Chromosome races in Rumex arcticus (Polygonaceae)

1972 ◽  
Vol 50 (2) ◽  
pp. 378-380
Author(s):  
Gerald A. Mulligan ◽  
Clarence Frankton

Rumex arcticus Trautv., a species found on the mainland of northwestern North America and in northeastern U.S.S.R., contains tetraploid (2n = 40), dodecaploid (2n = 120), and perhaps 2n = 160 and 2n = 200 chromosome races. Most North American plants are tetraploid and are larger in size and have more compound and contiguous inflorescences than typical R. arcticus. Typical plants of R. arcticus occur in the arctic U.S.S.R., St. Lawrence Island in the Bering Sea, and at the tip of the Seward Peninsula of Alaska, and they all have 120 or more somatic chromosomes. High polyploid plants of R. arcticus that resemble North American tetraploids in appearance apparently occur on the Kamchatka Peninsula. These have been called R. kamtshadalus Komarov or R. arcticus var. kamtshadalus (Kom.) Rech. f. by some authors.

2017 ◽  
Vol 39 (1) ◽  
pp. 115 ◽  
Author(s):  
DALE H. VITT

Orthotrichum fenestratum Card. & Thér, described from St. Paul Island and reported only from a few small islands in the Bering Sea and Aleutian Chain, was considered unique because of perforations in the exostome. Comparisons with the uncommon, but widespread, arctic-montane species, O. pylaisii Brid., indicates that like O. fenestratum, O. pylaisii also has exostomial perforations and these species are conspecific. The distribution of O. pylaisii is mapped for northwestern North America. Orthotrichum sordidum Sull. & Lesq. was described from eastern North America and then reported from East Asia and from scattered locations in Alaska and Greenland. All of the Alaskan specimens are O. pylaisii and also all of the Greenland specimens examined belong to this latter species; consequently O. sordidum should be removed from the floras of these northern regions. Similar to O. pylaisii, O. sordidum also has perforate (and fenestrate) exostome teeth, but differs in a number of features, including 8 vs.16 exostome teeth; deeply ribbed, emergent capsules vs. lightly ribbed, exserted capsules; and 8, well-developed endostome segments vs. rudimentary segments of O. pylaisii. Orthotrichum sordidum occurs almost exclusively on tree trunks, while O. pylaisii occurs on rock.


2012 ◽  
Vol 69 (7) ◽  
pp. 1180-1193 ◽  
Author(s):  
Zachary W. Brown ◽  
Kevin R. Arrigo

Abstract Brown, Z. W., and Arrigo, K. R. 2012. Contrasting trends in sea ice and primary production in the Bering Sea and Arctic Ocean. – ICES Journal of Marine Science, 69: . Satellite remote sensing data were used to examine recent trends in sea-ice cover and net primary productivity (NPP) in the Bering Sea and Arctic Ocean. In nearly all regions, diminished sea-ice cover significantly enhanced annual NPP, indicating that light-limitation predominates across the seasonally ice-covered waters of the northern hemisphere. However, long-term trends have not been uniform spatially. The seasonal ice pack of the Bering Sea has remained consistent over time, partially because of winter winds that have continued to carry frigid Arctic air southwards over the past six decades. Hence, apart from the “Arctic-like” Chirikov Basin (where sea-ice loss has driven a 30% increase in NPP), no secular trends are evident in Bering Sea NPP, which averaged 288 ± 26 Tg C year−1 over the satellite ocean colour record (1998–2009). Conversely, sea-ice cover in the Arctic Ocean has plummeted, extending the open-water growing season by 45 d in just 12 years, and promoting a 20% increase in NPP (range 441–585 Tg C year−1). Future sea-ice loss will likely stimulate additional NPP over the productive Bering Sea shelves, potentially reducing nutrient flux to the downstream western Arctic Ocean.


