Downward Migration of Coastal Conifers as a Response to Recent Land Emergence in Eastern Hudson Bay, Québec

1993 ◽  
Vol 40 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Yves Bégin ◽  
Dominique Bérubé ◽  
Martin Grégoire
Keyword(s):  
Picea Glauca ◽  
Age Distribution ◽  
White Spruce ◽  
High Water ◽  
Climatic Conditions ◽  
Water Levels ◽  
Hudson Bay ◽  
Sea Level Changes ◽  
Shoreline Retreat ◽  
Bay Area

AbstractPostglacial uplift in the eastern Hudson Bay area is among the most rapid in the world (300 m during the last 8000 yr). Although emergence curves based on 14 C-dated raised shorelines give a consistent basis for modeling relative sea-level changes, such a low-resolution dating method is inappropriate for estimating trends over recent decades. A major downward displacement of white spruce (Picea glauca (Moench) Voss) and tamarack (Larix laricina (DuRoi) K. Koch) occurred on protected shores as a response to shoreline retreat during this century. Analysis of the age distribution of trees indicates a progradation of white spruce and tamarack on gently sloping terrain ranging from 1.3 and 2.6 cm/yr, respectively, toward the sea. Improvement of climatic conditions during the 20th century favored such expansion which was probably faster than the real land emergence rates, but recent episodes of high water levels caused regression of forest margins over the highly exposed shores. Nevertheless, the downward trend of the treeline over this century substantiates the projections of 14C-dated coastal emergence curves during the modern period (1.0 to 1.3 cm/yr) by providing an estimate of the maximum rates of shoreline retreat.

Les coupes forestières dans les pessières à lichens: effets sur la croissance et la régénération des conifères (Whapmagoostui, Québec subarctique)

1988 ◽  
Vol 66 (6) ◽  
pp. 1013-1020 ◽  
Author(s):  
Ann Delwaide ◽  
Louise Filion
Keyword(s):  
Picea Glauca ◽  
Radial Growth ◽  
Growth Form ◽  
Black Spruce ◽  
Ground Cover ◽  
Climatic Conditions ◽  
Hudson Bay ◽  
Clear Cutting ◽  
Physical Conditions ◽  
Tree Harvesting

In the Whapmagoostui area (east of Hudson Bay), tree harvesting by Crée Indians in lichen woodlands affects the form and the growth of surviving trees and also the forest population dynamics. A study of the growth form of white spruce (Picea glauca (Moench) Voss.) and black spruce (Picea mariana (Mill.) B.S.P.) that have been pruned shows the efficiency of a total traumatic reiteration process. After several years, the annual radial growth was equivalent to that recorded before pruning. In clear-cutting areas (more than 75% of trees removed), the increase in the radial growth of spared trees was 400 to 700%. The main factors that govern the success of regeneration in cutting areas are the rather small extension of the openings (<0.005 km2), the low intensity of tree harvesting (<75% of trees over 90% of the surface), the physical conditions of the lichenous ground cover and the abundance of the lignified debris after clearing vegetation, and the climatic conditions in the subsequent years.

Nonlinear responses of white spruce growth to climate variability in interior Alaska

2013 ◽  
Vol 43 (4) ◽  
pp. 331-343 ◽  
Author(s):  
Andrea H. Lloyd ◽  
Paul A. Duffy ◽  
Daniel H. Mann
Keyword(s):  
Picea Glauca ◽  
Boreal Forests ◽  
General Circulation ◽  
Circulation Model ◽  
White Spruce ◽  
Climatic Conditions ◽  
Boosted Regression Trees ◽  
Temperature And Precipitation ◽  
Interior Alaska ◽  
And Function

Ongoing warming at high latitudes is expected to lead to large changes in the structure and function of boreal forests. Our objective in this research is to determine the climatic controls over the growth of white spruce (Picea glauca (Moench) Voss) at the warmest driest margins of its range in interior Alaska. We then use those relationships to determine the climate variables most likely to limit future growth. We collected tree cores from white spruce trees growing on steep, south-facing river bluffs at five sites in interior Alaska, and analyzed the relationship between ring widths and climate using boosted regression trees. Precipitation and temperature of the previous growing season are important controls over growth at most sites: trees grow best in the coolest, wettest years. We identify clear thresholds in growth response to a number of variables, including both temperature and precipitation variables. General circulation model (GCM) projections of future climate in this region suggest that optimum climatic conditions for white spruce growth will become increasingly rare in the future. This is likely to cause short-term declines in productivity and, over the longer term, probably lead to a contraction of white spruce to the cooler, moister parts of its range in Alaska.

scholarly journals Estimation of potential evapotranspiration with shallow lysimeters in a forest tree nursery

1995 ◽  
Vol 71 (6) ◽  
pp. 755-758 ◽  
Author(s):  
Jean Stein ◽  
Richard Caissy ◽  
André P. Plamondon ◽  
Pierre Y. Bernier
Keyword(s):  
Water Balance ◽  
Picea Glauca ◽  
Potential Evapotranspiration ◽  
Black Spruce ◽  
White Spruce ◽  
High Water ◽  
Forest Tree ◽  
Irrigation Scheduling ◽  
Daily Evapotranspiration ◽  
Water Contents

