Phytoliths Research Articles

Microarqueobotânica no Museu Nacional, UFRJ

Os primeiros estudos microarqueobotânicos, ainda que não fossem conhecidos por esse nome, remontam ao início do século XX. No entanto, a análise de fitólitos e grãos de amido recuperados de contextos arqueológicos no Brasil só começou a tomar forma há pouco mais de uma década, e ainda são poucos os grupos de pesquisa que estudam esses microvestígios no país. O Museu Nacional/UFRJ congrega um dos grupos pioneiros na área. Neste artigo é apresentado um breve histórico da disciplina no país e um pouco da trajetória dessa linha de pesquisa no Museu Nacional, incluindo os resultados preliminares de dois projetos recentes.

Corrigendum to “Identifying ancient water availability through phytolith analysis: An experimental approach” (Identifying ancient water availability through phytolith analysis: An experimental approach (2016) 73 (82–93), (S0305440316300930), (10.1016/j.jas.2016.07.006))

© 2019 The Author(s) The authors regret an error in the paper that does not affect the efficacy of the method. In the paper, we state that the ratio of phytolith forms calculated is the ratio of fixed (short) to sensitive (long) forms when in fact what is calculated is the ratio of sensitive to fixed forms. The authors would like to apologise for any confusion caused.

Advances in Geochemical Study of Phytolith Occluded Carbon

Advances in Geochemical Study of Phytolith Occluded Carbon

Phytolith Transport in Texturally Differentiated Soils

Phytolith Transport in Texturally Differentiated Soils

Diagnosis of medieval-era ploughing using phytolith analysis by the example of archaeological sites Kuckarki and Knyazhich of Moscow region

Территория Центральной России на протяжении всей истории подвергалась масштабным антропогенным воздействиям, экстенсивным по характеру, охватывавшим огромные площади и связанным в основном с сельским хозяйством. В то же время визуальные признаки подобного воздействия в дневных почвах сохраняются лишь первые сотни лет. С целью выявить наиболее устойчивые диагностические признаки былой распашки, нами были изучены: 1.экспонированные почвы археологического объекта Кукарки (Щелковский район), которые 500-600 лет назад предположительно распахивались; 2. последовательно погребенные в XIV-XV вв. под валом пашня и разновозрастные залежи археологического объекта Княжич (Коломенский кремль, г. Коломна). Анализ основных физико-химических свойств почв показал, что эти характеристики обладают различной степенью сохранности и сами по себе не могут служить надежными индикаторами агрогенного воздействия в прошлом. Наибольшей устойчивостью в почвах обладают признаки, связанные с содержанием и распределением фитолитов, которые могут служить диагностам и даже в отсутствие иных индикаторов.

The history of the phytolith investigations in Russia

В статье дается история развития фитолитного метода в России с момента первых работ до начала XXI века. Показано, что метод начал использоваться для решения фундаментальных вопросов эволюции черноземов, начиная с 1850 года, т.е. более 160 лет назад. Отмечается, что это одно из первых использований фитолитного анализа в науке в целом. Более того, именно в России фитолитный анализ был использован для решения генетических вопросов почвоведения, когда еще сама наука «почвоведение» не была выделена в самостоятельный раздел. За прошедшие почти 170 лет развитие фитолитологии в стране прошло через три стадии: единичные работы со значительным временным интервалом (середина XIX - первая половина XX веков); регулярные исследования отдельных ученых (вторая половина XX века); формирование научных коллективов в различных регионах страны с большим количеством публикаций по всем направлениям фитолитологии (XXI век).

Research progress and forecast of phytolith-occluded organic carbon stability in soil

As an important long-term terrestrial carbon fraction, the phytolith-occluded organic carbon (PhytOC) has become an important mechanism in the long-term terrestrial carbon sequestration. The contribution of PhytOC stability to the global terrestrial soil carbon pool is much greater than PhytOC stocks. The paper reviewed the formation mechanism and characteristics of PhytOC, the significance of studying the PhytOC stability, and the determinants of the PhytOC stability. PhytOC produced from different types of vegetations had significantly different stability. PhytOC produced from the same type of vegetations but under different growth environments also had different stability. The PhytOC in ancient soil was more stable than that in young soil. The morphological combinations of phytolith in plants were able to respond sensitively to saline-alkali concentrations and pH values in soil. The humidity and precipitation could affect the quantity, size, morphology, assemblages δ13C and δ18O of phytolith. The smaller the Si/Al ratio of phytolith was, the higher the stability would be.[Ch, 1 tab. 90 ref.]

