Growth responses of riparian Thuja occidentalis to the damming of a large boreal lake

Botany ◽  
2008 ◽  
Vol 86 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Bernhard Denneler ◽  
Yves Bergeron ◽  
Yves Bégin ◽  
Hugo Asselin
Keyword(s):  
Water Level ◽  
Ring Width ◽  
High Water ◽  
Water Levels ◽  
Growth Responses ◽  
Thuja Occidentalis ◽  
White Cedar ◽  
Physiological Limit ◽  
Eastern White Cedar ◽  
Canadian Boreal Forest

Growth responses of riparian eastern white cedar trees ( Thuja occidentalis L.) to the double damming of a large lake in the southeastern Canadian boreal forest was analyzed to determine whether the shoreline tree limit is the result of physiological flood stress or mechanical disturbances. The first damming, in 1915, caused a rise in water level of ca. 1.2 m and resulted in the death of the trees that formed the ancient shoreline forest, as well as the wounding and tilting of the surviving trees (by wave action and ice push) that constitute the present forest margin. The second damming, in 1922, did not further affect the water level, but did retard the occurrence of spring high water levels, as well as reduce their magnitude. However, this did not injure or affect the mortality of riparian eastern white cedars. Radial growth was not affected by flooding stress, probably because inundation occurred prior to the start of the growing season (1915–1921) or was of too short duration to adversely affect tree metabolism (after 1921). It follows that (i) the shoreline limit of eastern white cedar is a mechanical rather than a physiological limit, and (ii) disturbance-related growth responses (e.g., ice scars, partial cambium dieback, and compression wood) are better parameters than ring width for the reconstruction of long-term water level increases of natural, unregulated lakes.

Decreased fire frequency and increased water levels affect riparian forest dynamics in southwestern boreal Quebec, Canada

2008 ◽  
Vol 38 (5) ◽  
pp. 1083-1094 ◽  
Author(s):  
Bernhard Denneler ◽  
Hugo Asselin ◽  
Yves Bergeron ◽  
Yves Bégin
Keyword(s):  
Riparian Forest ◽  
Fire Frequency ◽  
Water Levels ◽  
Ice Age ◽  
Thuja Occidentalis ◽  
White Cedar ◽  
Fraxinus Nigra ◽  
Eastern White Cedar ◽  
Black Ash ◽  
Forest Fringe

The relative importance of fire and flooding on the population dynamics of eastern white-cedar ( Thuja occidentalis L.) and black ash ( Fraxinus nigra Marsh.) was evaluated in eight old-growth riparian stands of southwestern boreal Quebec, Canada. Rising water levels and decreasing fire frequency since the end of the Little Ice Age (ca. 1850) were expected to have favoured an inland migration of the riparian forest fringe, with the flood-tolerant black ash colonizing the lower parts of the shore terraces and eastern white-cedar the upper parts. Black ash was found to be restricted to the riparian zone (<200 cm elevation), whereas eastern white-cedar trees did not occur below 100 cm above lake level. Gaps of postfire eastern white-cedar recruitment were noted in stands exposed to riparian disturbances, whereas relatively continuous recruitment occurred at protected sites. Black ash, more tolerant to flooding and ice push, invaded the shore terrace sites left vacant by eastern white-cedar. The riparian forest fringe surrounding Lake Duparquet is currently migrating upland and this trend is expected to continue as water levels continue to increase and fire frequency continues to decrease during the 21st century.

Lake and inland dunes as interconnected Systems: The story of Lake Tresssee and an adjacent dune field (Schleswig-Holstein, North Germany)

The Holocene ◽  
2020 ◽  
pp. 095968362098168
Author(s):  
Christian Stolz ◽  
Magdalena Suchora ◽  
Irena A Pidek ◽  
Alexander Fülling
Keyword(s):  
Water Level ◽  
Bronze Age ◽  
Environmental Changes ◽  
High Water ◽  
Alluvial Fan ◽  
Water Levels ◽  
Lake Area ◽  
Dune Field ◽  
The North ◽  
Sand Drift

The specific aim of the study was to investigate how four adjacent geomorphological systems – a lake, a dune field, a small alluvial fan and a slope system – responded to the same impacts. Lake Tresssee is a shallow lake in the North of Germany (Schleswig-Holstein). During the Holocene, the lake’s water surface declined drastically, predominately as a consequence of human impact. The adjacent inland dune field shows several traces of former sand drift events. Using 30 new radiocarbon ages and the results of 16 OSL samples, this study aims to create a new timeline tracing the interaction between lake and dunes, as well, as how both the lake and the dunes reacted to environmental changes. The water level of the lake is presumed to have peaked during the period before the Younger Dryas (YD; start at 10.73 ka BC). After the Boreal period (OSL age 8050 ± 690 BC) the level must have undergone fluctuations triggered by climatic events and the first human influences. The last demonstrable high water level was during the Late Bronze Age (1003–844 cal. BC). The first to the 9th century AD saw slightly shrinking water levels, and more significant ones thereafter. In the 19th century, the lake area was artificially reduced to a minimum by the human population. In the dunes, a total of seven different phases of sand drift were demonstrated for the last 13,000 years. It is one of the most precisely dated inland-dune chronologies of Central Europe. The small alluvial fan took shape mainly between the 13th and 17th centuries AD. After 1700 cal. BC (Middle Bronze Age), and again during the sixth and seventh centuries AD, we find enhanced slope activity with the formation of Holocene colluvia.

