Collaborations

Vrn-A1 (VERNALIZATION A1) and Fr-A2 (FROST RESISTANCE A2) have been associated with variation in winter survival of wheat (Triticum aestivum L.). The beneficial alleles of Vrn-A1 and Fr-A2 are largely fixed in Canadian winter wheat germplasm, rendering the associated molecular markers ineffective for marker-assisted selection (MAS) in elite populations. The objectives were to (i) identify quantitative trait loci (QTLs) for winter survival in eastern Canada and determine their usefulness for MAS and (ii) explore the underlying genetic mechanisms of superior winter survival in the region. A subpopulation (n = 321) of the Canadian Winter Wheat Diversity Panel, consisting of genotypes that were fixed for the beneficial alleles of vrn-A1 and Fr-A2, was previously evaluated for winter survival in three eastern Canadian environments (Elora 2016–2017, CÉROM 2017–2018, and Elora 2017–2018). Genome-wide association mapping identified three significant QTLs for winter survival, a previously identified QTL on chromosome 5A, and two novel QTLs on chromosomes 5D and 7B. These QTLs were of low-to-moderate marker utility (0.1473–0.4796) and conferred a 0.7%–1.8% increase in mean winter survival. In silico analyses revealed that an array of biotic and abiotic stress responses are implicated in winter survival in eastern Canada, which challenges the notion that lethal temperature is the primary cause of winterkill in some regions. As significant winterkill events are sporadic in the region, it may be beneficial to identify individual components of winter survival that can be examined in artificial environments.

Riparian zones are biodiversity hotspots that play a fundamental role in the functioning of aquatic habitats. In logged boreal forests, the common practice is to maintain a fixed width of vegetation along rivers and lakes, without any other protective measures, and often neglecting small streams and ponds. To preserve the ecosystem services provided by riparian zones, management practices need to better integrate the natural variability in vegetation attributes along the lateral connectivity gradient in different hydrogeomorphic contexts. This study compared patterns of plant diversity and composition at the margin of five aquatic habitats, in four ecoregions of the Canadian boreal forest. Our results showed that species richness, the mean values for wetness requirements and the magnitude of changes in taxa composition decreased consistently along the lateral gradient, but that this effect was mediated by hydrogeomorphic settings. Specifically, we highlighted significant interactions between distance or elevation difference from the waterline and ecoregions or aquatic habitats, showing that the structure and extent of riparian vegetation along the local topographic gradient are shaped differently by the regional (climate) and hydrogeomorphic (flow regime) contexts. In addition, model ranking revealed that elevation difference best predicted changes in riparian vegetation structure and composition than distance from the waterline. For delineating functional forested strips, our results revealed thus the importance of taking into account both elevation and distance criteria but also of modulating the spatial extent of these strips according to the regional climatic context and the types of aquatic habitat.

Peatlands store significant amounts of carbon, which is released as greenhouse gases when peatlands are degraded. Restoration and rewetting can help prevent these emissions, while continuous monitoring is critical for evaluating their success. Using satellite-derived observations of essential climate variables, we conducted the first large-scale assessment of how peatland restoration influences land surface temperature (LST), albedo, and vegetation across 72 sites in North America and Europe. Our findings indicated that before restoration, degraded peatlands had a commonly lower daytime LST and albedo but higher nighttime LST, leaf area index (LAI), and fraction of absorbed photosynthetically active radiation (FPAR) compared to intact sites. The largest restoration-induced absolute values of monthly changes reached +3.18 °C (daytime LST), −1.22 °C (nighttime LST), −2.54 (LAI), −0.29 (FPAR), and −0.16 (albedo). While restored peatlands tended to align more closely with intact sites a decade after restoration began, the probability of this alignment varied depending on the climate variables. Restored peatlands became more similar than different to intact sites in nighttime LST and albedo after a post-restoration decade, with high similarity projected within five decades. Peatland restoration modifies local and regional climate and should be included in future climate projections.

