Colin P. Laroque

Colin P. Laroque
University of Saskatchewan | U of S · Department of Soil Science

PhD

About

97
Publications
14,393
Reads
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818
Citations
Additional affiliations
July 2003 - December 2013
Mount Allison University
Position
  • MAD Lab Director

Publications

Publications (97)
Article
Full-text available
The importance of trees in non-forest landscapes has been the focus of only a few studies. However, these trees provide many important ecosystem services. In this study, we mapped and quantified these trees using Sentinel-2 (S2) and very high-resolution (VHR) Google satellite imagery without any field campaigns. We performed a Random Forest (RF) cl...
Article
Full-text available
Changes are projected for the boreal biome with complex and variable effects on forest vegetation including drought‐induced tree mortality and forest loss. With soil and atmospheric conditions governing drought intensity, specific drivers of trees water stress can be difficult to disentangle across temporal scales. We used wavelet analysis and caus...
Article
In this research, we explore whether a dendrogeomorphological assessment of tree scarring can accurately summarize past ice‐jam flooding events occurring at a given reach of a river. A sample site was chosen with a history of ice‐jam flooding located in close proximity to a river gauge station. Samples were collected along a 200‐m stretch of riverb...
Article
Full-text available
Dendrochemistry, the study of elements found within tree rings, has been used to understand environmental changes from both natural and anthropogenic sources. When used appropriately, dendrochemistry can provide a greater understanding of the elemental changes in the environment. However, environmental and species-specific processes have been shown...
Preprint
Full-text available
In this research, we explore whether a dendrogeomorphological assessment of tree scarring can accurately summarize past ice-jam flooding events occurring at a given reach of a river. A sample site was chosen with a history of ice-jam flooding located in close proximity to a river gauge station. Samples were collected along a 200-metre stretch of ri...
Article
Field-based assessment of transpiration phenology in boreal tree species is a significant challenge. Here we develop an objective approach that uses stem radius change and its correlation with sapwood temperature to determine the timing of phenological changes in transpiration in mixed evergreen species. We test the stem-temp approach using a five...
Article
Full-text available
Studies of tree water source partitioning have primarily focused on the growing season. However, little is yet known about the source of transpiration before, during, and after snowmelt when trees rehydrate and recommence transpiration in the spring. This study investigates tree water use during spring snowmelt following tree's winter stem shrinkag...
Article
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In 2009, a group of concerned citizens in Halifax rallied to the banner of The Heritage Trust of Nova Scotia and the Ecology Action Centre to save an 18th-century building from demolition. Their case for preserving the building hinged on its unique heritage value; it having formerly housed the office of Charles Morris,Nova Scotia’s first Chief Surv...
Article
A comprehensive assessment of the tree growth/climate relationship was undertaken to better understand the potential impacts of climate change on the growth dynamics of four widespread and common boreal tree species, namely jack pine (Pinus banksiana), black spruce (Picea mariana), eastern larch (Larix laricina), and trembling aspen (Populus tremul...
Article
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The Moose Horn Pass Caribou Fence site (KjRx-1) consists of three wooden fences located in a remote area of the Mackenzie Mountains in Canada's Northwest Territories. Situated in the traditional homeland of the Shúhtagot'ine (Mountain Dene), they were used to assist past hunters to harvest northern mountain caribou by channeling multiple animals to...
Article
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There is a significant knowledge gap in the area of management of the vast shelterbelt network currently existing on agricultural lands in Canada and across the world. Throughout eight decades of shelterbelt planting in Saskatchewan, Canada, there are no available records of shelterbelt management practices used by land managers, such as herbicides...
Article
In many regions across western Canada’s boreal forest, drought impacts on long-term white spruce (Picea glauca (Moench) Voss) radial growth are poorly understood. This is also the case for white spruce shelterbelt trees south of their natural range in agricultural regions of the Canadian Prairies. Understanding how white spruce has responded to dro...
Article
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The boreal forest is a major contributor to the global climate system, therefore, reducing uncertainties in how the forest will respond to a changing climate is critical. One source of uncertainty is the timing and drivers of the spring transition. Remote sensing can provide important information on this transition, but persistent foliage greenness...