Evidence of high self-fertilization in natural populations of eastern white cedar (Thuja occidentalis)

1990 ◽  
Vol 68 (3) ◽  
pp. 663-668 ◽  
Author(s):  
Daniel J. Perry ◽  
Peggy Knowles
Keyword(s):  
Natural Populations ◽  
Outcrossing Rate ◽  
Significant Heterogeneity ◽  
Embryo Survival ◽  
Thuja Occidentalis ◽  
White Cedar ◽  
Northwestern Ontario ◽  
Outcrossing Rates ◽  
Self Fertilization ◽  
Eastern White Cedar

Arrays of open-pollinated seeds were assayed for allozyme polymorphisms at four loci (Mdh-1, Me, 6Pg-2, and Pgm) to obtain estimates of outcrossing rates for three eastern white cedar populations in northwestern Ontario, Canada. Multilocus population outcrossing rate estimates were low, ranging from 0.507 to 0.745, with significant heterogeneity among populations. Low stand densities and relatively high selfed embryo survival may have contributed to the low effective outcrossing rates observed. Single-tree multilocus outcrossing rate estimates were obtained for nine trees from one population. When estimated jointly with outcross pollen pool allele frequencies, these outcrossing rate estimates ranged from 0.253 to 1.023 with significant heterogeneity among trees. Key words: mating system, outcrossing rate, Thuja occidentalis L.

The effect of ground water-level on the yield of some common crops on a fen peat soil

1958 ◽  
Vol 50 (3) ◽  
pp. 243-252 ◽  
Author(s):  
H. H. Nicholson ◽  
D. H. Firth
Keyword(s):  
Ground Water ◽  
Water Level ◽  
Peat Soil ◽  
Good Condition ◽  
High Water ◽  
Water Levels ◽  
Ground Water Level ◽  
Potential Evaporation ◽  
Soil Moisture Deficit ◽  
Moisture Deficit

An account is given of a field experiment in the control of ground water-level in a Fen peat soil, together with its results on the yields of crops in a six-course rotation.The seasonal variations in rainfall are presented in terms of potential evaporation and soil moisture deficit. The effect of the water-level on the moistness of the soil above it is indicated. Even in a wet summer, drying was perceptible within 18–20 in. of the ground water-level between successive falls of rain.The fluctuations of the ground water-levels are discussed. Those of the high water-levels were chiefly due to individual incidences of rain causing rises short in duration, but sufficient in the case of water-levels within 20 in. of the surface to cause total waterlogging and surface ponding. Those of the deep water-levels were most influenced by evaporation, with steady and persistent falls during any rain-free period.The deterioration of the physical condition of the soil over high water-levels is shown in the result of sieving tests. In 6 years the loss of tilth over waterlevels within 20 in. of the surface was very marked and was discernible over those as low as 30 in.The possibilities of effectively using high ground water-levels occasionally in soils in good condition are shown by the results with celery and potatoes.

Patterns of Architectural Variation in Thuja occidentalis L. (Eastern White Cedar) from Upland and Lowland Sites

1991 ◽  
Vol 152 (4) ◽  
pp. 494-499 ◽  
Author(s):  
Christopher H. Briand ◽  
Usher Posluszny ◽  
Douglas W. Larson ◽  
Uta Matthes-Sears
Keyword(s):  
Thuja Occidentalis ◽  
White Cedar ◽  
Eastern White Cedar

Concentration of highway deicing agents along roadsides near London

1978 ◽  
Vol 56 (8) ◽  
pp. 1081-1085 ◽  
Author(s):  
A. C. Foster ◽  
M. A. Maun
Keyword(s):  
Filter Paper ◽  
Strong Correlation ◽  
Soil Samples ◽  
Freezing Rain ◽  
Thuja Occidentalis ◽  
White Cedar ◽  
The Road ◽  
Eastern White Cedar ◽  
Snow Storms ◽  
Deicing Agents

Analysis of snow and soil samples showed that the concentrations of Na and Cl were higher near the road and decreased with increasing distance from the pavement. The level of calcium in soil did not change with distance. The concentration of calcium in the foliage of eastern white cedar trees (Thuja occidentalis L.) facing the highway was not significantly different from the concentration in the foliage on the opposite side. The filter paper discs attached to the foliage accumulated significantly high amounts of salts on days with freezing rain or snow storms. A strong correlation was found between element levels in the foliage and the levels found in filter paper discs.