Abstract

Agroecology is increasingly used to study the evolution of farms and food systems, in which livestock plays a significant part. While large-scale specialized livestock farms are sometimes criticized for their contribution to climate change and nutrient cycle disruption, interest in alternative practices such as raising multiple species, integrating crop and livestock, relying on pasture, and marketing through short supply chains is growing. Through a narrative review, we aimed to determine if the scientific literature allowed for an evaluation of the agroecological contribution of alternative livestock farming practices. Taking advantage of ruminants’ capacity to digest human-inedible plant material such as hay and pasture on marginal land reduces the competition between livestock feed and human food for arable land. Taking advantage of monogastric animals’ capacity to digest food waste or byproducts limits the need for grain feed. Pasturing spreads manure directly on the field and allows for the expression of natural animal behavior. Animals raised on alternative livestock farms, however, grow slower and live longer than those raised on large specialized farms. This causes them to consume more feed and to emit more greenhouse gases per unit of meat produced. Direct or short supply chain marketing fosters geographical and relational proximity, but alternative livestock farms’ contribution to the social equity and responsibility principles of agroecology are not well documented. Policy aimed at promoting practices currently in place on alternative livestock farms is compatible with agroecology but has to be envisioned in parallel with a reduction in animal consumption in order to balance nutrient and carbon cycles.

Pathogenic bacteria use Type 3 effector proteins to manipulate host defenses and alter metabolism to favor their survival and spread. The non-model bacterial pathogen Xanthomonas phaseoli pv. manihotis (Xpm) causes devastating disease in cassava. The molecular role of Type 3 effector proteins from Xpm in causing disease is largely unknown. Here, we report that the XopAE effector from Xpm suppresses plant defense responses. Our results show that XopAE is a suppressor of basal defenses such as callose deposition and the production of reactive oxygen species. XopAE targets a small heat shock protein (Mep23-1 cochaperone) in cassava and its homolog Atp23-1 in Arabidopsis. XopAE localizes to the nucleus and in scattered points throughout the cell border, whereas Mep23-1 shows a nucleocytoplasmic localization. Upon interaction, XopAE hijacks Mep23-1 to the scattered points throughout the cell border, and they also interact in the nucleus. Our results indicate that the interaction between XopAE and Mep23-1 is essential for suppressing basal plant defense. This study is one of the first to address the molecular mechanisms deployed by Xpm to cause disease in cassava, a non-model crop plant.

The novel HIV-1 drugs GS-CA1 and the recently approved lenacapavir (GS-6207) target the viral structural protein capsid (CA). However, their multiple mechanisms of action have not been fully characterized. Here, we investigated the effects of GS-CA1 on the early stages of HIV-1 infection, specifically the steps involving the nuclear envelope, in comparison to the antiviral cytokine IFN-β. Mass spectrometry data indicated that nuclear envelope proteins were only modestly affected by either GS-CA1 treatment or HIV-1 infection, but combining the two had a more significant impact, altering the levels of many proteins including proteasomal components. GS-CA1 induced a small but clear accumulation of HIV-1 capsid cores at nuclear pores, as seen by microscopy, whereas IFN-β caused a strong accumulation of HIV-1 cores at the nuclear envelope but not specifically at nuclear pores. These observations are consistent with GS-CA1 inhibiting the nuclear translocation of HIV-1 capsid cores through nuclear pores.

