Variation In Abundance Research Articles

Unraveling the Role of Contaminants Reshaping the Microflora in Zea mays Seeds from Heavy Metal–Contaminated and Pristine Environment

Heavy metal (HM) contaminants are the emerging driving force for reshaping the microflora of plants by eradicating the non-tolerance and non-resistant microbes via their lethal effects. Seeds served as a prime source of ancestral microbial diversity hereditary transfer from generation to generation. However, the problem arises when they got exposed to metal contamination, does metal pollutant disrupt the delicate balance of microbial communities within seeds and lead to shifts in their microflora across generations. In this study, the endophytic community within Zea mays seeds was compared across three distinct regions in Yunnan province, China: a HM-contaminated site Ayika (AK), less-contaminated site Sanduoduo (SD), and a non-contaminated Site Dali (DL). High-throughput sequencing techniques were employed to analyze the microbial communities. A total of 492,177 high-quality reads for bacterial communities and 1,001,229 optimized sequences for fungal communities were obtained. These sequences were assigned to 502 and 239 operational taxonomic units (OTUs) for bacteria and fungi, respectively. A higher diversity was recorded in AK samples than in SD and DL. Microbial community structure analysis showed higher diversity and significant fluctuation in specific taxa abundance in the metal-polluted samples exhibiting higher response of microbial flora to HM. In AK samples, bacterial genera such as Gordonia and Burkholderia-Caballeronia-Paraburkholderia were dominant, while in SD Pseudomonas and Streptomyces were dominant. Among the fungal taxa, Fusarium, Saccharomycopsis, and Lecanicillium were prevalent in HM-contaminated sites. Our finding revealed the influential effect of HM contaminants on reshaping the seed microbiome of the Zea mays, showing both the resilience of certain important microbial taxa as well the shifts in the diversity in the contaminated and pristine conditions. The knowledge will benefit to develop effective soil remediation, reclamation, and crop management techniques, and eventually assisting in the extenuation of metal pollution's adverse effects on plant health and agricultural productivity.

Biodiversity measures of a grassland plant-pollinator community are resilient to the introduction of honey bees (Apis mellifera).

The prairies of Canada support a diversity of insect pollinators that contribute pollination services to flowering crops and wild plants. Habitat loss and use of managed pollinators has increased conservation concerns for wild pollinators, as mounting evidence suggests that honey bees (Apis mellifera) may reduce their diversity and abundance. Plant-pollinator community analyses often omit non-bee pollinators, which can be valuable contributors to pollination services. Here, we experimentally introduced honey bees to examine how their abundance affects the species richness, diversity, abundance, species composition, interaction richness, and interaction diversity of all wild pollinators, and of four higher taxa separately. We identified all insect pollinators and analyzed how honey bee abundance affected the above biodiversity metrics, controlling for flower abundance and flower species richness. Even with high honey bee densities, there was no change to any of these variables, except that beetle species diversity increased. All other taxa had no significant relationship to honey bee abundance. Considering the widespread use of managed honey bees, the effect they have on wild pollinators should be firmly established. Our results suggest that honey bees have little to no short-term impact on the wild pollinator community or its interactions with plants in this native grassland.

Mesona chinensis Benth. Extract Ameliorates Hyperlipidemia in High-Fat Diet-Fed Mice and Rats by Regulating the Gut Microbiota

