Sylvie Quideau | University of Alberta (original) (raw)

Papers by Sylvie Quideau

Research paper thumbnail of Next-Generation Sequencing of Protists as a Measure of Natural Soil Microbial Eukaryotic Community in the Oil Sands Region

Research paper thumbnail of Isotope applications to soil science at the University of Alberta — an historical perspective

Canadian Journal of Soil Science, 2020

For the past 70 yr, researchers in the Soil Science/Renewable Resources Department at the Univers... more For the past 70 yr, researchers in the Soil Science/Renewable Resources Department at the University of Alberta have used isotopes to study topics of ecological importance. This review highlights the soil isotope research conducted within our department over this time, including an historical overview of studies of interest. Analytical techniques and advances in instrumentation are discussed, focusing on the measurement of light stable isotope ratios (i.e., for C, H, N, S, and O) using isotope ratio mass spectrometry (IRMS). Early soil isotope work (1950–2000s) focused on agricultural soils and soil fertility issues. These studies included the use of radioactive isotopes such as 14C and 35S, and (or) artificially enriched stable isotopes including 15N-labelled fertilizers. More recently (2000–present), the scope of research widened to include natural-abundance stable isotope ratio studies as higher-sensitivity IRMS systems became more prevalent. Current isotope research topics inclu...

Research paper thumbnail of Isotope applications to soil science at the University of Alberta — an historical perspective

Canadian Journal of Soil Science, Dec 1, 2020

Research paper thumbnail of Earthworm-invaded boreal forest soils harbour distinct microbial communities

Earthworm invasion in North American forests has the potential to greatly impact soil microbial c... more Earthworm invasion in North American forests has the potential to greatly impact soil microbial communities by altering soil physicochemical properties, including structure, pH, nutrient availability, and soil organic matter (SOM) dynamics. While most research on the topic has been carried out in northern temperate forests, little is known about the impact of invasive earthworms on soil microbial communities in hemiboreal and boreal forests, characterized by a slower decay of organic matter (OM). Earthworm activities can increase OM mineralization, altering nutrient cycling and biological activity in a biome where low carbon (C) and nitrogen (N) availability typically limits microbial and plant growth. Here, we characterized and compared microbial communities of earthworm-invaded and non-invaded soils in previously described sites across three major soil types found in the Canadian (hemi)boreal forest using a space-for-time approach. Microbial communities of forest floors and surface mineral soils were characterized using phospholipid fatty acid (PLFA) analysis and metabarcoding of the 16S rRNA gene for bacteria and archaea and of the internal-transcriber-spacer-2 (ITS2) region for fungi. In forest floors, the effects of earthworm invasion were minor. In mineral soil horizons, earthworm invasion was associated with higher fungal biomass and greater relative abundance of ectomycorrhizal fungi. Oligotrophic bacteria (Acidobacteriota and Chloroflexi) were less abundant in invaded mineral soils, where Gram(+) : Gram(−) ratios were also lower, while the opposite was observed for the copiotrophic Bacteroidota. Additionally, earthworm-invaded mineral soils harboured higher fungal and bacterial species diversity and richness. Considering the important role of soil microbial communities for ecosystem functioning, such earthworm-induced shifts in their community composition are likely to impact nutrient cycling, as well as vegetation development and forest productivity at a large scale, as the invasion progresses in these (hemi)boreal systems.

Research paper thumbnail of Organic Matter Accumulation

Research paper thumbnail of Carbon and hydrogen isotopes of n ‐alkanes in soils reconstructed after mining disturbance

Journal of Environmental Quality, Mar 20, 2020

Ecosystem reconstruction after mining disturbance is a challenge considering the multitude of fac... more Ecosystem reconstruction after mining disturbance is a challenge considering the multitude of factors that affect soil formation and revegetation. In the boreal forest of western Canada, peat material is often used as the organic amendment for land reclamation to upland forest. Carbon and water dynamics of peat‐dominated ecosystems differ from natural upland forest soils. The objective of this work was to evaluate the evolution of soils reconstructed after mining disturbance using 13C and 2H analyses of n‐alkane tracers. Ten soils from natural ecosystems were sampled (0–10 cm) and compared with 11 soils from novel ecosystems ranging in age from 0 to 30 yr, as well as a fresh peat sample. Soils supported different vegetation, including pine (Pinus spp.), aspen (Populus spp.), and white spruce [Picea glauca (Moench) Voss]. Despite overlaps for some individual n‐alkanes, we found a dominance of n‐C25 in reconstructed soils, also dominant in the peat material, and a dominance of n‐C27 in natural soils, one of the dominant n‐alkanes in natural forest vegetation. In addition, there was a significant difference in odd n‐alkane δ2H and δ13C values between natural and reconstructed soils (p < .05). Differences in δ2H values, more negative for reconstructed soils than for natural soils, were attributed to changes in soil moisture, from wetter peat‐dominated soils to drier upland forests; among forest types, δ2H values were most negative under pine vegetation. The δ13C composition of odd n‐alkanes, in particular n‐C27, was significantly related to tree age (p < .05). Overall, both 2H and 13C isotopic signatures of odd n‐alkanes exhibited differences between natural and reconstructed soils. However, within the reconstructed soils, neither isotopic signature showed a clear evolution with age since reclamation.

