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Une première campagne annuelle de financement au profit du Naturaliste canadien

Denise Tousignant and Aurore Becker

Avocat et biologiste, Me Jean-François Girard

Pascal Bigras and Pierre M. Valiquette

Services et risques écosystémiques de la nature urbaine : un indice intégré appliqué au campus de l’UQTR

Jacob Isabelle, Thierry Laurent-St-Pierre, Laurent J. Lamarque, Alexandre Roy, Geneviève Bergeron, Pierre-André Bordeleau, Matteo Giacomazzo, Charles A. Martin, Jessika Malko, Sylvie Miaux, Asseye Neglo, Mathieu Point, Sébastien Rojo and Vincent Maire
Urban nature provides multiple benefits, both ecological and sociological, with the latter including supporting physical and mental health. Therefore, many municipal initiatives worldwide are focusing on identifying and maintaining these ecosystem services. However, this comes at a time when urban nature risks being severely affected by climate change. Despite this, few studies have examined the factors governing the combination of services provided by urban nature and the risks to which it is exposed. The present study aimed to quantify 6 services (soil permeability, surface temperature regulation, carbon sequestration, biodiversity, human-ecosystem interactions, and edible wild mushroom harvesting) and 5 risks (tree mortality, disease or decline, snow deposits, vulnerability to extreme weather, and invasive alien species) across 12 ecosystems on the campus of the Université du Québec à Trois-Rivières (Canada). The results show that services and risks vary according to ecosystem type. Young white pine stands and mature mixed stands provide the highest levels of services, while jack pine stands and younger mixed stands are most exposed to risks. Older ecosystems located farther from anthropogenic disturbances, deliver a greater number of services without increasing their average level of risk. This study provides a methodology that can be easily adjusted to evaluate the spatial dynamics of services delivered and risks faced by urban nature, thereby offering actionable recommendations for managers.

État des connaissances sur la richesse de l’odonatofaune de l’Abitibi-Témiscamingue : une population insoupçonnée de l’aeschne cintrée (Odonata : Aeshna constricta) au lac Abitibi, Québec

Michel Savard
The retrieval of a collection of odonate specimens obtained by botanist Jean Gagnon on Île Nepawa in Lac Abitibi (northwestern Abitibi-Témiscamingue, Québec, Canada) between 1997 and 1998, revealed the presence of a previously undetected population of the lance-tipped darner (Odonata: Aeshna constricta). The first insights into the rich odonatofauna of this region were provided by Brother Adrien Robert (early 1940s), carabidologist André Larochelle (1978), and odonatologist Jean-Guy Pilon (early 1990s). More recently, citizen scientists have helped fill a major knowledge gap by adding 33 species to the initial regional list drawn up in 2009, bringing the total number of species known to occur in the area to 95, including 11 that are identified as being in a precarious situation in the province.

Une riche odonatofaune au parc national du Mont-Saint-Bruno, Québec

Alain Mochon and Michel Savard
Odonate surveys conducted between 2012 and 2024 in the Parc national du Mont-Saint-Bruno (Montérégie, Québec, Canada) identified 64 species. Community composition varied significantly depending on the presence of fish, which is often linked to water depth. Sixteen species were found only at the shallow Lac des Atocas, including the amber-winged spreadwing (Lestes eurinus), azure bluet (Enallagma aspersum), and spatterdock darner (Rhionaeschna mutata), which are all associated with fishless lakes. By contrast, 13 species were found only at the deeper Lac du Moulin, including the skimming bluet (E. geminatum) and slender bluet (E. traviatum), both indicators of lakes with fish. From a conservation perspective, the park hosts 14 species considered at risk, 11 of which are found at Lac des Atocas, giving this site exceptional ecological value. Among these, 4 species are classified as “at very high risk of extinction or extirpation” (S1): the slender bluet, arrowhead spiketail (Zoraena obliqua), and ruby meadowhawk (Sympetrum rubicundulum), along with the only known population of the spatterdock darner in Québec. Additionally, among the 3 species whose distribution range has recently expanded into the province, and which have been recorded in the park, the blue dasher (Pachydiplax longipennis) has become well established.

Protection des érablières acéricoles contre la livrée des forêts au Québec : évaluation d’un premier programme de protection

Richard Berthiaume and Chantale Francoeur
The forest tent caterpillar moth (Malacosoma disstria Hübner) is a native species widely distributed throughout Canada and the United States. Its larvae are considered the most important defoliator of hardwood forests in Canada, and outbreaks can cover extensive areas. This species can cause significant infestations in maple forests, and considering the investment required to establish maple syrup production facilities, yield losses due to insect defoliation are a serious challenge. In fall 2024, inventories of overwintering forest tent caterpillar moth egg masses in the Témiscouata region (Québec, Canada) identified several areas where populations were high enough for significant defoliation to be expected the following spring. After obtaining a financial commitment from local landowners, SOPFIM (Société de protection des forêts contre les insectes et maladies) initiated its first insect control program in a hardwood forest context, namely in maple stands managed for maple syrup production. This aerial protection program involved the application of a biological insecticide (Bacillus thuringiensis var. kurstaki) over 3,606 ha of maple forest. Results show that treated stands were little affected by larvae of the forest tent caterpillar moth. Defoliation rates ranged from 2% to 13% in protected maple stands, and more than 75% of these stands showed less than 10% defoliation. This article outlines the main points, challenges and results of this operation, the first of its kind in Québec.