PhytOC in plant ecological system and its important roles in the global soil carbon sink.

As a substantial component of soil organic carbon occluded within phytoliths，PhytOC is a result of biomineralization within plants and highly resistant to decomposition in the soil environment. PhytOC accumulation rates have contributed about 15.0%-37.0% to the estimated global mean long-term soil carbon accumulation rate which is 2.4 gm-2a-1 over the last 10 000 years. There are ways to enhance both short and long-term carbon sequestration by cultivation of high PhytOC-yielding plant species of agricultural crops. Most of the economically important agricultural plant species such as barley，maize，rice，sorghum，sugarcane and wheat, are producers of phytoliths. It was estimated that the above-mentioned crops globally produced PhytOC of （5.08-12.01）106 ta-1. The paper reviewed the formation mechanism，characteristics and accumulation rate of PhytOC in the plant ecological system，the agronomy measures to improve the accumulation rate and its important role in the global soil carbon sink. ［Ch，56 ref.］

Phytolith production in wetland plants of the Hangzhou Xixi Wetlands ecosystem

Phytoliths，also referred to as plant opal，are silicified features that form as a result of biomineralization within plants and plays an important role in terrestrial biogeochemical cycles of carbon and silicon. This study selected 18 different plant species at the Xixi Wetlands in Zhejiang Province，to determine the phytolith content and its production flux using microwave，Walkley-Black digestion，and a correlation analysis. The main purpose of this study is to provide scientific reference for understanding the role of phytoliths in biogeochemical cycles of silicon and carbon. Results showed strong variation in phytolith content among the 18 plants：Cortaderia selloana（7.7%），Setaria viridis（7.6%），Digitaria ternata（6.9%），and Phragmites australis （6.6%）were higher than Salvinia natans（1.3%），Halerpestes cymbalaria（1.1%），and Canna indica L.（1.0%）. A positive correlation between phytolith content and total SiO2 in the 18 plants（R2=0.663 3，P＜0.01）was also found. Phytolith production flux was 4.48-129.92 gm-2a-1；phytolith sequestration of atmospheric CO2 was 0.16-1.03 gm-2a-1；and the phytolith sequestration rate of atmospheric CO2 was 8.29 ta-1. So，it is very important to improve the flux of aboveground plant phytolith production in wetlands ecosystems by selecting a plant with high-phytolith（silicon）content and high-ANPP（aboveground net primary production）yields for the plant Phragmites australis.［Ch，1 fig. 1 tab. 35 ref.］

Miscanthus-grassland history in the Sengokubara area of Hakone-machi, central Japan, inferred from phytolith and charcoal records

箱根町仙石原のススキ草原において，ローム層などの表層堆積物中の植物珪酸体と微粒炭の分析を行い，過去約1,000年間の植生変遷と人為活動との関係を検討した．ススキ草原内の深さ1.1mの試坑断面中から採取した41点の試料を分析した結果，草本起源の植物珪酸体7分類群，木本起源の植物珪酸体3分類群が認められた．ススキ属型の珪酸体は深度68cmから上方で多く検出され，それより下方ではネザサ節型の珪酸体が多く検出された．微粒炭は地表から深度62cmまで連続的に検出されたが，それより下方では不連続的に検出され，量も少なかった．土壌中に含まれる腐植の年代測定結果と合わせて考えると，調査地では西暦1200年頃までに火入れを伴う人為的影響を強く受けるようになり，ネザサ節のハコネダケが優占する植生から，ススキ草原が卓越する植生へと変化したと推察される．

MICROFITOLITOS DE LAS POACEAE ARGENTINAS: II. MICROFITOLITOS FOLIARES DE ALGUNAS ESPECIES DEL GENERO PANICUM (POACEAE, PANICEAE) DE LA PROVINCIA DE ENTRE RÍOS

