Seasonal changes in the standing crop of an epilithic algal population on the north shore of Great Slave Lake

1979 ◽  
Vol 57 (1) ◽  
pp. 17-22 ◽  
Author(s):  
James W. Moore
Keyword(s):  
Seasonal Changes ◽  
Dry Weight ◽  
Common Species ◽  
Filamentous Algae ◽  
Algal Population ◽  
Epilithic Algae ◽  
North Shore ◽  
The North ◽  
Great Slave Lake ◽  
Peak Abundance

Seasonal changes in the density of epilithic algae were determined from June 1975 to November 1976 at three sites on the north shore of Great Slave Lake. Densities increased rapidly in May immediately after the disappearance of ice, showed only small fluctuations during the summer, and waned during October. Microscopic algae, mainly Fragilaria capucina, Gomphonema olivaceum, G. ventricosa, Cymbella ventricosa, and other diatoms, reached peak abundance (2 × 109 μm3/cm2) on irregular occasions (July, September, October) throughout the growing season. However, filamentous algae, mainly Ulothrix zonata, reached maximum densities (60 mg/cm2 dry weight) during July of both years.Additional survey collections of epilithic algae were made at 14 sites in the east arm of the lake during June and July of 1975. The most common species included Tabellaria flocculosa, Rhopalodia gibba, Cymbella angustata, C. microcephala, Anomoeoneis vitrea, Achnanthes minutissima, and Ulothrix zonata. Algal densities were considerably less than those recorded from the north shore, a reflection of lower nutrient and alkalinity levels. Maximum abundances for microscopic and filamentous algae were 1.05 × 109 μm3/cm2 and 4.1 mg/cm2 respectively.

Epipelic and epiphytic algal communities in Great Slave Lake

1980 ◽  
Vol 58 (10) ◽  
pp. 1165-1173 ◽  
Author(s):  
James W. Moore
Keyword(s):  
Total Phosphorus ◽  
Seasonal Changes ◽  
Total Alkalinity ◽  
Algal Communities ◽  
Growth Cycles ◽  
Nitzschia Palea ◽  
North Shore ◽  
The North ◽  
Great Slave Lake ◽  
Achnanthes Minutissima

Seasonal changes in the densities of epiphytic and epipelic algae were determined during 1975 and 1976 at two sites on the north shore of Great Slave Lake. The epiphyton waxed rapidly in May and reached maximum densities of 5–6 × 108 μm3/cm2 in June. Although densities remained high during the summer, they fell rapidly in October, followed by a secondary peak in November. The main species were Tabellaria flocculosa, Achnanthes minutissima, Achnanthes linearis, Gomphonema intricatum, and Lyngbya diguetii. The epipelon, consisting largely of Nitzschia palea, Nitzschia dissipata, Fragilaria construens, and Oscillatoria spp., also showed spring and fall peaks in densities, with maximum populations of 4.2 × 108 μm3/cm2 being recorded in June and July. The growing season for both communities was limited by the formation of ice in the fall, whereas the maximum standing crop of the flora was at least partially restricted by low nutrient levels (total phosphorus, 0.008 mg/L; total alkalinity, 30 mg/L).Seasonal changes in the density of epipelon were monitored during 1977 and 1978 at a third site on the north shore of the lake, where total phosphorus and total alkalinity ranged up to 0.010 and 94 mg/L, respectively. Prevalent taxa included Cymatopleura elliptica, Epithemia turgida, Rhopalodia gibba, Cymbella spp., and Nostoc spp. The growth cycles of the flora were again characterized by spring and fall peaks in numbers. Algal densities were, however, high (up to 2.3 × 109 μm3/cm2), possibly a reflection of nutrient availability.Samples of epiphyton and epipelon were taken at an additional seven sites in the east arm of the lake during June and July 1975. The main epiphytic species were Cocconeis placentula, Achnanthes minutissima, and Tabellaria flocculosa, while prevalent epipelic taxa included Navicula graciloides, Fragilaria vaucheriae, Tabellaria flocculosa, and Achnanthes minutissima. Densities were less than those recorded from the three sites on the north shore, again possibly a reflection of nutrient availability.