Research paper thumbnail of Rhizosphere response to predicted vegetation shifts in boreal forest floors

Soil Biology & Biochemistry, Mar 1, 2021

Abstract The boreal forest is the single largest terrestrial store of carbon on Earth, and approx... more Abstract The boreal forest is the single largest terrestrial store of carbon on Earth, and approximately 25% of these carbon stocks are in the forest floor. Climate change is expected to alter boreal vegetation, and aspen-dominated stands will replace conifers in Western Canada. We investigated how these vegetation shifts could affect the composition and function of soil microbial communities, using forest floor samples from the Ecosystem Management Emulating Natural Disturbance (EMEND) project in northwestern Alberta, Canada. Soil microbial communities were surveyed in rhizosphere and bulk forest floor of 17-year-old spruce clear-cuts where aspen was naturally regenerating, mature stands of aspen and spruce, and 17-year-old clear-cuts of aspen. Phospholipid fatty acid (PLFA) analysis was used to characterize microbial community composition and multiple substrate induced respiration (MSIR) to quantify microbial community functional capacity. Carbon source utilization by microorganisms was investigated through natural abundance isotope analysis of individual PLFAs. Rhizosphere samples had a significantly higher proportion of fungi and a higher gram-negative to gram-positive bacteria ratio compared to bulk soil. Fungi and gram-negative bacteria biomarkers in the rhizosphere showed 13C depletion compared to bulk forest floor, indicating that they had assimilated more newly-photosynthesized carbon than bulk forest floor microbes. Aspen trees exerted a greater influence over their rhizospheres than spruce trees in terms of microbial community composition and functional capacity, and aspen rhizospheres showed the highest basal respiration. In less than two decades, aspen regeneration in former spruce stands shifted the composition of microbial communities towards that of native aspen stands, with the rhizosphere microbiome responding more quickly than bulk forest floor. This study suggests that predicted vegetation shifts in the boreal have the potential to cause more immediate and profound changes in the rhizosphere, and emphasizes the need to include the rhizosphere in future studies.

Research paper thumbnail of Linkages between the forest floor microbial community and resource heterogeneity within mature lodgepole pine forests

Soil Biology & Biochemistry, Aug 1, 2013

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights

Research paper thumbnail of Soils and palaeosols as archives of natural and anthropogenic environmental changes

