INVESTIGATION OF THE RELATIONSHIP BETWEEN RECENT WARM WINTER SURFACE TEMPERATURES AND GLACIAL MELTING IN SVALBARD AND THE RUSSIAN HIGH ARCTIC

2017 ◽  
Author(s):  
Elizabeth Dyer ◽  
◽  
Joan Ramage
Keyword(s):  
High Arctic ◽  
Warm Winter ◽  
Surface Temperatures ◽  
Glacial Melting ◽  
The Relationship

EREMAEIDAE (ACARI: ORIBATIDA) OF NORTH AMERICA

1993 ◽  
Vol 125 (S168) ◽  
pp. 1-193 ◽  
Author(s):  
Valerie M. Behan-Pelletier
Keyword(s):  
New Mexico ◽  
North America ◽  
North American ◽  
Cladistic Analysis ◽  
High Arctic ◽  
North American Species ◽  
Sister Taxon ◽  
Species Groups ◽  
Relationship Of ◽  
The Relationship

AbstractThe oribatid family Eremaeidae is represented in North America by two genera, Eremaeus and Eueremaeus, both widely distributed throughout the Palaearctic and Nearctic regions. In North America species in both genera are found in moist to arid habitats from New Mexico to the High Arctic. Reproduction is sexual, and both immatures and adults feed mainly on fungi.Revised diagnoses are presented for the Eremaeidae and genera Eremaeus and Eueremaeus. Eighteen species of Eremaeus, of which 14 are newly proposed, and 24 species of Eueremaeus, of which 15 are newly proposed, are recognized. Identification keys are provided for the world genera of Eremaeidae, and for adults of Eremaeus and Eueremaeus of North America. All but one North American species of these genera are described, and their geographical distributions mapped.North American Eremaeus species include E. appalachicus sp. no v., E. boreomontanus sp. nov., E. brevitarsus (Ewing), E. californiensis sp. nov., E. gracilis sp. nov., E. grandis Hammer, E. kananaskis sp. nov., E. kevani sp. nov., E. megistos sp. nov., E. monticolus sp. nov., E. nortoni sp. nov., E. occidentalis sp. nov., E. oresbios sp. nov., E. plumosus Woolley, E. porosus sp. nov., E. salish sp. nov., E. translamellatus Hammer, and E. walteri sp. nov. The immatures of four of these, E. kananaskis, E. occidentalis, E. oresbios, and E. translamellatus, are described.North American Eueremaeus include Eu. acostulatus sp. nov., Eu. aridulus sp. nov., Eu. columbianus (Berlese), Eu. foveolatus (Hammer), Eu. marshalli sp. nov., Eu. masinasin sp. nov., Eu. michaeli sp. nov., Eu. nahani sp. nov., Eu. nemoralis sp. nov., Eu. proximus (Berlese) comb, nov., Eu. woolleyi (Higgins) comb, nov., Eu. yukonensis sp. nov., and three informal species groups with the following included species in North America: (1) Eu. trionus group—Eu. trionus (Higgins) comb, nov., (2) Eu. stiktos group—Eu. carinatus sp. nov., Eu. higginsi sp. nov., Eu. stiktos (Higgins) comb, nov., Eu. tetrosus (Higgins) comb, nov., (3) Eu. chiatous group—Eu. alvordensis sp. nov., Eu. aysineep sp. nov., Eu. chiatous (Higgins) comb, nov., Eu. danos sp. nov., Eu. lindquisti sp. nov., Eu. magniporosus (Wallwork) comb, nov., and Eu. osoyoosensis sp. nov. The immatures of nine of these, Eu. masinasin, Eu. nahani, Eu. carinatus, Eu. higginsi, Eu. columbianus, Eu. proximus, Eu. woolleyi, Eu. stiktos, and Eu. tetrosus, are described. Kartoeremaeus reevesi Higgins and Eremaeus politus Banks are considered junior subjective synonyms of Eueremaeus columbianus (Berlese).A cladistic analysis of the genera comprising Eremaeidae: Eremaeus, Tricheremaeus, Eueremaeus (and included species groups), Proteremaeus, Carinabella, and Asperemaeus, indicates that Eremaeus is the sister taxon of Carinabella, and that Eueremaeus is the sister taxon of Proteremaeus. Tricheremaeus is the sister taxon of Eremaeus + Carinabella, and Asperemaeus is the sister taxon of Eueremaeus + Proteremaeus. The relationship of the Eremaeidae to the Megeremaeidae and Zetorchestidae is presented. Finally, I discuss the ecology and distribution of North American species of Eremaeidae.

scholarly journals Artificial Neural Network Modeling of High Arctic Phytomass Using Synthetic Aperture Radar and Multispectral Data

2021 ◽  
Author(s):  
Adam Collingwood ◽  
Paul Treitz ◽  
Francois Charbonneau ◽  
David M. Atkinson
Keyword(s):  
Synthetic Aperture Radar ◽  
High Arctic ◽  
Synthetic Aperture ◽  
The Arctic ◽  
Optical Data ◽  
Neural Network Modeling ◽  
Artificial Neural ◽  
Sar Data ◽  
The Relationship ◽  
Aperture Radar

Vegetation in the Arctic is often sparse, spatially heterogeneous, and difficult to model. Synthetic Aperture Radar (SAR) has shown some promise in above-ground phytomass estimation at sub-arctic latitudes, but the utility of this type of data is not known in the context of the unique environments of the Canadian High Arctic. In this paper, Artificial Neural Networks (ANNs) were created to model the relationship between variables derived from high resolution multi-incidence angle RADARSAT-2 SAR data and optically-derived (GeoEye-1) Soil Adjusted Vegetation Index (SAVI) values. The modeled SAVI values (i.e., from SAR variables) were then used to create maps of above-ground phytomass across the study area. SAVI model results for individual ecological classes of polar semi-desert, mesic heath, wet sedge, and felsenmeer were reasonable, with r2 values of 0.43, 0.43, 0.30, and 0.59, respectively. When the outputs of these models were combined to analyze the relationship between the model output and SAVI as a group, the r2 value was 0.60, with an 8% normalized root mean square error (% of the total range of phytomass values), a positive indicator of a relationship. The above-ground phytomass model also resulted in a very strong relationship (r2 = 0.87) between SAR-modeled and field-measured phytomass. A positive relationship was also found between optically derived SAVI values and field measured phytomass (r2 = 0.79). These relationships demonstrate the utility of SAR data, compared to using optical data alone, for modeling above-ground phytomass in a high arctic environment possessing relatively low levels of vegetation.

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