Antiquity ◽  
2015 ◽  
Vol 89 (345) ◽  
pp. 740-742 ◽  
Author(s):  
Herbert Maschner

This review considers three books on the archaeology of territories situated around the Bering Sea—a region often referred to as Beringia, adopting the term created for the Late Pleistocene landscape that extended from north-east Asia, across the Bering Land Bridge, to approximately the Yukon Territory of Canada. This region is critical to the archaeology of the Arctic for two fundamental reasons. First, it is the gateway to the Americas, and was certainly the route by which the territory was colonised at the end of the last glaciation. Second, it is the place where the entire Aleut-Eskimo (Unangan, Yupik, Alutiiq, Inupiat and Inuit) phenomenon began, and every coastal culture from the far north Pacific, to Chukotka, to north Alaska, and to arctic Canada and Greenland, has its foundation in the cultural developments that occurred around the Bering Sea.


ZooKeys ◽  
2020 ◽  
Vol 984 ◽  
pp. 59-81
Author(s):  
Cory S. Sheffield ◽  
Ryan Oram ◽  
Jennifer M. Heron

The bumble bee (Hymenoptera, Apidae, Bombini, Bombus Latreille) fauna of the Nearctic and Palearctic regions are considered well known, with a few species occurring in both regions (i.e., with a Holarctic distribution), but much of the Arctic, especially in North America, remains undersampled or unsurveyed. Several bumble bee taxa have been described from northern North America, these considered either valid species or placed into synonymy with other taxa. However, some of these synonymies were made under the assumption of variable hair colour only, without detailed examination of other morphological characters (e.g., male genitalia, hidden sterna), and without the aid of molecular data. Recently, Bombus interacti Martinet, Brasero & Rasmont, 2019 was described from Alaska where it is considered endemic; based on both morphological and molecular data, it was considered a taxon distinct from B. lapponicus (Fabricius, 1793). Bombus interacti was also considered distinct from B. gelidus Cresson, 1878, a taxon from Alaska surmised to be a melanistic form of B. lapponicus sylvicola Kirby, 1837, the North American subspecies (Martinet et al. 2019). Unfortunately, Martinet et al. (2019) did not have DNA barcode sequences (COI) for females of B. interacti, but molecular data for a melanistic female specimen matching the DNA barcode sequence of the holotype of B. interacti have been available in the Barcodes of Life Data System (BOLD) since 2011. Since then, additional specimens have been obtained from across northern North America. Also unfortunate was that B. sylvicola var. johanseni Sladen, 1919, another melanistic taxon described from far northern Canada, was not considered. Bombus johanseni is here recognized as a distinct taxon from B. lapponicus sylvicola Kirby, 1837 (sensuMartinet et al. 2019) in the Nearctic region, showing the closest affinity to B. glacialis Friese, 1902 of the Old World. As the holotype male of B. interacti is genetically identical to material identified here as B. johanseni, it is placed into synonymy. Thus, we consider B. johanseni a widespread species occurring across arctic and subarctic North America in which most females are dark, with rarer pale forms (i.e., “interacti”) occurring in and seemingly restricted to Alaska. In addition to B. johanseni showing molecular affinities to B. glacialis of the Old World, both taxa also inhabit similar habitats in the arctic areas of both Nearctic and Palearctic, respectively. It is also likely that many of the specimens identified as B. lapponicus sylvicola from far northern Canada and Alaska might actually be B. johanseni, so that should be considered for future studies of taxonomy, distribution, and conservation assessment of North American bumble bees.


