Publications

Article | La bataille de Montréal | par Anne Latendresse, professeure en géographie UQAM | Dans la revue Nouveaux Cahiers du socialisme | Automne 2021

ARTICLE

La bataille de Montréal

par Anne Latendresse | Professeure au Département de géographie de l’UQAM.

Dans la revue – Nouveaux Cahiers du socialisme | No 26, automne 2021

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Extrait de l’introduction.

Au moment où la campagne électorale municipale entre dans sa phase cruciale, les alignements se précisent. Deux grosses « pointures » sont en lice : Valérie Plante, mairesse en poste et cheffe de Projet Montréal, et Denis Coderre, ancien maire de Montréal de 2013 à 2017 et chef du parti Ensemble Montréal. Parallèlement, un certain nombre de personnes annoncent leur candidature aux postes de conseillers et conseillères de ville ou d’arrondissement, de même qu’à la mairie de chacun des 19 arrondissements. Actuellement, les deux principaux partis semblent opter pour une stratégie d’arrondissement et présentent des équipes à la mairie d’arrondissement et aux autres postes de conseillers.

Article | Tourisme mondial : sortir du « choc » pandémique | par Yann Roche | Dans la revue Diplomatie | Numéro de Juillet-Août 2021

Nouvelle publication | Article

Tourisme mondial : sortir du « choc » pandémique

Revue DIPLOMATIE | Numéro 110, Juillet-Août 2021
Dossier – Géoéconomie du tourisme – Dossier spécial consacré au tourisme mondial en temps de pandémie et réalisé en partenariat avec l’UQAM.

Cliquer ici ou sur l’image pour consulter la table complète de ce numéro.

AUTEUR
Yann Roche | professeur au département de géographie de l’UQAM et coprésident de l’Observatoire de géopolitique de la Chaire Raoul-Dandurand en Études stratégiques et diplomatiques de l’UQAM.

Article scientifique | Le droit au quartier et l’acceptation sociale de la gentrification: Les cas de deux processus de transformation urbaine à Nantes et Montréal | Leila Ghaffari, Abdelillah Hambouch et Juan-Luis Klein | Revue Canadienne de recherche urbaine | 2021

Nouvelle publication | Article scientifique

Le droit au quartier et l’acceptation sociale de la gentrification: Les cas de
deux processus de transformation urbaine à Nantes et Montréal

AUTEUR.E.S
Leila Ghaffari | Université du Québec à Montréal et Université de Tours
Abdelillah Hamdouch | Université de Tours et UMR CNRS CITERES
Juan-Luis Klein | Université du Québec à Montréal et CRISES

Revue Canadienne de recherche urbaine (RCRU) | Volume 30; Numéro 1 | 2021

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Résumé (en anglais seulement)

Relatively few studies on gentrification address the case of those citizens who manage to stay in their neighbourhoods, even if they suffer from various forms of marginalization provoked by the gentrification process. In this article, we study their reaction based on the Exit, Voice, Loyalty framework proposed by Hirschman (1970), according to which the voice-loyalty pair has the best potential for converting a situation considered as unsatisfactory. We analyse the acceptability of gentrification through Hirschman’s possibilities of reaction, on the base of two cases: Madeleine-Champ-de-Mars in Nantes and Hochelaga-Maisonneuve in Montreal. The former demonstrates the effectiveness of citizens’ mobilization within a context of collaboration while the latter illustrates the results of social mobilization within a context of confrontation. We assert that the expression of voice by residents, combined with political will, can mobilize citizens and initiate a process of negotiation and co-construction of the urban transformation favouring a socially acceptable gentrification. We also conclude that conflict plays an important role in establishing balanced negotiations between different stakeholders.

Article scientifique | Paludification reduces black spruce growth rate but does not alter tree water use efficiency in Canadian boreal forested peatlands | par Joannie Beaulne, Étienne Boucher, Michelle Garneau et Gabriel Magnan | Géographie et GÉOTOP UQAM | Revue Forest Ecosystems – Mai 2021

Nouvelle publication | Article scientifique

Paludification reduces black spruce growth rate but does not alter tree water use efficiency in Canadian boreal forested peatlands

AUTEUR.E.S
Joannie Beaulne | Étudiante à la maîtrise | Département de géographie, GEOTOP – UQAM
Étienne Boucher | Professeur | Département de géographie, GEOTOP – UQAM
Michelle Garneau | Professeure | Département de géographie, GEOTOP – UQAM
Gabriel Magnan | Chargé de cours | Département de géographie, GEOTOP – UQAM

Revue Forest Ecosystems | Volume 8; Article 28

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RÉSUMÉ (en anglais seulement)

Background
Black spruce (Picea mariana (Mill.) BSP)-forested peatlands are widespread ecosystems in boreal North America in which peat accumulation, known as the paludification process, has been shown to induce forest growth decline. The continuously evolving environmental conditions (e.g., water table rise, increasing peat thickness) in paludified forests may require tree growth mechanism adjustments over time. In this study, we investigate tree ecophysiological mechanisms along a paludification gradient in a boreal forested peatland of eastern Canada by combining peat-based and tree-ring analyses. Carbon and oxygen stable isotopes in tree rings are used to document changes in carbon assimilation rates, stomatal conductance, and water use efficiency. In addition, paleohydrological analyses are performed to evaluate the dynamical ecophysiological adjustments of black spruce trees to site-specific water table variations.

