Search Results (160)

AM fungi play a pivotal role in regulating ecosystem functioning and processes. However, the assembly of soil AM fungal communities and its drivers across Populus euphratica forests in extremely arid regions remain largely unclear. Here, we explored the composition and assembly processes of AM fungal communities in the soil of P. euphratica forests in northwest China. The results showed that soil salinity affected the composition, assembly processes, and network stability and complexity of AM fungal communities. Stochastic processes rather than deterministic processes dominated the community assembly of AM fungi. Habitat generalists were more susceptible to deterministic processes than specialists. In addition, the network analysis showed that fungal network complexity had a hump-shaped relationship with increasing soil salinity, while network stability had a U-shaped relationship. This research suggests that soil salinity plays an essential role in determining AM fungal community composition and assembly processes in P. euphratica forests of arid regions. Full article

This study investigates the ability of six pre-trained sentence transformers to organize medical knowledge by performing unsupervised clustering on 70 high-level Medical Subject Headings (MeSH) terms across seven medical specialties. We evaluated models from different pre-training paradigms: general-purpose, domain-adapted, and from-scratch domain-specific. The results reveal a clear performance hierarchy. A top tier of models, including the general-purpose MPNet and the domain-adapted BioBERT and RoBERTa, produced highly coherent, specialty-aligned clusters (Adjusted Rand Index > 0.80). Conversely, models pre-trained from scratch on specialized corpora, such as PubMedBERT and BioClinicalBERT, performed poorly (Adjusted Rand Index < 0.51), with BioClinicalBERT yielding a disorganized clustering. These findings challenge the assumption that domain-specific pre-training guarantees superior performance for all semantic tasks. We conclude that model architecture, alignment between the pre-training objective and the downstream task, and the nature of the training data are more critical determinants of success for creating semantically coherent embedding spaces for medical concepts. Full article

This study evaluated the physiological responses and biomass production of selected poplar and willow clones cultivated in form of phytoremediation buffer plantations on landfills in Vinča (near Belgrade) and Novi Sad, Serbia. Key parameters assessed included net photosynthesis (A), transpiration (E), stomatal conductance (g_s), and water use efficiency (WUE). Results indicated a significant Clone × Site interaction for net photosynthesis, suggesting environmental-specific clone responses. Transpiration and stomatal conductance exhibited site-stable expression between sites, implying conservative traits or similar hydrological conditions during measurements. Particularly, total site values for physiological parameters were higher at the Novi Sad site, likely due to continuous access of plants to groundwater. The weak correlation between WUE and biomass production suggests that favorable water conditions at both sites diminished the importance of water use efficiency for biomass accumulation. Poplar clone S1-8 exhibited the highest biomass production and leaf-level gas exchange traits (A, E, g_s, WUE), reflecting a fast-growth strategy through increased gas exchange. This clone’s consistent productivity across sites classifies it as a generalist, while willow clone 378 and poplar clone 135/81, with significantly higher biomasses at the Novi Sad site than at the Vinča site, can be considered as specialists. Use of both generalist and specialist clones in multiclonal plantations may enhance phytoremediation and biomass production stability across variable sites. These findings underscore the importance of selecting appropriate clones for phytoremediation on landfills and on contaminated lands in general. Full article

Forest plantations in the Neotropics aim to alleviate pressure on primary forests. This study synthesizes knowledge on pine species used in these plantations, emphasizing the challenges and potential of ectomycorrhizal fungi and bacteria as inoculants. An analysis of 98 articles identifies 23 pine species in Mexico and Central America and about 16 fast-growing species in South America. While pine plantations provide a habitat for generalist species, they reduce the richness of specialist species. Ectomycorrhizal fungi and bacterial diversity in plantations with introduced pines is up to 20% lower compared to native ecosystems. Suillus and Hebeloma are commonly used as mycorrhizal inoculants for Neotropical and introduced species, including Pinus ponderosa and Pinus radiata in South America. Commercial inoculants predominantly feature the fungal species Pisolithus tinctorius, alongside bacterial genera such as Bacillus, Cohnella, and Pseudomonas. This study emphasizes the importance of leveraging native microbial communities and their synergistic interactions with ECM fungi and bacteria to enhance seedling growth and quality. Such a combined approach can improve plantation survival, boost resilience to environmental stressors, and promote long-term productivity. These findings underscore the need to incorporate native fungi and bacteria into inoculant strategies, advancing sustainable forestry practices and ecosystem adaptation in the Neotropics. Full article

