A classification of terrestrial vegetation near McMurdo Sound, continental Antarctica

1973 ◽  
Vol 51 (12) ◽  
pp. 2339-2346 ◽  
Author(s):  
R. E. Longton
Keyword(s):  
Plant Cover ◽  
Terrestrial Vegetation ◽  
Mcmurdo Sound ◽  
Exposed Rock ◽  
Arid Conditions ◽  
Continental Antarctica ◽  
Total Plant ◽  
Sand And Gravel ◽  
The Antarctic

Eleven plant sociations are reported from the McMurdo Sound region of continental Antarctica, and they are grouped in the Alga, Fruticose and Foliose Lichen; Crustaceous Lichen; and Short Moss Turf and Cushion subformations of the Antarctic Non-vascular Cryptogam Tundra formation. Their inclusion necessitated only minor modification of a vegetation classification developed in the maritime Antarctic.The most widespread vegetation consisted of sparsely developed communities of turf- and cushion-forming mosses in habitats ranging from dry cinder slopes to sand and gravel in seepage areas and by meltwater streams. The bryophyte colonies seldom exceeded 4 cm in depth, and although total plant cover within the communities locally reached 85%, it was more frequently under 5%. The Sarconeunim association appeared to tolerate more arid conditions than the Bryum association, whose communities occasionally merged with algal sociations occupying certain of the streams. Exposed rock habitats normally supported at most small scattered thalli of crustaceous lichens, well-developed lichen communities being rare.

scholarly journals Metagenomes in the borderline ecosystems of the Antarctic cryptoendolithic communities

2019 ◽  
Author(s):  
Claudia Coleine ◽  
Davide Albanese ◽  
Silvano Onofri ◽  
Susannah G. Tringe ◽  
Christa Pennacchio ◽  
...  
Keyword(s):  
Life Forms ◽  
Base Line ◽  
Biological Processes ◽  
Dry Valleys ◽  
Taxonomic Analysis ◽  
Exposed Rock ◽  
Microbial Ecosystems ◽  
Continental Antarctica ◽  
Antarctic Expedition ◽  
The Antarctic

AbstractAntarctic cryptoendolithic communities are microbial ecosystems dwelling inside rocks of ice-free areas in Continental Antarctica. In Antarctica, these ecosystems were first described from the McMurdo Dry Valleys, accounted as the best analogous of the Martian environment on Earth and thought to be devoid of life until the discovery of these cryptic life-forms. Our results present the first shotgun metagenomes of Antarctic cryptoendolithic lichen-dominated communities from 18 differently sun-exposed rock samples collected during the XXXI Italian Antarctic Expedition (2015-16), along an altitudinal transect from 834 up to 3100 m a.s.l. Here, we provide the raw data obtained with Illumina Novaseq sequencer, followed by initial functional and taxonomic analysis.Our results extend understanding of the microbial diversity and biological processes in the Antarctic desert and represent an invaluable resource for the scientific community as a base-line for further studies of this kind to examine the mechanisms and pathways necessary for life to adapt and evolve in the extremes.

Structure of cliff vegetation on exposed cliffs and the effect of rock climbing

1996 ◽  
Vol 74 (4) ◽  
pp. 607-617 ◽  
Author(s):  
Victoria A. Nuzzo
Keyword(s):  
Plant Cover ◽  
Rock Climbing ◽  
Small Scale ◽  
Rock Fracturing ◽  
Community Groups ◽  
Bare Rock ◽  
Lichen Cover ◽  
Cliff Vegetation ◽  
Total Plant ◽  
The Impact