Abstract

Aims. Perennial forages in rotation with annual crops can improve agricultural resilience by increasing soil organic carbon. However, how nitrogen (N) sources interact with rotation diversity to influence soil nitrous oxide (N2O) emissions is not well understood. Methods During three snow-free seasons, N2O emissions, crop yields, and ancillary variables were measured at three experimental sites with contrasting soil textures (silty clay and sandy loam) in eastern Canada. Using a split-plot design, we compared a corn (Zea mays L.)-soybean (Glycine max [L.] Merr.)-corn rotation and a mixed perennial grass sward receiving N via: i) mineral fertilizer (MIN), ii) liquid dairy manure (LDM), and iii) inclusion of alfalfa (Medicago sativa L.) to the perennial forages with no additional N (LEG). Results When summed across sites over all three years, cumulative N2O emissions were greater for LDM than MIN in annual crops (8.75 ± 1.63 and 5.15 ± 0.96 kg N2O-N ha–1, respectively), but not in perennial grasses (2.95 ± 0.55 and 3.76 ± 0.70 kg N2O-N ha–1, respectively). When comparing N sources within each crop type over the three years, MIN generated greater yields than LDM in annual and perennial crops, but lower yield-scaled N2O emissions than LDM in annual crops only. During forages post-seeding years, area- and yield-scaled N2O emissions induced by LDM and LEG were lower than MIN. Conclusion Our results suggest that for a cool humid climate using LDM or LEG in perennial forages and MIN on annual crops can reduce overall N2O emissions, while generating similar or lower yield-scaled emissions.

Existence of potent in vitro regeneration system is a prerequisite for efficient genetic transformation and functional genomics of crop plants. In this study, two contrasting cultivars differencing in their in vitro regeneration efficiency were identified. Tissue culture friendly cultivar Golden Promise (GP) and tissue culture resistant DWRB91(D91) were selected as contrasting cultivars to investigate the molecular basis of regeneration efficiency through multiomics analysis. Transcriptomics analysis revealed 1487 differentially expressed genes (DEGs), in which 795 DEGs were upregulated and 692 DEGs were downregulated in the GP-D91 transcriptome. Genes encoding proteins localized in chloroplast and involved in ROS generation were upregulated in the embryogenic calli of GP. Moreover, proteome analysis by LC-MS/MS revealed 3062 protein groups and 16,989 peptide groups, out of these 1586 protein groups were differentially expressed proteins (DEPs). Eventually, GC-MS based metabolomics analysis revealed the higher activity of plastids and alterations in key metabolic processes such as sugar metabolism, fatty acid biosynthesis, and secondary metabolism. TEM analysis also revealed differential plastid development. Higher accumulation of sugars, amino acids and metabolites corresponding to lignin biosynthesis were observed in GP as compared to D91. A comprehensive examination of gene expression, protein profiling and metabolite patterns unveiled a significant increase in the genes encompassing various functions, such as ion homeostasis, chlorophyll metabolic process, ROS regulation, and the secondary metabolic pathway.

Little is known regarding the genes, compounds and physiological alternations that take place upon infection of black knot disease. This research aimed to unravel the genetic mechanism responsible for the resistance of Japanese plum (Prunus salicina L.) trees against black knot (Apiosporina morbosa Schwein.) using a Genome-Wide Association Study. Genotyping by Sequencing (GBS) was combined with a phenotyping system to analyze 200 genotypes of mixed origin. Population stratification identified four subpopulations, and the Fixed and Random Model Circulating Probability Unification (FarmCPU) algorithm was used for this analysis. Nineteen single nucleotide polymorphisms (SNPs) significantly associated with black knot disease resistance were discovered across five chromosomes. Linkage disequilibrium analysis identified 55 genes near these SNPs, with eight genes related to plant defense, immunity, and biotic stress response. One SNP mutation was found in the 5′ untranslated region of a gene regulating the first enzyme in phenylpropanoid biosynthesis. The results provide valuable insights into the genetic mechanisms behind BLACK KNOT disease resistance in Japanese plum and identifies potential markers for use in molecular breeding.

Earthen construction is considered as an ecological construction offering many advantages in terms of adaptation to climate change and reduction of CO2 emissions from buildings. The choice of a building material implies a suitable construction technique and an appropriate architecture according to the environmental conditions. The objective of this work is to study the thermal performance of two cob materials, a material traditionally composed of clay, water and wheat fibres through numerical simulations. Two walls designed with clay and four other walls designed with cob (with 3 or 6% fibres) are studied in view of their application in modern wood-frame structures. To this end, the one-dimensional transient heat equation through single-layer walls of 15 cm and 25 cm thickness is solved using the finite element discretization scheme. The thermal properties used for the numerical simulation are experimental data obtained from samples fabricated in a laboratory. The simulations are performed using climate data from Montreal (Canada), Reno (USA) and Djibouti (Africa). The results of the wall simulation are evaluated according to the influence of local meteorological conditions on the interior surface temperature for each type of wall.

