Performance of partitioning functional beta-diversity indices: Influence of functional representation and partitioning methods

2017 ◽  
Vol 26 (6) ◽  
pp. 753-762 ◽  
Author(s):  
Nicolas Loiseau ◽  
Gaëlle Legras ◽  
Jean-Claude Gaertner ◽  
Philippe Verley ◽  
Pascale Chabanet ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Diversity Indices ◽  
Partitioning Methods ◽  
Functional Representation

scholarly journals The Fecal Bacterial Microbiota in Horses with Equine Recurrent Uveitis

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 745
Author(s):  
Michelle Martin de Bustamante ◽  
Diego Gomez ◽  
Jennifer MacNicol ◽  
Ralph Hamor ◽  
Caryn Plummer
Keyword(s):  
Beta Diversity ◽  
High Throughput Sequencing ◽  
Illumina Miseq ◽  
Diversity Indices ◽  
Rrna Gene ◽  
Linear Discriminant ◽  
Alpha And Beta Diversity ◽  
Bacterial Microbiota ◽  
Healthy Control ◽  
Equine Recurrent Uveitis

The objective of this study was to describe and compare the fecal bacterial microbiota of horses with equine recurrent uveitis (ERU) and healthy horses using next-generation sequencing techniques. Fecal samples were collected from 15 client-owned horses previously diagnosed with ERU on complete ophthalmic examination. For each fecal sample obtained from a horse with ERU, a sample was collected from an environmentally matched healthy control with no evidence of ocular disease. The Illumina MiSeq sequencer was used for high-throughput sequencing of the V4 region of the 16S rRNA gene. The relative abundance of predominant taxa, and alpha and beta diversity indices were calculated and compared between groups. The phyla Firmicutes, Bacteroidetes, Verrucomicrobia, and Proteobacteria predominated in both ERU and control horses, accounting for greater than 60% of sequences. Based on linear discriminant analysis effect size (LEfSe), no taxa were found to be enriched in either group. No significant differences were observed in alpha and beta diversity indices between groups (p > 0.05 for all tests). Equine recurrent uveitis is not associated with alteration of the gastrointestinal bacterial microbiota when compared with healthy controls.

Landscape patterns influence communities of medium- to large-bodied vertebrates in undisturbed terra firme forests of French Guiana

2015 ◽  
Vol 31 (5) ◽  
pp. 423-436 ◽  
Author(s):  
Cécile Richard-Hansen ◽  
Gaëlle Jaouen ◽  
Thomas Denis ◽  
Olivier Brunaux ◽  
Eric Marcon ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Amazon Basin ◽  
French Guiana ◽  
Forest Ecology ◽  
Habitat Preferences ◽  
Diversity Indices ◽  
Landscape Patterns ◽  
Line Transect ◽  
Terra Firme ◽  
Association Index

Abstract:Whereas broad-scale Amazonian forest types have been shown to influence the structure of the communities of medium- to large-bodied vertebrates, their natural heterogeneity at smaller scale or within the terra firme forests remains poorly described and understood. Diversity indices of such communities and the relative abundance of the 21 most commonly observed species were compared from standardized line-transect data across 25 study sites distributed in undisturbed forests in French Guiana. We first assessed the relevance of a forest typology based on geomorphological landscapes to explain the observed heterogeneity. As previously found for tree beta-diversity patterns, this new typology proved to be a non-negligible factor underlying the beta diversity of the communities of medium- to large bodied vertebrates in French Guianan terra firme forests. Although the species studied are almost ubiquitous across the region, they exhibited habitat preferences through significant variation in abundance and in their association index with the different landscape types. As terra firme forests represent more than 90% of the Amazon basin, characterizing their heterogeneity – including faunal communities – is a major challenge in neotropical forest ecology.

scholarly journals Diversity Indices of Plant Communities and Their Rhizosphere Microbiomes: An Attempt to Find the Connection

