Modern pollen assemblages near the arctic tree line, Mackenzie Delta region, Northwest Territories

1974 ◽  
Vol 52 (2) ◽  
pp. 381-396 ◽  
Author(s):  
J. C. Ritchie
Keyword(s):  
Northwest Territories ◽  
Lake Sediment ◽  
Local Community ◽  
The Arctic ◽  
Forest Site ◽  
Mackenzie Delta ◽  
Forest Tundra ◽  
Transitional Area ◽  
Modern Pollen ◽  
Pollen Rain

Samples of surficial lake sediment and of moss polsters from 39 sites in the forest-tundra transitional area immediately east of the Mackenzie Delta, Northwest Territories, were investigated palynologically. Lake sediment samples within the forest and tundra regional vegetation zones are constant in pollen frequencies, but forest–tundra sites are very variable. Forest site spectra are composed of just over 50% arboreal types (spruce, 25–30%; birch, 30%), with 30–40% alder pollen. Tundra spectra have 60–70% non-arboreal types, and 10–15% each of alder and spruce. Forest–tundra values are variable, generally lying between the forest and tundra proportions. Polster samples show as much variability within as between regions, because of local effects. Polster samples indicate local community composition with the regional pollen rain variably masked by the local elements.

External scarring of whitefish, Coregonus nasus and C. clupeaformis complex, from the western Northwest Territories, Canada

1987 ◽  
Vol 65 (5) ◽  
pp. 1230-1239 ◽  
Author(s):  
J. D. Reist ◽  
R. A. Bodaly ◽  
R. J. P. Fudge ◽  
K. J. Cash ◽  
T. V. Stevens
Keyword(s):  
Arctic Ocean ◽  
Northwest Territories ◽  
Lateral Line ◽  
Parasitic Copepod ◽  
The Body ◽  
The Arctic ◽  
Mackenzie Delta ◽  
Unequal Distribution ◽  
Gill Net ◽  
The Arctic Ocean

Up to 40% of whitefish (Coregonus nasus and C. clupeaformis) sampled during spawning migrations from the area of the Mackenzie Delta, N.W.T., had external scars. Percent frequency of scarred individuals varied geographically from the Mackenzie mainstem and tributaries, where 20% were scarred, to Anderson river (2%), Cox Lake (16%), and Alaska (0–7%). Within the Mackenzie system fish captured at mainstem locations had approximately twice the frequency of scarring than did fish from tributary locations. Scars were classified as either slash or round type. Both scar types were located more frequently on the left side of the fishes and below the lateral line. Details of orientation and location on the body provided clues permitting the assignment of putative causation. Small round scars were restricted to locations with connections to the Arctic Ocean and were probably caused by the marine parasitic copepod Coregonicola or by Arctic lampreys (Lampetra japonica). Larger round scars were either the result of attacks by lampreys or by previous gill net capture. Unequal distribution and orientation on the body of slash scars indicated previous capture in gill nets or predation attempts by bears, birds, or piscivorous fishes.

Stomate and pollen content of lake surface sediments from across the tree line on the Taimyr Peninsula, Siberia

1996 ◽  
Vol 74 (7) ◽  
pp. 1009-1015 ◽  
Author(s):  
S. L. Clayden ◽  
L. C. Cwynar ◽  
G. M. MacDonald
Keyword(s):  
Taimyr Peninsula ◽  
Data Set ◽  
Picea Obovata ◽  
Forest Tundra ◽  
Modern Pollen ◽  
Vegetation Zones ◽  
Forest Sites ◽  
Pollen Content ◽  
Pollen Rain ◽  
Components Analysis