European Journal of Soil Science, Jul 1, 2014

The Fourth International Congress of the European Confederation of Soil Science Societies (ECSSS)... more The Fourth International Congress of the European Confederation of Soil Science Societies (ECSSS) ‘EUROSOIL 2012 Soil Science for the Benefit of Mankind and Environment’ took place in Bari (Italy) on 2–6 July 2012. It aimed to present and discuss many current issues of Soil Sciences, as well as provide an interactive forum for exchange of ideas by bringing together and promoting durable relationships among established and young soil scientists, technical and professional operators, industry and administrative representatives, policy makers and regulators. The session entitled ‘Soils and Sediments as Natural Archives’, convened by Claudio Zaccone, Sylvie Quideau, Alexander O. Makeev and Daniela Sauer, was devoted to recent studies using soils and palaeosols as potential records of both natural and human-induced processes that occurred during the past centuries to millennia. The basic concept of this session followed the idea that palaeosols together with lake and peat deposits, speleothems and ice-cores represent natural archives of past changes in the lithosphere, atmosphere, biosphere and hydrosphere on different temporal and spatial scales. In addition, anthropogenic activities have more recently created a new kind of soil archive: Technosols, which are young soils developing in technogenic ‘man-made’ parent materials. To understand better the real extent of natural and human impacts on environmental changes, it is very helpful to look back into the past by interpreting the processes that have taken place in a given soil or palaeosol; only in this way is it possible to know how ecosystems used to function prior to significant intervention by man. This is exactly where archives can be useful. Usually, different archives (natural and anthropogenic) are studied by different disciplines within soil science. However, different scientific communities, because of increasing specialization in their different fields, do not always interact, although they have the same goal: deciphering their respective records. This session was, to our knowledge, the first one that brought together colleagues working on different kinds of archives, carrying out pedological and multi-proxy studies in an attempt to ‘extract’ the information that is recorded in both natural and anthropogenic archives. The idea of the session was hence to provide an opportunity for exchanging ideas, concepts and approaches that have been developed in one discipline and might be useful also for another discipline and vice versa, thus for learning from each other. This session received numerous contributions, which included (noting only some of the main topics): (i) the use of different natural archives such as bogs, palaeosols, ancient dunes and sediments for reconstructing past climate and vegetation, (ii) the application of new techniques and approaches to obtain palaeoenvironmental and geoarchaeological information from different terrestrial records, (iii) the investigation of anthropogenic impacts on the soil environment over time, (iv) the reconstruction of soil-forming environments and landscapes of the past and (v) the quantification of pedogenesis in technogenic materials. This Special Section comprises a selection of papers showing new and original results in different types of palaeopedological archives, including recent palaeo-environmental reconstructions carried out in southern (Scarciglia et al., 2014; Zucca et al., 2014) and eastern Europe (Łanczont et al., 2014) and Mexico (Cruz-y-Cruz et al., 2014), as well as novel research on soils developed in urban, industrial and mining materials (Huot et al., 2014; Jangorzo et al., 2014).

Research paper thumbnail of Forest-floor chemical properties are altered by clear-cutting in boreal mixedwood forest stands dominated by trembling aspen and white spruce

Canadian Journal of Forest Research, Oct 1, 2005

Alterations in the chemical properties of the forest floor following clear-cut harvesting may hav... more Alterations in the chemical properties of the forest floor following clear-cut harvesting may have implications for forest productivity in boreal stands. We used proximate analysis, carbon-13 (13C) isotopic determination, and cross-polarization, magic-angle spinning (CPMAS) 13C nuclear magnetic resonance (NMR) spectroscopy to examine differences in the characteristics of the forest floors from uncut stands and clear-cut stands dominated by white spruce (Picea glauca (Moench) Voss; SPRUCE) and trembling aspen (Populus tremuloides Michx.; ASPEN) in northern Alberta. Proximate analysis revealed no difference in the chemical properties of forest floors from clear-cut and uncut stands in either stand type, but the acid-insoluble residue of forest floors from clear-cut ASPEN stands was enriched in 13C compared with those from uncut ASPEN stands. CPMAS 13C NMR spectroscopy revealed that forest floors from clearcuts were enriched in total aromatic C, particularly in ASPEN stands, and depleted in phenolic C, particularly in SPRUCE stands. These patterns indicate that forest floors from the clearcuts have become more humified, which may reflect stand-type differences in the amount of labile C available to the forest-floor microbial community and reductions in above- and below-ground inputs to the forest floor following clear-cutting in both stand types. Changes in the chemical properties of forest floors from clear-cut SPRUCE and ASPEN stands could exacerbate C limitation in these soils and alter patterns of nutrient cycling.

Research paper thumbnail of Forest Floor Composition in Aspen- and Spruce-Dominated Stands of the Boreal Mixedwood Forest

Soil Science Society of America Journal, Sep 1, 2004

Research paper thumbnail of Maintaining water and nutrients availability to plants in reclaimed oil sands soils

HAL (Le Centre pour la Communication Scientifique Directe), Sep 25, 2017

Research paper thumbnail of The effect of weeds on soil arbuscular mycorrhizal fungi and agronomic traits in spring wheat (<i>Triticum aestivum</i>L.) under organic management in Canada

Canadian Journal of Plant Science, Jul 1, 2015

Research paper thumbnail of Data for: High Resolution Measurement of Soil Carbon and Nitrogen with Imaging Spectroscopy

Imaging spectroscopy files can be provided upon request. There were not uploaded due to their size.