Mesona chinensis Benth. (or Platostoma palustre (Blume) A. J. Paton), an edible and medicinal plant, is the main ingredient in black jelly, Hsian-tsao tea, and beverages, and its processed products are popular in China as well as in Southeast Asian countries. Previous studies have shown that the alcohol extract of Mesona chinensis Benth. (MC) can reduce the accumulation of oleic acid and ameliorate hyperlipidemia. However, researchers have not yet determined whether it could improve intestinal permeability and metabolic dysfunction by controlling gut microbial dysbiosis and thus reducing hyperlipidemia. This study aimed to explore the potential mechanism by which MC regulates metabolic function disorders in hyperlipidemic high-fat diet (HFD)-fed rats and mice from the perspective of gut microbiota. This study analyzed the effects of MC on metabolic indices related to hyperlipidemia in HFD-fed rats and the abundance and diversity of the gut microbiota via 16S rRNA V3–4 region pyrosequencing to investigate the regulation of the gut microbiota by MC. We further confirmed that MC ameliorates hyperlipidemia by regulating the gut microbiota by simultaneously administering antibiotics and MC to C57BL/6 mice and measuring their metabolic indices. These results indicate that MC reduces the lipid concentration in the serum of HFD-fed rats, thereby significantly alleviating hyperlipidemia, and regulates the abundance ratio and diversity of the gut microbiota, thereby exerting a beneficial effect on hyperlipidemia. Our further antibiotic experiments in mice revealed that the administration of MC was unable to reduce body weight or serum and organ lipid concentrations in the antibiotic-treated group of hyperlipidemic mice. This study provides evidence that the microbiota is an alternative target for the antihyperlipidemic effect of MC.

Distribution characteristics of photoassimilates in walnut leaves to different organs

The understanding of photoassimilate distribution serves as the fundamental basis for scientific regulation of fruit quality. Currently, there is a scarcity of research on whole-plant scale photoassimilate distribution in walnut. In order to clarify the characteristics of leaf photoassimilates translocation to various organs in 5-year-old 'Wen185' (J. regia 'Wen185') walnut during the growing season, this study used the 13C isotope pulse labeling technique to label the whole plant of walnut trees in the growing season, temporal variations of 13C abundance (δ13C), 13C partition rate (R13C), leaf source strength and fruit sink strength were analyzed in various organs at different days after tree flowering. The findings indicated that during the periods of 30–70 days and 90–110 days after flowering, there was a higher distribution of 13C in fruits and vegetative branches. However, at 110–130 days after flowering, the predominant allocation of 13C shifted towards main trunk and roots. In-depth study of source leaves and sink fruits showed that chlorophyll content in leaves increased significantly 30–50 days after anthesis, indicating that they gradually became mature functional leaves. The increase of net photosynthetic rate led to increase of source strength, and the retention of photoassimilates in leaves was higher at this time. From 30 to 70 days after flowering, the fresh weight and volume of fruit increased rapidly, which increased the capacity of the sink and enhanced the competition ability against photoassimilates. The recovery of photosynthetic capacity of leaves from 90 to 110 days promoted the output of photoassimilates. At this time, walnut entered the oil conversion period, and the demand for photoassimilates increased. All these factors jointly promoted the unloading of photoassimilates in fruit. In summary, maintaining adequate material conditions and optimizing tree structure at 30-70d and 90-110d after anthesis are important for more efficient distribution of photoassimilates to fruit.

Effects of three elicitors on primary metabolism six days after treatment in healthy <i>Vitis vinifera</i> leaves and eight days after treatment in healthy and downy mildew-inoculated leaves

Elicitors can be used to reduce the application of conventional pesticides against grapevine diseases; however, they may disrupt plant primary metabolism. The long-term effects (more than 6 days after treatment) of applying plant defence stimulators (PDS) to protect grapevine from Plasmopara viticola were investigated. We studied the effect of three PDS (acibenzolar-S-methyl/ASM, potassium phosphonate/PHOS, methyl jasmonate/MeJA) and one surfactant (Triton) on gene expression and metabolite production in leaves of Vitis vinifera cv. Cabernet-Sauvignon before or after their inoculation with P. viticola. The molecular and biochemical results show the impact of these PDS on grapevine metabolism more than 6 days after treatment, and after inoculation. High-throughput q-RT-PCR revealed that sixty of the primary metabolism genes (ion homeostasis and hormones pathways) were modulated by all treatments, some modulations being specific to a given PDS. Meanwhile, 1H NMR studies revealed variations in metabolite abundances (amines, amino acids, organic acids, polyphenols and sugars), with some being common to all treatments (organic acid increase) and others specific to a single one. By combining two methodological approaches, it was possible to determine the specific effects of each PDS on Vitis. All PDS-induced resistance involved modulation of the primary metabolism. This innovative approach can be extended to vineyard studies in order to help better understand the variability of PDS effects in natura.

