Ephemeral habitat supports high fish α‐diversity and β‐diversity during drought in a subtropical semiarid wetland

Biotropica ◽  
2021 ◽  
Author(s):  
Thethela Bokhutlo ◽  
Eduardo R. Cunha ◽  
Kirk O. Winemiller
Keyword(s):  
Β Diversity ◽  
Α Diversity ◽  
Ephemeral Habitat ◽  
High Fish

Patterns in diversity and composition of the microbenthos of subarctic intertidal beaches with different morphodynamics

2020 ◽  
Vol 648 ◽  
pp. 19-38
Author(s):  
AI Azovsky ◽  
YA Mazei ◽  
MA Saburova ◽  
PV Sapozhnikov
Keyword(s):  
Species Abundance ◽  
Abundance Ratio ◽  
Wave Action ◽  
Coarse Grained ◽  
Sediment Properties ◽  
Β Diversity ◽  
Α Diversity ◽  
Wide Range ◽  
Similar Mode ◽  
Abundance And Diversity

Diversity and composition of benthic diatom algae and ciliates were studied at several beaches along the White and Barents seas: from highly exposed, reflective beaches with coarse-grained sands to sheltered, dissipative silty-sandy flats. For diatoms, the epipelic to epipsammic species abundance ratio was significantly correlated with the beach index and mean particle size, while neither α-diversity measures nor mean cell length were related to beach properties. In contrast, most of the characteristics of ciliate assemblages (diversity, total abundance and biomass, mean individual weight and percentage of karyorelictids) demonstrated a strong correlation to beach properties, remaining low at exposed beaches but increasing sharply in more sheltered conditions. β-diversity did not correlate with beach properties for either diatoms or ciliates. We suggest that wave action and sediment properties are the main drivers controlling the diversity and composition of the intertidal microbenthos. Diatoms and ciliates, however, demonstrated divergent response to these factors. Epipelic and epipsammic diatoms exhibited 2 different strategies to adapt to their environments and therefore were complementarily distributed along the environmental gradient and compensated for each other in diversity. Most ciliates demonstrated a similar mode of habitat selection but differed in their degree of tolerance. Euryporal (including mesoporal) species were relatively tolerant to wave action and therefore occurred under a wide range of beach conditions, though their abundance and diversity were highest in fine, relatively stable sediments on sheltered beaches, whereas the specific interstitial (i.e. genuine microporal) species were mostly restricted to only these habitats.

Gut microbiome of the emerald ash borer, Agrilus planipennis Fairmaire, and its relationship with insect population density

2020 ◽  
Vol 96 (8) ◽  
Author(s):  
Judith Mogouong ◽  
Philippe Constant ◽  
Robert Lavallée ◽  
Claude Guertin
Keyword(s):  
Population Density ◽  
Gut Microbiome ◽  
Emerald Ash Borer ◽  
Agrilus Planipennis ◽  
Economic Damage ◽  
Taxonomic Structure ◽  
Rrna Gene ◽  
Local Conditions ◽  
Β Diversity ◽  
Α Diversity

ABSTRACT The gut microbial communities of beetles play crucial roles in their adaptive capacities. Environmental factors such as temperature or nutrition naturally affect the insect microbiome, but a shift in local conditions like the population density on a host tree could also lead to changes in the microbiota. The emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an exotic wood borer that causes environmental and economic damage to ash trees in North America. This study aimed to describe the taxonomic structure of the EAB gut microbiome and explore its potential relationship with borer population size. The number of EAB adults collected per tree through a 75 km transect from an epicenter allowed the creation of distinct classes of population density. The Gammaproteobacteria and Ascomycota predominated in bacterial and fungal communities respectively, as determined by sequencing of the bacterial 16S rRNA gene and the fungal internal transcribed spacer ITS2. Species richness and diversity of the bacterial community showed significant dependence on population density. Moreover, α-diversity and β-diversity analysis revealed some indicator amplicon sequence variants suggesting that the plasticity of the gut microbiome could be related to the EAB population density in host trees.

scholarly journals Arthropod community structure in pastures of an island archipelago (Azores): looking for local–regional species richness patterns at fine-scales