Research paper thumbnail of Assessing structural and functional indicators of soil nitrogen availability in reclaimed forest ecosystems using15N-labelled aspen litter

Canadian Journal of Soil Science, Jun 1, 2018

Abstract: Landscape-level disturbance is a reality in many parts of the world including the Athab... more Abstract: Landscape-level disturbance is a reality in many parts of the world including the Athabasca oil sands region, Canada, and soils play an essential part in the overall reclamation process. Soils are reconstructed during reclamation to provide a foundation and a nutrient source for the novel ecosystems. However, reclamation is often monitored through structural indicators of soil quality, which may not reflect dynamic ecosystem functions such as nutrient cycling. Our objective was to determine if nutrient cycling was occurring on novel ecosystems and if standard structural measures of soil quality were appropriate indicators. We assessed soil quality and nitrogen cycling in reclaimed, harvested and undisturbed aspen forest sites following the addition of 15N-labelled aspen (Populus tremuloides Michx.) leaf litter to the soil surface. Structural soil quality indicators, including soil moisture and microbial carbon and nitrogen biomass, were higher on the undisturbed site, whereas soil microbial composition differed among sites. Yet, uptake of 15N by microbes and plants, which continued throughout the 52 mo field incubation, was comparable across all sites. These results indicate that differences in structural attributes between disturbed and undisturbed soils do not necessarily translate into differences in soil functioning related to nitrogen cycling. Instead, this case study supports exploring the use of stable isotope tracers to assess dynamic soil function indicators in reclaimed ecosystems. Being able to follow biogeochemical cycling as vegetation becomes established and new forests start to develop following reclamation is key to assessing the long-term sustainability of these novel ecosystems.

Research paper thumbnail of Quantification of Soil Health and Identification of Key Soil Health Indicators for Five Long-Term Crop Rotations

Research paper thumbnail of Soil Microbial Community Composition (PLFA) under Different Grazing Systems in the Canadian Prairies

AGU Fall Meeting Abstracts, Dec 1, 2018

Research paper thumbnail of Microbial processing of leaf- and root-derived organic matter in the boreal forest

Research paper thumbnail of Gray Luvisols are polygenetic

Canadian Journal of Soil Science, Mar 1, 2023

With respect to the pedosphere, human activities in the last 100 years have been the major driver... more With respect to the pedosphere, human activities in the last 100 years have been the major driver of soil change. Despite human activities being one of the main soil forming factors recognized by soil scientists (in addition to climate, organisms, parent material, relief, groundwater, and time), the Canadian System of Soil Classification (CSSC) emphasizes soil as a natural body. We argue human agricultural activities are direct and indirect drivers of significant changes to the carbon balance and cycling in A horizons of Gray Luvisolic soils in western Canada, resulting in changes to A horizon carbon stocks, structure, and micromorphology. Evidence from scientific literature, in-field soil profile observations, and the National Pedon Database are presented in support of our argument. We propose a polygenetic, two-stage model of Gray Luvisol soil formation. The first stage is dominated by the climate forcing of the Holocene, resulting in a relatively stable boreal forest ecosystem including perturbations from natural and human-induced wildfire and other disturbances. The second stage is dominated by direct, human-driven disturbances such as cultivation, release of exotic fauna (earthworms), and indirect human-driven disturbances associated with anthropogenic climate change. Further, we propose modest amendments to the CSSC to reflect a polygenetic model of soil genesis in Gray Luvisolic soils that preserve the balance between observation and interpretation inherent in the system.

Research paper thumbnail of Modelling nitrogen mineralization and plant nitrogen uptake as affected by reclamation cover depth in reclaimed upland forestlands of Northern Alberta

Biogeochemistry, May 25, 2020

Early forest re-establishment in landforms constructed from materials such as overburden or mine ... more Early forest re-establishment in landforms constructed from materials such as overburden or mine waste is partly determined by nitrogen (N) availability in reclamation covers. Here we examined whether the ecosystem model ecosys which simulates key processes governing N availability such as mineralization, plant N uptake and N return to soil through litterfall could be used to forecast potential N limitations for forest re-establishment in these constructed landforms. In this study, N cycling was simulated and tested against measured soil, foliar and surface litter N concentrations with three soil covers differing in thickness (35, 50, and 100 cm) in a 17-year-old forest reclamation site and in an analogue natural forested site in northern Alberta. Overall, results from this study demonstrated the applicability of the ecosys model in predicting nutrient cycling in reclaimed upland forestlands. Results of this study highlight the importance of optimum cover depth to ensure sufficient N is available for plant growth. Even though the modelled net N mineralization, N uptake and thereby plant productivity increased with cover depth, the foliar and surface litter N concentrations did not. A non-linear relationship between total soil nitrogen (TN) stocks and modelled net N mineralization indicated that cover depth, which determines TN stock, had little effect on net primary productivity beyond a threshold TN. This threshold was 17 Mg N ha-1 , similar to TN for the 100 cm cover, giving a net N mineralization rate of * 3.5 g N m-2 year-1 , and this was attributed to reduced microbial activity in deeper soil layers.