Results
Increasing peat accumulation considerably impacts forest growth, but no significant differences in tree water use efficiency (iWUE) are found between the study sites. Tree-ring isotopic analysis indicates no iWUE decrease over the last 100 years, but rather an important increase at each site up to the 1980s, before iWUE stabilized. Surprisingly, inferred basal area increments do not reflect such trends. Therefore, iWUE variations do not reflect tree ecophysiological adjustments required by changes in growing conditions. Local water table variations induce no changes in ecophysiological mechanisms, but a synchronous shift in iWUE is observed at all sites in the mid-1980s.

Conclusions
Our study shows that paludification induces black spruce growth decline without altering tree water use efficiency in boreal forested peatlands. These findings highlight that failing to account for paludification-related carbon use and allocation could result in the overestimation of aboveground biomass production in paludified sites. Further research on carbon allocation strategies is of utmost importance to understand the carbon sink capacity of these widespread ecosystems in the context of climate change, and to make appropriate forest management decisions in the boreal biome.

Nouvelle publication | Note scientifique sur les tourbières boréales et leur rôle majeur de puit de carbone | dans la revue Nature | par Joannie Beaulne, Michelle Garneau, Gabriel Magnan et Étienne Boucher de Géographie UQAM et du GÉOTOP | Janvier 2021

Peat deposits store more carbon than trees in forested peatlands of the boreal biome

AUTEUR.E.S
Joannie Beaulne | Étudiante à la maîtrise | Département de géographie – UQAM – GEOTOP
Michelle Garneau | Professeure | Département de géographie – UQAM – GEOTOP
Gabriel Magnan | Chargé de cours | Département de géographie – UQAM
Étienne Boucher | Professeur | Département de géographie – UQAM – GEOTOP

Scientific Reports 11, Article numéro 2657 | Janvier 2021

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RÉSUMÉ (en anglais seulement)
Peatlands are significant carbon (C) stores, playing a key role in nature-based climate change mitigation. While the effectiveness of non-forested peatlands as C reservoirs is increasingly recognized, the C sequestration function of forested peatlands remains poorly documented, despite their widespread distribution. Here, we evaluate the C sequestration potential of pristine boreal forested peatlands over both recent and millennial timescales. C stock estimates reveal that most of the carbon stored in these ecosystems is found in organic horizons (22.6–66.0 kg m−2), whereas tree C mass (2.8–5.7 kg m−2) decreases with thickening peat. For the first time, we compare the boreal C storage capacities of peat layers and tree biomass on the same timescale, showing that organic horizons (11.0–12.6 kg m−2) can store more carbon than tree aboveground and belowground biomass (2.8–5.7 kg m−2) even over a short time period (last 200 years). We also show that forested peatlands have similar recent rates of C accumulation to boreal non-forested peatlands but lower long-term rates, suggesting higher decay and more important peat layer combustion during fire events. Our findings highlight the significance of forested peatlands for C sequestration and suggest that greater consideration should be given to peat C stores in national greenhouse gas inventories and conservation policies.

Nouvelles publications sur les tourbières du nord du Québec dans le revue scientifique The Holocene| Équipe de Michelle Garneau (Étudiant.e.s et diplômé.e.s) – Géographie et Géotop UQAM | Guillaume Primeau, Mylène Robitaille, Nicole Sanderson et Simon van Bellen

Carbon accumulation in peatlands along a boreal to subarctic transect in eastern Canada

Guillaume Primeau, et Michelle Garneau

Départment de Géographie, Université du Québec à Montréal, Centre de recherche Geotop Canada , et GRIL-UQAM, Université du Québec à Montréal, Canada
Publié en ligne: 17 janvier 2021
https://doi.org/10.1177/0959683620988031

