Association Dicranoweisio-Deschampsietum ass. nov. in cold desert belt of Putorana plateau (Srednesibirskoe plateau)

2002 ◽  
pp. 32-41 ◽  
Author(s):  
N. V. Matveyeva

New association Dicranoweisio-Deschampsietum ass. nov. with 2 variants within the class Salicetea herbaceae Br.-Bl. 1947 is described for the cold desert belt of the Putorana plateau (Srednesibirskoe plateau). Its species composition represents the combination of species charac­ter for both the snow beds in the northern part of Taymyr peninsula (ass. Deschampsio-Cerastietum regelii Mat­veye­va 1994) and zonal vegetation of the polar deserts (асс. Aulacomnio-Deschampsietum prov., unpublished author’s data) on Bolshevik Isl. (Severnaya Zemlya Archipelago) with common dominating tufted grass De­schampsia borealis. Compare to the mentioned associa­tions it is poorer in species numbers within all groups of plants (vascular, mosses, liverworts, lichens) due to the restricted number of plain arctic species. Its horizontal structure demonstrates a larger similarity with the polar desert communities.

2006 ◽  
pp. 3-87 ◽  
Author(s):  
N. V. Matveyeva

Bolshevik Isl. is the one of the largest islands within the Severnaya Zemlya archipelago. It is situated in the southern part of the polar desert zone. In the course of three field work trips in 1997, 1998 and 2000 years 252 relevees were made in its southern part on three geomorphologic surfaces: coastal plain, inner upland close to glacier and ancient high river terraces. As the result 27 syntaxonomical units of different rank (15 associations, 2 subassociations, 2 variants, and 8 community types) were described using Braun-Blanquet approach. All syntaxa, except one, are new and mostly similar to communities described on Franz Josef Land. The problems were to put new syntaxa into the higher level units (including class) within the syntaxonomical hierarchy. The main bulk of syntaxa, both zonal and intrazonal ones, has to be preliminary placed into Salicetea herbaceae class although there is a lot of reasons to consider zonal syntaxa as a new class that is specific for the polar desert zone. In any case, there are no one syntaxon that can be referred to Loiseleurio-Vaccinietea class that combines zonal vegetation in the tundra zone. The wide ecological range of great majority of species as well as the changes of their intralandscape distribution compare to the tundra zone made additional difficulties in finding character and differential species. 340 species (vascular plants — 52, mosses — 97, liverworts — 41, lichens — 150), that compiles 73 % of the whole island flora and 84 % of its southern part, were recorded within the all relevees. Almost half of these (182) are very rare on the island and 127 species were met 1—2 times. There are 70 species with wide ecological range throughout all landscape types with such commonly distributed herbs as Saxifraga cernua, S. hyperborea and Stellaria ed­ward­sii, mosses Polytrichastrum alpinum and Sanionia uncinata and lichen Stereocaulon rivulorum among these. Phippsia algida, the character species for snow bed communities, occurs in about 70 % of syntaxa. Useful for differentiation of syntaxa have been appeared 87 species. Few species with wide distribution within a landscape demonstrate their preference to a certain syntaxon by higher abundance (preferential character species). These are mostly bryophytes: mosses Bryum cryophilum and Grimmia torquata, and liver­worts Gymnomitrion corallioides, Marsupella arctica and Scapania crassiretis. Cryptogam species predo­minate in the whole flora as well as in each syntaxon. The number of species varies from 12 to 70 per sample plots 5÷5 m and from 20 to 195 in different syntaxa. The richest in species (70 per community and about 190 for association) are zonal plant communities on the accumulative coastal plain in the region of Sol­nechnaya Bay, the poorest one, with 10 and 20 species consequently, is ass. Hygrohypno polari—Saxifragetosum hyperboreae that was described on the upland, close to glacier in the inner part of island.