Stratégie de conservation du hibou des marais (Asio flammeus) dans le sud du Québec : état des connaissances et recommandations

Jean-François Therrien, Catherine Dion, Francis Bordeleau, Pascal Côté and Jérôme Lemaître
The short-eared owl (Asio flammeus) has undergone a marked decline in North America, and its situation in Québec (Canada) is no exception. One of the major issues facing this species is the accidental destruction of nests in agricultural landscapes. This literature review explores conservation strategies used throughout the species’ range to maximize nesting success. Fifty-four documents were consulted, but no empirical studies were identified that measured the efficiency of different management strategies. This review compiles and makes recommendations on the conservation measures that could be considered for the short-eared owl in the province. Based on a comparison of studies on other grassland species, a strategy that uses various short (e.g. emergency intervention), medium (e.g. changes in agricultural practices), and long-term (e.g. awareness raising, land acquisition and stewardship) approaches is proposed. This strategy should help increase recruitment of the species in southern Québec.

Influence des modifications de l’occupation du sol dans la plaine inondable du lac Saint-Pierre sur l’habitat et le nombre potentiel de couples nicheurs de cinq espèces d’oiseaux

Benoît Jobin and Charles A. Martin
Land cover in the Lac Saint-Pierre floodplain (Québec, Canada) underwent marked changes between 1950 and 2016. The present study estimated the amount of suitable habitat in different land cover types available to support local bird populations. This allowed changes in the potential number of breeding pairs of five indicator species to be determined. The area of land under perennial crops considered large enough for breeding grassland birds (> 40 ha) was 33-fold lower in 2016 than in 1950. This represents a potential loss of 19,608 pairs of bobolink. Over the same period, the potential number of pairs of eastern wood-pewee is estimated to have doubled in suitable tracts of forest (> 100 ha, from 191 to 383 pairs) and swamp (> 100 ha, from 1,668 to 3,649 pairs). In appropriate-sized oldfield sites (> 5 ha), the number of pairs of eastern kingbird is estimated to have increased from 189 to 225. Suitable marshes (> 5 ha) are estimated to have hosted 13,464 pairs of Virginia rail in 2016, compared with 10,389 pairs in 1950, while in suitable-sized wet meadows (> 5 ha), Wilson’s snipe numbers are estimated to have fallen from 296 to 201 pairs. Population trends analyzed using eBird data collected during the period from 1983 to 2016 show similar changes for the five indicator species. Restoring habitat connected to residual habitat patches would increase the availability of suitable sites conducive to maintaining local breeding bird populations in the Lac Saint-Pierre floodplain.

Estuaire laurentin : limite amont de la section macrotidale

Benoît Gauthier and Jacques Labrecque
In recent years, there has been a marked increase in shoreline conservation efforts in Neuville and Saint-Augustin-de-Desmaures, two municipalities located on the north shore of the upper St. Lawrence Estuary (Québec, Canada). However, the most recent classification of this part of the estuary dates back more than 25 years and has been little publicized, used, or discussed. The present study reviews the upstream limit of the macrotidal freshwater section of the St. Lawrence Estuary and reports on its various sections and their boundaries. The range limit of 27 previously studied plant species was reassessed. For 18 of these, their distribution ends between Neuville and Cap-Rouge and can be explained by the important mean tidal range in this portion of the estuary of between 3.6 m and 3.7 m. As the sector in question is now within protected areas in Neuville and Saint-Augustin-de-Desmaures, in the future, it will be able to serve as a reference and example of tidal freshwater marshes and wetlands in the upper St. Lawrence.

Portrait de la flore forestière de Montréal et de ses îles environnantes

Alexandre Bergeron, Claude Lavoie and Stéphanie Pellerin
This study provides an overview of the forest flora of the Hochelaga Archipelago, also known as the Montréal Islands (Québec, Canada). Between 2009 and 2017, surveys conducted in 84 wooded patches documented 642 vascular plant taxa (67% of which were native), representing roughly one fifth of the vascular flora of the province. In contrast to those at-risk species encountered only sporadically, the black maple (Acer nigrum), which is listed as vulnerable in Québec, is frequent in Montréal and gives a distinctive appearance to several of its woodlands. Approximately 20 of the exotic taxa detected during the study are not yet listed as naturalized in the province. Older woodlands were distinguished by a diverse native flora dominated notably by Acer saccharum, Carya cordiformis, Cornus alternifolia, and Solidago flexicaulis. In contrast, small urban woodlands, often established through natural reforestation of former agricultural land, were typically species-poor and dominated by pioneer species, lianas, and invasive exotics such as Acer negundo, Anthriscus sylvestris, and Rhamnus cathartica. The widespread presence of calcareous substrates supports calcicolous species, whereas rare sandstone-based sites, particularly on Île Perrot, enhance regional diversity by hosting a distinct acidophilous flora. The dataset generated by this study provides a solid foundation for rigorous ecological monitoring and, more broadly, for guiding conservation actions focused on habitat representativeness and the maintenance of regional floristic diversity.

Principales maladies des arbres au Québec – Guide de terrain, 4e édition

Bruno Boulet