Plasmodiophora brassicae is an obligate biotroph that causes clubroot disease in cruciferous plants, including canola and Arabidopsis. In contrast to most known bacterial, oomycete and fungal pathogens that colonize at the host apoplastic space, the protist P. brassicae establishes an intracellular colonization within various types of root cells and secretes a plethora of effector proteins to distinct cellular compartments favourable for survival and growth of the pathogen during pathogenesis. Identification and functional characterization of P. brassicae effectors has been hampered by the limited understanding of this unique pathosystem. Here, we report a P. brassicae effector, PbPE23, containing a Ser/Thr kinase domain, that induces necrosis after heterologous expression by leaf infiltration in both host and non-host plants. While PbPE23 is an active kinase, the kinase activity itself is not required for triggering the necrosis in plants. PbPE23 shows a nucleocytoplasmic localization in Nicotiana benthamiana and its N-terminal 25TPdPAQKQ32 sequence, resembling the contiguous hydrophilic TPAP motif and Q-rich region in many Nep1-like proteins (NLPs) from plant-associated microbes, is required for the induction of necrosis. Further, transcript profiling of PbPE23 reveals its high expression at the transition stages from primary to secondary infection, suggesting its potential involvement in the development of clubroot disease.

The ability of organic cropping systems to sustain soil health may vary with management intensity. Little research has examined the impact of varying management practices on soil health within intensive organic field crop production systems. A field survey was conducted in the fall of 2019, 2020, and 2021 on 10 certified organic farms in Québec, Canada. Their cropping systems comprised an intensive three-year maize (Zea mays L.)-soybean (Glycine max [L.] Merr.) – small grain (i.e., winter or spring cereals) rotation. On each farm, soil health was measured on the three rotated crop fields in the fall of 2019, 2020, and 2021 (n = 90). The relationships between soil health indicators and indices of management practices were assessed. The 3-year Crop Diversity Index (CDI) ranged from 2 to 16 across the sampled fields, with the highest values observed where cover crops were used annually, and winter cereals were included in the rotation. Soil physical health indicators were positively influenced by higher CDI values. In contrast, higher Soil Tillage Intensity Ratings for tillage (STIRtillage) had a negative effect on soil organic carbon (SOC) concentrations. Soil health indicators did not vary among crop phases, except for water-stable aggregates (WSA) which was greater in small grain fields (43.5 %) than in soybean fields (33.9 %). The results from this study demonstrated that soil health was positively influenced by increased crop diversity and reduced tillage intensity. These findings will help organic growers choose and refine best management practices to maintain soil health when cropping intensively.

Cranberry fruit rot (CFR) has been a major challenge in cranberry production affecting fruit quality, particularly in Massachusetts and New Jersey. It is known to be a disease complex associated with several diverse fungi. This study provides the first comprehensive assessment of CFR fungal population dynamics across wild, organic, and conventional cranberry production systems in southeastern Massachusetts. By employing multiplex PCR, a high-throughput molecular method for the simultaneous detection of multiple fungi, we investigated the prevalence and diversity of 11 most commonly associated fruit rot fungi in 2021 and 2022, in 32 (23 conventional, 4 organic and 5 wild) and 50 (40 conventional, 4 organic and 6 wild) cranberry bogs respectively. Significant differences in the detection of CFR fungi were observed across these ecosystems. Conventional fields showed varied fruit rot incidence, ranging from 2-42% in 2021 and 1-48% in 2022. Species richness analysis indicated that on average, wild bogs were more species-rich and diverse, with 5.5 CFR fungi detected per sample compared to 4 CFR fungi in both conventional and organic bogs. Organic bogs exhibited a significant decline in species richness from 6 fungi in 2021 to 2 fungi in 2022. Except for Phomopsis vaccinii, which was not observed in organic bogs in either year, all 11 CFR fungi were detected across the ecosystems: some in both growing seasons and some in only one. Key CFR fungi such as Coleophoma empetri, Allantophomopsis cytisporea and Botryosphaeria vaccinii were consistently found across all ecosystems and both years of study. Analysis of year-to-year variation indicates that wild bogs exhibited higher fungal carryover, with 8 out of the 11 CFR fungi persisting from one year to the next, compared to 6 fungi in conventional bogs and 4 fungi in organic bogs. Notably, C. empetri, B. vaccinii, and A. cytisporea demonstrated year-to-year persistence across all three bog types. Among these, C. empetri exhibited the greatest persistence across all three ecosystems, with 96%, 100% and 60% of the conventional, organic and wild bogs maintaining its presence across both years. Colletotrichum spp. persisted in 43% of the conventional bogs but detected only in one of the two years studied in organic and wild bogs resulting in 0% persistence from one year to the next. The study also noted a general decrease in Botryosphaeria vaccinii and an increase in Physalospora vaccinii across all bog types. This research highlights the varying persistence and complex dynamics of CFR fungi across different cranberry ecosystems, as well as the potential impact of management practices on fungal populations.