2001 ◽  
pp. 6-16 ◽  
Author(s):  
L. L. Zanokha

The grassland vegetation which occurs in places of animal colonies or around human settlements in the Central-Siberian sector of the Arctic is referred to 2 new associations, namely Saxifrago cernuae—Alopecuretum alpini and Poo arcticae—Calamagrostietum holmii ass. nov., and also to 2 variants (inops and Astragalus umbellatus var. nov) of the previously described associa­tion Saxifrago hirculi—Poetum alpigenae (Zanokha, 1995). The first association is distributed within the whole Taymyr Peninsula and also the part of the polar desert subzone in the Bolshevik Isl. The grass cover is formed by Poa alpigena and Alopecurus alpinus in various combinations of their dominance. The ass. Poo arcticae—Calamagrostietum holmii is distributed only throughout the tundra zone of Taymyr; its grass layer consists of Calamagrostis holmii and Poa arctica. The mentioned variants of ass. Saxifrago hirculi—Poetum alpigenae occur locally in the vicinities of Dixon settlement.


Author(s):  
Philipp V. Sapozhnikov ◽  
Olga Yu. Kalinina ◽  
Anastasiya A. Snigirova

Modern taxocenes of benthic diatoms of coastal aquatic habitats of the Severnaya Zemlya archipelago were studied for the first time based on the materials of the expedition in summer 2019. The following habitats were studied: sublittoral, littoral, as well as semi-enclosed coastal water bodies. In the entire set of communities, a total of 180 species and subspecies (IST) of diatoms were noted. The local α-diversity of communities in the sublittoral was 6–26 species and IST (on average – 14.8), and for coastal locations, including the littoral – 12–51 species and IST (on average – 33). The floristic groups and coenotic groups of diatoms have been identified for sublittoral and coastal habitats. Significant differences were noted both among coastal taxocenes (average similarity of 23.41% in species composition and 9.78% in structure) and among sublittoral communities (19.51% and 34.54%, respectively). The entire spectrum of the noted on permanent slides species are photodocumented.


2019 ◽  
Vol 12 (3) ◽  
pp. 16-26
Author(s):  
Victor V. Kharitonov

Three first-year ice ridges have been examined with respect to geometry and morphology in landfast ice of Shokal'skogo Strait (Severnaya Zemlya Archipelago) in May 2018. Two of the studied ice ridges were located on the edge of the ridged field and were part of it, because their keels extended for a long distance deep into this field. Ice ridges characteristics are discussed in the paper. These studies were conducted using hot water thermal drilling with computer recording of the penetration rate. Boreholes were drilled along the cross-section of the ridge crest at 0.25 m intervals. Cross-sectional profiles of ice ridges are illustrated. The maximal sail height varied from 2.9 up to 3.2 m, the maximal keel depth varied from 8.5 up to 9.6 m. The average keel depth to sail height ratio varied from 2.8 to 3.3, and the thickness of the consolidated layer was 2.5-3.5 m. The porosity of the non-consolidated part of the keel was about 23-27%. The distributions of porosity versus depth for all ice ridges are presented.


2018 ◽  
Vol 23 (1) ◽  
pp. 1 ◽  
Author(s):  
Colin K. C. Wen ◽  
Li-Shu Chen ◽  
Kwang-Tsao Shao

