Morphological and isozyme variation in Salicornia europaea (s.l.) (Chenopodiaceae) in northeastern North America

1987 ◽  
Vol 65 (7) ◽  
pp. 1410-1419 ◽  
Author(s):  
S. L. Wolff ◽  
R. L. Jefferies
Keyword(s):  
North America ◽  
Atlantic Coast ◽  
Hudson Bay ◽  
Salicornia Europaea ◽  
Electrophoretic Variation ◽  
James Bay ◽  
Northeastern North America ◽  
Electrophoretic Patterns ◽  
Anther Length ◽  
Vegetative Characters

Morphological and electrophoretic variation has been documented within and among populations of Salicornia europaea L. (s.l.) in northeastern North America. Univariate and multivariate analyses (discriminant analyses) of measurements of floral and vegetative characters delimited three morphologically distinct groups of populations: Atlantic coast tetraploids (2n = 36), Hudson Bay diploids, and Atlantic coast and James Bay diploids (2n = 18). The two diploid groups were morphologically distinct from the midwestern diploid, S. rubra Nels., based on anther length, width of the scarious border of the fertile segment, and the overall width of the fertile segment. Electrophoretic evidence supported the delimitation of the three distinct morphological groups of populations of S. europaea with the exception of the population from James Bay, which had electrophoretic patterns identical with those of plants from Hudson Bay but resembled the Atlantic coast diploids morphologically. Most enzyme systems assayed were monomorphic. Only homozygous banding patterns were detected in diploid plants and electrophoretic variation was not observed within populations of S. europaea or S. rubra but was detected between groups of populations. Four multilocus phenotypes were evident; these corresponded to the major groups recognized on the basis of ploidy level and morphology. Reasons that may account for the paucity of isozymic variation are discussed.

Taxonomic status of diploid Salicornia europaea (s.l.) (Chenopodiaceae) in northeastern North America

1987 ◽  
Vol 65 (7) ◽  
pp. 1420-1426 ◽  
Author(s):  
S. L. Wolff ◽  
R. L. Jefferies
Keyword(s):  
North America ◽  
North American ◽  
Taxonomic Status ◽  
Distinct Group ◽  
Salicornia Europaea ◽  
Electrophoretic Variation ◽  
Northeastern North America ◽  
Anther Length ◽  
Length Width ◽  
Diploid Populations

The taxonomic status of diploid Salicornia europaea L. (s.l.) in northeastern North America has been evaluated based on morphological and electrophoretic variation within and between populations. Populations of two European diploid micro-species, S. ramosissima J. Woods and S. europaea (s.s.), and populations of the midwestern diploid, S. rubra A. Nels., were also examined, affording a comparison between North American S. europaea (s.l.) and recognized species. Anther length, width of the scarious border of the fertile segment, and floral perianth shape were used to subdivide North American diploid populations into two groups. These groups were morphologically distinct from S. rubra and the European microspecies. The electrophoretic profile was unique in each morphologically distinct group of populations of S. europaea (s.l.) in northeastern North America. Based on morphological, geographical, and electrophoretic differences, diploid populations of S. europaea (s.l.) from this region are assigned to one of the following two new species: S. maritima Wolff & Jefferies, sp.nov., and S. borealis Wolff & Jefferies, sp.nov. The tetraploids are retained in S. europaea (s.l.).

scholarly journals Origin of the southernmost Arctic tundra of continental North America

2018 ◽  
Vol 4 (4) ◽  
pp. 794-812
Author(s):  
Serge Payette ◽  
Vanessa Pilon ◽  
Mathieu Frégeau
Keyword(s):  
North America ◽  
Arctic Tundra ◽  
The Arctic ◽  
Hudson Bay ◽  
James Bay ◽  
Louis Xiv ◽  
Unusual Position ◽  
Crustal Uplift ◽  
Cold Wind ◽  
Boreal Environment

The Arctic tundra extends beyond the treeline north of 58°N in eastern North America and north of 66°N in western North America and Eurasia. A marked exception to this distribution is the azonal tundra situated as far south as 54°30′–45′N, in the Pointe-Louis-XIV area (JABA), along the fast-rising coasts of James Bay–Hudson Bay. The unusual position of JABA calls into question the influence of climate as the main causal factor for its existence. Macrocharcoal remains extracted from tundra and forest soils were used along a 105 km transect to date the onset of the boreal environment based on past occurrence of conifer fires. Assuming crustal uplift 1.3 m 100 year−1 and 2.4 m 100 year−1 over and before the last 1000 years, and after correcting site elevation at the time the oldest conifer fires occurred, trees established along the coast before 4000 cal. BP. Given charcoal distribution suggesting boreal vegetation in sites ≤13 m a.s.l., JABA was created after 4000 cal. BP when the flat, elongated peninsula emerged above marine waters. It is concluded that JABA origin was most likely caused by the synergistic impact of geophysical factors, isostatic uplift and topography, on a coastal environment already influenced by cold, wind-exposed conditions.