Biomasse et espèces de lichens terrestres disponibles pour le caribou dans le nord du Québec

1990 ◽  
Vol 68 (10) ◽  
pp. 2047-2053 ◽  
Author(s):  
Michel Crête ◽  
Claude Morneau ◽  
René Nault
Keyword(s):  
Plant Cover ◽  
Ground Cover ◽  
Dry Weight ◽  
Common Species ◽  
The West ◽  
The North ◽  
Precipitation Zone ◽  
Annual Consumption ◽  
Mat Thickness ◽  
Primary Unit

Following a two-stage sampling plan, 44 1-km2 primary units were systematically allocated between 53 and 59 ° latitude throughout northern Québec to estimate the biomass of terrestrial lichens. Lichens were collected in two secondary units (0.25 m2) located in parts of each primary unit where lichens were visible from a helicopter (lichen stratum). Overall, the lichen stratum covered 51% of the study area and lichen biomass averaged 1223 kg/ha (dry weight; SE = 201; n = 44). Almost 85% of the variance of this mean was attributable to variability between primary units. The biomass in the west was greater than in the east; it was the highest in the [Formula: see text]700-mm precipitation zone and the lowest in the 500- to 599-mm zone. Data on percent plant cover indicated mat mosses increased in importance over lichens in the east. There was a clear relationship between lichen biomass in secondary units on one hand and mat thickness and percent lichen ground cover on the other. Cladinia stellaris (Opiz) Brodo was the most common species; Alectoria ochroleuca (Hoffm.) Mass. and Cornicularia divergens Ach. were typical of the north, whereas Cladina mitis (Sandst.) Hustich characterized the south of the study area. The annual consumption of lichens by caribou was probably 0.5-0.9% of the available biomass in 1987. Key words: biomass, caribou, Cladina, lichens, Quebec.

On Riccia marginata and related species (Ricciaceae, Marchantiophyta)

2012 ◽  
Vol 46 ◽  
pp. 298-305 ◽  
Author(s):  
A. D. Potemkin ◽  
T. Ahti
Keyword(s):  
Related Species ◽  
Lake Ladoga ◽  
Leningrad Region ◽  
Sem Images ◽  
North Shore ◽  
The North ◽  
Molecular Studies ◽  
The Future ◽  
The Town

Riccia marginata Lindb. was described by S. O. Lindberg (1877) from the outskirts of the town of Sortavala near the north shore of Lake Ladoga, Republic of Karelia, Russia. The species has been forgotten in most recent liverwort accounts of Europe, including Russia. Lectotypification of R. marginata is provided. R. marginata shares most characters with R. beyrichiana Hampe ex Lehm. It differs from “typical” plants of R. beyrichiana in having smaller spores, with ± distinctly finely areolate to roughly papillose proximal surfaces and a narrower and shorter thallus, as well as in scarcity or absence of marginal hairs. It may represent continental populations of the suboceanic-submediterranean R. beyrichiana, known in Russia from the Leningrad Region and Karelia only. The variability of spore surfaces in R. beyrichiana is discussed and illustrated by SEM images. A comparison with the spores of R. bifurca Hoffm. is provided. The question how distinct R. marginata is from R. beyrichiana needs to be clarified by molecular studies in the future, when adequate material is available. R. marginata is for the time being, provisionally, included in R. beyrichiana.

TEACHING THE GEOLOGIC HERITAGE OF MINNESOTA’S NORTH SHORE AT THE NORTH HOUSE FOLK SCHOOL, GRAND MARAIS

2020 ◽  
Author(s):  
James D. Miller ◽  
◽  
John C. Green
Keyword(s):  
North Shore ◽  
The North

Conflict, Population Movement, and Microscale Social Networks in Northern Iroquoian Archaeology

2021 ◽  
Vol 86 (2) ◽  
pp. 350-367
Author(s):  
Jennifer Birch ◽  
John P. Hart
Keyword(s):  
Social Networks ◽  
Sixteenth Century ◽  
Lake Ontario ◽  
Population Movement ◽  
Network Ties ◽  
The West ◽  
Local Networks ◽  
North Shore ◽  
The North ◽  
Specific Sequences