2004 ◽  
Vol 94 (2) ◽  
pp. 111-121 ◽  
Author(s):  
P.A.V. Borges ◽  
V.K. Brown
Keyword(s):  
Species Richness ◽  
Regional Scale ◽  
Local Scale ◽  
Local Species Richness ◽  
Β Diversity ◽  
Arthropod Species ◽  
Α Diversity ◽  
Local Species ◽  
Richness Patterns

AbstractThe arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local–regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= α diversity) and regional species richness was estimated at the pasture level (= γ diversity) with the ‘first-order-Jackknife’ estimator. Three related issues were addressed: (i) the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii) quantification of the relative contributions of α and β diversity to regional diversity using additive partitioning; and (iii) the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing β-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.

A quantitative null model of additive diversity partitioning: examining the response of beta diversity to extinction

Paleobiology ◽  
2007 ◽  
Vol 33 (1) ◽  
pp. 116-124 ◽  
Author(s):  
Karen M. Layou
Keyword(s):  
Null Model ◽  
Sampling Strategy ◽  
Diversity Partitioning ◽  
Opposite Pattern ◽  
Β Diversity ◽  
Α Diversity ◽  
Before And After ◽  
Four Levels ◽  
Total Diversity ◽  
Selective Extinction

Paleobiological diversity is often expressed as α (within-sample), β (among-sample), and γ (total) diversities. However, when studying the effects of extinction on diversity patterns, only variations in α and γ diversities are typically addressed. A null model that examines changes in β diversity as a function of percent extinction is presented here.The model examines diversity in the context of a hierarchical sampling strategy that allows for the additive partitioning of γ diversity into mean α and β diversities at varying scales. Here, the sampling hierarchy has four levels: samples, beds, facies, and region; thus, there are four levels of α diversity (α1, α2, α3, α4) and three levels of β diversity (β1, β2, and β3). Taxa are randomly assigned to samples within the hierarchy according to probability of occurrence, and initial mean α and β values are calculated. A regional extinction is imposed, and the hierarchy is resampled from the remaining extant taxa. Post-extinction mean α and β values are then calculated.Both non-selective and selective extinctions with respect to taxon abundance yield decreases in α, β, and γ diversities. Non-selective extinction with respect to taxon abundance shows little effect on diversity partitioning except at the highest extinction magnitudes (above 75% extinction), where the contribution of α1 to total γ increases at the expense of β3, with β1 and β2 varying little with increasing extinction magnitude. The pre-extinction contribution of α1 to total diversity increases with increased probabilities of taxon occurrence and the number of shared taxa between facies. Both β1 and β2 contribute equally to total diversity at low occurrence probabilities, but β2 is negligible at high probabilities, because individual samples preserve all the taxonomic variation present within a facies. Selective extinction with respect to rare taxa indicates a constant increase in α1 and constant decrease in β3 with increasing extinction magnitudes, whereas selective extinction with respect to abundant taxa yields the opposite pattern of an initial decrease in α1 and increase in β3. Both β1 and β2 remain constant with increasing extinction for both cases of selectivity. By comparing diversity partitioning before and after an extinction event, it may be possible to determine whether the extinction was selective with respect to taxon abundances, and if so, whether that selectivity was against rare or abundant taxa.Field data were collected across a Late Ordovician regional extinction in the Nashville Dome of Tennessee, with sampling hierarchy similar to that of the model. These data agree with the abundant-selective model, showing declines in α, β, and γ diversities, and a decrease in α1 and increase in β3, which suggests this extinction may have targeted abundant taxa.

scholarly journals Exploration of Intrinsic Microbial Community Modulators in the Rice Endosphere Indicates a Key Role of Distinct Bacterial Taxa Across Different Cultivars

2021 ◽  
Vol 12 ◽  
Author(s):  
Pei Wang ◽  
Xiao Kong ◽  
Hongsong Chen ◽  
Youlun Xiao ◽  
Huijun Liu ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Rice Cultivars ◽  
Rice Varieties ◽  
Microbial Network ◽  
Β Diversity ◽  
Group I ◽  
Α Diversity ◽  
Microbe Interactions ◽  
Endophytic Bacterial Community ◽  
Group Ii

