Suitability of phytoliths as a quantitative process tracer for soil erosion studies

<p>Phytoliths are a plant microfossil commonly used as qualitative archive markers in archaeological and paleoecological studies. Their potential uniqueness to the vegetation cover, robustness to weathering, and lack of chemical alteration along the paths make them a potentially suitable tracer for quantitative erosion studies.<br>In this pilot study, we explore the potential of phytoliths in a sediment fingerprinting study in the Ceguera catchment (28 km2) in NE Spain. The phytolith concentrations and morphologies of four land cover classes (agricultural land, badland, forest, and shrubland) were analyzed, and their contributions to four sediment mixture samples along the river course were modelled. Phytoliths concentrations allowed us to discriminate sources sufficiently, albeit with limited sample size. The performance of the phytoliths as the tracer was tested by reproducing the sources of artificial sediment mixture samples with satisfactory recall ratio. Results identified badlands to be the main contributor, with 84–96% of the sediment load to the sinks, followed by shrublands (median 5%) and agricultural lands (median 2%). Additionally, an intensively used agricultural area in the SW of the catchment was well indicated. These major findings can be reproduced by other conventional erosion studies from this area, indicating that phytoliths are suited to quantifying erosion patterns in mesoscale catchments.</p>

Extirpations and extinctions: a plant microfossil-based history of the demise of rainforest and wet sclerophyll communities in the Lake George basin, Southern Tablelands of NSW, south-east Australia

Sites recording the extinction or extirpation of tropical–subtropical and cool–cold temperate rainforest genera during the Plio–Pleistocene aridification of Australia are scattered across the continent, with most preserving only partial records from either the Pliocene or Pleistocene. The highland Lake George basin is unique in accumulating sediment over c. 4 Ma although interpretation of the plant microfossil record is complicated by its size (950km2), neotectonic activity and fluctuating water levels. A comparison of this and other sites confirms (1) the extinction of rainforest at Lake George was part of the retreat of Nothofagus-gymnosperm communities across Australia during the Plio–Pleistocene; (2) communities of warm- and cool-adapted rainforest genera growing under moderately warm-wet conditions in the Late Pliocene to Early Pleistocene have no modern analogues; (3) the final extirpation of rainforest taxa at Lake George occurred during the Middle Pleistocene; and (4) the role of local wildfires is unresolved although topography, and, elsewhere, possibly edaphic factors allowed temperate rainforest genera to persist long after these taxa became extinct or extirpated at low elevations across much of eastern Australia. Araucaria, which is now restricted to the subtropics–tropics in Australia, appears to have survived into Middle Pleistocene time at Lake George, although the reason remains unclear.

International Code for Phytolith Nomenclature (ICPN) 2.0

Background Opal phytoliths (microscopic silica bodies produced in and between the cells of many plants) are a very resilient, often preserved type of plant microfossil. With the exponentially growing number of phytolith studies, standardization of phytolith morphotype names and description is essential. As a first effort in standardization, the International Code for Phytolith Nomenclature 1.0 was published by the ICPN Working Group in Annals of Botany in 2005. A decade of use of the code has prompted the need to revise, update, expand and improve it. Scope ICPN 2.0 formulates the principles recommended for naming and describing phytolith morphotypes. According to these principles, it presents the revised names, diagnosis, images and drawings of the morphotypes that were included in ICPN 1.0, plus three others. These 19 morphotypes are those most commonly encountered in phytolith assemblages from modern and fossil soils, sediments and archaeological deposits. An illustrated glossary of common terms for description is also provided.

Hasil Analisis Mikrofosil Tumbuhan (phytolith) Situs Wineki dan Padang Hadoa, di Kawasan Lembah Besoa, Sulawesi Tengah.

