Isoetes laurentiana, sp. nov. (Isoetaceae) endemic to freshwater tidal marshes in eastern Quebec, Canada

Botany ◽  
2019 ◽  
Vol 97 (11) ◽  
pp. 571-583 ◽  
Author(s):  
D.F. Brunton ◽  
P.C. Sokoloff ◽  
J.F. Bolin ◽  
D.F. Fraser
Keyword(s):  
Tidal Marsh ◽  
River Estuary ◽  
Tidal Marshes ◽  
Species At Risk ◽  
International Union ◽  
Freshwater Tidal Marsh ◽  
Local Abundance ◽  
C Value ◽  
Erect Leaves ◽  
St Lawrence River

Morphological, phytogeographic, ecological, preliminary genetic, and C-value evidence indicates that populations of Isoetes confined to freshwater tidal marsh habitats along the St. Lawrence River in Quebec, Canada, represent an undescribed endemic species, proposed here as Isoetes laurentiana sp. nov. The combination of short velum coverage (ca. 10%) over a plain (unstreaked) sporangium, broad (ca. 1.0 mm) erect leaves, small megaspores (ca. 459 μm) with more densely convoluted-reticulate, almost echinate ornamentation, and its occurrence within an exceptional habitat, readily distinguish I. laurentiana from I. tuckermanii A.Braun with which it was formerly combined. Isoetes laurentiana is one of a series of endemic taxa of the floristically extraordinary St. Lawrence River estuary. Some populations of I. laurentiana are immense; in cultivation it demonstrates the capacity for prolific production of new individuals, which is presumably necessary to sustain such local abundance. Isoetes laurentiana is of national and global phytogeographic significance, but is not considered to represent a species at risk according to standards from the International Union for Conservation of Nature.

The influence of salinity on Scirpus americanus tidal marshes in the St. Lawrence River estuary, Québec

1985 ◽  
Vol 63 (5) ◽  
pp. 920-927 ◽  
Author(s):  
J. Deschênes ◽  
J.-B. Sérodes
Keyword(s):  
Fresh Water ◽  
Lower Limit ◽  
Brackish Water ◽  
Saline Water ◽  
River Estuary ◽  
Considerable Effect ◽  
Tidal Marshes ◽  
Brackish Waters ◽  
Scirpus Americanus ◽  
St Lawrence River

The amount of sodium in the aboveground part of the stalks of Scirpus americanus taken at the peak of biomass is a good indicator of the amount of salinity in the waters flooding the tidal marshes of an estuary. In fresh water, the Na concentrations remain below 10 000 and then increase sharply up to 20 000 – 30 000 mg/kg in brackish waters. Even though this plant can grow under brackish conditions, salinity has a considerable effect on the percentage of submersion it can withstand. Consequently, in the presence of saline water, the lower limit of the vegetation regresses towards the shore. In the case of fresh water, Scirpus americanus occupies the lower part of marshes up to an average of 75% of submersion, while in brackish water it extends to about 35% and then disappears when waters are more saline.

Rates and Probable Causes of Freshwater Tidal Marsh Failure, Potomac River Estuary, Northern Virginia, USA

Wetlands ◽  
2013 ◽  
Vol 33 (6) ◽  
pp. 1037-1061 ◽  
Author(s):  
Ronald J. Litwin ◽  
Joseph P. Smoot ◽  
Milan J. Pavich ◽  
Erik Oberg ◽  
Brent Steury ◽  
...  
Keyword(s):  
Tidal Marsh ◽  
River Estuary ◽  
Potomac River ◽  
Freshwater Tidal Marsh

Isoetes ×blondeaui hyb. nov. (Isoetaceae), a new hybrid quillwort from eastern Quebec, Canada

Botany ◽  
2020 ◽  
Vol 98 (10) ◽  
pp. 555-562
Author(s):  
D.F. Brunton ◽  
P.C. Sokoloff
Keyword(s):  
Tidal Marsh ◽  
Morphological Characteristics ◽  
Quebec City ◽  
Marsh Habitat ◽  
Freshwater Tidal Marsh ◽  
Distinguishing Features ◽  
St Lawrence River

The hybrid between diploid Isoetes echinospora and tetraploid I. laurentiana is reported from six sites along the St. Lawrence River near Quebec City. Morphological characteristics and distinguishing features are identified, and the binomial I. ×blondeaui, hyb. nov. is proposed. All occurrences are in biogeographically significant freshwater tidal marsh habitat. The hybrid is expected to occur in small numbers within most large I. laurentiana populations.