Detection and Quantification of Drug-Protein Adducts in Human Liver.

Covalent protein adducts formed by drugs or their reactive metabolites are risk factors for adverse reactions, and inactivation of cytochrome P450 (CYP) enzymes. Characterization of drug-protein adducts is limited due to lack of methods identifying and quantifying covalent adducts in complex matrices. This study presents a workflow that combines data-dependent and data-independent acquisition (DDA and DIA) based liquid chromatography with tandem mass spectrometry (LC-MS/MS) to detect very low abundance adducts resulting from CYP mediated drug metabolism in human liver microsomes (HLMs). HLMs were incubated with raloxifene as a model compound and adducts were detected in 78 proteins, including CYP3A and CYP2C family enzymes. Experiments with recombinant CYP3A and CYP2C enzymes confirmed adduct formation in all CYPs tested, including CYPs not subject to time-dependent inhibition by raloxifene. These data suggest adducts can be benign. DIA analysis showed variable adduct abundance in many peptides between livers, but no concomitant decrease of unadducted peptides. This study sets a new standard for adduct detection in complex samples, offering insights into the human adductome resulting from reactive metabolite exposure. The methodology presented will aid mechanistic studies to identify, quantify and differentiate between adducts that result in adverse drug reactions and those that are benign.

Single-colony MALDI mass spectrometry imaging reveals spatial differences in metabolite abundance between natural and cultured Trichodesmium morphotypes.

Trichodesmium, a globally significant N2-fixing marine cyanobacterium, forms extensive surface blooms in nutrient-poor ocean regions. These blooms consist of a dynamic assemblage of Trichodesmium species that form distinct colony morphotypes and are inhabited by diverse microorganisms. Trichodesmium colony morphotypes vary in ecological niche, nutrient uptake, and organic molecule release, differentially impacting ocean carbon and nitrogen biogeochemical cycles. Here, we assessed the poorly studied spatial abundance of metabolites within and between three morphologically distinct Trichodesmium colonies collected from the Red Sea. We also compared these results with two morphotypes of the cultivable Trichodesmium strain IMS101. Using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) coupled with liquid extraction surface analysis (LESA) tandem mass spectrometry (MS2), we identified and localized a wide range of small metabolites associated with single-colony Trichodesmium morphotypes. Our untargeted MALDI-MSI approach revealed 80 unique features (metabolites) shared between Trichodesmium morphotypes. Discrimination analysis showed spatial variations in 57 shared metabolites, accounting for 62% of the observed variation between morphotypes. The greatest variations in metabolite abundance were observed between the cultured morphotypes compared to the natural colony morphotypes, suggesting substantial differences in metabolite production between the cultivable strain IMS101 and the naturally occurring colony morphotypes that the cultivable strain is meant to represent. This study highlights the variations in metabolite abundance between natural and cultured Trichodesmium morphotypes and provides valuable insights into metabolites common to morphologically distinct Trichodesmium colonies, offering a foundation for future targeted metabolomic investigations.IMPORTANCEThis work demonstrates that the application of spatial mass spectrometry imaging at single-colony resolution can successfully resolve metabolite differences between natural and cultured Trichodesmium morphotypes, shedding light on their distinct biochemical profiles. Understanding the morphological differences between Trichodesmium colonies is crucial because they impact nutrient uptake, organic molecule production, and carbon and nitrogen export, and subsequently influence ocean biogeochemical cycles. As such, our study serves as an important initial assessment of metabolite differences between distinct Trichodesmium colony types, identifying features that can serve as ideal candidates for future targeted metabolomic studies.

The potential for species distribution models to distinguish source populations from sinks.