2021 ◽  
Vol 9 (11) ◽  
pp. 2339
Author(s):  
Aleksei O. Zverev ◽  
Arina A. Kichko ◽  
Aleksandr G. Pinaev ◽  
Nikolay A. Provorov ◽  
Evgeny E. Andronov
Keyword(s):  
Microbial Communities ◽  
Plant Communities ◽  
Plant Diversity ◽  
Beta Diversity ◽  
Mutual Influence ◽  
Plant Root ◽  
Alpha Diversity ◽  
Diversity Indices ◽  
Alpha And Beta Diversity ◽  
Highly Correlated

The rhizosphere community represents an “ecological interface” between plant and soil, providing the plant with a number of advantages. Despite close connection and mutual influence in this system, the knowledge about the connection of plant and rhizosphere diversity is still controversial. One of the most valuable factors of this uncertainty is a rough estimation of plant diversity. NGS sequencing can make the estimations of the plant community more precise than classical geobotanical methods. We investigate fallow and crop sites, which are similar in terms of environmental conditions and soil legacy, yet at the same time are significantly different in terms of plant diversity. We explored amplicons of both the plant root mass (ITS1 DNA) and the microbial communities (16S rDNA); determined alpha- and beta-diversity indices and their correlation, and performed differential abundance analysis. In the analysis, there is no correlation between the alpha-diversity indices of plants and the rhizosphere microbial communities. The beta-diversity between rhizosphere microbial communities and plant communities is highly correlated (R = 0.866, p = 0.01). ITS1 sequencing is effective for the description of plant root communities. There is a connection between rhizosphere communities and the composition of plants, but on the alpha-diversity level we found no correlation. In the future, the connection of alpha-diversities should be explored using ITS1 sequencing, even in more similar plant communities—for example, in different synusia.

scholarly journals Unimodal Relationships of Understory Alpha and Beta Diversity along Chronosequence in Coppiced and Unmanaged Beech Forests

Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 101 ◽  
Author(s):  
Sándor Bartha ◽  
Roberto Canullo ◽  
Stefano Chelli ◽  
Giandiego Campetella
Keyword(s):  
Beta Diversity ◽  
Management Practices ◽  
Multiple Scales ◽  
Forest Succession ◽  
Spatial Scales ◽  
Alpha Diversity ◽  
Structural Diversity ◽  
Diversity Indices ◽  
Alpha And Beta Diversity ◽  
Coppice Management

Patterns of diversity across spatial scales in forest successions are being overlooked, despite their importance for developing sustainable management practices. Here, we tested the recently proposed U-shaped biodiversity model of forest succession. A chronosequence of 11 stands spanning from 5 to 400 years since the last disturbance was used. Understory species presence was recorded along 200 m long transects of 20 × 20 cm quadrates. Alpha diversity (species richness, Shannon and Simpson diversity indices) and three types of beta diversity indices were assessed at multiple scales. Beta diversity was expressed by a) spatial compositional variability (number and diversity of species combinations), b) pairwise spatial turnover (between plots Sorensen, Jaccard, and Bray–Curtis dissimilarity), and c) spatial variability coefficients (CV% of alpha diversity measures). Our results supported the U-shaped model for both alpha and beta diversity. The strongest differences appeared between active and abandoned coppices. The maximum beta diversity emerged at characteristic scales of 2 m in young coppices and 10 m in later successional stages. We conclude that traditional coppice management maintains high structural diversity and heterogeneity in the understory. The similarly high beta diversities in active coppices and old-growth forests suggest the presence of microhabitats for specialist species of high conservation value.

Investigating the role of the gastrointestinal microbiome in response to immune checkpoint inhibitors (ICIs) among patients (pts) with metastatic renal cell carcinoma (mRCC).