Research paper thumbnail of Next-Generation Sequencing of Protists as a Measure of Natural Soil Microbial Eukaryotic Community in the Oil Sands Region

Research paper thumbnail of Isotope applications to soil science at the University of Alberta — an historical perspective

Canadian Journal of Soil Science, 2020

For the past 70 yr, researchers in the Soil Science/Renewable Resources Department at the Univers... more For the past 70 yr, researchers in the Soil Science/Renewable Resources Department at the University of Alberta have used isotopes to study topics of ecological importance. This review highlights the soil isotope research conducted within our department over this time, including an historical overview of studies of interest. Analytical techniques and advances in instrumentation are discussed, focusing on the measurement of light stable isotope ratios (i.e., for C, H, N, S, and O) using isotope ratio mass spectrometry (IRMS). Early soil isotope work (1950–2000s) focused on agricultural soils and soil fertility issues. These studies included the use of radioactive isotopes such as 14C and 35S, and (or) artificially enriched stable isotopes including 15N-labelled fertilizers. More recently (2000–present), the scope of research widened to include natural-abundance stable isotope ratio studies as higher-sensitivity IRMS systems became more prevalent. Current isotope research topics inclu...

Research paper thumbnail of Isotope applications to soil science at the University of Alberta — an historical perspective

Canadian Journal of Soil Science, Dec 1, 2020

Research paper thumbnail of Earthworm-invaded boreal forest soils harbour distinct microbial communities

Earthworm invasion in North American forests has the potential to greatly impact soil microbial c... more Earthworm invasion in North American forests has the potential to greatly impact soil microbial communities by altering soil physicochemical properties, including structure, pH, nutrient availability, and soil organic matter (SOM) dynamics. While most research on the topic has been carried out in northern temperate forests, little is known about the impact of invasive earthworms on soil microbial communities in hemiboreal and boreal forests, characterized by a slower decay of organic matter (OM). Earthworm activities can increase OM mineralization, altering nutrient cycling and biological activity in a biome where low carbon (C) and nitrogen (N) availability typically limits microbial and plant growth. Here, we characterized and compared microbial communities of earthworm-invaded and non-invaded soils in previously described sites across three major soil types found in the Canadian (hemi)boreal forest using a space-for-time approach. Microbial communities of forest floors and surface mineral soils were characterized using phospholipid fatty acid (PLFA) analysis and metabarcoding of the 16S rRNA gene for bacteria and archaea and of the internal-transcriber-spacer-2 (ITS2) region for fungi. In forest floors, the effects of earthworm invasion were minor. In mineral soil horizons, earthworm invasion was associated with higher fungal biomass and greater relative abundance of ectomycorrhizal fungi. Oligotrophic bacteria (Acidobacteriota and Chloroflexi) were less abundant in invaded mineral soils, where Gram(+) : Gram(−) ratios were also lower, while the opposite was observed for the copiotrophic Bacteroidota. Additionally, earthworm-invaded mineral soils harboured higher fungal and bacterial species diversity and richness. Considering the important role of soil microbial communities for ecosystem functioning, such earthworm-induced shifts in their community composition are likely to impact nutrient cycling, as well as vegetation development and forest productivity at a large scale, as the invasion progresses in these (hemi)boreal systems.

Research paper thumbnail of Organic Matter Accumulation

Research paper thumbnail of Carbon and hydrogen isotopes of n ‐alkanes in soils reconstructed after mining disturbance

Journal of Environmental Quality, Mar 20, 2020

Ecosystem reconstruction after mining disturbance is a challenge considering the multitude of fac... more Ecosystem reconstruction after mining disturbance is a challenge considering the multitude of factors that affect soil formation and revegetation. In the boreal forest of western Canada, peat material is often used as the organic amendment for land reclamation to upland forest. Carbon and water dynamics of peat‐dominated ecosystems differ from natural upland forest soils. The objective of this work was to evaluate the evolution of soils reconstructed after mining disturbance using 13C and 2H analyses of n‐alkane tracers. Ten soils from natural ecosystems were sampled (0–10 cm) and compared with 11 soils from novel ecosystems ranging in age from 0 to 30 yr, as well as a fresh peat sample. Soils supported different vegetation, including pine (Pinus spp.), aspen (Populus spp.), and white spruce [Picea glauca (Moench) Voss]. Despite overlaps for some individual n‐alkanes, we found a dominance of n‐C25 in reconstructed soils, also dominant in the peat material, and a dominance of n‐C27 in natural soils, one of the dominant n‐alkanes in natural forest vegetation. In addition, there was a significant difference in odd n‐alkane δ2H and δ13C values between natural and reconstructed soils (p &lt; .05). Differences in δ2H values, more negative for reconstructed soils than for natural soils, were attributed to changes in soil moisture, from wetter peat‐dominated soils to drier upland forests; among forest types, δ2H values were most negative under pine vegetation. The δ13C composition of odd n‐alkanes, in particular n‐C27, was significantly related to tree age (p &lt; .05). Overall, both 2H and 13C isotopic signatures of odd n‐alkanes exhibited differences between natural and reconstructed soils. However, within the reconstructed soils, neither isotopic signature showed a clear evolution with age since reclamation.