While species distribution models (SDM) are frequently used to predict species occurrences to help inform conservation management, there is limited evidence evaluating whether habitat suitability can reliably predict intrinsic growth rates or distinguish source populations from sinks. Filling this knowledge gap is critical for conservation science, as applications of SDMs for management purposes ultimately depend on these typically unobserved population or metapopulation dynamics. Using linear regression, we associated previously published population level estimates of intrinsic growth and abundance derived from a Bayesian analysis of mark-recapture data for 17 bird species found in the contiguous United States with SDM habitat suitability estimates fitted here to opportunistic data for these same species. We then used the area under the ROC curve (AUC) to measure how well SDMs can distinguish populations categorized as sources and sinks. We built SDMs using two different approaches, boosted regression trees (BRT) and generalized linear models (GLM), and compared their source/sink predictive performance. Each SDM was built with presence points obtained from eBird (a web-available database) and 10 environmental variables previously selected to model intrinsic growth rates and abundance for these species. We show that SDMs built with opportunistic data are poor predictors of species demography in general; both BRT and GLM explained very little spatial variation of intrinsic growth rate and population abundance (median R2 across 17 species was close to 0.1 for both SDM methods). SDMs, however, estimated higher suitability for source populations as compared to sinks. Out of 13 species which had both source and sink populations, both BRT and GLM had AUC values greater than 0.7 for 7 species when discriminating between sources and sinks. Habitat suitability have the potential to be a useful measure to indicate a population's ability to sustain itself as a source population; however more research on a diverse set of taxa is essential to fully explore this potential. This interpretation of habitat suitability can be particularly useful for conservation practice, and identification of explicit cases of when and how SDMs fail to match population demography can be informative for advancing ecological theory.

TRNA and tsRNA: From Heterogeneity to Multifaceted Regulators.

As the most ancient RNA, transfer RNAs (tRNAs) play a more complex role than their constitutive function as amino acid transporters in the protein synthesis process. The transcription and maturation of tRNA in cells are subject to stringent regulation, resulting in the formation of tissue- and cell-specific tRNA pools with variations in tRNA overall abundance, composition, modification, and charging levels. The heterogeneity of tRNA pools contributes to facilitating the formation of histocyte-specific protein expression patterns and is involved in diverse biological processes. Moreover, tRNAs can be recognized by various RNase under physiological and pathological conditions to generate tRNA-derived small RNAs (tsRNAs) and serve as small regulatory RNAs in various biological processes. Here, we summarize these recent insights into the heterogeneity of tRNA and highlight the advances in the regulation of tRNA function and tsRNA biogenesis by tRNA modifications. We synthesize diverse mechanisms of tRNA and tsRNA in embryonic development, cell fate determination, and epigenetic inheritance regulation. We also discuss the potential clinical applications based on the new knowledge of tRNA and tsRNA as diagnostic and prognostic biomarkers and new therapeutic strategies for multiple diseases.

GW3, encoding a member of the P450 subfamily, controls grain width by regulating the GA4 content in spikelets of rice (Oryza sativa L.).

A stable QTL, GW3, controlling grain width was identified in two populations. Its causal gene LOC_Os03g04680 was verified by gene-based haplotype analysis, expression analysis, gene knockout and complementation transgenic tests. Grain width (GW) is one of the key traits affecting grain size and determines grain yield and appearance quality in rice. Mining gene loci and elite alleles controlling GW is necessary. The GW phenotypes of the two populations were investigated in three environments, which showed abundant phenotypic variation. GW3, encoding a P450 subfamily protein, was identified and validated as a causal gene by gene-based haplotype analysis, expression analysis, gene knockout and complementation transgenic tests. The accessions with large GW values had high gene expression levels. In addition, the GW of the accessions with the GG allele was significantly greater than that of the accessions with the AA allele. The Hap 1 and Hap 3 were identified as elite haplotypes, which can increase GW. The expression levels of OsKO1, OsGA3ox1, OsGA20ox1 and OsGA20ox2 in the young panicle of A7444 were significantly greater than those in the young panicle of the mutants, indicating that GW3 may be involved in the gibberellins (GA) biosynthesis pathway to regulate GW. GA4 content detection and electron scanning analysis revealed that GA4 regulates GW by affecting glume cell size. These results provide new insights for studying the genetic mechanism of rice GW and provide a material basis for breeding high-yield rice varieties.