Microbial communities associated with the plant phyllosphere and endosphere can have both beneficial as well as detrimental effects on their hosts. There is an ongoing debate to which extend the phyllosphere and endosphere microbiome assembly is controlled by the host plant how pronounced cultivar effects are. We investigated the bacterial and fungal communities from the phyllosphere and endosphere of 10 different rice cultivars grown under identical environmental conditions in the frame of a targeted approach to identify drivers of community assembly. The results indicated that the endophytic bacterial communities were clearly separated into two groups. The α-diversity and microbial network complexity within Group I were significantly lower than in Group II. Moreover, the genera Nocardioides, Microvirga, and Gaiella were significantly more abundant in Group II and only present in the interaction networks of this group. These three genera were significantly correlated with α- and β-diversity of the endophytic bacterial community and thus identified as major drivers of the endosphere community. We have identified keystone taxa that shape endophytic bacterial communities of different rice cultivars. Our overall findings provide new insights into plant-microbe interactions, and may contribute to targeted improvements of rice varieties in the future.

scholarly journals Ecological and microbiological diversity of chigger mites, including vectors of scrub typhus, on small mammals across stratified habitats in Thailand

2019 ◽  
Author(s):  
Kittipong Chaisiri ◽  
A. Christina Gill ◽  
Alexandr A. Stekolnikov ◽  
Soawapak Hinjoy ◽  
John W. McGarry ◽  
...  
Keyword(s):  
Species Richness ◽  
Scrub Typhus ◽  
Bacterial Pathogen ◽  
Febrile Illness ◽  
Asia Pacific ◽  
Habitat Types ◽  
Widespread Species ◽  
Human Land Use ◽  
Β Diversity ◽  
Α Diversity

AbstractScrub typhus, caused by a bacterial pathogen (Orientia spp.), is a potentially life-threatening febrile illness widely distributed in the Asia-Pacific region and is emerging elsewhere. The infection is transmitted by the larval stage of trombiculid mites (“chiggers”) that often exhibit low host specificity. Here, we present an analysis of chigger ecology for 38 species sampled from 11 provinces of Thailand and microbiomes for eight widespread species. In total, >16 000 individual chiggers were collected from 1 574 small mammal specimens belonging to 18 species across four horizontally-stratified habitat types. Chigger species richness was positively associated with higher latitudes, dry seasonal conditions, and host maturity; but negatively associated with increased human land use. Human scrub typhus incidence was found to be positively correlated with chigger species richness. The bacterial microbiome of chiggers was highly diverse, with Sphingobium, Mycobacterium, Neisseriaceae and various Bacillales representing the most abundant taxa. Only Leptotrombidium deliense was found to be infected with Orientia. β-diversity, but not α-diversity, was significantly different between chigger species and geographic regions, although not between habitat types. This first field survey of the chigger microbiome provides a framework for future studies on interactions between pathogens and other symbionts in these understudied vectors.

Pilot trial of vitamin D3 and calcifediol in healthy vitamin D deficient adults: does it change the fecal microbiome?

2021 ◽  
Author(s):  
Albert Shieh ◽  
S Melanie Lee ◽  
Venu Lagishetty ◽  
Carter Gottleib ◽  
Jonathan P Jacobs ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Relative Abundance ◽  
Vitamin D3 ◽  
Pilot Trial ◽  
Fecal Microbiota ◽  
Small Sample ◽  
Rrna Gene ◽  
Β Diversity ◽  
Α Diversity

