to examine the implication of natural and anthropogenic factors in the landscape changes of the region, investigations were carried out at Kota Cina and the Deli Valley. Two approaches were developed: (1) a geomorphological approach to reconstitute the hydro-sedimentary dynamics of Kota Cina site and its valley; (2) a biogeographical approach to reconstruct the vegetation changes at Kota Cina from a phytolith analysis of the site deposits. This work highlights important paleoenvironment changes as response to unique forcings. The pre-Holocene volcanism of the region generated a major filling of the valley by its detritism. The Holocene hydro-sedimentary response has altered the geomorphology of the region through a strong incision and significant sediment transfer. Finally, during the historical period, new landscape changes took place with the environment anthropisation, especially from the XIXth century with the development of colonial plantations

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Zhao, Zhijun. "Rice domestication in the middle Yangtze Region, China : an application of phytolith analysis /". free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9823337.

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Corteletti, Rafael. "Projeto arqueológico Alto Canoas - Paraca: um estudo da presença Jê no planalto Catarinense". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/71/71131/tde-19042013-093054/.

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Nesta tese vou apresentar novos dados sobre padrões de ocupação dos Jê Meridionais e minhas interpretações sobre a história deste povo, com base em meu estudo de caso, do Alto Rio Canoas, região de Urubici, em Santa Catarina, Brasil. No planalto, os camposde altitude e a mata de araucária dominam a paisagem. Nas serrarias de Urubici, as nascentes de vários arroios e rios começam em zonas húmidas, com solos rasos e pedregosos, na área dos campos, a cerca de 1800m de altitude. Estas águas correm através de vales incisos florestados pela mata de araucária criando cachoeiras e corredeiras, que acabam por se transformar no meândrico Rio Canoas, que flui no meio de um vale largo e plano, em torno de 1000m acima do nível do mar. A montanhosa região de Urubici foi intensamente pesquisada na década de 60, mas depois disso, a pesquisa ficou estagnada. Os principais pontos deste projeto foram: Primeiro, foram revisadas e atualizadas as pesquisas anteriores, revisitando a maioria dos sítios arqueológicos mapeados na década de 60, atribuindo-lhes coordenadas geográficas, fotos e mapas, e descrições ambientais recentes. Segundo, além da visita aos sítios mapeados previamente, foi realizado um mapeamento oportunista de novos sítios, baseado em entrevistas com membros da comunidade local, o que gerou um novo mapa arqueológico da região. Terceiro, com base nessas informações e nas novas escavações em sítios específicos, iniciou-se a reflexão sobre as paisagens Jê do Sul, com o objetivo de compreender a história de longo prazo e o sistema de assentamento da tradição arqueológica Taquara-Itararé. Quarto, a partir das análises de grãos de amido de fitólitos, a partir de restos carbonizados de alimento aderidos a parede da cerâmica coletada na escavação do sítio Bonin, foram obtidos novos dados, importantíssimos para pensar novas formas de interpretação na arqueologia da tradição Taquara-Itararé. Tais análises trouxeram evidências de produção de alimentos como Zea mays, Cucurbitasp., Manihotsp., e o consumo alimentar de Phaseolussp. e Dioscoreasp. entre outros, o que, sem dúvida, é uma chave para pensar em outro tipo de organização social, mobilidade e economia para os povos proto-Jê Meridional. Em quinto lugar, no sentido de pensar uma \"estratigrafia paisagem do Jê Meridional\" um banco de dados SIG foi utilizado como uma ferramenta para criar modelos virtuais de, por exemplo, a análise visibilidade acumulada entre sítios e análise de rotas de menor custo.
In this thesis I will present new data on Southern Jêsettlement patterns, and my interpretations regarding the history of these people, based on my case study, from the Upper Canoas River, Urubici region, in Santa Catarina state, Brazil. On the highland plateau, the High Altitude Grasslands (or Campos) and the Paraná Pine Forest dominate the landscape. In the Urubici hills, various headwaters begin in wetland areas, with shallow and rocky soils, on Campos, around 1800m altitude. These waters flow through incised valleys forested by Paraná Pine and create waterfalls and rapids, which eventually turn into the meandering Canoas River that flows in the middle of a wide and flat valley, around 1000m above sea level. The mountainous Urubici region was intensively researched in the 60\'s, but after that, research wasstagnated. The main points of this project were: First, I reviewed and updated previous research, which involved relocating the sites mapped in the 60\'s, assigning them geographical coordinates, photos and maps, and improving environmental descriptions. Second, I carried out an inspection of previously recorded sites and carried out opportunistic survey, based on interviews with members of the local community, looking for new sites, and making a new archaeological map of the region. Third, based on this information and my new excavations at targeted sites, I aimed to think about the Southern Jê landscapes, with a view to understanding the long-term history and the settlement pattern of the Taquara-Itararé archaeological tradition. Fourth, starch grain and phytoliths analysis from charred food remains founded in pottery, collected at Bonin site excavation, achieved important new data for new interpretive ways on Taquara-Itararé archaeology, bringing to us food production evidences of Zea mays, Cucurbitasp., Manihotsp., and food consumption of Phaseolussp.,Dioscoreasp. and others, what is a key to think another kind of social organization, mobility and economy for southern proto-Jê people. Fifth, in a way to think the \"southern Jê landscape stratigraphy\" aGIS database were used like a tool to create virtual models of, for example, cumulative viewshed analysis and least coast pathway analysis.