Uncertainty in coastal flooding: modelling and visualisation

2020 ◽  
Author(s):  
John Maskell
Keyword(s):  
Water Level ◽  
Storm Surge ◽  
Return Period ◽  
Flood Risk ◽  
High Water ◽  
Coastal Flooding ◽  
Water Levels ◽  
Tidal Range ◽  
The Uk ◽  
Flood Maps

&lt;p&gt;Two case studies are considered in the UK, where uncertainty and drivers of coastal flood risk are explored through modelling and visualisations. Visualising the impact of uncertainty is a useful way of explaining the potential range of predicted or simulated flood risk to both expert and non-expert stakeholders.&lt;/p&gt;&lt;p&gt;Significant flooding occurred in December 2013 and January 2017 at Hornsea on the UK East Coast, where storm surge levels and waves overtopped the town&amp;#8217;s coastal defences. Uncertainty in the potential coastal flooding is visualised at Hornsea due to the range of uncertainty in the 100-year return period water level and in the calculated overtopping due to 3 m waves at the defences. The range of uncertainty in the simulated flooding is visualised through flood maps, where various combinations of the uncertainties decrease or increase the simulated inundated area by 58% and 82% respectively.&lt;/p&gt;&lt;p&gt;Located at the mouth of the Mersey Estuary and facing the Irish Sea, New Brighton is affected by a large tidal range with potential storm surge and large waves. Uncertainty in the coastal flooding at the 100-year return period due to the combination of water levels and waves is explored through Monte-Carlo analysis and hydrodynamic modelling. Visualisation through flood maps shows that the inundation extent at New Brighton varies significantly for combined wave and surge events with a joint probability of 100 years, where the total flooded area ranges from 0 m&lt;sup&gt;2&lt;/sup&gt; to 10,300 m&lt;sup&gt;2&lt;/sup&gt;. Waves are an important flood mechanism at New Brighton but are dependent on high water levels to impact the coastal defences and reduce the effective freeboard. The combination of waves and high-water levels at this return level not only determine the magnitude of the flood extent but also the spatial characteristics of the risk, whereby flooding of residential properties is dominated by overflow from high water levels, and commercial and leisure properties are affected by large waves that occur when the water level is relatively high at the defences.&lt;/p&gt;

Comparative seed morphology of Thuja occidentalis (eastern white cedar) from upland and lowland sites

1992 ◽  
Vol 70 (2) ◽  
pp. 434-438 ◽  
Author(s):  
Christopher H. Briand ◽  
Usher Posluszny ◽  
Douglas W. Larson
Keyword(s):  
Significant Variation ◽  
Morphological Characters ◽  
Seed Morphology ◽  
Right Wing ◽  
Habitat Types ◽  
Thuja Occidentalis ◽  
White Cedar ◽  
Character Variation ◽  
Eastern White Cedar ◽  
Individual Trees

As part of an investigation of the extent of habitat-specific variation in Thuja occidentalis L., cones were collected from cliff (dry upland) and swamp (wet lowland) sites in southern Ontario. The number of seeds per cone, number of fully developed seeds per cone, seed fresh weight, length, and width, length and width of embryo area, and length and width of right wing were determined. Seed yield on a per cone basis did not vary between habitat types or among sites within habitats. There was, however, significant variation among trees within sites. Individual seed characters did not vary between habitat types, but significant variation existed among sites within habitats, among trees within sites, and among cones within trees. Only the width of right wing failed to show cone to cone variation within individual trees. The majority of explainable variance for all characters could be apportioned to trees within sites. This and a relatively low degree of cone to cone variation suggest that the seed morphological characters were under strong maternal control. Differences among sites are thought to be the result of local environmental variation rather than genetic differences. The lack of habitat-specific seed character variation indicates that contrasting moisture regimes have little effect on quantitative seed morphology. No evidence exists for ecotypic variation with respect to seed morphology. Key words: Thuja occidentalis, eastern white cedar, seed morphology, ecotypes, cliff, swamp.

Dynamique d'une bordure forestière et variations récentes du niveau du fleuveSaint-Laurent

1988 ◽  
Vol 66 (10) ◽  
pp. 1905-1913 ◽  
Author(s):  
Yves Bégin ◽  
Jean Lavoie
Keyword(s):  
Plant Community ◽  
Woody Plants ◽  
Community Dynamics ◽  
Direct Evidence ◽  
Ring Width ◽  
High Water ◽  
Water Levels ◽  
Exposed Site ◽  
Plant Community Dynamics ◽  
Saint Lawrence River

The forested shoreline of the Saint Lawrence River upper estuary is frequently damaged by spring ice, currents, and waves during episodes of high water levels. A dendroecological analysis of the significant river floods, as recorded by ring-width patterns of uprooted woody plants, population growth and decay structures, and scars caused by ice on trees within the shore environment, provides direct evidence of a landward migrating shoreline. Regressive succession of vegetation is associated with a general rise in year-to-year flood levels. Plant community dynamics and shore sediment migration were investigated in a particularly exposed site between Grondines and Sainte-Anne-de-la-Pérade. Most of the oldest sublittoral trees are undergoing slow degradation and hydrophilous shrubby stands show extensive expansion within the shoreline habitat, which is associated with an important landward displacement of sediments. These ecological and geomorphological results concur with the general rising trend of flood levels of the Saint Lawrence during the last 30 years.

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