Foliar phytolith morphology of 8 species the Panicum ( P. bergii Arechav., P. decipiens Nees. ex Trin., P. dichotomiflorum Michx., P. gouinii Fourn., P. hians Elliott, P. laxum Sw., P. prionitis Nees and P. sabulorum Lam.) present in the prairie of Entre Rios Province, was described. Cluster analysis (UPGMA) and ordination by principal component analysis (PCA) were performed on 49 morphological characters from the 8 phytolith assemblages (OTUs). The results defined four groups: the first group includes P. laxum assemblage, the second one P. hians and P. decipiens assemblages, the third grollp P. prionitis assemblage and the last one with P. dichotomiflorum + [P. sabulorum + (P. bergii +P. gouinii)] assemblages. The 8 phytolith assemblages showed Panicoideae affinity ( sensu Twiss, 1992), and differed from the typical phytolith assemblages of other subfamilies. This study supported the previous infrageneric classification proposed by Zuloaga et al. (1993), with the exception of subgenus Dichanthelium wich appeared in this analysis related to species of subgenus Panicum .

Micormorphological diversity in leaf epidermal anatomy of Brachiaria species using elemental dispersive spectrophotometer analysis

In this study the micromorphological diversity linked to different elements silica bodies, epidermal leaf anatomy and elemental dispersive spectrophotometer (EDS) analysis (LM, SEM) of five species of genus Brachiaria was carried out. The technique of EDS analysis for grass taxonomy is used first time in Pakistan. This examination indicates variations in leaf blade epidermal characters such as shapes of silica bodies, prickles, and microhair and macrohair form. EDS analysis of the phytoliths determines a new structure used as an aid in phytosystematic characterization. The quantitative analysis provides silicon as a new taxonomic character to distinguish different species of the genus Brachiaria. Key words: Epidermal anatomy, micropalynological diversity, elemental dispersive spectrophotometer.

Morphotype diversity of phytoliths in Hungarian soil profiles

A talajok környezettörténeti kutatásokban való alkalmazásának egyik lehetséges módja, hogy a növényekben képződő, kémiai és fizikai tényezőknek egyaránt hosszú ideig ellenálló növényi opálszemcsék (fitolitok) által közvetített élőhelyi képet megfejtsük. A növényi opálszemcsék együttese a talajban történő felhalmozódás révén, a felszínt benépesítő növényvilág lenyomatát adja. Egy adott vegetációra jellemző fitolitegyüttes jellegét elsődlegesen a létrehozó növényzet befolyásolja, ugyanakkor a másodlagos – talajképződési és emberi – tényezők figyelembe vétele, számszerűsítése is fontos szereppel bír. A talajokban felhalmozódó növényi opálszemcsék minőségi elemzése révén konkrét növényi életközösségeket (élőhelyeket) jellemezhetünk; mennyiségi elemzésükkel, illetve talajainkban megfigyelhető eloszlásukkal pedig a növényi életközösségek talajfejlődésre kifejtett hatását, azok monotonitását és/vagy szakaszosságát ismerhetjük meg. Dolgozatomban 20 talajszelvény, 117 rétegmintával jellemzett fitolitismereti adatbázisát dolgozom fel. A vizsgálat célja, hogy a recens életközösségekhez hasonlóan, a megjelenő fitolit morfotípusok mennyiségi és minőségi jellemzőinek a figyelembevételével jellemezzem az egyes talajok által megjelenített élőhelyek fitolitképzési potenciálját, illetve visszacsatolást találjak a jelenségek és a talajok múltja között. Ehhez az ökológiában is alkalmazott diverzitási indexeket hívom segítségül. A morfotípus-diverzitási értékek egy talajszelvény fejlődésének összetettségét is megmutatja, így az eredmények alapján három, egymástól eltérő típust határoltam el. Az első típus, amelyik esetében a természetes és mesterséges hatások eredményeképpen növekedik a fitolitok és a morfotípusok száma, tehát a természetes fejlődési folyamathoz képest fitolittöbblet jelentkezik. A második típus esetében a talajszelvény helyzetéből adódóan fitolit- és szervesanyag-veszteség keletkezik, amely közvetlenül csökkenti a talaj morfotípus-változatosságát és fitolitmennyiségét, míg a harmadik típusba az intakt szelvényeket soroltam, ahol a szelvény fitolitösszletét csak a szelvényen tenyésző vegetáció alakítja, külső hatás nem játszik közre. Ebben a tekintetben ez egy belső folyamatok által, a külső folyamatok kizárásával fejlődő típus.