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Résumé (en anglais)
In this study, we investigated the links between peat carbon accumulation and past ecological and hydrological conditions in three peatlands (Bouleau, Mista, Auassat) which developed along a South-North transect within a watershed encompassing the boreal and subarctic domain in Eastern Canada. Peatland development and long-term apparent rates of carbon accumulation (LORCA) were asynchronous in the watershed, suggesting an influence of both latitude and topography (altitude) on the length of the growing season (GGD0). Results show that peat initiation within the three peatlands (respectively ca. 9070, 8400, and 6270 cal BP) was delayed after the deglaciation and that LORCA (respectively 35.5, 15.4, and 9.0 g C m−2 yr−1) decreased from South to North. Peatland development and fen to bog transitions were found to be almost synchronous for the two southernmost sites. The fen to bog transition in the northernmost subarctic site was delayed until the 20th century, owing to the less favorable climatic conditions. This suggests that recent warming has extended the length of the growing season and increased Sphagnum growth enough to potentially influence an ecosystem state-shift as observed in other Subarctic regions of eastern Canada.

Long-term and recent ecohydrological dynamics of patterned peatlands in north-central Quebec (Canada)

Auteur.e.s | Mylène RobitailleMichelle GarneauSimon van BellenNicole K. Sanderson

Publié en ligne : 18 janvier 2021
Articlehttps://doi.org/10.1177/0959683620988051

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Résumé (en anglais)
Peatlands are natural ecosystems that provide archives of the hydrological cycle, ecological processes and terrestrial carbon dynamics. In the north-central region of Quebec (eastern Canada), patterned peatlands developed in topographic depressions of the Precambrian Shield following the Laurentide Ice Sheet retreat. These peatlands display characteristics similar to appa mires and other peatlands that developed at the ecotone between the open (taiga) and closed boreal forest biomes of the Northern Hemisphere, and also correspond to the biogeographic limit between ombrotrophic and minerotrophic peatlands. During the Neoglacial cooling period in northeastern Canada, patterned peatlands, mainly oligotrophic fens, registered a hydrological disequilibrium expressed by an increase in surface wetness as aquatic microforms expanded to the detriment of terrestrial surfaces. Ecohydrological trajectories were reconstructed from a detailed study of two patterned peatlands in order to document their sensitivity to climate variations. To do this, plant macrofossil and testate amoeba data were combined with peat carbon accumulation rates, C:N ratios, 210Pb and 14C chronologies. Data show that peatlands initiated ca 6500 cal. y BP as ombrotrophic or minerotrophic systems depending on site-specific conditions, followed by a general increase in surface wetness during the Neoglacial cooling until the end of the Little Ice Age. A relatively synchronous ecosystem state shift from oligotrophic to more ombrotrophic conditions was registered at the beginning of the 20th century in central and lateral cores of both study sites, evoking the likely influence of recent warming on peat accumulation. These results suggest a potential northward migration of the biogeographic limit of the ombrotrophic peatland distribution during the 20th century, which could have implications for the role of these ecosystems as C sinks at the continental scale. Overall, these peatlands have stored a mean carbon mass of ca 100 kg m− 2.

Article scientifique sur les reconstitutions paléohydrologiques des tourbières dans la revue The Holocene| par Gabriel Magnan et Michelle Garneau – Géographie et Géotop UQAM | Janvier 2021

A comparison of Holocene testate amoeba assemblages and paleohydrological records from pollen slides and wet-sieved peat

Gabriel MagnanTerri Lacourse, et Michelle Garneau
Publié:  3 novembre 2020 
https://doi.org/10.1177/0959683620961520

Volume: 31 issue: 1, page(s): 73-82
Publié en ligne: 3 novembre 2020

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Résumé (en anglais)
In this study, we compared new testate amoeba records produced by the conventional water-based wet-sieving method to testate amoeba data from previous palynological analyses of two Holocene peat profiles from British Columbia, Canada. We used 132 paired samples from the same peat cores to compare the composition of testate amoeba assemblages between the two methods and evaluate the potential of palynological testate amoeba records as quantitative paleohydrological proxies in peatlands. Our results suggest that the palynological treatments (acetolysis, 10% KOH and 150 µm sieving) substantially reduce test concentrations, diversity and richness in most pollen-slide samples. The smaller sieve size used in the palynological treatment (i.e. 150 µm) removed only a small fraction of the total tests, but could introduce a species-specific bias in assemblage composition. However, major shifts between wet and dry conditions, as shown by the water table depth (WTD) reconstructions using wet-sieved samples, were relatively well captured by the palynological datasets in most instances. The palynological assemblages with counts of >50 tests (n = 30) provided WTD estimates similar to those inferred from the wet-sieved samples as the most dominant hydrophilous and xerophilous taxa were relatively well represented in the pollen-slide samples in the two studied peat cores. Testate amoeba data from pollen slides can provide useful paleohydrological information particularly when combined with other paleoenvironmental proxies. Nonetheless, if the goal is to generate quantitative paleohydrological reconstructions, we recommend that testate amoeba analyses be conducted using the wet-sieving method, as testate amoeba concentrations, diversity and richness are typically much lower in samples prepared with palynological treatments.