Pathogenic bacteria use Type 3 effector proteins to manipulate host defenses and alter metabolism to favor their survival and spread. The non-model bacterial pathogen Xanthomonas phaseoli pv. manihotis (Xpm) causes devastating disease in cassava. The molecular role of Type 3 effector proteins from Xpm in causing disease is largely unknown. Here, we report that the XopAE effector from Xpm suppresses plant defense responses. Our results show that XopAE is a suppressor of basal defenses such as callose deposition and the production of reactive oxygen species. XopAE targets a small heat shock protein (Mep23-1 cochaperone) in cassava and its homolog Atp23-1 in Arabidopsis. XopAE localizes to the nucleus and in scattered points throughout the cell border, whereas Mep23-1 shows a nucleocytoplasmic localization. Upon interaction, XopAE hijacks Mep23-1 to the scattered points throughout the cell border, and they also interact in the nucleus. Our results indicate that the interaction between XopAE and Mep23-1 is essential for suppressing basal plant defense. This study is one of the first to address the molecular mechanisms deployed by Xpm to cause disease in cassava, a non-model crop plant.

It has long been suggested that soil compaction indices should be monitored as part of a routine soil management program. Moreover, in addition to properties related to storage of gases and fluid within a bulk volume (i.e., bulk density [BD] and air porosity [θa]), some authors have suggested that properties linked to fluid and gas exchanges such as gas diffusion and hydraulic conductivity should be used to assess the physical health of soils. Given the risk of severe compaction due to the increasing size of farm equipment and the lack of long rotation in cash crop production, data on soil storage and exchange properties need to be collected. The objective of this study was to assess the physical soil health of the top 30 cm of 18 southern Quebec corn fields using a set of indicators. The data were also used to determine crop response to nitrogen fertilization. The results showed that over 93% of the corn fields had a relative gas diffusivity (Ds/Do) below the 0.03 threshold at both 15- and 30-cm depth, suggesting substantial crop growth limitations. They also showed that around 40% of the soils had subsurface drainage problems linked to a low saturated hydraulic conductivity (49% at 15 cm and 47% at 30 cm lower than 0.001 cm s−1). The levels of relative gas diffusivity were low, not only limiting crop growth but also likely reducing nitrogen efficiency through increasing risk of denitrification. Moreover, the results suggest that in some fields, high yields can be achieved with as little as 60 and up to 215 kg of nitrogen per hectare, and that slow-draining soils will have a very poor response to N fertilization, leading to lower net revenues and nitrogen losses. Overall, the findings suggest that appropriate soil conservation and water management practices based on soil physical health criteria like relative gas diffusivity and hydraulic conductivity must be implemented to maintain or improve soil productivity and health in the face of climate change.