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Guntzer, Flore. "Impact de la culture intensive de céréales sur les stocks de silice biodisponible dans les sols européens". Aix-Marseille 3, 2010. http://www.theses.fr/2010AIX30064.

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Le silicium est présent dans les mêmes proportions que la plupart des macronutriments dans les végétaux, et est reconnu pour être un élément bénéfique pour leur croissance. Le silicium a beau être abondant dans le sol, les formes solides sous lesquelles on le trouve ne sont pas disponibles pour les plantes. Dans des écosystèmes naturels, les phytolithes (particules de silice amorphe d'origine végétale) sont l'une des sources de silicium les plus importantes pour les plantes car à pH > 4, leur cinétique de dissolution est plus rapide que celles des minéraux silicates. Or dans les sols cultivés où l'on exporte les végétaux, les phytolithes ne reviennent pas au sol. Nous avons étudié des sols cultivés sous céréales pour mesurer l'impact de l'exportation des récoltes sur le stock de silice amorphe. Il en résulte que tous les sols étudiés sont appauvris. Dans un deuxième temps, nous avons étudié différents amendements en silice. Il en ressort que la restitution de pailles, même sur un laps de temps court, a un réel impact sur les stocks de silice amorphe et pourrait être une méthode simple pour atténuer l'appauvrissement des stocks de silice biodisponible dans les sols cultivés
Silicon is found in the same proportions as most macronutrients in plants and is known to be beneficial for their growth. Although silicon is one of the main constituents of soil, most of the forms under which it is found are not available for plants. In natural ecosystems, phytoliths (amorphous silica particle recycled by plants) are one of the main sources of silicon for plants as their dissolution cinetic is way faster than that of other silicate minerals at pH > 4. However in cultuvated soils where the crops are exported, phytoliths do not come back to the soil. We studied soils cultivated with cereals to asses the impact of the exportation of crops on the amorphous silica stock. All studied soils were poor in amorphous silica. We also studied the effect of different Si fertilization. Restoration of straw to the soil, even for a short period of time, has a real impact on the stock of amorphous silica. This means the restitution of straw could be a simple remediation for the decrease of the bioavailable silica stock of cultivated soils

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Walshaw, Sarah Catherine. "Reconstruction of environment in early Bronze Age Syria through phytolith analysis on human dental calculus". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ46995.pdf.

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Ryan, P. L. "Diversity of plant and land use during the Near Eastern Neolithic : phytolith perspectives from Çatalhöyük". Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/645476/.

