scholarly journals The Recent Spread and Potential Distribution of Phragmites australis subsp. australis in Canada

2011 ◽  
Vol 125 (2) ◽  
pp. 95 ◽  
Author(s):  
Paul M. Catling ◽  
Gisèle Mitrow
Keyword(s):  
Nova Scotia ◽  
Phragmites Australis ◽  
Potential Distribution ◽  
Common Reed ◽  
River Valley ◽  
Occurrence Rate ◽  
Quebec City ◽  
Herbarium Specimens ◽  
Rate Of Spread ◽  
St Lawrence River

To provide information on geographic occurrence, rate of spread, and potential distribution of European Common Reed, Phragmites australis subsp. australis, in Canada, we measured 1740 herbarium specimens from 21 collections across Canada, entered the information into a database, and mapped and analyzed these records. The European subspecies australis was first documented in Canada 100 years before it was recognized as an alien invader. It was not until the invading plants had entered a phase of rapid local increase after 1990 that they attracted sufficient attention that a comparison of the invasive and non-invasive plants was made. By 2001, two different races had been distinguished, and soon after they were separated as different subspecies. The first Canadian collection of the alien subsp. australis was made in southwestern Nova Scotia in 1910. By the 1920s, it occurred in southern Nova Scotia, along the St. Lawrence River near Quebec City and at Montreal. The first southwestern Ontario specimen was collected in 1948. Thus by 1950 subsp. australis was known from only four relatively small areas of Canada based on 22 collections. At this same time, the native race, subsp. americanus, had a widespread distribution in Canada represented by 325 collections. This strongly supported the comparable and limited distribution of subsp. australis at the time. By 1970, subsp. australis had spread locally but was still found only in southwestern Nova Scotia, in the St. Lawrence River valley, and in southwestern Ontario. By 1990, subsp. australis had become much more frequent in the St. Lawrence River valley and in southwestern Ontario, and it had extended westward into eastern Ontario. By 2010, it had spread throughout much of southern Ontario and southern Quebec, and it had a more extensive distribution in Atlantic Canada, but the biggest change was its spread into western Canada. It appeared in northern Ontario, northwestern Ontario, southern Manitoba, and interior southern British Columbia. The rate of spread is increasing and within a decade or two, based on the extent of appropriate plant hardiness zones currently occupied, it is expected to become abundant in the prairie provinces and across most of southern Canada.

Observational Study of Wind Channeling within the St. Lawrence River Valley

2009 ◽  
Vol 48 (11) ◽  
pp. 2341-2361 ◽  
Author(s):  
Marco L. Carrera ◽  
John R. Gyakum ◽  
Charles A. Lin
Keyword(s):  
Surface Wind ◽  
Hudson River ◽  
Geostrophic Wind ◽  
The United States ◽  
River Valley ◽  
Quebec City ◽  
Surface Winds ◽  
Eastern Canada ◽  
St Lawrence River ◽  
Pressure Driven

Abstract The presence of orography can lead to thermally and dynamically induced mesoscale wind fields. The phenomenon of channeling refers to the tendency for the winds within a valley to blow more or less parallel to the valley axis for a variety of wind directions above ridge height. Channeling of surface winds has been observed in several regions of the world, including the upper Rhine Valley of Germany, the mountainous terrain near Basel, Switzerland, and the Tennessee and Hudson River Valleys in the United States. The St. Lawrence River valley (SLRV) is a primary topographic feature of eastern Canada, extending in a southwest–northeast direction from Lake Ontario, past Montreal (YUL) and Quebec City (YQB), and terminating in the Gulf of St. Lawrence. In this study the authors examine the long-term surface wind climatology of the SLRV and Lake Champlain Valley (LCV) as represented by hourly surface winds at Montreal, Quebec City, and Burlington, Vermont (BTV). Surface wind channeling is found to be prominent at all three locations with strong bidirectionalities that vary seasonally. To assess the importance of the various channeling mechanisms the authors compared the joint frequency distributions of surface wind directions versus 925-hPa geostrophic wind directions with those obtained from conceptual models. At YUL, downward momentum transport is important for geostrophic wind directions ranging from 240° to 340°. Pressure-driven channeling is the dominant mechanism producing northeasterly surface winds at YUL. These northeasterlies are most prominent in the winter, spring, and autumn seasons. At YQB, pressure-driven channeling is the dominant physical mechanism producing channeling of surface winds throughout all seasons. Of particular importance, both YUL and YQB exhibit countercurrents whereby the velocity component of the wind within the valley is opposite to the component above the valley. Forced channeling was found to be prominent at BTV, with evidence of diurnal thermal forcing during the summer season. Reasons for the predominance of pressure-driven channeling at YUL and YQB and forced channeling at BTV are discussed.

scholarly journals Recent Invasion, Current Status and Invasion Pathway of European Common Reed, Phragmites australis subspecies australis, in the Southern Ottawa District

2006 ◽  
Vol 120 (3) ◽  
pp. 307 ◽  
Author(s):  
Paul M. Catling ◽  
Susan Carbyn
Keyword(s):  
Phragmites Australis ◽  
Common Reed ◽  
Current Status ◽  
Past Century ◽  
Herbarium Specimens ◽  
Buffer Zones ◽  
The Past ◽  
Native North American ◽  
Natural Wetlands ◽  
Invasion Pathway

A survey of populations of native North American Common Reed (Phragmites australis subsp. americanus) and the introduced invasive alien, European Common Reed (Phragmites australis subsp. australis) was conducted in four eastern Ontario townships in 2003. The historical status of the two taxa in the region was evaluated through reference to herbarium specimens collected over the past century. The introduced subspecies appears to have entered the district in the 1970s and subsequently assumed dominance but was not recognized as an alien until 2003. It is now widespread in the four townships where ninety-five populations were recorded during the 2003 survey. Of these, 25 were referable to the native subspecies which was localized and 70 were referable to the introduced subspecies which was widespread. The native subspecies occurs in natural wetlands and also spreads to roadsides, but the introduced subspecies is much more strongly associated with roads, where the rhizomes extend onto gravel shoulders and are broken and transported by construction equipment, graders, ploughs, mowers, and in the treads of many kinds of vehicles. Sensitive wetlands should have buffer zones exceeding 1000 m to prevent colonization of subsp. australis. Monitoring of the two subspecies will be essential to the protection of native biodiversity, since early detection of the alien subspecies in a sensitive wetland will offer the best opportunity for control.

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.

scholarly journals Title: Influences of reduced iron and magnesium on growth and photosynthetic performance of Phragmites australis subsp. americanus (North American common reed)

2017 ◽  
Vol 137 ◽  
pp. 30-38 ◽  
Author(s):  
Kevin G. Willson ◽  
Angela N. Perantoni ◽  
Zachary C. Berry ◽  
Matthew I. Eicholtz ◽  
Yvette B. Tamukong ◽  
...  
Keyword(s):  
Phragmites Australis ◽  
North American ◽  
Common Reed ◽  
Photosynthetic Performance
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