The study of microbial communities of the plant phyllosphere in remote locations using DNA-based approaches is limited by the challenges associated with their preservation in the field and during transportation. Freezing is a common DNA preservation strategy, but it may be unsuitable for leaf samples, or inaccessible in some locations. Other methods such as desiccation, ethanol or commercial preservatives are potential alternative DNA preservation methods for ambient temperature storage. In this study, we assessed the efficacy of desiccation (with silica gel packs), and of three preservation solutions (95% ethanol, RNAlater, LifeGuard) for the preservation of epiphytic phyllosphere communities of Populus tremuloides and Picea glauca at ambient indoor temperature (21 °C) for up to three weeks. We assessed effects on DNA concentration and quality and used metabarcoding to detect changes in bacterial and fungal communities between treatments over time. A secondary study was conducted on leaves of Populus grandidentata to further test the ability of the desiccation treatment to resolve differences between sampling sites. Silica gel packs were identified as effective ambient temperature preservative of phyllosphere bacterial and fungal communities. There were some changes in the communities compared to immediate extraction due to this treatment, but these changes did not affect the ability to distinguish tree species and sampling locations. Overall, our study supports the use of silica gel pack short term preservation at ambient temperature for phyllosphere samples intended for DNA-based microbial community analyses.

The development of building envelope systems with low carbon footprint materials and improved hygrothermal properties is still in progress. For geosourced materials, one of the main objectives is to achieve optimal hygrothermal efficiency. Cob, a material made of clay, plant fibres, and water, stands out for its low carbon footprint and ease of application on timber-framed building structures. The main goal of this study is to assess the hygrothermal performance of eight heavy cob wall systems in eight cities in African, European, and American climates. An extensive laboratory characterization is carried out to measure the hygrothermal properties of each material. The thermal conductivity obtained after the measurements is 0.75 W/m.K and 0.87 W/m.K for red and beige clay samples, respectively, 0.52 W/m.K for the cob with 3 % fibres, and 0.2 W/m.K for the cob with 6 % fibres samples, and the porosity rates are 21, 20, 37, and 45 for the clay and cob samples, respectively. The hygrothermal simulation showed that the interior temperature of the walls made of cob with 6 % fibres and a thickness of 25 cm remained stable, regardless of external climate variations. Applying beige clay plasters to the exterior and interior surfaces of cob walls or timber structures improved thermal performance in terms of heating or cooling energy demand but also increased the walls’ moisture absorption. This increased moisture enhances the risk of mold growth within the wall structure. When used as infill materials in timber structures, the simulated composite systems generally exhibit good hygrothermal performance. However, in cold climate zones with high precipitation and heavily clouded skies, the walls may be exposed to risks of mold development. To prevent mold in these walls, install a rain screen or an air/vapor barrier membrane between the plaster and cob. This helps manage moisture and ensures proper wall drying.

Background To align with climate goals, greenhouse gas (GHG) emissions from agriculture must be reduced significantly. Cultivated peatlands are an important source of such emissions. One proposed measure is to convert arable fields on peatlands to grassland, as the Intergovernmental Panel on Climate Change (IPCC) default emission factors (EF) for organic soils are lower from grasslands. Yet, these EFs are based on limited data with high variability and comparisons are difficult due to differences in climate, soil properties, and crop management. This systematic review synthesizes available evidence on the effects of converting cropland to grassland on GHG emissions from peat and organic-rich soils in temperate and boreal climates using data from comparable fields. Methods Literature was searched using five bibliographic databases, four archives or search engines for grey literature, and Google Scholar. Eligibility screening was performed in two steps on (1) title/abstract, with consistency among reviewers assessed by double-screening 896 articles, and (2) full text screened by two reviewers. Eligible articles were critically appraised independently by at least two reviewers. Disagreements were reconciled through discussions. Data and key metadata are presented in narrative synthesis tables, including risk of bias assessments. Meta-analyses comparing grasslands with croplands were performed using raw mean difference as the effect size. Review findings A total of 10,352 unique articles were retrieved through the literature searches, and 18 articles including 29 studies were considered relevant to answer the review question. After critical appraisal, it was concluded that two articles reported the same data, so a total of 28 studies, comprising 34 comparisons were included in the systematic review. Most of the included studies were conducted in the Nordic countries and Germany, one in Belarus and one in Canada. A meta-analysis was conducted on 24 studies pairing cropland and grassland sites. No significant differences in carbon dioxide (CO2) or methane (CH4) emissions were found. Emissions of nitrous oxide (N2O) from grasslands were found to be 7.55 kg ha−1 y−1 lower than from cropland, however the sensitivity analysis showed that the difference was not robust, making it uncertain whether conversion from cropland to grassland has a significant effect on N2O emissions from organic soils. The difference was also smaller when root crops were excluded from the comparator group. Further, net ecosystem exchange (NEE) of CO2 and net ecosystem carbon balance (NECB) were higher in grasslands compared to croplands in cases where the grasslands were fertilized. Conclusions This systematic review underlines the ambiguity of GHG emissions from peatlands and their relationship to land use. Our understanding of the factors influencing emissions from these soils remains incomplete, and the specific impact of land use on emissions is still unclear. CO2 emissions represent a major part of the climate impact of cultivated peat soils, so the data analyzed allow to draw the conclusion that a conversion from arable to grassland would not lead to large benefits in terms of GHG emissions, especially if root crops are not part of the arable crop rotation, or the grassland is fertilized. 