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Based in the Konya Basin of Central Anatolia, the Neolithic site of Çatalhöyük (East Mound) is important to our understanding of the development of early agricultural societies. Occupied between 7400-7100 cal BC to 6200-5900 cal BC, the site is notable for its extended period of occupation, large size and densely packed architecture. Research into Neolithic plant and land use has generally focused upon agricultural crops and the environments in which they are grown, and less is known about the role of wild plants and the non-food use of plants in the later Neolithic. This project used phytolith analysis, a micro-botanical technique, as a way of exploring patterns of plant and land use. Phytoliths present in sediments collected from middens and buildings were analysed to investigate plants exploited for food, fuel, craft activities, and construction. Unusually abundant macroscopically visible silicified (phytolith) remains, including from plant artifacts, also offered direct evidence for certain types and locations of plant-use. A wide range of plant-uses and pathways has highlighted how phytolith assemblages relate to different kinds of ‘input sources’, and how certain environmental habitats may be reflected in the different types of original materials found in archaeological contexts. Quantified analysis of sediments has detected temporal changes in plants present throughout the site occupation, including a dramatic increase in amounts of Phragmites australis. This increase probably reflects the invasive potential of that particular wetland reed, and may be the result of anthropogenic impact. Whilst the use of cereals, in particular wheat, is emphasised, wild plants were also stored for food and used for a wide range of other purposes. The role of wild plants in diversification strategies, together with the sustainability of their exploitation, should be further considered at other Neolithic sites and may have varied in relation to the diversity of Near Eastern environments.

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García-Granero, Fos Juan José. "From gathering to farming in semi-arid Northern Gujarat (India): a multi-proxy approach". Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/351960.

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Understanding how human societies adapted to past environmental and climatic variability is fundamental to face present and future climatic events, particularly in highly vulnerable arid and semi-arid regions. Northern Gujarat (northwestern India) is a semi-arid ecotone where high intra- and inter-annual precipitation variability has a great impact on the availability of resources and, consequently, on human populations that depend upon them. The main aim of this thesis is to understand how and why plant-related subsistence strategies changed throughout the Holocene in northern Gujarat, with special emphasis on the transition from gathering to farming. This study considers macro and microbotanical remains from two hunter-gatherer occupations (Vaharvo Timbo and the Mesolithic levels at Loteshwar) and two agro-pastoral camps (Datrana IV and the Anarta levels at Loteshwar) to understand how early and middle Holocene populations interacted with the environment in terms of livelihood strategies. Moreover, archaeobotanical remains from one late Holocene urban settlement (Shikarpur) are also analysed to ascertain how urban societies exploited this semi-arid environment in terms of plant acquisition and consumption. The results show that hunter-gatherer groups that inhabited northern Gujarat during the early-mid (semi)permanent water bodies, including grasses, pulses, sedges, tubers and sesame. Holocene exploited a wide range of wild plants originating from The progressive weakening of the Indian Summer Monsoon ca. 7000 years ago compelled human populations to adopt semi-nomadic pastoralism and plant cultivation, which resulted in the domestication of several small millet species, pulses and sesame. With the advent of settled urban life in the late Holocene the inhabitants of northern Gujarat developed a more intensive land-use strategy involving a cereal-pulse intercropping agricultural system. This study is an illustrative example of human adaptation to climatic and environmental changes in semi-arid regions. From a methodological perspective, the results of this thesis show that an integrated multi-proxy approach, in which several botanical proxies and a broad-spectrum sampling strategy are used together, is the best possible way to explore diet and plant use strategies in past societies. Future research will integrate archaeobotanical data in a multi-disciplinary perspective to help designing sustainable land use strategies in northern Gujarat and other marginal areas worldwide.
Aquesta tesi s’ha dut a terme en el marc del projecte NoGAP (North Gujarat Archaeological Project), un acord de col·laboració entre el grup de recerca CaSEs (Complexity and Socio-Ecological Dynamics) del Departament d’Arqueologia i Antropologia de la Institució Milà i Fontanals del Consell Superior d’Investigacions Científiques (IMF-CISC, Barcelona), i el Departament d’Arqueologia i Història Antiga de la Maharaja Sayajirao University of Baroda (MSUB, Vadodara, Índia). Les mostres arqueològiques analitzades com a part d’aquesta tesi doctoral provenen de tres excavacions desenvolupades dins el marc del projecte NoGAP (Loteswar al 2009, Datrana IV al 2010 i Vaharvo Timbo al 2011), i una excavació del Departament d’Arqueologia i Història Antiga de la MSUB (Shikarpur al 2012). El treball de laboratori es dugué a terme majoritàriament al laboratori BioGeoPal de la IMF-CSIC. Aquesta tesi es presenta com a compendi de sis articles publicats a revistes de reconegut prestigi internacional. Alguns dels articles són metodològics i d’altres es centren en un cas d’estudi, però tots tenen una mateixa finalitat: entendre el paper dels recursos vegetals en la subsistència de les poblacions que ocuparen el Gujarat del Nord durant l’holocè. Dos d’aquests articles versen sobre la identificació de mills petits (el principal cultiu al Gujarat del nord durant la prehistòria) al registre arqueològic mitjançant l’estudi de col·leccions de referència de plantes modernes, i estan publicats a Archaeological and Anthropological Sciences (Madella et al. 2013) i Vegetation History and Archaeobotany (García-Granero et al. enviat per publicació a). Els altres quatre articles discuteixen els resultats de l’anàlisi de les restes arqueobotàniques dels quatre jaciments mencionats, i estan publicats a Vegetation History and Archaeobotany (García-Granero et al. 2015), Current Anthropology (García-Granero et al. en premsa), Archaeological and Anthropological Sciences (García-Granero et al. enviat per publicació b) i de nou Vegetation History and Archaeobotany (García-Granero et al. enviat per publicació c). Aquesta tesi està organitzada en dues parts principals: la Introducció (Capítols 1-4) i la Discussió (Capítols 5-7). La Introducció inclou la Presentació de la tesi (Capítol 1), les Preguntes de la Recerca (Capítol 2), el Marc de la Recerca (Capítol 3) i els Materials i Mètodes emprats (Capítol 4); mentre que la Discussió inclou els Resultats Principals (Capítol 5), la Discussió d’aquests resultats (Capítol 6) i les Conclusions (Capítol 7). Els sis articles que formen part d’aquesta tesi es presenten a continuació, ja sigui en format final (articles publicats) o adaptats a l’estil de la resta de la tesi (articles encara en procés de revisió/publicació). Finalment, s’inclouen una sèrie d’apèndixs amb les dades en brut de les anàlisis arqueobotàniques