Presentation
Our understanding of the source of transpiration and how phenological and hydrological processes affect tree water use are based mainly on temperate and tropical zones. In cold regions, as trees emerge from winter dormancy, tree water storage refilling sinks large volume of water. Understanding the timing of snowmelt, tree water storage refilling,...
Article
Full-text available
There is lack of guidelines helping land managers to locate suitable areas for planting new shelterbelt agroforestry systems on their landbases. The goal of this study was to create land suitability maps for deciduous, coniferous, and shrub shelterbelt agroforestry systems establishment across a wide range of climatic and soil zones of Saskatchewan...
Article
Aim Recent and rapid warming is reorganizing terrestrial vegetation, creating novel species assemblages, and shifting range limits. Relative to the evergreen species that currently dominate much of the boreal forest landscape, Larix (larch) distributions may be particularly responsive to climatic change due to their deciduous habit, and quick growt...
Article
Insect defoliation events are a major forest disturbance in the boreal forest in Canada. Reconstructing previous events are crucial to understanding natural factors that lead to insect defoliation periods, improving our ability to predict future infestations and increasing the reliability of forest management plans and pest control programs. Resear...
Article
The goal of this paper is to apply dendroclimatological methods to the analysis of two commonly planted shelterbelt tree species, Fraxinus pennsylvanica (green ash), and Picea glauca (white spruce), to assess their current relationship with climate and determine how their growth may be affected by climate change in the moisture limited region of so...
Article
Shelterbelts sequester and store atmospheric carbon as a direct result of the growth of trees and thus present an opportunity for climate change mitigation. The objectives of this paper were to quantify the growth characteristics and to estimate the carbon stocks of six common shelterbelt species in Saskatchewan: hybrid poplar, Manitoba maple, Scot...
Article
For more than a century, planted shelterbelts in Saskatchewan, Canada have protected farmyards from the elements, decreased soil erosion, sequestered atmospheric carbon, as well as provided many other ecological functions. It is estimated that there are >60,000 km of planted shelterbelts throughout the province, and considerably more in all of the...
Article
Full-text available
Study of soils in St. John’s, Canada showed elevated Pb levels representing a potential ex-posure risk for young children. Old trees growing in the city present a potential annually-resolved record of Pb levels over past centuries that provides important temporal and spatial dimensions to Pb exposure risk assessment. This paper reports the results...
Article
Full-text available
This research is the first published study to report a relationship between climate variables and plastron growth increments of turtles, in this case the endangered Nova Scotia Blanding's turtle (Emydoidea blandingii). We used techniques and software common to the discipline of dendrochronology to successfully cross-date our growth increment data s...
Article
In Canadian physical geography, the ethical implications of research occurring in Indigenous spaces and places have historically been overlooked. Physical geographers, particularly those working in northern Canada, are beginning to recognize that our research takes place in a sensitive social space and the knowledge we pursue has ethical and moral...
Article
The Government of Canada’s farm assistance programs have affected >80 % of Canada’s agricultural land base. One important program in the Prairie Provinces was the prairie shelterbelt program (PSP). A significant aspect of the PSP was shelterbelt tree planting to protect farmyard infrastructure and reduce soil erosion. The main goal of this paper wa...
Article
Full-text available
Abstrakt. Badania dotyczące zawartości ołowiu w glebach przeprowadzone w St. John's (wschodnia Kanada) wykazały znaczne przekroczenie dopuszczal-nych norm, szczególnie w centralnej, najstarszej części miasta. Chcąc odtwo-rzyć zmienność czasowo-przestrzenną zanieczyszczenia ołowiem w przeszłości, zdecydowano się wykorzystać przyrosty roczne starych...
Article
The relationship between monthly climate predictors and radial growth of Engelmann spruce (Picea engelmanni Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt) were explored using both a standard dendroclimatological approach and a multiple adaptive regressions splines (MARS) framework. Consistent with previous research, the radial growth of f...
