Biology subjects

Faticov, M.

Publications and source records attributed to Faticov, M..

6 recordsLinked to original sources

bioRxiv2026

Fungal-beetle networks in deadwood are modular and shaped by tree species and deadwood type

Deadwood is a key habitat for forest biodiversity, yet how tree species and deadwood type shape linked fungal-beetle communities remain poorly understood. We explored saproxylic fungi and beetles in a large-scale restoration experiment on birch, pine, and spruce deadwood created as burned standing trees, felled logs, girdled trees, high stumps, and uprooted trees. As expected, we found that tree species was the main driver of both fungal and beetle community composition, while deadwood type was the second most important driver. Fungal-beetle community correlations were context dependent: significant multivariate correlations were detected for pine and spruce, but not birch, and were strongest in burned standing pine, burned standing spruce, and girdled spruce. Across all tree species and deadwood types, fungal-beetle co-occurrence networks were consistently less nested and more modular than expected by chance, indicating structured, compartmentalized associations of fungi and beetles even within single deadwood units. SynthesisThese results show that maintaining diverse tree species and deadwood types is essential to retain specialized multitrophic communities and the ecological processes they support.

ecology↗

bioRxiv2026

Montreal Urban Observatory: research platform to monitor urban forest ecosystems for global change adaptation and health

As urban populations grow, cities are increasingly seen not only as drivers of climate change but also as critical arenas for implementing mitigation and adaptation strategies. Urban forests and green infrastructure play a vital role in shaping environmental quality and human health, yet access to these benefits remains inequitable. The Montreal Urban Observatory was designed to investigate the complex relationships among biodiversity, ecosystem functioning, and human health. Twenty-five permanent plots were established across the Island of Montreal, strategically located along gradients in vegetation cover, population density, and mean household income. Interdisciplinary research within the Observatory focuses on themes including urban forest structure and function, abiotic conditions, biodiversity, ecological interactions, natures contributions to people, related human health outcomes, and developing novel methodological approaches. The Observatory supports long-term, cross-scale monitoring and fosters collaborative research on urban social-ecological systems, thus contributing to global initiatives to enhance urban sustainability and equity through nature-based solutions. Early results confirm the relevance of the main gradients for several organisms and response variables, from microbes to trees and abiotic factors. For example, sampling all trees, public and private, within a radius of 200m centered on each plot revealed significant differences in the diversity and structure of private and public trees, including an overwhelming dominance of Thuya occidentalis not captured in commonly used public tree inventories.

ecology↗

bioRxiv2025

Season and city shape urban bioaerosol composition beyond vegetation and socioeconomic gradients

Urban vegetation varies with socio-economic gradients, as lower-income neighborhoods often host sparser and less diverse green spaces. This disparity may affect respiratory health by influencing exposure to bioaerosols. Understanding the characteristics of this aerobiome could help anticipate risks related to allergies and other respiratory conditions. Here, we hypothesized that urban vegetation cover and socio-economic status shape urban bioaerosols. We sampled bioaerosols at 65 sites across three Canadian cities of varying population size and density using an active air sampler over four months, and characterized their bacterial, fungal, and pollen composition using amplicon sequencing. Seasonal alpha diversity varied significantly for fungi and pollen. Based on beta diversity, sampling period alone explained up to 40% of pollen, 29% of fungal, and 11% of bacterial community composition variation. In contrast, vegetation cover explained only a minor portion of the variance in bioaerosol composition, and median household income, almost none. These findings provide a critical baseline for understanding the urban aerobiome and highlight the need to study how vegetation identity and diversity, rather than cover alone, may shape bioaerosol dynamics in cities. As cities grow and urban greening initiatives expand, demystifying the aerobiome dynamics becomes an urgent public health priority.