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Albert, Cristóbal Rosa Maria. "Study of ash layers through phytolith analyses from the Middle Paleolithic levels of Kebara and Tabun caves". Doctoral thesis, Universitat de Barcelona, 1999. http://hdl.handle.net/10803/2606.

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The Levant, and Israel in particular, possesses a rich archaeological record of prehistoric caves from the Middle and Upper Paleolithic periods. Some of these caves have been subjected to intensive multidisciplinary studies, providing information not only on the archaeological record, but also on the diagenetic processes that have affected this archaeological record through time.

One of the most interesting remains preserved in these caves is the ashy features or hearths. They are usually abundant and often visually well preserved. Ash accumulations are sometimes meters thick. Their presence has made it possible to use and develop new techniques in order to obtain more information about the fire related activities carried out in the cave, the functionality of these hearths and their significance in the social life of past cultures.

One of the techniques used for the study of hearths involves the analysis of phytoliths. Phytolith analyses in prehistoric hearths can be used for a variety of purposes. These include the identification of ash remains, even in locations where they are not visible to the naked eye due to diagenetic alteration; the identification, in a specific hearth, of the use of wood/bark as opposed to other types of vegetation such as grasses, and the identification of different species of trees and/or other plants used as fuel in a specific hearth. It is also conceivable that the latter two sources of information could provide indications of possible uses of fire (cooking, warmth, technical purposes, etc.) based on the different fuels used.