Persistence evaluation of fecal pollution indicators in dewatered sludge and dewatering filtrate of municipal sewage sludge: The impacts of ambient temperature and conditioning treatments

Sludge resource utilization is one of the important routines for transmitting fecal pollution to water and soil, and sludge dewatering is a crucial step for sludge resource utilization. However, it remains unclear the decay characteristics and persistence of fecal pollution indicators after sludge dewatering. In this study, the persistence of six fecal pollution indicators, namely E. coli (EC), human-specific HF183 Bacteroides (HF183), human adenovirus (HAdV), human JC and BK polyomavirus (JCPyV and BKPyV), and crAssphage, in dewatered sludge cake and dewatering filtrate deriving from raw sewage sludge, as well as three types of sludge conditioned with polyacrylamide (PAM), Fenton's reagent, or Fe[III] and CaO were analyzed. The quantitative polymerase chain reaction (qPCR) and viability-qPCR methods were used to analyze the variation in abundances and infectivity of fecal pollution indicators in dewatered sludge cake or dewatering filtrate over the storage time, respectively. Decay predications of fecal pollution indicators over time were modeled using either the first-order or the biphasic decay model. The qPCR results revealed that fecal pollution indicators in dewatered sludge cake persisted longer than those in dewatering filtrate at the same temperature. Increasing temperature can accelerate the decay of fecal pollution indicators in both dewatered sludge cake and dewatering filtrate. Notably, sludge conditioning treatment may prolong the persistence of fecal pollution indicators in both dewatered sludge cake and dewatering filtrate. Viability-qPCR results indicated that the fecal pollution indicators (except HAdV) in dewatered sludge cakes deriving from both raw sewage sludge and conditioned sludges remained infectious for up to 30 days. After a storage period of 40 days, the abundances of fecal pollution indicators (except for EC) in sludge conditioned with Fenton's reagent were effectively decreased and meanwhile the infectivity of EC was reduced, exhibiting the lowest levels of fecal pollution. Therefore, both ambient temperature and conditioning treatment greatly impacted the decay characteristics and persistence of fecal pollution indicators in dewatered sludge cake and dewatering filtrate, and selecting suitable conditioning method can minimize environmental risks associated with fecal pollution in sewage sludge.

Differential Effects of Chewing Lice on Body Condition across Host Age and Sex in Rough-legged Hawks (Buteo lagopus).

Chewing lice infesting avian hosts can significantly affect host health and fitness. Here, we present quantitative data on host body condition and louse abundance observed from 121 Rough-legged Hawks (Buteo lagopus) sampled across the North American nonbreeding range. Among hawks examined, louse prevalence was 71%, with a mean abundance and intensity of 9.1 and 12.8 lice, respectively. We identified lice as Craspedorrhynchus sp., either Craspedorrhynchus dilatatus or Craspedorrhynchus taurocephalus, dependent on future taxonomic revision of the genus. Female and juvenile hawks had greater louse intensity and prevalence compared with male and adult hawks, respectively. Host body condition, measured as a breast muscle score (keel score), was negatively correlated with louse abundance after controlling for host age and sex. Possible explanations for these patterns include the following: sex-biased louse transfer between adults and nestlings, when female nestlings experience increased transfer loads; body size differences between males and females, when females are larger than males in each life stage; and preening limitations in females and juveniles, when both spend more time hunting and less time preening relative to adult males. Our results corroborate previous studies suggesting that the primary sources of intraspecific variation in louse abundance are host body size and preening limitations.

Soil animal communities demonstrate simplification without homogenization along an urban gradient.