microbiology↗

bioRxiv2025

Plant sexual and asexual contributions to the seed microbiome

The seed microbiome plays a key role in the assembly of the plant microbiome, which has major impacts on plant functioning. Nonetheless, little is known about the origin of the seed microbiome. We investigated the relative contributions of two hypothesized transmission routes: sexual inheritance (via reproductive organs) and asexual inheritance (via the plant vascular system). To do that, we sampled shoot endophytes both before bloom and at seed maturity stages, apple flower ovaries and pollen sacs, and mature seeds from field-grown apple trees (Malus domestica BO_SCPLOWORKHC_SCPLOW. cv Gala Galaxy Selecta). We showed that bacterial richness, diversity and composition differ among tissue types, with shoots before bloom harboring a higher diversity than ovary and pollen. Source tracking revealed that both sexual (30.3%) and asexual (23.8%) pathways contributed to seed microbiome assembly, with shoots at seed maturity being the dominant source. Notably, a large proportion (49.5%) of the seed microbiome originated from unknown sources. Lastly, the transmission pathways significantly differed among bacterial genera, with Pseudomonas primarily linked to shoots, Rhizobacter to pollen and Burkholderia to the ovary. Insights into seed microbiome origin offers new opportunities to enhance seed health and crop productivity through microbiome-assisted breeding.

ecology↗

bioRxiv2023

Moss species, sections, and land use type drive moss-associated microbial taxonomy and functions in boreal forests

Moss-microbe interactions contribute to ecosystem processes in boreal forests. Yet, how host-specific characteristics and the environment drive the composition and metabolic potential of moss microbiomes is still poorly understood. In this study, we use shotgun metagenomics to identify the taxonomy and metabolic potential of the bacteria of four moss species of the boreal forests of Northern Quebec, Canada. To characterize moss bacterial community composition and diversity, we assembled the genomes of 110 potentially novel bacterial species. Our results highlight that moss genus, species, gametophyte section, and to a lesser extent soil pH and soil temperature, drive moss-associated bacterial community composition and diversity. In the brown gametophyte section, two Stigonema spp. showed partial pathway completeness for photosynthesis and nitrogen fixation, while all brown-associated Hyphomicrobiales had complete assimilatory nitrate reduction pathways and many nearly complete carbon fixation pathways. Several brown-associated species showed partial to complete pathways for coenzyme M and F420 biosynthesis, important for methane metabolism. In addition, green-associated Hyphomicrobiales (Methylobacteria spp.) displayed potential for the anoxygenic photosystem II pathway. Overall, our findings demonstrate how host-specific characteristics and environmental factors shape the composition and metabolic potential of moss bacteria, highlighting their roles in carbon fixation, nitrogen cycling, and methane metabolism in boreal forests.

microbiology↗

bioRxiv2020

Search for top-down and bottom-up drivers of latitudinal trends in insect herbivory in oak trees in Europe

AimThe strength of species interactions is traditionally expected to become stronger toward the Equator. However, recent studies have reported opposite or inconsistent latitudinal trends in the bottom-up (plant quality) and top-down (natural enemies) forces driving insect herbivory, possibly because these forces have rarely been studied concomitantly. This makes previous attempts to understand the effect of large scale climatic gradients on insect herbivory unsuccessful. LocationEurope Time period2018-2019 Major taxa studiedQuercus robur MethodsWe used scholar-based citizen science to simultaneously test for latitudinal variation in plant-herbivore-natural enemy interactions. We further investigated the underlying climatic factors associated with variation in herbivory, leaf chemistry and attack rates in Quercus robur across its complete latitudinal range in Europe. We quantified insect herbivory and the occurrence of specialist herbivores as well as leaf chemistry and bird attack rates on dummy caterpillars on 261 oak trees. ResultsClimatic factors rather than latitude per se were the best predictors of the large-scale (geographical) variation in the incidence of gall-inducers and leaf-miners as well as of leaf nutritional quality. However, insect herbivory, plant chemical defences (leaf phenolics) and bird attack rates were not influenced by latitude or climatic factors. The incidence of leaf-miners increased with increasing concentrations of hydrolysable tannins and decreased with those of condensed tannins, whereas the incidence of gall-inducers increased with increasing leaf soluble sugar concentration and decreased with increasing leaf C:N ratios. However, neither other traits nor bird attack rates varied with insect herbivory. Main conclusionsThese findings help to refine our understanding of the bottom-up and top-down mechanisms driving geographical variation in plant-herbivore interactions, and urge for further examination of the drivers of insect herbivory on trees.

ecology↗