Abstract Purpose To determine whether correcting vitamin D deficiency with cholecalciferol (vitamin D3, D3) or calcifediol (25-hydroxyvitamin D3, 25(OH)D3) changes gut microbiome composition. Methods 18 adults with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] <20 ng/ml) received 60 mcg/day of D3 or 20 mcg/day of 25(OH)D3 for 8 weeks. Changes in serum 25(OH)D, 1,25-diydroxyvitamin D (1,25(OH)2D), and 24,25-dihydroxyvitamin D (24,25(OH)2D) were assessed. We characterized composition of the fecal microbiota using 16S rRNA gene sequencing, and examined changes in α-diversity (Chao 1, Faith’s Phylogenetic Diversity, Shannon Index), β-diversity (DEICODE), and genus-level abundances (DESeq2). Results Vitamin D3 and 25(OH)D3 groups were similar. After 8 weeks of vitamin D3, mean 25(OH)D and 24,25(OH)2D increased significantly, but 1,25(OH)2D did not (25(OH)D: 17.8 to 30.1 ng/ml [p=0.002]; 24,25(OH)2D: 1.1 to 2.7 ng/ml [p=0.003]; 1,25(OH)2D: 49.5 to 53.0 pg/ml [p=0.9]). After 8 weeks of 25(OH)D3, mean 25(OH)D, 24,25(OH)2D, and 1,25(OH)2D increased significantly (25(OH)D: 16.7 to 50.6 ng/ml [p<0.0001]; 24,25(OH)2D: 1.3 to 6.2 ng/ml [p=0.0001]; 1,25(OH)2D: 56.5 to 74.2 pg/ml [p=0.05]). Fecal microbial α-diversity and β-diversity did not change with D3 or 25D3 supplementation. Mean relative abundance of Firmicutes increased and mean relative abundance of Bacterioidetes decreased from baseline to four weeks, but returned to baseline by study completion. DESeq2 analysis did not confirm any statistically significant taxonomic changes. Main conclusions In a small sample of healthy adults with vitamin D deficiency, restoration of vitamin D sufficiency with vitamin D3 or 25(OH)D3 did not lead to lasting changes in the fecal microbiota.

The microbial characteristics of patients with esophageal squamous cell carcinoma before and after immunotherapy.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e16016-e16016
Author(s):  
Jing Zuo ◽  
Wenjing Lv ◽  
Yudong Wang ◽  
Zhisong Fan ◽  
Li Feng ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
16S Rrna ◽  
Esophageal Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Fecal Samples ◽  
Β Diversity ◽  
Α Diversity ◽  
Before And After ◽  
New Ideas

e16016 Background: Esophageal squamous cell carcinoma (ESCC) is a common malignancy without effective therapy. Immune checkpoint–oriented immunotherapies have shown considerable promise and the advent of esophageal microbiome provides researchers with new ideas. Methods: DNA was extracted from blood, oral mucosal, saliva, urine, fecal samples from 20 ESCC patients before and after immunotherapy. Total microbial genomic DNA samples were extracted using an OMEGA Soil DNA Kit (D5625-01). The V3–V4 regions of bacterial 16S rRNA genes were amplified by PCR using the forward primer and the reverse primer and were sequenced with Illumina MiSeq platform. In order to comprehensively evaluate the α diversity of microbial communities, we used Chao1 and Observed Species indices to characterize the richness, Shannon and Simpson indices to characterize the diversity. PCoA were used to analyze differences in β diversity. Functions of 16S rRNA sequences were predicted using the PICRUSt2 and KEGG databases. Results: A comparison of blood, oral mucosal, saliva, urine, fecal samples of ESCC patients before and after immunotherapy showed that α diversity was not statistically significant. In terms of β diversity, no statistically significant differences were detected within blood, oral mucosal, saliva, urine, fecal samples of ESCC patients before and after immunotherapy. In ESCC patients treated before immunotherapy, the α diversity and β diversity of blood, oral mucosal, saliva, urine, fecal samples were different, and in ESCC patients treated after immunotherapy had the same rule. At the phylum level, the top 5 microbes in ESCC patients before and after immunotherapy were Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Fusobacteria. At the genus level, the top 5 microbes in ESCC patients before immunotherapy were Aquabacterium, Streptococcus, Prevotella, Veillonella, Bacteroides, and in ESCC patients after immunotherapy were Aquabacterium, Streptococcus, Prevotella, Faecalibacterium, Veillonella. In terms of the microbial functions in ESCC patients before and after immunotherapy, the metabolic pathways accounted for the most. Conclusions: This study is conducive to exploring new mechanisms for tumor cells to evade host immune surveillance, providing new ideas and new strategies for the microecology-based immunotherapy of ESCC.