Spatial and temporal variations in the species composition of assemblages are common in many marine organisms, including fishes. Variations in the fish species composition of subtidal coral reefs have been well documented, however much less is known about such differences for intertidal fish assemblages. This is surprising, given that intertidal fishes are more vulnerable to terrestrial human disturbances. It is critical to evaluate the ecology and biology of intertidal fishes before they are severely impacted by coastal development, especially in developing countries such as those in the tropical western Pacific region where coastal development is rapidly increasing. In this study, we investigated the species composition, abundance, biomass and species number (richness) for intertidal fish assemblages in subtropical (northern) and tropical (southern) Taiwan across four seasons by collecting fishes from tidepools using clove oil. We also examined the gut contents of collected fishes to identify their trophic functional groups in order to investigate regional and seasonal variations for different trophic groups. We found significant differences in the species composition of tidepool fish assemblages between subtropical and tropical Taiwan. Bathygobius fuscus, Abudefduf vaigiensis and Istiblennius dussumieri were dominant species in subtropical Taiwan, whereas Bathygobius coalitus, Abudefduf septemfasciatus and Istiblennius lineatus were dominant in tropical Taiwan. Other species such as Bathygobius cocosensis, Abudefduf sordidus and Istiblennius edentulus were common in both regions. For trophic groups, omnivores and detritivores had or showed trends towards higher species numbers and abundances in the subtropical region, whereas herbivores, planktivores and general carnivores had or showed trends towards higher species numbers and biomass in the tropical region. Overall, many intertidal fish species and trophic groups showed differences in abundance, biomass and species number between subtropical and tropical Taiwan. Further studies on large scale geographical gradients in trophic groups and species compositions in the Indo-west Pacific region are encouraged to assist with ecosystem monitoring and assessment. Keywords: Intertidal fishes, spatio-temporal pattern, feeding guild, diet


Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 36 ◽  
Author(s):  
Victoria B. Ershova ◽  
Andrei V. Prokopiev ◽  
Andrey K. Khudoley ◽  
Tom Andersen ◽  
Kåre Kullerud ◽  
...  

U–Pb and Lu–Hf isotope analyses of detrital zircons collected from metasedimentary rocks from the southern part of Kara Terrane (northern Taimyr and Severnaya Zemlya archipelago) provide vital information about the paleogeographic and tectonic evolution of the Russian High Arctic. The detrital zircon signatures of the seven dated samples are very similar, suggesting a common provenance for the clastic detritus. The majority of the dated grains belong to the late Neoproterozoic to Cambrian ages, which suggests the maximum depositional age of the enclosing sedimentary units to be Cambrian. The εHf(t) values indicate that juvenile magma mixed with evolved continental crust and the zircons crystallized within a continental magmatic arc setting. Our data strongly suggest that the main provenance for the studied clastics was located within the Timanian Orogen. A review of the available detrital zircon ages from late Neoproterozoic to Cambrian strata across the wider Arctic strongly suggests that Kara Terrane, Novaya Zemlya, Seward Peninsula (Arctic Alaska), Alexander Terrane, De Long Islands, and Scandinavian Caledonides all formed a single tectonic domain during the Cambrian age, with clastics predominantly sourced from the Timanian Orogen.


Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2466 ◽  
Author(s):  
Nela ◽  
Bandyopadhyay ◽  
Singh ◽  
Glazovsky ◽  
Lavrentiev ◽  
...  

Glacier velocity is one of the most important parameters to understand glacier dynamics. The Severnaya Zemlya archipelago is host to many glaciers of which four major ice caps encompassing these glaciers are studied, namely, Academy of Sciences, Rusanov, Karpinsky, and University. In this study, we adopted the differential interferometric synthetic aperture radar (DInSAR) method utilizing ALOS-2/PALSAR-2 datasets, with a temporal resolution of 14 days. The observed maximum velocity for one of the marine-terminating glaciers in the Academy of Sciences Ice Cap was 72.24 cm/day (≈263 m/a). For the same glacier, an increment of 3.75 times the flow rate was observed in 23 years, compared to a previous study. This has been attributed to deformation in the bed topography of the glacier. Glaciers in other ice caps showed a comparatively lower surface velocity, ranging from 7.43 to 32.12 cm/day. For estimating the error value in velocity, we selected three ice-free regions and calculated the average value of their observed movement rates by considering the fact that there is zero movement for ice-free areas. The average value observed for the ice-free area was 0.09 cm/day, and we added this value in our uncertainty analysis. Further, it was observed that marine-terminating glaciers have a higher velocity than land-terminating glaciers. Such important observations were identified in this research, which are expected to facilitate future glacier velocity studies.


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