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Koeltz discount for ECR *ISDR* members!!!

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Great news:
Hannah Hartung and Andrea Burfeid (ECR representatives) have negotiated with Per Koeltz in the last couple of months and came to a fantastic agreement: subscribed Young ISDR members with an active membership in ISDR, can get a 33% discount for Koeltz Botanical Books at any time they would like to order (not tied to conference offers). If applicable and interested, please contact us!

Per Koeltz also provided an interesting enterprise: if you are willing to write a proper book review  about one of the books, you will get a free book copy. Contact us, if you are interested and we will mediate contact details.
Finally, Koeltz will provide prizes for the Young ISDR activities in the future. Therefore, Koeltz is our first official sponsor. More info about this coming soon!


Paleolimnology: Diatomeas subfosiles del Lago Nahuel Huapi (Brazo Blest), Argentina

Diatomeas subfosiles del Lago Nahuel Huapi (Brazo Blest), ArgentinaGarcía, M.L. & Maidana, N.I.
Subfossil diatoms from Lago Nahuel Huapi (Brazo Blest), Argentina. The main objective of 
this study was to analyze subfossil diatoms from Nahuel Huapi Lake (Brazo Blest) in order to increase the 
knowledge about the region’s phycoflora, which until nowadays has been poorly studied. There were 47 
genera and 114 infrageneric taxa recorded, from which 1 is recorded for first time for Argentina and 18 are 

new records for Northern Patagonia (Argentina).

DOI: https://botanicaargentina.org.ar/diatomeas-bacillariophyceae-subfosiles-del-brazo-blest-del-lago-nahuel-huapi-argentina/
Link: https://botanicaargentina.org.ar/diatomeas-bacillariophyceae-subfosiles-del-brazo-blest-del-lago-nahuel-huapi-argentina/

Paleolimnology: Little Ice Age to present paleoenvironmental reconstruction based on multyproxy analyses from Nahuel Huapi Lake (Patagonia, Argentina)

Little Ice Age to present paleoenvironmental reconstruction based on multyproxy analyses from Nahuel Huapi Lake (Patagonia, Argentina)
Serra, M.N, García, M.L., Maidana, N.I, Villarosa,G., Lami, A. & Massaferro, J.
Lakes are ideal sites to study environmental changes since they preserve climatic, anthropogenic, and volcanic signals in their sediments. Brazo Blest is one of the most important ramifications of Lake Nahuel Huapi and it is an interesting site to study climatic variations as it receives direct discharge of heavy suspended sediments loads from Tronador Glacier through the Frías River, as a result of the abrasion of the bedrock and runoff from the surrounding Valdivian Forest. A short sediment core from Brazo Blest was analyzed for chironomid and diatom assemblages and pigments in order to reconstruct environmental changes during the last 100 years in the basin under study. This multiproxy study also included geochemical and physical analyses and reveals changes in the pro…

Diatom Taxonomy: Staurosira patagonica sp. nov. a new diatom (Bacillariophyta) from Santa Cruz province, Argentina

Staurosira patagonica sp. nov. a new diatom (Bacillariophyta) from Santa Cruz province, ArgentinaGarcía, M.L., Maidana, N.I., Ector, L. & Morales, E.A
This paper presents several Navicula sensu stricto species identified during a palaeocological study of a sediment core from Lake Miedwie in the vicinity of Szczecin, north-western Poland. Light microscopic examination of 91 samples revealed Navicula cari to be abundant as well as an unidentified diatom species corresponding to Navicula paracari, published by Lange-Bertalot as a manuscript name but not properly validated. A formal description of Navicula paracari is provided with a comparison to similar species including N. cari. Navicula cari is distinguished from N. paracari in having longer valves on average, lower stria density (distinguished with scanning electron microscopy) and by the presence of a prominent external sternum. Navicula microcari is mainly distinguished by distinctly narrower valves and a higher areola density. 

Diatom Taxonomy: Cocconeis neuquina Frenguelli (Bacillariophyta): emended description, lectotypification, ecology and geographical distribution.

Cocconeis neuquina Frenguelli (Bacillariophyta): emended description, lectotypification, ecology and geographical distribution. 
García, M.L., Echazú, D.M. Romero O. E. & Maidana, N. I. 

In this article, we examine the type material of Cocconeis neuquina Frenguelli from the type locality in Neuquén province and other samples in southern Santa Cruz province (Patagonia, Argentina). Cocconeis neuquina is a small species with an oval-subcircular to broadly elliptical valve outline. The sternum valve is externally convex, striae are radiate and uniseriate, and areolae are rounded towards the mantle. The raphe valve is externally concave, the raphe is straight and filiform, striae are uniseriate, slightly radiate, and the first areola close to the mantle is drop-shaped. With this contribution we aim to clarify the morphology of this species, provide a more detailed description of valve ultrastructure, present its lectotypification and extend its geographical distribution.