Vegetational structure of exposed dolomitic cliffs in the driftless region of northwest Illinois was quantified from 186 quadrats on five cliffs. All cliffs were sparsely vegetated, with a total of 41 species (14 lichen and 27 vascular) recorded in the upper 6 m. On all cliffs, cover averaged 16.03%, with lichen contributing 10.23% cover and vascular vegetation 5.80% cover. Seventy percent of all vegetation grew within 3 m of the cliff top. Linear regression indicated that both cover and density of vascular, but not lichen, flora increased with increased fracturing and decreased with distance from the cliff top. TWINSPAN arranged the quadrats into five groups that differed in lichen and vascular cover and a sixth group that consisted of bare rock. Spatial distribution of the community groups occurred at a small scale, influenced by small scale differences in rock fracturing, slope, weathering, and likely moisture availability. Climbing significantly reduced lichen cover and lichen species density by 50%, from 13.7% cover and 2.4 species/0.25 m2 on unclimbed cliffs, to 6.7% cover and 1.2 species/0.25 m2 on climbed cliffs. Climbing did not have an apparent effect on vascular vegetation, which ranged from 2.74 to 10.62% cover on individual cliffs. Total plant cover averaged 19.7% on three unclimbed cliffs and 12.3% on two climbed cliffs, because of the impact on lichen cover. Although climbed cliffs had lower lichen cover, distribution of TWINSPAN-defined community groups was similar on both climbed and unclimbed cliffs, indicating that environmental and physical variables were the primary determinants of cliff flora on these vertical exposed cliffs. Keywords: cliff, vegetation, lichen, rock climbing, rock fractures.

Summer–winter transitions in Antarctic ponds I: The physical environment

2011 ◽  
Vol 23 (3) ◽  
pp. 235-242 ◽  
Author(s):  
Ian Hawes ◽  
Karl Safi ◽  
Brian Sorrell ◽  
Jenny Webster-Brown ◽  
David Arscott
Keyword(s):  
Physical Environment ◽  
Average Rate ◽  
Growth Period ◽  
Ice Formation ◽  
Freezing Process ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Continental Antarctica ◽  
The Antarctic ◽  
Summer Growth

AbstractMeltwater ponds are one of the most widespread aquatic habitats in ice-free areas of continental Antarctica. While most studies of such systems occur during the Antarctic summer, here we report on ice formation and water column attributes in four meltwater ponds on the McMurdo Ice Shelf during autumn, when they went from ice-free to > 80 cm thickness of ice. Ice thickness grew at an average rate of 1.5 cm d-1 in all ponds and as ice formed, salts and gases were excluded. This resulted in conductivity rising from 3–5 to > 60 mS cm-1 and contributed to the ebullition of gases. Incorporation of gas bubbles in the ice resulted in a high albedo and under-ice irradiance declined faster than incident, the former falling below 1 W m-2 (daily average) by early April. After two months of ice formation, only 0–15% of the volume of each pond was still liquid, although this represented 5–35% of the pond sediment area, where much of the biological activity was concentrated. We suggest that the stresses that the freezing process imposes may be as important to structuring the biotic communities as those during the more benign summer growth period.

Description of new chiactine-bearing sponges provides insights into the higher classification of Calcaronea (Porifera: Calcarea)

Zootaxa ◽  
2019 ◽  
Vol 4615 (2) ◽  
pp. 201
Author(s):  
ADRIANA ALVIZU ◽  
JOANA R. XAVIER ◽  
HANS TORE RAPP
Keyword(s):  
New Species ◽  
Phylogenetic Reconstruction ◽  
Molecular Data ◽  
Phylogenetic Study ◽  
Two New Species ◽  
Close Relationship ◽  
New Material ◽  
Relationship Of ◽  
The Antarctic

A recent phylogenetic study revealed a close relationship between chiactine-bearing (family Achramorphidae, order Leucosolenida) and pugiole-bearing (order Baerida) calcaronean sponges as well as new putative taxa within Achramorphidae. In this study, we present a revision of chiactine-bearing sponges based on morphological re-examination of type material and recently collected specimens, in addition to new molecular data for the ribosomal 18S and C-region of the 28S. We provide re-descriptions for all known chiactine-bearing species, and further describe two new species from the Antarctic (Achramorpha antarctica sp. nov. and Megapogon schiaparellii sp. nov.) and two new species and a new genus from the Nordic Seas (Achramorpha ingolfi sp. nov. and Sarsinella karasikensis gen. nov. sp. nov.). The new phylogenetic reconstruction based on ribosomal 18S and C-region of the 28S confirms previous findings about the close relationship of some members of Baerida and the family Achramorphidae of the order Leucosolenida. However, new material and the addition of molecular data from the type species of both taxa would be required to formally propose changes at (sub-)ordinal levels within the classification of Calcaronean sponges. 