1987 ◽  
Vol 9 ◽  
pp. 236-236
Author(s):  
D.J. Cavalieri ◽  
C.L. Parkinson

The seasonal sea-ice cover of the combined Bering and Okhotsk Seas at the time of maximum ice extent is almost 2 × 106 km2 and exceeds that of any other seasonal sea-ice zone in the Northern Hemisphere. Although both seas are relatively shallow bodies of water overlying continental shelf regions, there are important geographical differences. The Sea of Okhotsk is almost totally enclosed, being bounded to the north and west by Siberia and Sakhalin Island, and to the east by Kamchatka Peninsula. In contrast, the Bering Sea is the third-largest semi-enclosed sea in the world, with a surface area of 2.3 × 106 km2, and is bounded to the west by Kamchatka Peninsula, to the east by the Alaskan coast, and to the south by the Aleutian Islands arc.While the relationship between the regional oceanography and meteorology and the sea-ice covers of both the Bering Sea and Sea of Okhotsk have been studied individually, relatively little attention has been given to the occasional out-of-phase relationship between the fluctuations in the sea-ice extent of these two large seas. In this study, we present 3 day averaged sea-ice extent data obtained from the Nimbus-5 Electrically Scanning Microwave Radiometer (ESMR-5) for the four winters for which ESMR-5 data were available, 1973 through 1976, and document those periods for which there is an out-of-phase relationship in the fluctuations of the ice cover between the Bering Sea and the Sea of Okhotsk. Further, mean sea-level pressure data are also analyzed and compared with the time series of sea-ice extent data to provide a basis for determining possible associations between the episodes of out-of-phase fluctuations and atmospheric circulation patterns.Previous work by Campbell and others (1981) using sea-ice concentrations also derived from ESMR-5 data noted this out-of-phase relationship between the two ice packs in 1973 and 1976. The authors commented that the out-of-phase relationship is “... surprising as these are adjacent seas, and one would assume that they had similar meteorologic environments”. We argue here that the out-of-phase relationship is consistent with large-scale atmospheric circulation patterns, since the two seas span a range of longitude of about 60°, corresponding to a half wavelength of a zonal wave-number 3, and hence are quite susceptible to changes in the amplitude and phase of large-scale atmospheric waves.


1991 ◽  
Vol 44 (1) ◽  
pp. 1-10 ◽  
Author(s):  
David H. Lewis ◽  
Mimi George

The tip of the Chukotskiy Peninsula in the Soviet Far East is 86 km from mainlandAlaska and its mountains are clearly visible from St Lawrence Island. It is a ruggedtreeless land that straddles the Arctic Circle between the Bering Sea and the ArcticOcean. In winter it is snow-covered and the sea stays frozen until May.


Polar Record ◽  
1956 ◽  
Vol 8 (52) ◽  
pp. 22-23 ◽  
Author(s):  
P. D. Baird

The Arctic Institute of North America was established in 1945 in two small rooms in McGill University, with a staff consisting of Dr Lincoln Washburn and a secretary, who made up for the lack of equipment and facilities by abundant energy and enthusiasm. Since then the Institute's growth has been considerable, always in the direction of its three main objectives—to form a centre for reference information and study on the North American Arctic, to encourage arctic scientific research in any field, and to disseminate arctic information by means of a journal, other publications, and lectures.


2014 ◽  
Vol 10 (6) ◽  
pp. 4425-4468
Author(s):  
D. Zanchettin ◽  
O. Bothe ◽  
F. Lehner ◽  
P. Ortega ◽  
C. C. Raible ◽  
...  

Abstract. Reconstructions of past climate behavior often describe prominent anomalous periods that are not necessarily captured in climate simulations. Here, we illustrate the contrast between an interdecadal strong positive phase of the winter Pacific/North American pattern (PNA) in the early 19th century that is described by a PNA reconstruction based on tree-rings from northwestern North America, and a slight tendency towards negative winter PNA anomalies during the same period in an ensemble of state-of-the-art coupled climate simulations. Additionally, a pseudo-proxy investigation with the same simulation ensemble allows assessing the robustness of PNA reconstructions using solely geophysical predictors from northwestern North America for the last millennium. The reconstructed early-19th-century positive PNA anomaly emerges as a potentially reliable feature, although it is subject to a number of sources of uncertainty and potential deficiencies. The pseudo-reconstructions demonstrate that the early-19th-century discrepancy between reconstructed and simulated PNA does not stem from the reconstruction process. Instead, reconstructed and simulated features of the early-19th-century PNA can be reconciled by interpreting the reconstructed evolution during this time as an expression of internal climate variability, hence unlikely to be reproduced in its exact temporal occurrence by a small ensemble of climate simulations. However, firm attribution of the reconstructed PNA anomaly is hampered by known limitations and deficiencies of coupled climate models and uncertainties in the early-19th-century external forcing and background climate conditions.


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