Related species of parasitoid Hymenoptera often coexist on a certain host, but many details of interactions between these organisms remain unclear. The present review summarizes the main existing concepts and facts and suggests principal patterns and mechanisms that allow for the coexistence of several members of a particular parasitoid genus at the expense of the same host. Although the successful introduction of exotic parasitic wasps into the existing ecosystems often leads to the competitive displacement of related parasitoids, mere spatial and/or temporal niche partitioning between these insects is also possible. Nevertheless, many cases of coexistence of related wasp species on the same host defy simple explanations since they apparently result from complex interactions between the host and its parasitoids. The main characteristics of the oviposition process, i.e., egg volume, fecundity, and duration of the egg-laying period, are likely to correlate with other basic features of life-history strategies in parasitoid Hymenoptera. Specialist parasitic wasps often aggregate over the host patches, whereas generalists can be randomly distributed, thus reducing the degree of interspecific competition among parasitoids. However, some of the coexisting parasitic wasps, usually the weakest competitors, must also have access to enemy-free space to survive. Full article

Acid rain and understory vegetation removal are critical drivers altering soil ecosystem alterations. However, the mechanisms by which these factors influence soil moisture dynamics, nutrient availability, and microbially mediated enzyme activities remain insufficiently elucidated. This study investigated the impacts of simulated acid rain and understory vegetation removal on soil properties, enzyme activities, and microbial community in a subtropical Cinnamomum camphor (Linn) Presl plantation. The results indicated that acid rain and understory vegetation removal significantly decreased the soil organic carbon (SOC) while concurrently elevating the C-acquiring enzyme activities and microbial C limitation. Understory vegetation removal markedly reduced the soil moisture, nutrient availability, and N- and P-acquiring enzyme activities. Additionally, acid rain increased the bacterial diversity, but the understory vegetation removal increased the fungal diversity. Moreover, both acid rain and understory vegetation removal enhanced the bacterial community deterministic processes and destabilized the community by shifting generalists toward specialists, but had no significant effect on the fungal community structure. Partial least squares path modeling revealed that the bacterial stability loss intensified the C limitation, while the fungal stability regulated the P limitation. Collectively, the findings highlighted the critical role of understory vegetation in buffering the soil microclimate and nutrient cycling, and demonstrated that bacterial communities are more responsive to acid rain and understory vegetation removal than fungal communities. This study provides insights into the mechanisms by which anthropogenic disturbances alter soil ecological functions in subtropical plantations, emphasizing the need for integrated forest management strategies to conserve and manage soil ecosystems in subtropical plantations. Full article

Bacterial viruses (phages) are abundant and ecologically impactful, but laboratory-based experimental model systems vastly under-represent known phage diversity, particularly for ssDNA phages. Here, we characterize the genomes and infection properties of two unrelated marine flavophages—ssDNA generalist phage phi18:4 (6.5 Kbp) and dsDNA specialist phage phi18:1 (39.2 Kbp)—when infecting the same Cellulophaga baltica strain #18 (Cba18), of the class Flavobacteriia. Phage phi18:4 belongs to a new family of ssDNA phages, has an internal lipid membrane, and its genome encodes primarily structural proteins, as well as a DNA replication protein common to ssDNA phages and a unique lysis protein. Phage phi18:1 is a siphovirus that encodes several virulence genes, despite not having a known temperate lifestyle, a CAZy enzyme likely for regulatory purposes, and four DNA methyltransferases dispersed throughout the genome that suggest both host modulation and phage DNA protection against host restriction. Physiologically, ssDNA phage phi18:4 has a shorter latent period and smaller burst size than dsDNA phage phi18:1, and both phages efficiently infect this host. These results help augment the diversity of characterized environmental phage–host model systems by studying infections of genomically diverse phages (ssDNA vs. dsDNA) on the same host. Full article

Landscapes can be selectively used by different carnivore species, leading to habitat specialization, which acts as a limiting resource for maintaining healthy populations. Between 1 March 2021 and 31 March 2022, we set up 30 camera traps in three different landscapes of central Chile: (a) Mediterranean coastal sclerophyllous forest (SF), (b) Mediterranean coastal thorn forest (TF), and (c) exotic monoculture tree plantations (MP), with a total capture effort of 10,046 camera-days (3098 TF, 3446 MP, and 3502 SF). We described the daily activity patterns for each native carnivore species recorded in each landscape, based on the density of independent records per hour of the day. We assessed the overlap between the activity patterns of each carnivore species in the different macrohabitats based on their coefficient of overlapping (Δ). We identified 9120 carnivore records, corresponding to 3888 independent events: 3140 for Lycalopex fox species, 276 for guiña Leopardus guigna, 434 for skunk Conepatus chinga, and 38 for the lesser grison Galictis cuja. Our study revealed differences of activity patterns with high to medium overlap, among landscape types for C. chinga and Lycalopex spp.—for skunk, between native forests and exotic monoculture tree plantations, and for foxes, among all landscape types. The carnivore community of the highly anthropized central Chile is mostly composed of habitat generalists and habitat specialists with high adaptability to landscape fragmentation, which has been crucial for their long-term survival. Full article