Research paper thumbnail of Rhizosphere response to predicted vegetation shifts in boreal forest floors

Soil Biology & Biochemistry, Mar 1, 2021

Abstract The boreal forest is the single largest terrestrial store of carbon on Earth, and approx... more Abstract The boreal forest is the single largest terrestrial store of carbon on Earth, and approximately 25% of these carbon stocks are in the forest floor. Climate change is expected to alter boreal vegetation, and aspen-dominated stands will replace conifers in Western Canada. We investigated how these vegetation shifts could affect the composition and function of soil microbial communities, using forest floor samples from the Ecosystem Management Emulating Natural Disturbance (EMEND) project in northwestern Alberta, Canada. Soil microbial communities were surveyed in rhizosphere and bulk forest floor of 17-year-old spruce clear-cuts where aspen was naturally regenerating, mature stands of aspen and spruce, and 17-year-old clear-cuts of aspen. Phospholipid fatty acid (PLFA) analysis was used to characterize microbial community composition and multiple substrate induced respiration (MSIR) to quantify microbial community functional capacity. Carbon source utilization by microorganisms was investigated through natural abundance isotope analysis of individual PLFAs. Rhizosphere samples had a significantly higher proportion of fungi and a higher gram-negative to gram-positive bacteria ratio compared to bulk soil. Fungi and gram-negative bacteria biomarkers in the rhizosphere showed 13C depletion compared to bulk forest floor, indicating that they had assimilated more newly-photosynthesized carbon than bulk forest floor microbes. Aspen trees exerted a greater influence over their rhizospheres than spruce trees in terms of microbial community composition and functional capacity, and aspen rhizospheres showed the highest basal respiration. In less than two decades, aspen regeneration in former spruce stands shifted the composition of microbial communities towards that of native aspen stands, with the rhizosphere microbiome responding more quickly than bulk forest floor. This study suggests that predicted vegetation shifts in the boreal have the potential to cause more immediate and profound changes in the rhizosphere, and emphasizes the need to include the rhizosphere in future studies.

Research paper thumbnail of Linkages between the forest floor microbial community and resource heterogeneity within mature lodgepole pine forests

Soil Biology & Biochemistry, Aug 1, 2013

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights

Research paper thumbnail of Soils and palaeosols as archives of natural and anthropogenic environmental changes