Surface-sediment samples from 23 lakes on the Taimyr Peninsula were collected along a transect from tundra to forest and analyzed for their pollen and coniferous stomate content. Larix sibirica, the dominant tree in forest–tundra and forest vegetation zones, is poorly represented in the pollen spectra, never exceeding 8%. To examine the correspondence between the modern pollen rain and the vegetation zones of tundra, forest–tundra, and forest, a principal components analysis was applied to the pollen percentages. Betula and Alnus account for the greatest variance in the data set, and the set of tundra sites farthest north is distinct from the forest sites farthest south. Stomates of L. sibirica are present in all samples from sites where Larix trees are present, and some samples contained higher concentrations of stomates than pollen of Larix. Picea obovata stomates are found less consistently and less abundantly than Larix stomates.

scholarly journals Disjunctions of Needle-leaved Sedge (Carex duriuscula) and Thread-leaved Sedge (Carex filifolia) in the Husky Lakes area of Northwest Territories—first records for the Canadian true Arctic and possible Pleistocene relicts

2020 ◽  
Vol 134 (3) ◽  
pp. 231-240
Author(s):  
Paul M. Catling ◽  
Brenda Kostiuk
Keyword(s):  
North America ◽  
Northwest Territories ◽  
Canadian Arctic ◽  
Arctic Region ◽  
The Arctic ◽  
Mackenzie Delta ◽  
Arctic Vegetation ◽  
Relict Vegetation ◽  
The Arctic Region

Disjunctions are reported for Needle-leaved Sedge (Carex duriuscula) and Thread-leaved Sedge (Carex filifolia) into the Arctic region of Northwest Territories at the Husky Lakes south of Tuktoyaktuk. These are significant additions to the Canadian Arctic flora and may be part of a group of relicts of the Arctic vegetation of the Pleistocene, specifically the Tundra-steppe. The occurrence of relict vegetation east of the Mackenzie Delta is east of its frequently cited eastern limit in North America.

Identifying the tundra – forest border in the stomate record: an analysis of lake surface samples from the Yellowknife area, Northwest Territories, Canada

1996 ◽  
Vol 74 (5) ◽  
pp. 796-800 ◽  
Author(s):  
Barbara C. S. Hansen ◽  
Glen M. MacDonald ◽  
Katrina A. Moser
Keyword(s):  
Northwest Territories ◽  
Picea Glauca ◽  
The Arctic ◽  
Tree Line ◽  
Forest Tundra ◽  
Surface Samples ◽  
Pollen Surface ◽  
Closed Forest ◽  
Common Tree ◽  
Potential Use

Conifer stomata were identified in surface samples from lakes in the treeline zone near Yellowknife, Northwest Territories, to assess the potential use of fossil stomata for reconstructing past changes in the arctic tree line. Stomata of Larix, Pinus, Picea mariana, and Picea glauca were distinguished. Conifer stomata were absent in samples from tundra lakes, whereas they were generally present in forest–tundra and forest lakes. Stomate analysis recorded the presence of Larix trees in the area; in contrast, the pollen of this relatively common tree was infrequent in pollen surface samples from the same sites. Conifer stomate analysis, however, is not able to resolve differences between forest–tundra and closed forest. The potential of stomata for providing improved resolution of past locations of the tree line, coupled with the presence of stomata in lakes that would lack good macrofossil records, suggest that stomate analysis will become an important technique supplementing pollen analysis for reconstructing past tree-line changes. Keywords: Northwest Territories, conifer stomata and pollen, tree line, tundra, forest–tundra, closed forest.

Pollen Taphonomy in a Canyon Stream

1987 ◽  
Vol 28 (3) ◽  
pp. 393-406 ◽  
Author(s):  
Patricia L. Fall
Keyword(s):  
Surface Soil ◽  
Pollen Grains ◽  
Close Correlation ◽  
Soil Samples ◽  
Alluvial Deposits ◽  
Modern Pollen ◽  
Pollen Types ◽  
Pollen Rain ◽  
Arid Steppe ◽  
Turbulent Water

AbstractSurface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae-Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