Phytoliths are plant microfossil made of silica that varies in shape and size. Variations of form happen when silica in soil is absorbed by plants then transported and deposited in various parts of plant cells. When the plant dies, the plant's organic matter decomposes and leaves the inorganic material of silica, which we know by the name of phytoliths. Silica can survive in various environmental conditions, That’s make phytoliths are important data for scientific research including archeology. Phytoliths analysis on soil samples from prehistoric Besoa Valley’s site aimed to reveal past environmental conditions and also find out the possibility of an economical plant utilization. Extraction performed on 18 soil samples from Wineki (box K1) and the Padang Hadoa sites (box K2 and K3). Techniques were performed using Sodium Polytungstate heavy flotation. Phytoliths identification results reveal palmae plants dominate the entire site, other phytolith derived from sample are Poaeceae, Cyperaceae and also two types of economic plants Oryza and Musaceae. Difference vegetation on past (dominated by palm) and current conditions (dominated by grasses)can indicate their changing environmental conditions either due to natural or due to human intervention. The existence of Oryza and Musaceae in Padang Hadoa sites can be an indication of the use by Padang Hadoa’s prehistoric occupant.Keyword : phytolith, Besoa Valley, Oryza, Musaceae Phytoliths merupakan mikrofosil tumbuhan berbahan silica yang bervariasi secara bentuk dan ukuran. Variasi bentuk phytolith terjadi ketika silica dalam tanah terserap oleh tumbuhan kemudian terangkut dan terdeposisi pada bermacam bagian sel tumbuhan. Ketika tumbuhan mati, material organic tumbuhan membusuk dan meninggalkan material anorganik berupa silica yang kemudian kita kenal dengan nama phytoliths. Sifat silica yang dapat terawetkan diberbagai kondisi lingkungan menjadikan phytoliths data penting bagi penelitian ilmiah termasuk bagi arkeologi. Analisis phytoliths pada sampel tanah dari kawasan prasejarah Lembah Besoa ini bertujuan untuk mengungkapkan kondisi lingkungan masa lalu dan juga mengetahui kemungkinan adanya pemanfaatan tumbuhan. Ekstraksi dilakukan pada 18 sampel tanah dari Wineki ( kotak K1 ) dan situs Padang Hadoa ( kotak K2 dan K3 ). Teknik yang dilakukan yakni dengan pengambangan menggunakan mineral berat Sodium Polytungstate. Hasil identifikasi mengungkapkan tumbuhan jenis palem mendominasi seluruh situs dibandingkan dengan jenis tumbuhan lain. Jenis tumbuhan lain yang dapat diidentifikasi dari sampel yaitu jenis Poaeceae, Cyperaceae dan juga dua jenis tumbuhan ekonomis Oryza dan Musaceae. Perbedaan vegetasi di masa lalu (yang didominasi oleh palem) dan kondisi saat ini (didominasi oleh rumput ) dapat menunjukkan adanya perubahan kondisi lingkungan baik karena alam atau karena campur tangan manusia. Keberadaan Oryza dan Musaceae di situs Padang Hadoa dapat menjadi indikasi adanya pemanfaatan jenis tumbuhan tersebut oleh manusia pendukung situs Padang Hadoa ini.Kata kunci: phytolith, Lembah Besoa, Oryza, Musaceae

Cretaceous and Cenozoic dinoflagellate cysts and other palynomorphs from the western and eastern margins of the Labrador–Baffin Seaway

New palynological analysis of samples from 13 offshore wells on the Canadian Margin and six wells on the West Greenland Margin has led to a new event biostratigraphic framework for Cretaceous–Cenozoic strata of the Labrador Sea – Davis Strait – Baffin Bay (Labrador–Baffin Seaway) region. This framework is based on about 150 dinoflagellate cyst taxa and 30 acritarch, algal, fungal and plant microfossil (mostly miospore) taxa. In the systematics we include three new genera of dinocysts (Scalenodinium, Simplicidinium and Taurodinium), 16 new species of dinocysts (Chiropteridium gilbertii, Chytroeisphaeridia hadra, Cleistosphaeridium elegantulum, Cleistosphaeridium palmatum, Dapsilidinium pseudoinsertum, Deflandrea borealis, Evittosphaerula? foraminosa, Ginginodinium? flexidentatum, Hystrichosphaeridium quadratum, Hystrichostrogylon digitus, Impletosphaeridium apodastum, Scalenodinium scalenum, Surculosphaeridium convocatum, Talladinium pellis, Taurodinium granulatum and Trithyrodinium? conservatum), four emendations of dinocyst genera (Alterbidinium, Chatangiella, Chiropteridium and Surculosphaeridium), six new combinations for dinocyst species (Alterbidinium biaperturum, Deflandrea majae, Kleithriasphaeridium mantellii, Simplicidinium insolitum, Spongodinium grossum, Spongodinium obscurum), one new acritarch species (Fromea quadrangularis), one new miospore species (Baculatisporites crenulatus) and one new combination for miospores (Tiliaepollenites crassipites). Most of the taxa included provide age information, almost exclusively last occurrences (range ‘tops’), but some are useful mainly for environmental interpretations. Collectively, they provide a powerful tool for helping to establish the geological history of the Labrador–Baffin Seaway.