Daily evapotranspiration values (ETL) were obtained during three consecutive summers from water balance measurements on eight shallow drainable lysimeters in similarly planted nursery beds of either white spruce [Picea glauca (Moench) Voss] or black spruce [Picea mariana (Mill) B.S.P.]. Values of ETL and of potential evapotranspiration (PET), calculated with the Penman equation, were nearly equal for most of the sampled days during the first two years. During the last year of study, the ratio ETL/PET was reduced to 0.8 due to a lack of water input (precipitation and irrigation) to the lysimeters. Water balance measurements from the surrounding seedling beds showed that values of actual evapotranspiration (AET) for the first two years were 0.61 times those of either PET or ETL. Rates of evapotranspiration in the lysimeters remained high because of the high water contents in the shallow lysimeters induced by the presence of a zero tension plane at the base of the lysimeters, above the drainage holes. Results indicate that well-watered shallow lysimeters can be used to estimate values of PET and be used directly for the purpose of driving water balance models for irrigation scheduling. Key words: water relations, irrigation scheduling, lysimeters, evapotranspiration, white spruce, black spruce

Das waldreiche obere Theresiental (Transkarpatien, Ukraine) – geografisch-ökologische und sozioökonomische Beschreibung | The forest-rich upper Theresian Valley (Transcarpathia, Ukraine): a geographic-ecological and socio-economical description

2007 ◽  
Vol 158 (1-2) ◽  
pp. 14-21
Author(s):  
Vasyl Sabadosh ◽  
Oleg Suprunenko
Keyword(s):  
Forest Management ◽  
High Water ◽  
The State ◽  
Water Levels ◽  
Private Companies ◽  
Foreign Investors ◽  
Wood Processing ◽  
Job Opportunities ◽  
Orange Revolution

The upper Theresian Valley lies along the southwest-facing ridge of the Ukrainian Carpathians. Despite expansive forestation high water levels are frequent. The forest belongs to the state and is centrally administrated. Felling is sometimes outsourced to private companies and private companies have also been founded to process the timber. Job opportunities have become fewer and illegal work is increasing. A new democratic awareness has emerged since the «Orange Revolution» in 2004. With foreign investors, however, new risks emerge. The authors recommend giving monies from forest management to the communities, the founding of new wood processing enterprises and more transparent information.

scholarly journals The effects of ENSO, climate change and human activities on the water level of Lake Toba, Indonesia: a critical literature review

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hendri Irwandi ◽  
Mohammad Syamsu Rosid ◽  
Terry Mart
Keyword(s):  
Climate Change ◽  
Water Level ◽  
Human Activities ◽  
Southern Oscillation ◽  
Climatic Conditions ◽  
Water Levels ◽  
Dominant Factor ◽  
Climate Projections ◽  
Continuous Increase ◽  
The Future

AbstractThis research quantitatively and qualitatively analyzes the factors responsible for the water level variations in Lake Toba, North Sumatra Province, Indonesia. According to several studies carried out from 1993 to 2020, changes in the water level were associated with climate variability, climate change, and human activities. Furthermore, these studies stated that reduced rainfall during the rainy season due to the El Niño Southern Oscillation (ENSO) and the continuous increase in the maximum and average temperatures were some of the effects of climate change in the Lake Toba catchment area. Additionally, human interventions such as industrial activities, population growth, and damage to the surrounding environment of the Lake Toba watershed had significant impacts in terms of decreasing the water level. However, these studies were unable to determine the factor that had the most significant effect, although studies on other lakes worldwide have shown these factors are the main causes of fluctuations or decreases in water levels. A simulation study of Lake Toba's water balance showed the possibility of having a water surplus until the mid-twenty-first century. The input discharge was predicted to be greater than the output; therefore, Lake Toba could be optimized without affecting the future water level. However, the climate projections depicted a different situation, with scenarios predicting the possibility of extreme climate anomalies, demonstrating drier climatic conditions in the future. This review concludes that it is necessary to conduct an in-depth, comprehensive, and systematic study to identify the most dominant factor among the three that is causing the decrease in the Lake Toba water level and to describe the future projected water level.

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.

WHITE SPRUCE AND THE SPRUCE BUDWORM: DEFINING THE PHENOLOGICAL WINDOW OF SUSCEPTIBILITY

1997 ◽  
Vol 129 (2) ◽  
pp. 291-318 ◽  
Author(s):  
Robert K. Lawrence ◽  
William J. Mattson ◽  
Robert A. Haack
Keyword(s):  
Picea Glauca ◽  
High Performance ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
White Spruce ◽  
Shoot Elongation ◽  
Larval Survival ◽  
Strongly Correlated ◽  
Negative Effect ◽  
Foliar Traits

AbstractSynchrony of insect and host tree phenologies has often been suggested as an important factor influencing the susceptibility of white spruce, Picea glauca (Moench) Voss, and other hosts to the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). We evaluated this hypothesis by caging several cohorts of spruce budworm larvae on three white spruce populations at different phenological stages of the host trees, and then comparing budworm performance with host phenology and variation of 13 foliar traits. The beginning of the phenological window of susceptibility in white spruce occurs several weeks prior to budbreak, and the end of the window is sharply defined by the end of shoot growth. Performance was high for the earliest budworm cohorts that we tested. These larvae began feeding 3–4 weeks prior to budbreak and completed their larval development prior to the end of shoot elongation. Optimal synchrony occurred when emergence preceded budbreak by about 2 weeks. Larval survival was greater than 60% for individuals starting development 1–3 weeks prior to budbreak, but decreased to less than 10% for those starting development 2 or more weeks after budbreak and thus completing development after shoot elongation ceased. High performance by the budworm was most strongly correlated with high levels of foliar nitrogen, phosphorous, potassium, copper, sugars, and water and low levels of foliar calcium, phenolics, and toughness. These results suggest that advancing the usual phenological window of white spruce (i.e. advancing budbreak prior to larval emergence) or retarding budworm phenology can have a large negative effect on the spruce budworm’s population dynamics.

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