European Journal of Soil Science, Jul 1, 2014

The Fourth International Congress of the European Confederation of Soil Science Societies (ECSSS)... more The Fourth International Congress of the European Confederation of Soil Science Societies (ECSSS) ‘EUROSOIL 2012 Soil Science for the Benefit of Mankind and Environment’ took place in Bari (Italy) on 2–6 July 2012. It aimed to present and discuss many current issues of Soil Sciences, as well as provide an interactive forum for exchange of ideas by bringing together and promoting durable relationships among established and young soil scientists, technical and professional operators, industry and administrative representatives, policy makers and regulators. The session entitled ‘Soils and Sediments as Natural Archives’, convened by Claudio Zaccone, Sylvie Quideau, Alexander O. Makeev and Daniela Sauer, was devoted to recent studies using soils and palaeosols as potential records of both natural and human-induced processes that occurred during the past centuries to millennia. The basic concept of this session followed the idea that palaeosols together with lake and peat deposits, speleothems and ice-cores represent natural archives of past changes in the lithosphere, atmosphere, biosphere and hydrosphere on different temporal and spatial scales. In addition, anthropogenic activities have more recently created a new kind of soil archive: Technosols, which are young soils developing in technogenic ‘man-made’ parent materials. To understand better the real extent of natural and human impacts on environmental changes, it is very helpful to look back into the past by interpreting the processes that have taken place in a given soil or palaeosol; only in this way is it possible to know how ecosystems used to function prior to significant intervention by man. This is exactly where archives can be useful. Usually, different archives (natural and anthropogenic) are studied by different disciplines within soil science. However, different scientific communities, because of increasing specialization in their different fields, do not always interact, although they have the same goal: deciphering their respective records. This session was, to our knowledge, the first one that brought together colleagues working on different kinds of archives, carrying out pedological and multi-proxy studies in an attempt to ‘extract’ the information that is recorded in both natural and anthropogenic archives. The idea of the session was hence to provide an opportunity for exchanging ideas, concepts and approaches that have been developed in one discipline and might be useful also for another discipline and vice versa, thus for learning from each other. This session received numerous contributions, which included (noting only some of the main topics): (i) the use of different natural archives such as bogs, palaeosols, ancient dunes and sediments for reconstructing past climate and vegetation, (ii) the application of new techniques and approaches to obtain palaeoenvironmental and geoarchaeological information from different terrestrial records, (iii) the investigation of anthropogenic impacts on the soil environment over time, (iv) the reconstruction of soil-forming environments and landscapes of the past and (v) the quantification of pedogenesis in technogenic materials. This Special Section comprises a selection of papers showing new and original results in different types of palaeopedological archives, including recent palaeo-environmental reconstructions carried out in southern (Scarciglia et al., 2014; Zucca et al., 2014) and eastern Europe (Łanczont et al., 2014) and Mexico (Cruz-y-Cruz et al., 2014), as well as novel research on soils developed in urban, industrial and mining materials (Huot et al., 2014; Jangorzo et al., 2014).

Research paper thumbnail of Forest-floor chemical properties are altered by clear-cutting in boreal mixedwood forest stands dominated by trembling aspen and white spruce

Canadian Journal of Forest Research, Oct 1, 2005

Alterations in the chemical properties of the forest floor following clear-cut harvesting may hav... more Alterations in the chemical properties of the forest floor following clear-cut harvesting may have implications for forest productivity in boreal stands. We used proximate analysis, carbon-13 (13C) isotopic determination, and cross-polarization, magic-angle spinning (CPMAS) 13C nuclear magnetic resonance (NMR) spectroscopy to examine differences in the characteristics of the forest floors from uncut stands and clear-cut stands dominated by white spruce (Picea glauca (Moench) Voss; SPRUCE) and trembling aspen (Populus tremuloides Michx.; ASPEN) in northern Alberta. Proximate analysis revealed no difference in the chemical properties of forest floors from clear-cut and uncut stands in either stand type, but the acid-insoluble residue of forest floors from clear-cut ASPEN stands was enriched in 13C compared with those from uncut ASPEN stands. CPMAS 13C NMR spectroscopy revealed that forest floors from clearcuts were enriched in total aromatic C, particularly in ASPEN stands, and depleted in phenolic C, particularly in SPRUCE stands. These patterns indicate that forest floors from the clearcuts have become more humified, which may reflect stand-type differences in the amount of labile C available to the forest-floor microbial community and reductions in above- and below-ground inputs to the forest floor following clear-cutting in both stand types. Changes in the chemical properties of forest floors from clear-cut SPRUCE and ASPEN stands could exacerbate C limitation in these soils and alter patterns of nutrient cycling.

Research paper thumbnail of Forest Floor Composition in Aspen- and Spruce-Dominated Stands of the Boreal Mixedwood Forest

Soil Science Society of America Journal, Sep 1, 2004

Research paper thumbnail of Maintaining water and nutrients availability to plants in reclaimed oil sands soils

HAL (Le Centre pour la Communication Scientifique Directe), Sep 25, 2017

Research paper thumbnail of The effect of weeds on soil arbuscular mycorrhizal fungi and agronomic traits in spring wheat (<i>Triticum aestivum</i>L.) under organic management in Canada

Canadian Journal of Plant Science, Jul 1, 2015

Research paper thumbnail of Data for: High Resolution Measurement of Soil Carbon and Nitrogen with Imaging Spectroscopy

Imaging spectroscopy files can be provided upon request. There were not uploaded due to their size.