Land use change threatens global biodiversity and compromises ecosystem functions, including pollination and food production. Reduced taxonomic α-diversity is often reported under land use change, yet the impacts could be different at larger spatial scales (i.e., γ-diversity), either due to reduced β-diversity amplifying diversity loss or increased β-diversity dampening diversity loss. Additionally, studies often focus on taxonomic diversity, while other important biodiversity components, including phylogenetic diversity, can exhibit differential responses. Here, we evaluated how agricultural and urban land use alters the taxonomic and phylogenetic α-, β-, and γ-diversity of an important pollinator taxon—bees. Using a multicontinental dataset of 3117 bee assemblages from 157 studies, we found that taxonomic α-diversity was reduced by 16%–18% in both agricultural and urban habitats relative to natural habitats. Phylogenetic α-diversity was decreased by 11%–12% in agricultural and urban habitats. Compared with natural habitats, taxonomic and phylogenetic β-diversity increased by 11% and 6% in urban habitats, respectively, but exhibited no systematic change in agricultural habitats. We detected a 22% decline in taxonomic γ-diversity and a 17% decline in phylogenetic γ-diversity in agricultural habitats, but γ-diversity of urban habitats was not significantly different from natural habitats. These findings highlight the threat of agricultural expansions to large-scale bee diversity due to systematic γ-diversity decline. In addition, while both urbanization and agriculture lead to consistent declines in α-diversity, their impacts on β- or γ-diversity vary, highlighting the need to study the effects of land use change at multiple scales.

Abstract

Questions: How does the type of swamp, that is, riverine vs palustrine, shapeunderstorey and overstorey plant communities? Beyond swamp type, how dospatial, topographic, soil and landscape characteristics determine the taxonomic andfunctional structure of swamp communities?Location: Southern Québec, Canada.Methods: We sampled riverine and palustrine swamp plant communities in twowatersheds within two ecoregions with contrasting land use. At the site scale (n = 56),we analyzed differences between riverine and palustrine swamps in plant richnessand cover, species composition, and mean and dispersion values for ecological andmorphological traits. At the plot scale (n = 213), we assessed the relative influence ofa set of environmental parameters on species richness and cover, as well as on traitvalues using mixed models and on species composition using redundancy analysis.Results: Species composition and the mean value of traits varied significantly betweenthe two types of swamps. While riverine swamps hosted more non-native speciesand were composed of more mesophilic species, shorter in height and with dominantresource acquisition strategies, palustrine swamps sheltered more non-vascular taxaand tall hygrophilous vascular species with more conservative resource strategies. Thesurrounding landscape and local microtopography within swamps had a significanteffect on plant community structure. Species diversity and trait dispersion increasedfrom agricultural-dominated to forest-dominated landscapes, and from homogeneousto heterogeneous substrates.Conclusions: Habitats provided by riverine and palustrine swamps are complementaryfor wetland biodiversity. Our results underline the need to develop conservationplans to protect a wide variety of freshwater swamp types; for example, managementactions that maintain or promote heterogeneous topographic forms at the site scale,and continuity of forest cover at the landscape scale.