Conference Paper
Climate change has resulted in the northward migration of many tree species in Canada and is likely to continue as greenhouse gas emissions continue to alter weather patterns. The northern range limit and expansion of trees has been frequently studied but there has been little research concerning the effects of climate change on the fluctuations th...
Conference Paper
Full-text available
Background/Question/Methods Current vegetation models predict that as climate warms, forests will replace large areas of tundra. However, observed treeline response to climate warming has been highly variable across the alpine and subarctic. Site-level data can provide local-scale information but has limited use for understanding the influence of...
Article
Shelterbelts have played an important role in prairie agriculture since the late 1800s; however, little is known about how these shelterbelts may be affected by climate change. The objective of this study was to determine if shelterbelt species, which are heavily influenced by human activity, express a common radial-growth signal within and between...
Conference Paper
The recession of alpine glaciers in western Canada has proceeded unabated since the end of the Little Ice Age (LIA) in the 1860s. The following paper attempts to map the recession of one of the largest alpine glaciers in the Columbia Icefield, the Saskatchewan Glacier, located on the border of Banff and Jasper National Parks in Alberta, Canada. Usi...
Article
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The Lake Rossignol Wilderness Area is a 4100 ha protected area in Queens County, Nova Scotia. In July, 2006, the Protected Areas Branch of Nova Scotia Environment invited 34 scientists, students and volun-teers to conduct a four day bioblitz of this little studied protected area. Surveys were conducted for reptiles, fish, vascular plants, fungi, li...
Article
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In dendrochronology, temporal patterns in radial growth are considered an expression of historical climate processes that cannot be measured. Dendrochronological networks, developed to characterize the geographical and temporal patterns of tree rings, have additional spatial information that can add to our understanding of historical climate condit...
Article
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This paper examines the dendrochronological analysis that was needed to establish the construction date of the Val Comeau canoe. The canoe was unearthed in northeastern New Brunswick after a large storm hit the area. It is currently housed at the New Brunswick Provincial Museum in Saint John, and had been radiocarbon dated to 440 ± 50 years. After...
Article
This paper examines the variability in the relationship between climate and radial growth of black spruce (Picea mariana (Mill.) B.S.P.) and white spruce (Picea glauca (Moench) Voss) trees across central Labrador, Eastern Canada. Using climate-sensitive trees, an 11-year running Pearson correlation is applied to local records to examine the relatio...
Article
The Sydney Steel Plant emitted toxic pollutants into the local area for almost 100 years. Although no paper record exists of the amount and spatial variability of the pollutants emitted, a natural record exists locked in the annual growth of native tree species in the region. Studies have shown that temperate trees can incorporate local metal pollu...
Article
Despite their suitability for dendroclimatological research, the boreal regions of central and western Labrador remain under-researched. In an attempt to evaluate the growth trends and climatic response of this region's trees, master chronologies have been developed for its four dominant conifer species. Balsam fir (Abies balsamea (L.) Mill.), whit...
Conference Paper
Eastern spruce budworm (Choristoneura fumiferana) is an insect known for its destructive impact on coniferous forests across the Maritimes. Trees experience considerable stress during spruce budworm outbreaks as the budworm defoliates forest stands, leading to the reduction or elimination of an individual tree’s annual-growth ring. Outbreaks have h...
Article
Full-text available
Coastal alpine forests are highly vulnerable to oceanic climate trends, yet these diverse environmental interactions remain poorly understood. We used a multispecies perspective to try to better assess the radial growth response of alpine treeline species within the Northeast Atlantic region of North America to climate variables using bootstrapped...
Conference Paper
Full-text available
Joggins was one of the first places in North America where coal was mined. In this paper we employ dendrochronology to date timber pit props preserved within relic coal mine workings on the closely adjacent Fundy and Dirty seams. These remains comprise a system of adits created through ‘room and pillar’ mining. Of the seventy-three samples collecte...
Article
Full-text available
As many insect outbreak reconstructions are typically based on targeted single-site sampling, researchers have often been limited in their ability to draw conclusions about regional trends as opposed to local trends in the data. The results of this paper demonstrate the value of a systematic sampling design when studying spatio-temporal processes t...