scholarly journals Biogeomorphic modeling to assess resilience of tidal marsh restoration to sea level rise and sediment supply

2021 ◽  
Author(s):  
Olivier Gourgue ◽  
Jim van Belzen ◽  
Christian Schwarz ◽  
Wouter Vandenbruwaene ◽  
Joris Vanlede ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Tidal Marsh ◽  
Model Performance ◽  
Suspended Sediments ◽  
Sediment Supply ◽  
Tidal Marshes ◽  
Marsh Restoration ◽  
Tidal Marsh Restoration ◽  
Increasing Demand

Abstract. There is an increasing demand for creation and restoration of tidal marshes around the world, as they provide highly valued ecosystem services. Yet, tidal marshes are strongly vulnerable to factors such as sea level rise and declining sediment supply. How fast the restored ecosystem develops, how resilient it is to sea level rise, and how this can be steered by restoration design, are key questions that are typically challenging to assess. In this paper, we apply a biogeomorphic model to a planned tidal marsh restoration by dike breaching. Our modeling approach integrates tidal hydrodynamics, sediment transport and vegetation dynamics, accounting for relevant fine-scale flow-vegetation interactions (less than 1 m2) and their impact on vegetation and landform development at the landscape scale (several km2) and on the long term (several decades). Our model performance is positively evaluated against observations of vegetation and geomorphic development in adjacent tidal marshes. Model scenarios demonstrate that the restored tidal marsh can keep pace with realistic rates of sea level rise and that its resilience is more sensitive to the availability of suspended sediments than to the rate of sea level rise. We further demonstrate that restoration design options can steer marsh resilience, as it affects the rates and spatial patterns of biogeomorphic development. By varying the width of two dike breaches, which serve as tidal inlets to the restored marsh, we show that a larger difference in the width of the two inlets leads to more diversity in restored habitats. This study showcases that biogeomorphic modeling can support management choices in restoration design to optimize tidal marsh development towards sustainable restoration goals.

scholarly journals Relationship Among Breeding, Molting, and Wintering Areas of Male Barrow's Goldeneyes (Bucephala Islandica) in Eastern North America

The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 676-684 ◽  
Author(s):  
Michel Robert ◽  
Réjean Benoit ◽  
Jean-Pierre L. Savard
Keyword(s):  
North American ◽  
River Estuary ◽  
North American Population ◽  
American Population ◽  
Adult Males ◽  
Breeding Area ◽  
The North ◽  
Bucephala Islandica ◽  
The Mean ◽  
St Lawrence River

Abstract Little is known of the eastern North American population of Barrow's Goldeneyes (Bucephala islandica), which was recently listed as “of special concern” in Canada. In 1998 and 1999, we marked 18 adult males wintering along the St. Lawrence River, Québec, with satellite transmitters to document their breeding, molting, and wintering distribution and phenology, and to describe timing and routes of their spring, molt, and fall migrations. Thirteen males moved inland from the St. Lawrence River to breed; the spring migration averaged 5.9 days, and birds arrived on breeding areas on average 9 May. All breeding areas were inland, on the north shore of the St. Lawrence River estuary and gulf. Breeding areas averaged 64.8 km from the St. Lawrence corridor. Males stayed on their respective breeding area a mean of 34.5 days, and left on average 11 June. Twelve males were tracked to their molting areas, one of which stayed on its wintering area until 5 June and flew directly to its molting area. Their molt migration averaged 18.6 days, and the mean arrival date on molting areas was 30 June. All molting areas were located north and averaged 986 km from breeding areas. Four males molted in Hudson Bay, four in Ungava Bay, two in northern Labrador, one on Baffin Island, and one inland, near the Québec–Labrador border. The mean length of stay on the molting areas was 105.3 days, and the mean date of departure from molting areas was 4 October. All goldeneyes for which the radio still functioned during fall migration returned to winter in the St. Lawrence River estuary, on average 6 November. Our results refute the idea that the main breeding area of the eastern North American population of Barrow's Goldeneyes is located in northern Québec and Labrador and rather indicate that it is in the boreal forest just north of the St. Lawrence River estuary and gulf. They also indicate that Barrow's Goldeneye males undertake a genuine molt migration, and highlight the importance of molting areas because birds stayed there approximately four months each year.