Cyclamen mite is a pest of strawberry that is difficult to control due to its small size and preference for inhabiting concealed spaces in new plant growth. Steam treatment of transplants effectively reduces some strawberry pathogens and may be a valuable tool against cyclamen mite. Strawberry transplants (“Jewel” and “Annapolis”) that were artificially infested with cyclamen mite were steam-treated at 44°C for 1 h or at 48°C for 0.5 h. Both treatments reduced cyclamen mite numbers by > 99% compared to the control, and 44°C for 1 h had no negative effects on plant survival, growth or yield. In a second, similar, field experiment, transplants (“Jewel”) were categorized by crown size as small (6–8 mm) and large (10–13 mm) and steam-treated at 44°C for 1 or 4 h. Steam treatments reduced cyclamen mite numbers by 92–93% compared to the control, but in the 4 h treatment, survival of small crowns was 40%. Steam treatment of strawberry transplants at 44°C for 1 h is an effective tool and may reduce reliance on miticides for cyclamen mite control. Additional research is needed to determine the optimal steam treatment protocols for cyclamen mite control and to understand the effect of the steam treatment on strawberry transplants with different crown sizes.

Multi-criteria decision-making (MCDM) methods provide a framework for addressing sustainable forest management challenges, especially under climate change. This study offers a systematic review of MCDM applications in forest management from January 2010 to March 2024. Descriptive statistics were employed to analyze trends in MCDM use and geographic distribution. Thematic content analysis investigated the appearance of MCDM indicators supplemented by Natural Language Processing (NLP). Factorial Correspondence Analysis (FCA) explored correlations between models and publication outlets. We systematically searched Web of Science (WoS), Scopus, Google Scholar, Semantic Scholar, CrossRef, and OpenAlex using terms such as ‘MCDM’, ‘forest management’, and ‘decision support’. We found that the Analytical Hierarchy Process (AHP) and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) were the most commonly used methods, followed by the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE), the Analytic Network Process (ANP), GIS, and Goal Programming (GP). Adoption varied across regions, with advanced models such as AHP and GIS less frequently used in developing countries due to technological constraints. These findings highlight emerging trends and gaps in MCDM application, particularly for argan forests, emphasizing the need for context-specific frameworks to support sustainable management in the face of climate change.

Understanding the molecular mechanisms governing leaf morphogenesis and phase transition in Cannabis sativa is critical for optimizing its growth, development and yield. In this study, we conducted a comparative transcriptomic analysis to investigate the gene expression patterns associated with leaf development and the transition from vegetative to reproductive phases in cannabis plants. Following germination, cannabis plants display a distinct leaf developmental pattern. While the specific number of leaflets varies among cultivars, here we focused on the White Widow cultivar as a model. It showed an increase in the number of serrated leaflets from one (L1) to nine (L5) in a node-specific manner. Subsequently, the number of leaflets decreased from eight (L6) to three (L9). The transition from vegetative to reproductive phases, marked by the appearance of solitary flowers and a shift from opposite to alternate leaf phyllotaxy, occurred at node 7 and node 12, respectively. Analysis of gene expression revealed 1358 differentially expressed genes, with 1,182 genes showing differential expression across all leaves. Notably, several genes involved in leaf morphogenesis (e.g. YAB, AGO5, and TCP4) were found to be upregulated in compound leaves (L2) compared to simple leaves (L1), implying a role in leaflet formation and overall leaf morphology. Furthermore, several genes associated with phase transition and flowering (e.g. SPLs, ELFs, SOC1, and CEN-Like) exhibited specific expression patterns during the transition from vegetative to reproductive phases. These findings provide valuable insights into the genetic regulation of leaf morphogenesis and phase transition in cannabis.