Association of subjective global assessment of nutritional status with gut microbiota in hemodialysis patients: a case–control study

2020 ◽  
Author(s):  
Ting-Yun Lin ◽  
Szu-Chun Hung
Keyword(s):  
Nutritional Status ◽  
Gut Microbiota ◽  
Global Assessment ◽  
Hemodialysis Patients ◽  
Adverse Outcomes ◽  
Subjective Global Assessment ◽  
Protein Energy Wasting ◽  
Β Diversity ◽  
Protein Energy ◽  
Α Diversity

Abstract Background Protein-energy wasting (PEW) is prevalent and associated with adverse outcomes in patients with chronic kidney disease (CKD). However, the pathogenesis of PEW in CKD patients has not been fully identified. The gut microbiota has been implicated in the regulation of host metabolism and energy balance. Therefore, we aimed to explore the association between nutritional status and the composition of the gut microbiota in hemodialysis patients. Methods Gut microbial diversity and taxonomy were examined in 88 hemodialysis patients with PEW (n = 22) and normal nutritional status (n = 66) who were matched 1:3 for age and sex. Nutritional status was assessed by using the 7-point subjective global assessment (SGA) score (1–3 = severe PEW; 4–5 = moderate PEW and 6–7 = normal nutrition). The gut microbiota was assessed by 16S ribosomal RNA gene sequencing. Results Patients with normal nutritional status had a significantly higher body mass index and physical activity and serum albumin levels, but significantly lower levels of inflammatory cytokines than patients with PEW. The most striking finding was that the α-diversity of the gut microbiota was significantly lower in patients with PEW. In a multivariate analysis, the SGA score was independently and positively associated with α-diversity (P = 0.049). Patients with or without PEW were different with respect to the principal coordinate analysis of β-diversity. Notably, the relative abundance of Faecalibacterium prausnitzii, a butyrate-producing bacteria, was markedly reduced in patients with PEW. Conclusion In hemodialysis patients, PEW assessed with the SGA was associated with gut dysbiosis.

scholarly journals Ecological and microbiological diversity of chigger mites, including vectors of scrub typhus, on small mammals across stratified habitats in Thailand

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Kittipong Chaisiri ◽  
A. Christina Gill ◽  
Alexandr A. Stekolnikov ◽  
Soawapak Hinjoy ◽  
John W. McGarry ◽  
...  
Keyword(s):  
Species Richness ◽  
Scrub Typhus ◽  
Bacterial Pathogen ◽  
Febrile Illness ◽  
Asia Pacific ◽  
Habitat Types ◽  
Widespread Species ◽  
Human Land Use ◽  
Β Diversity ◽  
Α Diversity

Abstract Background Scrub typhus, caused by a bacterial pathogen (Orientia spp.), is a potentially life-threatening febrile illness widely distributed in the Asia-Pacific region and is emerging elsewhere. The infection is transmitted by the larval stage of trombiculid mites (“chiggers”) that often exhibit low host specificity. Here, we present an analysis of chigger ecology for 38 species sampled from 11 provinces of Thailand and microbiomes for eight widespread species. Results In total, > 16,000 individual chiggers were collected from 1574 small mammal specimens belonging to 18 species across four horizontally-stratified habitat types. Chigger species richness was positively associated with higher latitudes, dry seasonal conditions, and host maturity; but negatively associated with increased human land use. Human scrub typhus incidence was found to be positively correlated with chigger species richness. The bacterial microbiome of chiggers was highly diverse, with Sphingobium, Mycobacterium, Neisseriaceae and various Bacillales representing the most abundant taxa. Only Leptotrombidium deliense was found to be infected with Orientia and another potential pathogen, Borrelia spp., was frequently detected in pools of this species. β-diversity, but not α-diversity, was significantly different between chigger species and geographic regions, although not between habitat types. Conclusion Our study identified several key environmental and host-derived correlates of chigger species richness across Thailand, which in turn impacted on human scrub typhus incidence. Moreover, this first extensive field survey of the chigger microbiome revealed species- and province-level variation in microbial β-diversity across the country, providing a framework for future studies on interactions between pathogens and other symbionts in these understudied vectors.

Sign in / Sign up

Export Citation Format

Share Document