Urbanization profoundly impacts biodiversity and ecosystem function, exerting an immense ecological filter on the flora and fauna that inhabit it, oftentimes leading to simplistic and homogenous ecological communities. However, the response of soil animal communities to urbanization remains underexplored, and it is unknown whether their response to urbanization is like that of aboveground organisms. This study investigated the influence of urbanization on soil animal communities in 40 public parks along an urbanization gradient. We evaluated soil animal abundance, diversity, and community composition and related these measures to urban and soil characteristics at each park. The most urbanized parks exhibited reduced animal abundance, richness, and Shannon diversity. These changes were influenced by many variables underscoring the multifaceted influence of urbanization on ecological communities. Notably, contrary to our expectation, urbanization did not lead to community homogenization; instead, it acted stochastically, creating unique soil animal assemblages. This suggests that urban soil animal communities are concomitantly shaped by deterministic and stochastic ecological processes in urban areas. Our study highlights the intricate interplay between urbanization and soil animal ecology, challenging the notion of urban homogenization in belowground ecosystems and providing insight for managing and preserving belowground communities in urban areas.

Variation in Relative Abundance of Small Mammal Species Caught in Two Different Ecosystems and Implicated in the Spread of Emerging Pathogens in Mali

Background: Small rodents and insectivores are potential reservoirs of many pathogens transmissible to humans, such as bacteria, parasites and viruses responsible for epidemics in sub-Saharan Africa, particularly in West Africa. Few studies on small mammal species in West Africa are available. Our previous findings from a study investigating emerging pathogens in two localities in Mali has determined the prevalence of pathogens in small mammals (rodents and insectivores). We used the data collected from this small mammal population with different eco-climatic characteristics to test hypothesis that small mammal distribution in different eco-climatic settings could explain the diversity and frequency of pathogens they carry. Methods: Sessions of trapping were carried out in December 2016 in Faladjè and Bougouni with “Besançon tous services” (BTS) wire mesh traps baited with peanut butter and/or onion. All animals captured were identified morphologically. Results: Out of 123 small rodents and insectivores captured over 674 trap-nights, 75 (60.97%) were from Faladjè and 48 (39.02%) from Bougouni. Of these, six species of small rodents belonged to the family Muridae (Mastomys erythroleucus, Mastomys natalensis, Rattus rattus, Praomys daltoni, Gerbilliscus gambianus, Taterillus gracilis) and two species of insectivores associated with the genus Crocidura spp. belonged to the family Soricidae and Erinaceidae (Crocidura cf olivieri and Atelerix cf albiventris), respectively. There is low species diversity within these two areas, but the variation in relative abundance is significant (binomial test, p ˂ 0.05) between Faladjè and Bougouni. Mastomys erythroleucus was the most dominant species (57.33%, 43/75) in Faladjè, while R. rattus dominated (37.5%,18/48) in Bougouni. Conclusions: These two species of small mammals potentially involved in the transmission of bacteria, parasites and pathogenic viruses to humans are differently present in two distinct eco-climatic areas in Mali.

Effects of Intercropping of Sisal and Three Different Leguminous Plants on Soil Bacterial Diversity

Intercropping is widely utilised in agricultural production to enhance land use efficiency because of its benefits, such as heightened crop productivity and optimised resource utilisation. We investigated the effects of Pinto peanut/sisal (HST), Stylo/sisal (strT) and Grona styracifolia/sisal (JqT) intercropping systems on soil bacterial communities compared with sisal continuous cropping (CK) by using Illumina MiSeq high-throughput sequencing technology. The intercropping system significantly increased the total nitrogen (TN), soil pH and soil moisture levels and decreased the levels of available phosphorus (AP) and available potassium (AK). Minimal variations were observed in Shannon’s and Simpson’s diversity indices between the monoculture and intercropping systems as well as among different intercropping systems. The most abundant phyla observed within the four groups were Proteobacteria, Acidobacteria, Cyanobacteria and Bacteroidetes. At the phylum level, the relative abundances of Proteobacteria, Acidobacteria, Cyanobacteria and Bacteroidetes were 37.37–54.35%, 10.54–21.21%, 3.46–20.43% and 2.15–5.67%, respectively. Compared with ZCK, StrT, JqT and HST treatments led to higher abundance of Cyanobacteria (from 3.46% to 20.43%, 11.37% and 16.58%, respectively) and Bacteroidetes (from 2.15% to 5.67%, 5.21% and 5.10%, respectively). The results of the linear discriminant analysis of effect sizes demonstrated notable variations in the relative abundance of bacterial taxa among various intercropping systems. The dominant categories of the genus in strT and JqT groups were Blastocatellia and Blastocatellaceae-Subgroup4, while Firmicutes was the dominant category of the genus in the HST group. The structure of bacterial communities did not vary between intercropping and monoculture systems. The findings indicated that the impact of the intercropping system on the bacterial community structure was not contingent on the specific intercropping patterns employed.