Recherche collaborative dans le Nord canadien | Récit de recherche par Pénélope Germain Chartrand (Géographie UQAM) et Nia Perron (Université de Montréal) | publié dans Acfas Magazine

Faire de la recherche collaborative dans le Nord canadien

AUTEURES
Pénélope Germain Chartrand | Étudiante à la maîtrise – Géographie UQAM
Nia Perron | Étudiante – Université de Montréal

Rubrique : Récits de recherche

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Photographie de Pénélope Germain (Géographie UQAM) Chartrand et Nia Perron (Université de Montréal).

Publication cartographique| Géologie de surface de Palos Park Quadrangle, Cook County, Illinois | Auteurs: Olivier Caron (Géographie, UQAM) et B.B. Curry | 2019

AUTEURS
Olivier J. Caron | Professeur invitéGéographie UQAM
B.B. Curry |

TITRE
Surficial geology of Palos Park Quadrangle, Cook County, Illinois: Illinois State Geological

Illinois State Geological Survey, USGS-STATEMAP
contract report, 2 feuillets
Programme: STATEMAP
2019

Échelle: 1:24 000

Description (en anglais)
Two 35″ x 30″ map sheets; sheet 1 contains map, legends, and 1 figure; sheet 2 includes 2 cross sections and 3 figures, including bedrock surface topography map and sediment thickness map. A brief report is also included on the second map sheet.

Pour en savoir plus, cliquez ici ou sur l’image.

Référence recommandée pour citation:
Caron, O.J. and B.B. Curry, 2019, Surficial geology of Palos Park Quadrangle, Cook County, Illinois: Illinois State Geological Survey, USGS-STATEMAP contract report, 2 sheets, 1:24,000.

Article | Prominent role of volcanism in Common Era climate variability and human history | Dans le revue Dendrochronologia, décembre 2020

À lire aussi | Les volcans et le climat de Pierre-Étienne Caza
ACTUALITÉS UQAM | 3 novembre 2020

Journal Dendrochronologia

Volume 64, Décembre 2020 (125757)

Auteurs

Ulf Büntgen, Dominique Arseneault, Étienne Boucher (Géographie UQAM), Olga V. Churakova, (Sidorova), Fabio Gennaretti, Alan Crivellaro, Malcolm K. Hughes, Alexander V. Kirdyanov, Lara Klippel, Paul J. Krusic, Hans W. Linderholm, Fredrik C. Ljungqvist, Josef Ludescher, Michael McCormick, Vladimir S. Myglan, Kurt Nicolussi, Alma Piermattei, Clive Oppenheimer, Frederick Reinig, Michael Sigl, Eugene A.Vaganov, Jan Esper

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Résumé (en anglais)

Climate reconstructions for the Common Era are compromised by the paucity of annually-resolved and absolutely-dated proxy records prior to medieval times. Where reconstructions are based on combinations of different climate archive types (of varying spatiotemporal resolution, dating uncertainty, record length and predictive skill), it is challenging to estimate past amplitude ranges, disentangle the relative roles of natural and anthropogenic forcing, or probe deeper interrelationships between climate variability and human history. Here, we compile and analyse updated versions of all the existing summer temperature sensitive tree-ring width chronologies from the Northern Hemisphere that span the entire Common Era. We apply a novel ensemble approach to reconstruct extra-tropical summer temperatures from 1 to 2010 CE, and calculate uncertainties at continental to hemispheric scales. Peak warming in the 280s, 990s and 1020s, when volcanic forcing was low, was comparable to modern conditions until 2010 CE. The lowest June–August temperature anomaly in 536 not only marks the beginning of the coldest decade, but also defines the onset of the Late Antique Little Ice Age (LALIA). While prolonged warmth during Roman and medieval times roughly coincides with the tendency towards societal prosperity across much of the North Atlantic/European sector and East Asia, major episodes of volcanically-forced summer cooling often presaged widespread famines, plague outbreaks and political upheavals. Our study reveals a larger amplitude of spatially synchronized summer temperature variation during the first millennium of the Common Era than previously recognised.

Faculté des sciences humaines de l’UQAM

Incontournable du domaine des sciences humaines et sociales, la Faculté des sciences humaines de l’UQAM propose des programmes d’études solidement ancrés tant sur le plan théorique qu’empirique. Elle offre un milieu universitaire dynamique, stimulant et inclusif propice à la réalisation de recherches novatrices, à la liberté intellectuelle et à la démocratisation des savoirs.

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Coordonnées

Département de géographie
Local A-4030
1255, St-Denis
Montréal (Québec) H2X 3R9