In this study, five poplar clones (Populus deltoides cl. PE19/66, cl. S1-8, cl. 135/81, and Populus × euramericana cl. I-214, cl. Pannonia) and two white willow clones (Salix alba cl. 380, cl. 107/65-9) were tested in pot trials. The aim was to evaluate their potential for phytoextraction of nine heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in three substrates, two based on soil from landfills near Belgrade and Novi Sad, and one control treatment based on nursery soil. The shoot content of all analyzed heavy metals was the highest in the BG substrate with the highest content of heavy metals and the lowest in the control substrate. White willow clone 107/65-9 achieved the highest accumulation of Cd, Cr, Fe, Ni and Pb and along with another willow clone 380 is found to act as generalists. Poplar clones performed more as specialists: I-214 and Pannonia for copper, PE 19/66 for manganese and S1-8 for nickel and zinc. Considerable differences among examined clones in heavy metal accumulation and reaction to substrates should be taken into consideration in further pot and field trials as well as in phytoremediation projects on landfills. Full article

Albugo spp. are biotrophic parasites that cause white rust in Brassicaceae species, with significant crop losses. The generalist A. candida and the specialist A. laibachii infect Arabidopsis thaliana, and the pathosystem Albugo–Arabidopsis is a model for research in molecular genetics of plant–pathogen interactions. The occurrence of infection by Albugo in wild populations of Arabidopsis and data on the genetics of resistance-susceptibility are compatible with a hypothesis of host–pathogen coevolution. However, the negative impact of Albugo infection on Arabidopsis—a requirement for coevolution—has not been shown under field conditions. To address this question, we analysed the demography and the dynamics of Albugo infection in a wild Arabidopsis population in central Spain and measured plant fitness-related traits. Infection increased mortality by 50%, although lifespan, the fraction of plants that reproduced and seed production were reduced only in plants from the spring cohorts. Despite these negative effects, simulations of demographic dynamics showed that the population growth rate remained unaffected even at unrealistically high infection incidences. The lack of negative effects in autumn–winter cohorts suggests compensatory mechanisms in longer-lived plants. Results support the hypothesis of Albugo–Arabidopsis coevolution. Full article

Whether specialist pests can cause more damage to their host plants than generalist pests is a critical issue in both basic biology and nonnative species management. To date, there is no consensus on how we define “specialist vs. generalist” pests and how we should assess forest damage or impacts (volume loss vs. mortality). Here, we comparatively investigate whether nonnative generalist pests may cause more damage to US forests than nonnative specialist pests using two frameworks: (1) the “binary or dichotomous approach” through a largely arbitrary classification of specialist and generalist pests, and (2) the “specialist-generalist continuum”. We measure damage or impact in two ways, one by the total host volume infested and the other by total host mortality. In the binary comparison, generalists infested more host tree volume per pest species than specialists, but the latter (mostly pathogens) caused higher mortality of host trees. The “specialist-generalist continuum” concept could reveal a different pattern regarding pest invasions and impacts when there is no clear separation between generalists and specialists in a community or region. Therefore, we suggest using the “continuum” approach to address related questions in future studies, thus offering new insights into pest invasions that have deeper implications for forest pest monitoring and management. Full article

The increase in the provision of English language teaching programs in primary school contexts in Asia has resulted in a concomitant increase in non-specialist teachers, often generalist homeroom teachers, to address the shortage. However, non-specialist teachers often lack the pedagogical training necessary for effective English instruction, which often negatively impacts their self-efficacy. This study was designed to examine the effects of a professional development workshop, aimed at improving “classroom English” proficiency, on these teachers’ self-efficacy. It also explored sources influencing self-efficacy during the in-class implementation of what they learned in the workshop. Quantitative results revealed that the immediate impact of the training was substantial, leading to a rapid increase in self-efficacy. However, this effect appeared to diminish after three months of teaching. Qualitative findings indicated that non-specialist teachers’ perceptions of capability were significantly influenced by collegial assurances and support from individuals who evaluated their progress and achievements. Notably, support from specialist teachers emerged as a critical factor in sustaining or diminishing the enhanced self-efficacy of non-specialist teachers. These findings highlight the importance of providing needs-based, continuous professional development opportunities and establishing robust peer-support systems within schools to ensure the effective translation of training outcomes into classroom practices. Full article