DOI: https://doi.…

Taxonomy: Staurosirella andino-patagonica sp. nov. (Bacillariophyta) from lake sediments in Patagonia, Argentina.

Staurosirella andino-patagonica sp. nov. (Bacillariophyta) from lake sediments in Patagonia, ArgentinaGuerrero, J.M., García, M.L. & Morales, E.A.
Staurosirella andino-patagonica, a new araphid diatom found in Holocene and recent surface sediments from lakes located in the Andes and adjacent steppe of Patagonia (Argentina), is described on the basis of light and scanning electron microscopy observations and comparison with related taxa. Although the elliptic valve outline of the new taxon resembles the smaller specimens of several Staurosirella species, ultrastructural features such as the presence of two spines on each virga and their distinct morphology -serrated with thickenings at the base- make Staurosirella andino-patagonica unique within the genus. Our study contributes to the knowledge of the Patagonian araphid diatom flora, a rather unexplored geographic area, and so we assume that, as additional areas are studied in detail, they will likely continue to yield new taxa.

DOI:…

Paleolimnology: Historical eruptions of Lautaro Volcano and their impacts on lacustrine ecosystems in southern Argentina

Historical eruptions of Lautaro Volcano and their impacts on lacustrine ecosystems in southern ArgentinaMayr, C., Smith, R.E, García, M.L., Massaferro, J., Lücke, A., Dubois, N., Maidana, N.I., Meier, W. J-H., Wissel, J. & Zolitschka
Lacustrine sediment sequences were obtained from Lagunas Verde and Gemelas Este, two small lakes located east of the southern Patagonian Ice Field and close to the village of El Chaltén, in Argentinian Patagonia. Four tephra layers were identified in each of the short sediment sequences and characterised using individual glass-shard tephra chemistry to determine provenance. Bulk sediment geochemistry and diatom assemblages were analysed to understand the impact of the tephra deposits on the lake ecosystems. Age-depth models for the cores were established by 137Cs and 210Pb dating. Tephra deposits in Laguna Gemelas Este were dated to AD 1986–1998, 1943–1968, 1927–1955, and 1849–1892, and the tephra deposits in Laguna Verde were dated to AD 1940–1970, 18…

DNA Taxonomy: New Aulacoseira species (Bacillariophyta) from the Argentinean Patagonia and re-examination of type material of Melosira perpusilla Frenguelli

Aulacoseira species(Bacillariophyta) from the Argentinean Patagonia and re-examination of type material of Melosira perpusilla Frenguelli. 
Phytotaxa 408 (3): 161-177. 


García, M.L., Morales, E.A., Guerrero, J.M., Tremarin, P.I. & Maidana, N.I. 2019.



We present a detailed morphological analysis with light and scanning electron microscopy of two new small Aulacoseira species occurring in lacustrine sediments from small lakes in the provinces of Santa Cruz and Neuquén (Patagonia, Argentina). These species differ from similar taxa by unique combinations of characters. Aulacoseira lauquenensis sp. nov. can be differentiated by its broad collum, deep and solid ringleist and presence of short, spatulate and forked-tip spines. Aulacoseira liucoensis sp. nov. is distinguished by the presence of a marginal row of valve face areolae, straight mantle rows of coarse areolae, developed collum, protruding ringleist and conical, anchor-tip spines. Additionally, we re-examine the type material of Me…

Antarctic Diatoms (paleo) on BBC

Watch this short video explaining the diatom research component in paleo-oceanography in Antarctica. Basing models on ice core diatoms, as explained by Steve Bohaty. Take a look:
https://www.bbc.com/reel/video/p07bvx51/the-time-machines-unlocking-antarctica-s-past

Meet the ISDR council entry June 2019

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Meet Andrea Burfeid Castellanos, the elected co-ECR explains how she ended up with diatoms and as ECR representative.
Continuing the line of Meet the ISDR Council: https://youngisdr.blogspot.com/p/blog-page_12.html

PhD project to study at UNSW Australia Friend or foe: Fungal drivers of emerging marine diseases

Expression of interest stage is open for students to apply for a Scientia PhD scholarship to study Marine Symbioses and Disease. Please see the attached flyer for more information. You can find more information regarding the scholarship and how to apply at: https://www.scientia.unsw.edu.au/scientia-phd-scholarships/friend-or-foe-fungal-drivers-emerging-marine-diseases-0.
Note EOI stage closes 21st July 2019

Diatom of the Month June 2019 - Subarctic diatom metacommunity

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