scholarly journals Whimbrel populations differ in trans-atlantic pathways and cyclone encounters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bryan D. Watts ◽  
Fletcher M. Smith ◽  
Chance Hines ◽  
Laura Duval ◽  
Diana J. Hamilton ◽  
...  
Keyword(s):  
North America ◽  
Atlantic Coast ◽  
Safety Net ◽  
Hudson Bay ◽  
Mackenzie Delta ◽  
Migration Routes ◽  
Storm Activity ◽  
Caribbean Islands ◽  
South Atlantic Coast ◽  
Migration Pathways

AbstractEach year hundreds of millions of birds cross the Atlantic Ocean during the peak of tropical cyclone activity. The extent and consequences of migrant-storm interactions remain unknown. We tracked whimbrels from two populations (Mackenzie Delta; Hudson Bay) to examine overlap between migration routes and storm activity and both the frequency and consequence of storm encounters. Here we show that Mackenzie Delta and Hudson Bay whimbrels follow different routes across the ocean and experience dramatically different rates of storm encounters. Mackenzie Delta whimbrels departed North America from Atlantic Canada, made long ($$\bar{x}$$ x ¯  = 5440 ± 120.3 km) nonstop flights far out to sea that took several days ($$\bar{x}$$ x ¯  = 6.1 ± 0.18) to complete and encountered storms during 3 of 22 crossings. Hudson Bay whimbrels departed North America from the south Atlantic Coast, made shorter ($$\bar{x}$$ x ¯  = 3643 ± 196.2 km) nonstop flights across the Caribbean Basin that took less time ($$\bar{x}$$ x ¯  = 4.5 ± 0.29) to complete and encountered storms during 13 of 18 crossings. More than half of Hudson Bay storm encounters resulted in groundings on Caribbean islands. Grounded birds required longer ($$\bar{x}$$ x ¯  = 30.4 ± 5.32 days) to complete trans-Atlantic crossings and three were lost including 2 to hunters and 1 to a predator. One of the Mackenzie Delta whimbrels was lost at sea while crossing the Intertropical Convergence Zone. Whimbrels use two contrasting strategies to cross the Atlantic including (1) a long nonstop flight around the core of storm activity with a low likelihood of encountering storms but no safety net and (2) a shorter flight through the heart of Hurricane Alley with a high likelihood of encountering storms and a safety network of islands to use in the event of an encounter. Demographic consequences of storm encounters will likely play a role in the ongoing evolution of trans-Atlantic migration pathways as global temperatures continue to rise.

scholarly journals Distribution and taxonomy of Isoetes tuckermanii subsp. acadiensis, comb. nov. (Isoetaceae) in North America

2019 ◽  
Vol 132 (4) ◽  
pp. 360-367 ◽  
Author(s):  
Daniel F. Brunton
Keyword(s):  
North America ◽  
Narrow Range ◽  
Atlantic Coast ◽  
Sensu Stricto ◽  
Weight Of Evidence ◽  
Molecular Evidence ◽  
Distinctive Features ◽  
Northeastern North America ◽  
Intermediate Morphology ◽  
Sterile Hybrids

Isoetes acadiensis is an emergent aquatic lycophyte of freshwater shores found in a narrow range along the Atlantic coast of northeastern North America where it frequently coexists with Isoetes tuckermanii (sensu stricto [s. str.]). Apparently fertile plants with intermediate morphology occur commonly in mixed populations. No sterile hybrids between the two taxa have been detected. Although I. acadiensis maintains a distinctive geographic distribution (within and smaller than that of I. tuckermanii [s. str.]), exhibits molecular evidence of genetic distinctiveness, and has morphologically distinctive features in most populations, the weight of evidence suggests it is not distinct from I. tuckermanii at a species level. Accordingly, I. tuckermanii subsp. acadiensis, comb. nov. is proposed as the appropriate designation for this biogeographically important Acadian endemic.

FABRIC OF THE LITHOSPHERE IN NORTHEASTERN NORTH AMERICA

2019 ◽  
Author(s):  
Yiran Li ◽  
◽  
Vadim Levin ◽  
Zhenxin Xie
Keyword(s):  
North America ◽  
Northeastern North America

Early Maize in Northeastern North America: A Comment on Emerson and Colleagues

2021 ◽  
Vol 86 (2) ◽  
pp. 425-427
Author(s):  
John P. Hart ◽  
William A. Lovis ◽  
M. Anne Katzenberg
Keyword(s):  
North America ◽  
Great Lakes ◽  
Empirical Evidence ◽  
River Valley ◽  
Human Bone ◽  
Northeastern North America ◽  
Isotopic Evidence ◽  
St Lawrence River

Emerson and colleagues (2020) provide new isotopic evidence on directly dated human bone from the Greater Cahokia region. They conclude that maize was not adopted in the region prior to AD 900. Placing this result within the larger context of maize histories in northeastern North America, they suggest that evidence from the lower Great Lakes and St. Lawrence River valley for earlier maize is “enigmatic” and “perplexing.” Here, we review that evidence, accumulated over the course of several decades, and question why Emerson and colleagues felt the need to offer opinions on that evidence without providing any new contradictory empirical evidence for the region.

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