MODERN POLLEN RAIN STUDIES IN EASTERN ONTARIO

1963 ◽  
Vol 41 (2) ◽  
pp. 243-252 ◽  
Author(s):  
James E. King ◽  
Ronald O. Kapp
Keyword(s):  
United States ◽  
Long Range ◽  
Southwestern United States ◽  
Pollen Trap ◽  
Modern Pollen ◽  
Pollen Rain ◽  
Moss Polsters ◽  
Eastern Ontario

Moss polsters were collected at 15 sites between Toronto and Lake Timagami, Ontario, and at 4 localities in the Lake Timagami area for the purpose of determining the regional pollen rain and its local variations. Pollen percentages of Acer, Quercus, Ambrosia, Chenopodiaceae, Compositae, and Gramineae decrease northward and Picea, Pinus, and Betula increase at the more northerly sites. From the three most northern sites a regional pollen rain was calculated by averaging the percentages from nine pollen spectra. In this area the regional pollen rain is dominated by Picea (15%), Pinus (38%), and Betula (22%). At one site a grain of Ephedra was recovered, apparently carried in by long range drift. The nearest place that it grows naturally is in the southwestern United States. Various pollen trap types were investigated and it was found that all types of moss polsters and some types of decaying stumps (depending on their moisture-holding capacity) were effective in preserving the modern pollen rain.

Pseudoditrichum mirabile gen. et sp. nov. (Musci: Pseudoditrichaceae fam. nov.), a unique moss from Great Bear Lake, Northwest Territories

1974 ◽  
Vol 52 (4) ◽  
pp. 701-705 ◽  
Author(s):  
William Campbell Steere ◽  
Zennoske Iwatsuki
Keyword(s):  
Northwest Territories ◽  
New Genus ◽  
The Arctic ◽  
Phylogenetic Position ◽  
New Genus And Species ◽  
Arctic Circle ◽  
New Family ◽  
Bear Lake ◽  
Evolutionary Level

The name Pseudoditrichum mirabile Steere et Iwatsuki is proposed for a minute moss with leafy stem 1-3 mm high and seta 6 mm long; it was collected on calcareous silt near the Sloan River, Great Bear Lake, Northwest Territories, only a few miles south of the Arctic Circle. The gametophytic characters agree well with those of the Ditrichaceae, a relatively primitive family, but the peristome is clearly double, with the inner and outer teeth opposite, which thereby indicates a much more advanced phylogenetic position, perhaps at the evolutionary level of the Funariaceae. As the combination of gametophytic and sporophytic characteristics exhibited by this moss does not occur in any existing family of mosses, it is therefore deemed necessary to create the new family Pseudoditrichaceae for the new genus and species described here.

Co-producing Sea-Ice Predictions with Stakeholders Using Simulation

2021 ◽  
Keyword(s):  
Sea Ice ◽  
Local Community ◽  
Economic Value ◽  
Arctic Region ◽  
Production Model ◽  
The Arctic ◽  
Simulation Game ◽  
Climate Services ◽  
Diverse Range ◽  
Uncertainty Information

Abstract Forecasts of sea-ice evolution in the Arctic region for several months ahead can be of considerable socio-economic value for a diverse range of marine sectors and for local community supply logistics. However, subseasonal-to-seasonal (S2S) forecasts represent a significant technical challenge, while translating user needs into scientifically manageable procedures and robust user confidence requires collaboration among a range of stakeholders. We developed and tested a novel, transdisciplinary co-production approach that combined socio-economic scenarios and participatory, research-driven simulation-gaming to test a new S2S sea-ice forecast system with experienced mariners in the cruise tourism sector. Our custom-developed computerized simulation-game ICEWISE integrated sea-ice parameters, forecast technology and human factors, as a participatory environment for stakeholder engagement. We explored the value of applications-relevant S2S sea-ice prediction and linked uncertainty information. Results suggest that the usefulness of S2S services is currently most evident in schedule-dependent sectors but expected to increase due to anticipated changes in the physical environment and continued growth in Arctic operations. Reliable communication of uncertainty information in sea-ice forecasts must be demonstrated and trialed before users gain confidence in emerging services and technologies. Mariners’ own intuition, experience, and familiarity with forecast service provider reputation impact the extent to which sea-ice information may reduce uncertainties and risks for Arctic mariners. Our insights into the performance of the combined foresight/simulation co-production model in brokering knowledge across a range of domains demonstrates promise. We conclude with an overview of the potential contributions from S2S sea-ice predictions and from experiential co-production models to the development of decision-driven and science-informed climate services.