scholarly journals Annual and Seasonal Variation in Shorebird Abundance in the St. Lawrence River Estuary during Fall Migration

2018 ◽  
Vol 131 (3) ◽  
pp. 203-214 ◽  
Author(s):  
Yves Turcotte ◽  
Jean-Francois Lamarre ◽  
Joel Bety
Keyword(s):  
General Trend ◽  
River Estuary ◽  
Abundant Species ◽  
Western Hemisphere ◽  
Ecological Value ◽  
Reserve Network ◽  
Semipalmated Sandpiper ◽  
Peak Abundance ◽  
Effective Conservation ◽  
St Lawrence River

Many north American shorebird populations are declining. it is therefore urgent to identify major sites used during their annual cycle to achieve effective conservation measures. our objective was to expand some aspects of the knowledge base needed to assess the ecological value of the St. Lawrence River Estuary for shorebird conservation. Here, we present the results of the most intensive shorebird survey ever conducted in the St. Lawrence River Estuary during fall migration. Surveys were conducted between St-Jean-Port-Joli and St-Simon-sur-Mer, Quebec, Canada, in 2011 and 2012, from late June/early July through late november, corresponding to the migration period of all species potentially present in the study area. The Semipalmated Sandpiper (Calidris pusilla) was one of the two most abundant species during both years of our study (most abundant species, followed by Dunlin [Calidris alpina] and Black-bellied Plover [Pluvialis squatarola] in 2011; second to Blackbellied Plover in 2012). Considering the entire shorebird community, abundance of individuals peaked in early September. Peak abundance occurred earlier for adults than for juveniles. For most species, juveniles largely outnumbered adults. Juveniles were relatively less abundant in 2012 than in 2011. This reflected a general trend observed in northeastern north America between those years, suggesting a lower breeding success in 2012. Given its importance as a staging site for juvenile birds (study area used annually by up to a few hundred thousand shorebirds) and therein, its conservation value, we recommend that the St. Lawrence River Estuary should be included within the Western Hemisphere Shorebird Reserve network.

scholarly journals Effects of Tidal Scenarios on the Methane Emission Dynamics in the Subtropical Tidal Marshes of the Min River Estuary in Southeast China

2019 ◽  
Vol 16 (15) ◽  
pp. 2790 ◽  
Author(s):  
Jiafang Huang ◽  
Min Luo ◽  
Yuxiu Liu ◽  
Yuxue Zhang ◽  
Ji Tan
Keyword(s):  
High Tide ◽  
River Estuary ◽  
Tidal Marshes ◽  
Tidal Wetlands ◽  
Ch4 Emission ◽  
Air Exposure ◽  
Southeast China ◽  
Min River ◽  
Min River Estuary

In order to accurately estimate the effects of tidal scenarios on the CH4 emission from tidal wetlands, we examined the CH4 effluxes, dissolved CH4 concentrations, and environmental factors (including in situ pH, Eh and electrical conductivity, porewater SO42−, NO3−, and NH4+) during inundation and air-exposure periods in high- and low-tide seasons in the Min River Estuary in southeast China. By applying static and floating chambers, our results showed that the CH4 effluxes during the inundation periods were relatively constant and generally lower than those during the air-exposed periods in both seasons. When compared, the CH4 effluxes during the air-exposed periods were significantly higher in the high-tide season than those in the low-tide season. In contrast, CH4 effluxes during the inundation periods were significantly lower in the high-tide season than those in the low-tide season. During the inundation periods, dissolved CH4 concentrations were inversely proportional to in situ Eh. Under air-exposed conditions, CH4 effluxes were proportional to in situ pH in both seasons, while the dissolved CH4 concentrations were negatively correlated with the porewater SO42− concentrations in both seasons. Our results highlighted that CH4 effluxes were more dynamic between inundation and air-exposure periods compared to low- and high-tide seasons.

scholarly journals Tidal exchange between a freshwater tidal marsh and an impacted estuary: the Scheldt estuary, Belgium

2009 ◽  
Vol 85 (2) ◽  
pp. 197-207 ◽  
Author(s):  
Stefan Van Damme ◽  
Dehairs Frank ◽  
Tackx Micky ◽  
Beauchard Olivier ◽  
Struyf Eric ◽  
...  
Keyword(s):  
Tidal Marsh ◽  
Scheldt Estuary ◽  
Tidal Exchange ◽  
Freshwater Tidal Marsh
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