Article
Full-text available
Joggins, Nova Scotia, was one of the first places in North America where coal was mined. Dendrochronological meth-ods were employed to date timber pit props preserved within relic coal mine workings on the closely adjacent Fundy and Dirty seams. These remains comprise a system of "openings" that represent formerly underground mines, now exposed by...
Article
This paper investigates the relationship between visually apparent stage of decay of coarse woody debris (CWD) and time since death of decaying balsam fir (Abies balsamea L.) and black spruce (Picea mariana [P. Mill]) in old-growth forests in western Newfoundland and in the Cape Breton Highlands (CBH) of Nova Scotia. These sites are two of the leas...
Article
Tree-ring radial expansion estimator (TREE) is an integrated radial growth model that allows users to define short-term climate change scenarios to anticipate the impact upon mature trees found growing at high elevation on Vancouver Island, British Columbia. Five individualistic models were built to represent the radial growth behaviour of mountain...
Article
Abstract The results of this dendrogeomorphological study provide evidence of the active movement of Hilda rock glacier, a tongue-shaped rock glacier in the Columbia Icefield region of Banff National Park. Cross-sectional samples were cut from 44 detrital subalpine fir (Abies Iasiocarpa (Hook.) Nutt.) and Engelmann spruce (Picea engelmannii Parry)...
Article
Biologically-based deterministic multiple regression models are developed to investigate the consequences of future climates on the radial-growth response of five high-elevation conifer species on Vancouver Island. Historical climate data and tree-ring chronologies are used to establish robust relationships between climate and radial growth. Couple...
Article
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This paper describes the nature of treeline dynamics and upper-elevation tree establishment patterns on southern Vancouver Island, British Columbia. We examined tree growth, climate and seedling relationships at three upper-elevation locations using standard dendroecolog- ical approaches. Our data suggest that this habitat has experienced species-s...
Article
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We analyzed tree rings to determine the time of death for 18 moribund and dead trees used as roosts by bats on northern Vancouver Island. We crossdated 29 increment core samples with tree-ring chronologies of living trees to estimate when the trees died. After they die, yellow-cedar (Chamaecyparis nootkatensis) trees deteriorate slowly and remain s...
Article
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Dendroglaciological techniques are used to provide evidence of historical rock glacier activity at Hilda Creek rock glacier in the Canadian Rockies. The research focuses on the sedimentary apron of the outermost morainal deposit, where excavations in 1997 uncovered six buried tree boles that had been pushed over and entombed by distally spilled deb...
Article
Full-text available
Dendroglaciological tech- niques are used to provide evidence of histor- ical rock glacier activity at Hilda Creek rock glacier in the Canadian Rockies. The research focuses on the sedimentary apron of the out- ermost morainal deposit, where excavations in 1997 uncovered six buried tree boles that had been pushed over and entombed by distally spill...
Article
Full-text available
Yellow-cedar (Chamaecyparis nootkatensis(D. Don) Spach) are the oldest known coniferous trees in Canada. This paper reports on the first dendrochronological investigation of yellow-cedar trees at montane sites on Vancouver Island. Mature yellow-cedar trees were selected for study at four sites along a 200-km northwest-southeast transect. Trees olde...
Article
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Dendrochronological investigations at Moving Glacier provide the first calendar-dating of a Little Ice Age glacier advance on Vancouver Island. In 1931, Moving Glacier was within 30 to 50 m of a distinct trimline and terminal moraine marking its maximum Little Ice Age extent. A reconnaissance of the site in 1993 revealed the presence of sheared in...
Article
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Rae Glacier is a small cirque glacier located in the front ranges of the Canadian Rocky Mountains. In 1990 and 1991 field research was completed to describe the physical glaciology of Rae Glacier and to characterize historical glaciological trends at the site. Ablation and surface movement rates were measured using a network of stakes drilled into...
Article
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This research project was carried out to determine the date of construction of Acadian structures located in the Village Historique Acadien (VHA), near the town of Caraquet, New Brunswick, eastern Canada. The structures were of various ages and originally came from different locations throughout the province. One hundred and eighty two wood cores w...