We employ social network analysis of collar decoration on Iroquoian vessels to conduct a multiscalar analysis of signaling practices among ancestral Huron-Wendat communities on the north shore of Lake Ontario. Our analysis focuses on the microscale of the West Duffins Creek community relocation sequence as well as the mesoscale, incorporating several populations to the west. The data demonstrate that network ties were stronger among populations in adjacent drainages as opposed to within drainage-specific sequences, providing evidence for west-to-east population movement, especially as conflict between Wendat and Haudenosaunee populations escalated in the sixteenth century. These results suggest that although coalescence may have initially involved the incorporation of peoples from microscale (local) networks, populations originating among wider mesoscale (subregional) networks contributed to later coalescent communities. These findings challenge previous models of village relocation and settlement aggregation that oversimplified these processes.

Gichi Bitobig, Grand Marais: Early Accounts of the Anishinaabeg and the North Shore Fur Trade by Timothy Cochrane

2019 ◽  
Vol 45 (1) ◽  
pp. 128-129
Author(s):  
Wayne Ratzlaff
Keyword(s):  
Fur Trade ◽  
North Shore ◽  
The North

scholarly journals Structure of three subtropical bat assemblages (Chiroptera) in the Andean rainforests of Argentina

Mammalia ◽  
2016 ◽  
Vol 80 (1) ◽  
Author(s):  
Mariano S. Sánchez
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Seasonal Changes ◽  
Common Species ◽  
Guild Structure ◽  
Trophic Guild ◽  
Long Tail ◽  
Mist Net ◽  
Yungas Forests

AbstractI evaluated bat assemblages in terms of species richness, relative abundance, trophic guild structure, and seasonal changes at three sites along of the Southern Yungas forests. A total of 854 individuals were captured, representing 25 species of three families, with an effort of 27,138 m of mist net opened per hour. Subtropical assemblages showed a similar structure to those from tropical landmark, with a dominance of frugivorous Phyllostomid; in addition, a few species were abundant, followed by a long tail of less common species. However, subtropical sites differed due to the dominance of the genus

Seismicity and faulting in the Charlevoix zone of the St. Lawrence Valley

1984 ◽  
Vol 74 (2) ◽  
pp. 595-603
Author(s):  
F. M. Anglin
Keyword(s):  
Active Zone ◽  
Continuous Monitoring ◽  
North Shore ◽  
The North ◽  
Earthquake Zone ◽  
St Lawrence River

Abstract Continuous monitoring of the seismically active Charlevoix zone since late 1977 has delineated the boundaries of the earthquake zone under the north shore and has enabled an association to be made with surface mapped faults that strike along the St. Lawrence Valley and dip to the southeast. Within the active zone, aseismic volumes are found under parts of the St. Lawrence River and another elongated zone of activity is found to the southeast on unmapped faults dipping under the river. The previous suggestions that the activity is related to old rift faults, which have been later weakened by a meteor impact, would seem to be upheld.

scholarly journals Mass mortality of Northern Map Turtles (Graptemys geographica)

2015 ◽  
Vol 129 (1) ◽  
pp. 80 ◽  
Author(s):  
Jordan Catrysse ◽  
Emily Slavik ◽  
Jonathan Choquette ◽  
Ashley E. Leifso ◽  
Christina M. Davy
Keyword(s):  
Lake Erie ◽  
Mass Mortality ◽  
Species At Risk ◽  
Long Term Effects ◽  
North Shore ◽  
The North ◽  
The Poor ◽  
Map Turtles ◽  
Graptemys Geographica

We report a mass mortality of Northern Map Turtles (Graptemys geographica [LeSueur, 1817]) on the north shore of Lake Erie, Ontario, Canada. Thirty-five dead adult females were recovered from a nesting area over a period of four weeks. Predation and boat strikes were both excluded as potential cause of death, but the actual cause could not be determined because of the poor condition of the carcasses. Other possible explanations for the mortality include poisoning, drowning, and infection with an unidentified pathogen. Mass mortality in long-lived species, such as turtles, can have long-term effects on population growth and is a cause for concern in a species at risk.

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