Research paper thumbnail of Assessing structural and functional indicators of soil nitrogen availability in reclaimed forest ecosystems using15N-labelled aspen litter

Canadian Journal of Soil Science, Jun 1, 2018

Abstract: Landscape-level disturbance is a reality in many parts of the world including the Athab... more Abstract: Landscape-level disturbance is a reality in many parts of the world including the Athabasca oil sands region, Canada, and soils play an essential part in the overall reclamation process. Soils are reconstructed during reclamation to provide a foundation and a nutrient source for the novel ecosystems. However, reclamation is often monitored through structural indicators of soil quality, which may not reflect dynamic ecosystem functions such as nutrient cycling. Our objective was to determine if nutrient cycling was occurring on novel ecosystems and if standard structural measures of soil quality were appropriate indicators. We assessed soil quality and nitrogen cycling in reclaimed, harvested and undisturbed aspen forest sites following the addition of 15N-labelled aspen (Populus tremuloides Michx.) leaf litter to the soil surface. Structural soil quality indicators, including soil moisture and microbial carbon and nitrogen biomass, were higher on the undisturbed site, whereas soil microbial composition differed among sites. Yet, uptake of 15N by microbes and plants, which continued throughout the 52 mo field incubation, was comparable across all sites. These results indicate that differences in structural attributes between disturbed and undisturbed soils do not necessarily translate into differences in soil functioning related to nitrogen cycling. Instead, this case study supports exploring the use of stable isotope tracers to assess dynamic soil function indicators in reclaimed ecosystems. Being able to follow biogeochemical cycling as vegetation becomes established and new forests start to develop following reclamation is key to assessing the long-term sustainability of these novel ecosystems.

Research paper thumbnail of Quantification of Soil Health and Identification of Key Soil Health Indicators for Five Long-Term Crop Rotations

Research paper thumbnail of Soil Microbial Community Composition (PLFA) under Different Grazing Systems in the Canadian Prairies

AGU Fall Meeting Abstracts, Dec 1, 2018

Research paper thumbnail of Microbial processing of leaf- and root-derived organic matter in the boreal forest

Research paper thumbnail of Gray Luvisols are polygenetic

Canadian Journal of Soil Science, Mar 1, 2023

With respect to the pedosphere, human activities in the last 100 years have been the major driver... more With respect to the pedosphere, human activities in the last 100 years have been the major driver of soil change. Despite human activities being one of the main soil forming factors recognized by soil scientists (in addition to climate, organisms, parent material, relief, groundwater, and time), the Canadian System of Soil Classification (CSSC) emphasizes soil as a natural body. We argue human agricultural activities are direct and indirect drivers of significant changes to the carbon balance and cycling in A horizons of Gray Luvisolic soils in western Canada, resulting in changes to A horizon carbon stocks, structure, and micromorphology. Evidence from scientific literature, in-field soil profile observations, and the National Pedon Database are presented in support of our argument. We propose a polygenetic, two-stage model of Gray Luvisol soil formation. The first stage is dominated by the climate forcing of the Holocene, resulting in a relatively stable boreal forest ecosystem including perturbations from natural and human-induced wildfire and other disturbances. The second stage is dominated by direct, human-driven disturbances such as cultivation, release of exotic fauna (earthworms), and indirect human-driven disturbances associated with anthropogenic climate change. Further, we propose modest amendments to the CSSC to reflect a polygenetic model of soil genesis in Gray Luvisolic soils that preserve the balance between observation and interpretation inherent in the system.

Research paper thumbnail of Modelling nitrogen mineralization and plant nitrogen uptake as affected by reclamation cover depth in reclaimed upland forestlands of Northern Alberta

Biogeochemistry, May 25, 2020

Early forest re-establishment in landforms constructed from materials such as overburden or mine ... more Early forest re-establishment in landforms constructed from materials such as overburden or mine waste is partly determined by nitrogen (N) availability in reclamation covers. Here we examined whether the ecosystem model ecosys which simulates key processes governing N availability such as mineralization, plant N uptake and N return to soil through litterfall could be used to forecast potential N limitations for forest re-establishment in these constructed landforms. In this study, N cycling was simulated and tested against measured soil, foliar and surface litter N concentrations with three soil covers differing in thickness (35, 50, and 100 cm) in a 17-year-old forest reclamation site and in an analogue natural forested site in northern Alberta. Overall, results from this study demonstrated the applicability of the ecosys model in predicting nutrient cycling in reclaimed upland forestlands. Results of this study highlight the importance of optimum cover depth to ensure sufficient N is available for plant growth. Even though the modelled net N mineralization, N uptake and thereby plant productivity increased with cover depth, the foliar and surface litter N concentrations did not. A non-linear relationship between total soil nitrogen (TN) stocks and modelled net N mineralization indicated that cover depth, which determines TN stock, had little effect on net primary productivity beyond a threshold TN. This threshold was 17 Mg N ha-1 , similar to TN for the 100 cm cover, giving a net N mineralization rate of * 3.5 g N m-2 year-1 , and this was attributed to reduced microbial activity in deeper soil layers.