Abundance Trends of Immature Stages of Ticks at Different Distances from Hiking Trails from a Natural Park in North-Western Italy.

Hiking trails may act as hotspots at the wildlife-human interface, posing an acarological risk for people and their pets. Ticks that are maintained in the environment by wild animals may quest on people walking along the trails. Assessing the risk of tick bites for people involved in outdoor activities is a further step in mitigating the risk of tick-borne diseases. This work describes the variation of tick abundance along a gradient of distances from hiking trails, where wildlife passage is favored by higher accessibility. Hiking trails with dense vegetation on the sides were sampled for ticks along a 100 m dragging transect, located in a natural park in North-Western Italy. Additional transects were replicated at 1, 2 and 4 m away from the trail on both sides. After morphological identification, descriptive statistics and modeling were applied to determine the abundance patterns across distances. Larvae were most abundant near the trail, peaking at 1 m and dropping sharply at further distances. Nymphs showed a more gradual and consistent decrease at progressing distance from the trail. Few adults were collected, preventing the identification of a clear trend. With higher tick abundance, the immediate vicinity of hiking trails may represent a source of acarological risk for humans and pets.

Variation in SSRs at different genomic regions and implications for the evolution and identification of Armillaria gallica.

Armillaria spp. are devastating forest pathogens. Due to its low pathogenicity and abundant genetic variation, Armillaria gallica exhibited a unique and beneficial symbiosis with Gastrodia elata, which was used as a traditional Chinese medicine. However, the variation and population structure of A. gallica populations have rarely been investigated. Hence, we analyzed the evolution and variation in simple sequence repeats (SSRs) in three Armillaria genomes: A. gallica, A. cepistipes, and A. ostoyae to assess the genetic diversity and population structure of 14 A. gallica strains. Genome analysis revealed that SSRs were more abundant in the intergenic region than the intron and exon region, as was the SSR density. Compared with other two genomes, SSR density was the lowest in exon region and largest in the intron region of A. gallica, with significant variation in genic region. There were 17 polymorphic markers in A. gallica genome was identified, with 26.7% in genic region, which is higher than that of 18.8% in the intergenic region. Moreover, a total of 50 alleles and 42 polymorphic loci were detected among these A. gallica strains. The averaged polymorphism information content (PIC) was 0.4487, ranged from 0.2577 to 0.6786. Both principal coordinate analysis (PCoA) and population structure analyses based on the genotype data of SSRs divided the strains into two clusters. The cluster I included all the strains from high-altitude G. elata producing areas and some low-altitude areas, while the strains in Cluster II originated from low-altitude G. elata producing areas. These results indicated that substantial genome-specific variation in SSRs within the genic region of A. gallica and provide new insights for further studies on the evolution and breeding of A. gallica.

Seasonal Dynamics and Avian Diversity along the Adyar Riverbank: Insights from a Year-Long Survey

The avian survey conducted along the Adyar Riverbank (Manapakkam) from January 2023 to December 2023 documented a total of 3120 individual birds across 75 species from 16 avian orders, highlighting the significant biodiversity within this urban ecosystem. This study aimed to assess seasonal variations in bird diversity and abundance, emphasizing the river’s role as an important habitat. The highest diversity was observed during winter, specifically in February 2023, with a diversity index of 296.80 and a Simpson’s index of 0.22. A total of 36 species and 636 individuals were recorded. In contrast, the lowest diversity was observed in summer, particularly in July 2023, with a diversity index of 29.29 and a Simpson’s index of 0.05, corresponding to 18 species and 114 individuals. The monsoon and post-monsoon periods exhibited a prominent increase in diversity due to the arrival of migratory species and improved habitat conditions. Important species recorded throughout the year included the Paddy Field Pipit, House Crow, and Rufous Treepie, while conservation-significant species such as the Black-headed Ibis and Spot-billed Pelican were also observed. Thus, the present study underscores the Adyar River’s ecological importance and highlights the need for continuous monitoring and targeted conservation efforts to maintain avian biodiversity in urban river ecosystems.