Herein, we explored the ecologic niches of generalist and specialist species within the subalpine vegetation zone, a habitat of Abies sp. distributed throughout South Korea and China. We included Abies sp. habitats in inland areas of South Korea and parts of the Manchurian region of China. Rhododendron schlippenbachii Maxim., Acer pseudosieboldianum (Pax) Kom., Picea jezoensis (Siebold & Zucc.) Carrière, Betula ermanii Cham., Acer komarovii Pojark., Pinus koraiensis Siebold & Zucc., Betula davurica Pall., Betula costata Trautv., Quercus mongolica Fisch. ex Ledeb, and Sorbus commixta Hedl. were selected as generalist species. Betula chinensis Maxim., Betula platyphylla var. japonica (Miq.) H. Hara, Euonymus pauciflorus Maxim., Salix maximowiczii Kom., Cornus walteri F.T. Wangerin, Carpinus laxiflora (Siebold & Zucc.) Blume, Populus davidiana Dode, Philadelphus tenuifolius Rupr. & Maxim., Rhododendron brachycarpum D. Don ex G. Don, and Larix olgensis var. koreana (Nakai) Nakai were selected as specialist species. NMS ordination analysis showed that specialist, generalist, and other plant species distribution correlated with basal area at breast height, stand density, and species diversity index. Generalist species could be grouped based on Quercus sp., Betula sp., and Acer sp. niche spaces. Specialist species shared ecological niches with plant species found in the limestone zone, sedimentary rock zone, and valley area. Full article

The ability to accurately quantify biodiversity is fundamental to understanding ecological trends, identifying drivers of declines, and selecting effective conservation options. Scientists and resource managers have grappled with what metrics best show relevant biodiversity patterns and are still practical enough to aid on-the-ground resource conservation. Our purpose is to construct empirically derived, functional habitat guilds for prairie stream fish, then recommend future directions for constructing and using diversity metrics that aid field-based conservation. Working in the Upper Neosho River, KS, USA, we used univariate methods, cluster analysis, non-metric multi-dimensional scaling, and an analysis of similarity to functionally group stream fish taxa. The 11 most abundant fish species grouped into seven ecological guilds: riffle specialist, pool specialist, riffle generalist, pool generalist, riffle–run generalist, pool–run generalist, and generalist. Combining the habitat type and strength of association added ecological accuracy to our species groups. Employing multiple statistical methods increased confidence and generality in our grouping results. Moving forward will require a coordinated, coalition-driven, conservation-related strategy on which researchers and practitioners collaborate to synthesize diverse empirical results, organize general principles of structure and function, and balance accuracy with practicality. Full article

Current methods for studying the effects of climate change on plants and pollinators can be grouped into two main categories. The first category involves using species distribution models (SDMs) to generate habitat suitability maps, followed by applying climate change scenarios to predict the future distribution of plants and pollinators separately. The second category involves constructing interaction matrices between plants and pollinators and then either randomly removing species or selectively removing generalist or specialist species, as a way to estimate how climate change might affect the plant–pollinator network. The primary limitation of the first approach is that it examines plant and pollinator distributions separately, without considering their interactions within the context of a pollination network. The main weakness of the second approach is that it does not accurately predict climate change impacts, as it arbitrarily selects species to remove without knowing which species will truly shift, decline, or increase in distribution due to climate change. Therefore, a new approach is needed to bridge the gap between these two methods while avoiding their specific limitations. In this context, we introduced an innovative approach that first requires the creation of binary climate suitability maps for plants and pollinators, based on SDMs, for both the current and future periods. This step aligns with the first category of methods mentioned earlier. To assess the effects of climate change within a network framework, we consider species co-overlapping in a geographic matrix. For this purpose, we developed a Python program that overlays the binary distribution maps of plants and pollinators, generating interaction matrices. These matrices represent potential plant–pollinator interactions, with a ‘0’ indicating no overlap and a ‘1’ where both species coincide in the same cell. As a result, for each cell within the study area, we can construct interaction matrices for both the present and future periods. This means that for each cell, we can analyze at least two pollination networks based on species co-overlap. By comparing the topology of these matrices over time, we can infer how climate change might affect plant–pollinator interactions at a fine spatial scale. We applied our methodology to Chile as a case study, generating climate suitability maps for 187 plant species and 171 pollinator species, resulting in 2906 pollination networks. We then evaluated how climate change could affect the network topology across Chile on a cell-by-cell basis. Our findings indicated that the primary effect of climate change on pollination networks is likely to manifest more significantly through network extinctions, rather than major changes in network topology. Full article