Sabbea gen. nov., a new diatom genus (Bacillariophyta) from continental Antarctica

Phytotaxa ◽  
2019 ◽  
Vol 418 (1) ◽  
pp. 42-56 ◽  
Author(s):  
JORDAN BISHOP ◽  
KATEŘINA KOPALOVÁ ◽  
JOSHUA P. DARLING ◽  
NICHOLAS O. SCHULTE ◽  
TYLER J. KOHLER ◽  
...  
Keyword(s):  
New Genus ◽  
Morphological Characteristics ◽  
Sensu Stricto ◽  
Morphological Features ◽  
Marine Diatom ◽  
Continental Antarctica ◽  
Diatom Genus ◽  
Antarctic Continent ◽  
Vestfold Hills ◽  
The Antarctic

The non-marine diatom flora of the Antarctic Continent includes several endemic taxa recorded over the past 100 years. One of these taxa, Navicula adminensis D.Roberts & McMinn, was described from the Vestfold Hills, East Antarctica. Detailed light and scanning electron microscopy observations have shown that based on its morphological features, the species does not belong to the genus Navicula sensu stricto. To determine the most closely related genera to N. adminensis, the morphological features of Adlafia, Kobayasiella, Envekadea, Stenoneis, Berkeleya, Climaconeis, and Parlibellus were compared with those of N. adminensis. Although each of these genera shows one or more similar features, none of them accommodates the salient morphological characteristics of N. adminensis. Therefore, a new genus, Sabbea gen. nov., is herein described, and Navicula adminensis is formally transferred to the new genus as Sabbea adminensis comb. nov. The genus Sabbea is characterized by uniseriate striae composed of small, rounded areolae occluded externally by individual hymenes, a rather simple raphe structure with straight, short proximal ends and short terminal raphe fissures, open girdle bands with double perforation and a very shallow mantle.

Exposure and Nutrients As Delimiters of Lichen Communities in Continental Antarctica

1995 ◽  
Vol 27 (6) ◽  
pp. 505-516 ◽  
Author(s):  
M.J. Hovenden ◽  
R.D. Seppelt
Keyword(s):  
Species Distributions ◽  
Vegetation Patterns ◽  
Terrestrial Vegetation ◽  
Nutrient Levels ◽  
North East ◽  
Continental Antarctica ◽  
Wilkes Land ◽  
Windmill Islands ◽  
Casey Station

AbstractLichens dominate the terrestrial vegetation of the ice-free regions of continental Antarctica. Vegetation patterns were studied in the Windmill Islands Oasis, Wilkes Land, continental Antarctica, in relation to edaphic features to elucidate the factors that govern lichen distribution and abundance. Vegetation was studied on a low rounded knoll on Clark Peninsula some 3 km North East of the present Casey station. Substratum nutrient levels vary considerably across the knoll due to the presence of an abandoned penguin rookery on the crest and the uneven topography provides both sheltered and exposed sites. Along a 130 m-long transect crossing the knoll from South to North, a total of 25 species of lichen and one moss were identified, the vegetation being dominated by Umbilicaria decussata, Pseudephebe minuscula, Usnea sphacelata and U. antarctica. TWINSPAN analysis of species distributions identified six sociations, the distribution of which were related to substratum structure and chemistry. Several species were restricted to nutrient-rich zones while late-lying snow restricted all species to varying degrees.