Linking summer nutrition to behavior and performance of black‐tailed deer

AbstractMany large‐herbivore populations are regulated at least in part by bottom‐up forces, and thus relationships between herbivores and their habitat are of fundamental importance to wildlife managers. Variation in nutritional resources—and how herbivores respond to that variation—influences rates of nutrient intake, which directly affect nutritional condition, pregnancy rates, timing of parturition, offspring birth mass, and survival. Accordingly, nutrition‐focused research holds great potential for uncovering the mechanisms that govern population performance of large herbivores and for assessing the nature and magnitude of bottom‐up limitations. We quantified relationships between the foodscape (i.e., spatiotemporal variation in forage quality and abundance) in southwestern Oregon, USA, and black‐tailed deer (Odocoileus hemionus columbianus) behavior and performance, with a focus on the influence of maternal nutrition on fawn survival. We hypothesized that black‐tailed deer performance (i.e., fawn birth mass and survival) is influenced by the availability of high‐quality forage during spring and summer and patterns of foodscape use exhibited by individual deer. From 2016–2023 we monitored movement and survival of adult female black‐tailed deer and their offspring. We also conducted intensive vegetation sampling and used generalized additive modeling to map the foodscape available to deer in spring and summer. Suitable forage biomass (i.e., maximum biomass of forage that together exceeded quality thresholds for supporting one fawn) was highly variable across space and time, and our top foodscape model explained 70% of the variation in suitable biomass (adjusted R2 = 0.70). We observed a strong, positive relationship between use of the foodscape by maternal females prior to parturition and fawn birth mass. Although maternal foodscape use after parturition did not influence the probability of fawn survival, survival increased with increasing birth mass. These results suggest that the effects of nutrition on fawn survival in our study system are indirectly mediated by maternal behavior (i.e., use of the foodscape) and the corresponding effects on birth mass of fawns. Our study adds to a growing body of literature supporting a fundamental link between foodscape use and population performance of large herbivores. Wildlife managers can use the dynamic models we developed to assess habitat quality and to make quantitative predictions about how different management actions (e.g., forest thinning) are likely to influence habitat quality and performance of black‐tailed deer.

Missing the biodiversity for the bee: Natural land management strategies impact functional invertebrate diversity in commercial cranberry production

Abstract Simplification of agricultural environments is linked to declines in biodiversity. Improving the floral diversity within and around these areas may result in more robust and diverse ecosystems. We investigated how floral resource abundance, diversity, and species composition in a cranberry agricultural system correlated to the abundance and overall invertebrate diversity and to the abundance and diversity of specific invertebrate groups of agricultural importance (e.g. parasitoids, phytophagous taxa, pollinators and predators). This study focused on habitats immediately surrounding cranberry production and included grassy dikes under a managed system (‘dike’), and semi‐natural areas growing on the surrounding support land (‘semi‐natural’). Floral resource availability and diversity tended to be similar between habitats, while invertebrate richness, diversity and composition differed. As the availability of floral resources increased, invertebrate abundance increased but diversity decreased. Overall invertebrate community composition differed with the specific species and availability of floral resources. The habitat type and floral resource composition impacted some agriculturally important groups, as pollinator abundance was higher in the semi‐natural habitat, and parasitoid abundance varied with floral resource composition across both habitats. These results suggest that managing the structural and floral resource diversity associated with agroecosystems can help support local biodiversity. However, these systems may disproportionately benefit more common taxonomic groups. The difference in responses of individual taxonomic groups also highlights the potential tradeoffs of focusing on only a subset of biodiversity aspects.