An interpretation of the phytolith data from an ashy feature or hearth needs to be based both, on the morphological characteristics and the quantitative analyses of the phytoliths. This provides information on the absolute number of phytoliths produced by the trees and other plant taxa present in the area, and on the number of phytoliths per unit weight of sediment. This in tum may indicate, for example, the extent of mixing of ash with other soils, the relative proportions of say wood ash and grasses in a hearth, or the use of fruits from trees or other parts of the trees.

This study focuses on the ash layers frorn two prehistoric caves in Israel, Tabun and Kebara, both located on Mount Carmel, Israel (Figure 1). Tabun was occupied during the Lower and Middle Paleolithic periods and Kebara was occupied during the Middle and Upper Paleolithic periods. Both caves have visible hearths, with those in Kebara being particularly impressive.

Alternative modes of occupation of Tabun Cave during the deposition of the Mousterian Levels B and C, have been proposed. Garrod & Bate (1937) interpreted the archaeological record of both levels as being indicative of domestic occupationaI activities. Jelinek et al. (1973) proposed that the presence of articulated limb bones of "Dama mesopotamica" in the Level B sediments below the cave chimney, indicated that the cave was used as a natural game trap. They also noted that the white ash layers in Level C extended across the whole cave, and proposed that this was due to the burning of natural vegetation in the cave. The study carried out in Tabun cave aims at clarifying the modes of occupation during these periods.

Level B sediments closely resembles the terra rossa soil, that is common in this region. Burning activity is inferred from charcoal fragments observed in thin sections. A minor wood ash component is present based on the preponderance of phytoliths with a variable, irregular morphology, produced mostly in wood and bark as compared to those with a consistent or characteristic morphology, as well as phytoliths with shapes characteristics of those formed in wood and bark of local trees. Thus fires were produced in the cave during this period. The cave may also have been used as a game trap.

Level C is composed of multiple layers of brown, black and white sediments. Micromorphology, mineralogy and phytolith analyses all show that these layers are mixtures of terra rossa soil and ash, with the latter being abundant in the white layers. The phytoliths in these layers are derived almost entirely from wood and bark, and not from grasses. These observations are consistent with a domestic occupational mode.

Kebara cave is a well studied archaeological site. It contains abundant visible hearths and ash-derived minerals that are the major component of the Mousterian sediments. The latter are in varying states of preservation. Furthermore, archeobotanic information is available from charred remains. Kebara cave is thus an ideal location to study the potential of phytoliths to provide information on the mode of fire used in the cave, to assess the input of other plant materials, as well as to determine the effects of diagenesis on phytolith preservation.

Sixteen samples were analyzed in terms of their mineralogy, phytolith contents per unit weight of acid insoluble fraction, and phytolith morphologies. In general the preservation of the phytoliths is good, except for the two samples in which the mineral component at present is largely ash-derived calcite. The cave sediments contain about ten times more phytoliths than those present in the four samples analyzed from outside the cave. The major source of plant material input into the cave is clearly from the wood and bark used for the fuel for fires. The grass phytoliths present in the samples are also thought to have been brought into the cave mainly associated with the wood/bark fuel. Sediments from the hearths, as well as those between the hearths, contain abundant wood/bark phytoliths. The two samples of the latter contain also appreciable amounts of phytoliths not known to be present in wood and bark, as do other hearth-derived samples. Plant materials other than those used as fuel, were thus also brought into the cave.

The study about Kebara cave shows that phytoliths analysis, in conjunction with detailed mineralogical, stratigraphic, archaeobotanic and field information, can provide a more complete understanding of the use of plant materials in prehistoric caves for both fuel and other purposes.

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Crespin, Julien. "Analyse de la composition isotopique en oxygène ([delta][18]O) des phytolithes de bois et des diatomées lacustres pour la mise au point de nouveaux traceurs paléoclimatiques continentaux". Aix-Marseille 3, 2008. http://www.theses.fr/2008AIX30065.