Inuit vulnerability and adaptive capacity to climate change in Ulukhaktok, Northwest Territories, Canada

Polar Record ◽  
2009 ◽  
Vol 46 (2) ◽  
pp. 157-177 ◽  
Author(s):  
Tristan Pearce ◽  
Barry Smit ◽  
Frank Duerden ◽  
James D. Ford ◽  
Annie Goose ◽  
...  
Keyword(s):  
Climate Change ◽  
Northwest Territories ◽  
Adaptive Capacity ◽  
Adaptive Strategies ◽  
The Arctic ◽  
Future Climate Change ◽  
Sources Of Information ◽  
Structured Interviews ◽  
Climate Change Research ◽  
Climate Conditions

ABSTRACTClimate change is already being experienced in the Arctic with implications for ecosystems and the communities that depend on them. This paper argues that an assessment of community vulnerability to climate change requires knowledge of past experience with climate conditions, responses to climatic variations, future climate change projections, and non-climate factors that influence people's susceptibility and adaptive capacity. The paper documents and describes exposure sensitivities to climate change experienced in the community of Ulukhaktok, Northwest Territories and the adaptive strategies employed. It is based on collaborative research involving semi-structured interviews, secondary sources of information, and participant observations. In the context of subsistence hunting, changes in temperature, seasonal patterns (for example timing and nature of the spring melt), sea ice and wind dynamics, and weather variability have affected the health and availability of some species of wildlife important for subsistence and have exacerbated risks associated with hunting and travel. Inuit in Ulukhaktok are coping with these changes by taking extra precautions when travelling, shifting modes of transportation, travel routes and hunting areas to deal with changing trail conditions, switching species harvested, and supplementing their diet with store bought foods. Limited access to capital resources, changing levels of traditional knowledge and land skills, and substance abuse were identified as key constraints to adaptation. The research demonstrates the need to consider the perspectives and experiences of local people for climate change research to have practical relevance to Arctic communities such as for the development and promotion of adaptive strategies.

scholarly journals Relación lluvia de polen-vetación en selvas de Quintana Roo

2017 ◽  
pp. 31 ◽  
Author(s):  
Gerald A. Islebe ◽  
Rogel Villanueva-Gutiérrez ◽  
Odilón Sánchez-Sánchez
Keyword(s):  
Zea Mays ◽  
Quintana Roo ◽  
Vegetation Types ◽  
Pollen Data ◽  
Indicator Taxa ◽  
Modern Pollen ◽  
Pollen Content ◽  
Ordination Techniques ◽  
Ordination Analysis ◽  
Pollen Rain

Modern pollen rain was studied along a 450 km long transect between Cancun-La Unión (Belizean border). Ten moss samples were collected in different vegetation types and analyzed for pollen content. The data were analyzed with classification (TWINSPAN), ordination analysis (DCA) and different association indices. Classification and ordination techniques allowed us to recognize three different pollen signals from semievergreen forest (with Maclura, Apocynaceae, Moraceae, Sapotaceae, Araceae, Cecropia, Celtis, Eugenia and Bursera), acahual (with con Coccoloba, Metopium, Anacardiaceae, Urticales, Melothria, Croton, Palmae) and disturbed vegetation (with Zea mays, Mimosa and Asteraceae ) . The degree of over-representation and underrepresentation of the pollen data with respect to the modem vegetation was established, being under-represented mostly entomophilous species. We can conclude that the actual pollen signal can be used for calibrating paleosignals, if clear groups of indicator taxa can be established.

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