Temporal variability of fluxes of eolian‐transported freshwater diatoms, phytoliths, and pollen grains off Cape Blanc as reflection of land‐atmosphere‐ocean interactions in northwest Africa

Fluxes of airborne freshwater diatoms (FD), phytoliths (PH), and pollen grains (PO) collected with sediment traps off Cape Blanc, northwest Africa, from 1988 till 1991 are presented. Both continental rainfall variations and wind mean strength and direction play a key role in the temporal fluctuations of the fluxes of eolian traces in the pelagic realm. Drier conditions in Northern Africa in 1987 could have preceded the high lithogenic input and moderate FD flux in 1988. The PH peak in summer 1988 was probably caused by increased wind velocity. Wetter rainy seasons of 1988/89 might have promoted a significant pollen production in summer 1989, and FD in late 1989 and early 1990, as well as contributed to the reduction of the lithogenic flux in 1989/90. Decreased fluxes of FD, PH and PO, and higher contribution of the 6–11 μm lithogenic fraction in 1991 would mainly reflect minor intensity and decreased amount of continental trade winds. Air‐mass backward trajectories confirm that the Saharan Air Layer is predominantly involved in the spring/summer transport. Trade winds play a decisive role in the fall/winter months, but also contribute to the transport during late spring/summer. Origin of wind trajectories does not support a direct relationship between transporting wind‐layers and material source areas in Northern Africa. High winter fluxes of eolian tracers and high amount of trade winds with continental origin in summer warn against a simplistic interpretation of the seasonal eolian signal preserved in the sediments off Cape Blanc, and the wind layer involved in its transport.

Seasonal climatic variation recorded by phytolith assemblages from the Baoji loess sequence in central China over the last 150 000 a

The results from the regressive relation of phytolith assemblages from modern surface soils and climatic parameter show variations in temperature and precipitation and evolution of vegetation pattern since the last 150000 a in the Baoji loess section. The impact of changing monsoon intensity in different periods in this area is discussed.

Platy Quartz Phytoliths found in the Fossil Forest Deposits, Axel Heiberg Island, Northwest Territories, Canada

The occurrence of quartz particles having a platy morphology found in the white layers within the fossil forest deposits of Axel Heiberg Island, was further confirmed by optical and electron microscopic examinations. The platy quartz crystals were concentrated in the finer fractions. The δ 18O values of fractions enriched in platy quartz crystals ranged from +13.7 to +16.6 %0. These values were higher than those obtained for coarser fractions. The platy morphology and crystallographic character of the quartz particles concentrated in the finer size fractions are uncharacteristic both of aerosol derived material and of secondary silica. These findings and information available for the paleoenvironment of the study area favor a biogenic origin for the platy quartz. The oxygen-isotope data are consistent with this hypothesis. Tafelige Quarz-Phytolithe aus Ablagerungen fossiler Walder auf der Axel Heiberg Insel, NW-Territorium, Kanada Quarzteilchen mit einer tafeligen Morphologie, die in weisen Schichten von Ablagerungen fossiler Walder auf der Axel Heiberg Insel gefunden wurden, wurden mit optischen und elektronenmikroskopischen Untersuchungen weiter bestarkt. Die tafeligen Quarzkristalle wurden in den feinen Fraktionen konzentriert. Die δ 18O Werte der Fraktionen, die mit tafeligen Quarzkristallen angereichert wurden, variierten zwischen +13.7 und +16.6 %0. Diese Werte waren etwas hoher als die Werte fur die groben Fraktionen. Die tafelige Morphologie und die kristallographischen Eigenschaften der Quarzproben, die in den feinen Fraktionen konzentriert wurden, sind uncharakteristisch fur Materialien, die von Aerosols abstammen und von sekundarer Kieselerde. Diese Befunde und die Information uber die Palaoumgebung des studierten Gebiets begunstigen einen biogenen Ursprung fur den tafeligen Quarz. Die bestimmten Sauerstoffisotop-Daten waren auch in Ubereinstimmung mit dieser Hypothese.