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Ce travail a permis d'appliquer avec succès la technique d'extraction de l'oxygène par. Afin de palier au manque de marqueurs quantitatifs des paléoclimats continentaux, ce travail s'attache à définir de nouvelles relations entre [delta][18]O"silice biogenique", [delta][18]O"eau de formation" et température. Pour ce faire, la technique d'extraction de l'oxygène par fluorination-laser IR a été appliqué avec succès à l'analyse [delta][18]O de très petits échantillons de silice biogénique. Pour la première fois, une relation thermo-dépendante entre [delta][18]O"phytolithes de bois" et [delta][18]O"précipitation" est mise en évidence, pour des assemblages phytolithiques de forêts tropicales humides (Queensland, Australie). Une relation thermo-dépendante entre [delta][18]O"diatomees", et [delta][18]O"eau du lac" obtenue pour le lac d'Annecy confirme les relations mises en évidence pour les diatomées. Ces relations pourront servir de bases à l'interprétation d'enregistrements quaternaires[delta][18]O"phytolithes" (e. G. Région Australo-Pacifique) et [delta][18]O"diatomées" (lacs)
In order to compensate for the scarcity of quantitative terrestrial paleoclimate proxies, this PhD thesis aim to define new thermo-dependant relationships between [delta][18]O"biogenic silica" and [delta][18]O"forming water". The IR Laser-Fluorination technique for extracting oxygen was successfully used for analyzing [delta][18]O composition of small to minute samples of biogenic silica. For the first time a thermo-dependant relationship between [delta][18]O"wood phytoliths" and [delta][18]O"rainfall" is evidenced, for phytolith assemblages from rainforests (Queensland, Australia). The thermo-dependant relationships between [delta][18]O"lake diatoms" and [delta][18]O"lake water" obtained from the lake ofAnnecy (France) supports the previous calibration obtained for lacustrine diatoms. These relationships will be used as references for interpreting [delta][18]O"phyitoliths" (e. G. From the Australo-Pacific area) and S^Odiaioms (from lakes) quaternary records

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McCune, Jenny Lyn. "The long-term history of plant communities on southeastern Vancouver Island based on vegetation resurveys and phytolith analysis". Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45618.

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Terrestrial plant communities are complex systems, and major storehouses of global biodiversity. The composition of a plant community today is contingent on conditions that have occurred throughout its history. Therefore, an understanding of current plant community structure requires an understanding of its origin and its variability over time. In this thesis, I investigate the history of plant communities on southeastern Vancouver Island, Canada, at two time scales. These communities are now highly fragmented and threatened by human disturbance, but they also have a long history of management by indigenous peoples. To quantify changes due to recent urbanization, I resurveyed 184 vegetation plots originally surveyed in 1968. I documented striking increases in plot-level and total species richness, but a decline in the variation in plant community composition between plots, a phenomenon called ‘biotic homogenization’. Exotic species were more likely than natives to increase over time, but exotic colonizations were not correlated with biotic homogenization or native declines. Plant life history traits predicted colonizations based on landscape context within 500m of a plot, but extirpations were rare and much less predictable, suggesting time lags in plant community response to landscape disturbance and fragmentation, and a potential extinction debt. I used plant microfossils called phytoliths extracted from soil to investigate changes in plant communities prior to European settlement. I established that the ratio of asterosclereid phytoliths produced in the needles of Douglas-fir (Pseudotsuga menziesii) to the rondel phytoliths produced by most grasses can accurately distinguish between Douglas-fir dominated forests and Garry oak (Quercus garryana) savannah habitats today. I then examined changes in this ratio with depth at seven local sites, finding that infilling by Douglas-fir forest first began at different times, depending on the site. However, some savannah sites have supported grassy vegetation for at least two thousand years. Active management to maintain open conditions will be necessary to preserve rare species that evolved in these conditions. These investigations demonstrate that examining the history of plant communities can reveal surprises and challenge assumptions about how they respond to disturbance. This knowledge can improve ecological theory, and inform management and conservation strategies.

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Levin, Maureece. "Food Production, Environment, and Culture in the Tropical Pacific: Evidence for Prehistoric and Historic Plant Cultivation in Pohnpei, Federated States of Micronesia". Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/19669.