The Déjà vu System of International Trusteeship in Continental Antarctica: A Textual Analysis

2021 ◽  
Vol 12 (1) ◽  
pp. 108-131
Author(s):  
Xueping Li
Keyword(s):  
United Nations ◽  
Protected Areas ◽  
Environmental Protection ◽  
Textual Analysis ◽  
Intrinsic Values ◽  
Continental Antarctica ◽  
Antarctic Treaty ◽  
Deja Vu ◽  
Déjà Vu ◽  
The Antarctic

In the name of environmental protection, the Antarctic Treaty Consultative Meeting seems to have borrowed the paradigm of international trusteeship of the United Nations for managing the Antarctic land-based protected areas. By comparing and analysing the critical questions highly concerned, this paper offers preliminary thoughts on the development and refinement of the conception of land-based protected areas as a déjà vu system of international trusteeship and its surrounding legal applications and implications in continental Antarctica, and challenges the direction followed by this system in protecting Antarctic intrinsic values in legal discourse.

scholarly journals Wilderness and aesthetic values in the Antarctic

Polar Record ◽  
2001 ◽  
Vol 37 (203) ◽  
pp. 337-352 ◽  
Author(s):  
Rosamunde Codling
Keyword(s):  
Intrinsic Value ◽  
Working Definition ◽  
Character Assessment ◽  
Antarctic Treaty ◽  
Landscape Character ◽  
Definition Of ◽  
Objective Description ◽  
The Antarctic ◽  
Aesthetic Values

AbstractIn Article 3 of the 1991 Protocol on Environmental Protection to the Antarctic Treaty, the Antarctic Treaty Consultative Parties committed themselves to ‘the protection of the Antarctic environment…and the intrinsic value of Antarctica, including its wilderness and aesthetic values.’ The phraseology of the Protocol requires clarification. ‘Wilderness and aesthetic values’ links two disparate concepts, best handled by separation. Annex V, Article 3, of the Protocol covers many topics, and their assessment must be by a composite of frameworks specifically designed for the different purposes set out in the Annex.A working definition of wilderness in the Antarctic is suggested: ‘Any part of the Antarctic in which neither permanent habitation nor any other permanent evidence of present or past human presence is visible.’ Using this, a very high proportion of the continent will be recognised as having wilderness status. The phrase ‘aesthetic values’ should be seen as part of a wider process—Landscape Character Assessment—that is at present unknown to most in the Antarctic community. It is based on the principle of objective description and classification of landscape character. This basic characterisation can then be put to different uses, one of which may be to make more subjective judgements or evaluations that lead to area designations.

Contrasting phylogeographical patterns for springtails reflect different evolutionary histories between the Antarctic Peninsula and continental Antarctica

2009 ◽  
Vol 37 (1) ◽  
pp. 103-119 ◽  
Author(s):  
Angela McGaughran ◽  
Giulia Torricelli ◽  
Antonio Carapelli ◽  
Francesco Frati ◽  
Mark I. Stevens ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Continental Antarctica ◽  
The Antarctic

scholarly journals Additions to the lichen flora of Victoria Land, Antarctica

2011 ◽  
Vol 32 (2) ◽  
pp. 123-138 ◽  
Author(s):  
Jerzy Smykla ◽  
Beata Krzewicka ◽  
Karina Wilk ◽  
Steven Emslie ◽  
Lucyna Śliwa
Keyword(s):  
Ross Sea ◽  
Land Area ◽  
Victoria Land ◽  
Continental Antarctica ◽  
The Antarctic ◽  
Lichen Flora

Additions to the lichen flora of Victoria Land, Antarctica Lichens of relict penguin colonies and sites affected by active penguin colonies were investigated in Victoria Land, Ross Sea sector, continental Antarctica. A total of 17 coastal sites, seven in northern and ten in southern Victoria Land, have been investigated across 7° of latitude from 71° to 78°S. Altogether 40 taxa of lichens have been identified. Four of the recorded species are new to the Antarctic - Caloplaca erecta, C. soropelta, C. tominii and Physcia tenella; two species are new to the Victoria Land area - Lecania nylanderiana and Lecanora polytropa. The first lichen records from Beaufort Island are also provided. Data presented here expand the knowledge on the occurrence, diversity and distribution of Victoria Land lichens.

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