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Food production, or the cultivation and processing of edible materials, is closely linked to both the physical environment and human social systems. This is especially true on the islands of Remote Oceania, where cultivation of plants introduced with colonization has always been a key component of survival. This project centers on the production systems of an island in the west central Pacific: Pohnpei, Micronesia. It addresses the fundamental question of how food production is related to changes in social and physical environments and also addresses the optimum ways to archaeologically study plant remains in tropical oceanic environments with poor preservation. In order to examine these questions, this project looks at human-environment interrelationships using historical ecology. A multi-pronged approach was used in this research. Archaeological survey was used to identify prehistoric and historic features on the landscape and to map the distribution of food production activities. Excavation of selected archaeological features, including breadfruit fermentation pits, yam enclosures, and cooking features, was conducted to examine formation patterns. Paleoethnobotanical analysis included collection and analysis of flotation samples for carbonized plant macroremain analysis and sediment samples for phytolith analysis. Finally, because a reference collection is key to all paleoethnobotanical research, plant specimens from multiple Pacific locations were collected and processed for phytolith reference. Botanical data show that phytolith analysis is very useful in the Pacific region, as many economically important taxa produce phytoliths. However, because of differential silica uptake, it should be used in conjunction with other methods. Archaeological phytolith analysis of the garden landscape shows disturbance caused by pigs, which were introduced historically, a change from the prehistoric phytolith record, which shows no major shifts. Combined analysis of plant macroremains and phytoliths from secure archaeological contexts shows the use of banana leaves in breadfruit cooking in the historic period, highlighting the importance of multi-method paleoethnobotanical study. These data point towards an anthropogenic environment and stable agricultural system that was present in late prehistoric Pohnpei. Major changes occurred in the historic period, although production of plant foods that were important for centuries continues to flourish today.

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Shillito, Lisa Marie. "Investigating traces of activities, diet and seasonality in middens at Neolithic catalhoyuk : An integration of microstratigraphic, phytolith and chemical analyses". Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529968.

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This research examines formation processes of middens and the associated activities at the site of Catalh6yuk, Turkey. Using this site as a case study, this research has wider significance for understanding the Neolithic of the region and for the study of middens in general. Middens are a unique deposit in that they contain traces of activities that may not be found in cleaner contexts such as floors, and contain materials such as ash, animal dung, phytoliths and coprolites which can inform on plant resource use, diet and subsistence strategies at a high temporal resolution. In this research thin section micromorphology is used, combined with phytolith analysis of individual layers, to examine both the composition and associations of finely stratified midden deposits in situ. Additional analyses of mineral components using FT-IR and SEM-EDX has been carried out, along with biomolecular analysis of organic residues in coprolites by GC-MS, to further characterise material that is difficult to analyse by thin section alone. This integrated analysis contributes to the understanding of midden formation processes and activities, as well as environment, agriculture, plant resource use, diet and fuel use. This analysis has developed a new method for classifying complex midden deposits based on their micro-inclusions and micro-structure, and has identified key deposits such as hackberry pericarps in coprolites, which can potentially be used as seasonal "markers". Examination of midden deposits has provided direct evidence for the use of dung as fuel through the presence of faecal spherulites and reed phytoliths in fuel ash layers, and FT-IR analysis of material embedded in ash indicates clay deposits which could be linked to large open-air firing of pottery. This has wider significance for understanding early pyrotechnology during the Neolithic, and the widespread use of wetland resources i.e. reeds. The dominance of reed phytoliths in the midden assemblage supports the idea of a local wetland environment during the Neolithic. However, thin section observations indicate that phytolith taphonomy at the site is currently poorly understood, and that phytolith size is not a reliable indicator of the growing environment. The samples analysed were found to contain surprisingly few cereals, which also raises questions about the taphonomy of the non-charred cereal remains, and the role of crop growing in the economy. Analysis of coprolites, a frequent deposit in middens, has indicated the presence of lithocholic acid and coprostanol which indicate a human origin for much of this material. This has raised interesting questions on the idea of cleanliness, and has allowed further analysis of diet through observing phytoliths and other inclusions, such as bone, embedded in coprolites, both in situ in thin section, and through examination of extracted phytoliths.

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