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 730-730 ◽  
Author(s):  
Anika Agarwal ◽  
Jennifer Modliszewski ◽  
Lauren Davey ◽  
Marco Reyes-Martinez ◽  
Daniella Runyambo ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Checkpoint Inhibitors ◽  
Predictive Biomarkers ◽  
Alpha Diversity ◽  
Diversity Indices ◽  
P Value ◽  
Diversity Analysis ◽  
Microbial Composition ◽  
Response Factors ◽  
Microbial Dna

730 Background: ICIs are effective in mRCC, but one pertinent clinical need is to identify predictive biomarkers for response. The PD-1 receptor has been implicated in regulating gastrointestinal commensal bacteria, with varied immune interactions, thereby impacting response to ICIs. We evaluated bacterial taxa and ICI outcomes in mRCC pts. Methods: Fecal samples from 22 mRCC pts were collected at baseline, week (wk)-4 on ICI, and upon disease progression. Pts were grouped as responders (R, complete or partial response) or non-responders (NR, stable or progressive disease). Microbial DNA was isolated by next generation DNA sequencing. The V4 region of bacterial 16S ribosomal RNA was amplified from extracted DNA and analyzed for bacterial abundance, as well as alpha diversity indices (number of amplicon sequence variants [ASVs], Shannon’s Index, Faith’s Phylogenetic Diversity, and Pielou’s evenness) and beta diversity indices on ASVs (Bray-Curtis, Jaccard, and unweighted/weighted UniFrac dissimilarity measures). Results: Beta diversity analysis at baseline showed no difference in microbial composition between Rs and NRs. However, beta diversity analysis did show a significant change in composition from baseline to wk 4 in R vs NR pts (Bray Curtis p-value=0.03). Among mRCC pts with CR to ICIs, counts of bacteria in the phylum Verrucomicrobia had an upward trend from baseline to wk 4. All mRCC pts with CR (n=3) had Akkermansia at wk 4. However, Akkermansia colonization was not sufficient for response, present in 7/9 Rs and 6/11 NRs. Conclusions: Baseline microbiome differences between ICI Rs and NRs are not enough to predict outcomes. Diversity changes between baseline and wk-4 on treatment could be an early predictor of response. Factors other than presence of Akkermansia (tumor or host-specific, Akkermansia strain variation, or other bacteria in the microenvironment) may contribute to response. Further species and strain-level profiling of the microbiota, tumor-specific genomic alterations, host immune response, and increasing sample size of ICI-treated patients may improve detection of significant differences between Rs and NRs.

scholarly journals Degrees of compositional shift in tree communities vary along a gradient of temperature change rates over one decade: Application of an individual-based temporal beta-diversity concept

2020 ◽  
Author(s):  
Ryosuke Nakadai
Keyword(s):  
Temperature Change ◽  
Community Composition ◽  
Beta Diversity ◽  
Temporal Patterns ◽  
Diversity Indices ◽  
Temporal Changes ◽  
Individual Identity ◽  
Relative Speed ◽  
Identity Information ◽  
Temporal Beta Diversity

AbstractTemporal patterns in communities have gained widespread attention recently, to the extent that temporal changes in community composition are now termed “temporal beta-diversity”. Previous studies of beta-diversity have made use of two classes of dissimilarity indices: incidence-based (e.g., Sørensen and Jaccard dissimilarity) and abundance-based (e.g., Bray–Curtis and Ružička dissimilarity). However, in the context of temporal beta-diversity, the persistence of identical individuals and turnover among other individuals within the same species over time have not been considered, despite the fact that both will affect compositional changes in communities. To address this issue, I propose new index concepts for beta-diversity and the relative speed of compositional shifts in relation to individual turnover based on individual identity information. Individual-based beta-diversity indices are novel dissimilarity indices that consider individual identity information to quantitatively evaluate temporal change in individual turnover and community composition. I applied these new indices to individually tracked tree monitoring data in deciduous and evergreen broad-leaved forests across the Japanese archipelago with the objective of quantifying the effect of climate change trends (i.e., rates of change of both annual mean temperature and annual precipitation) on individual turnover and compositional shifts at each site. A new index explored the relative contributions of mortality and recruitment processes to temporal changes in community composition. Clear patterns emerged showing that an increase in the temperature change rate facilitated the relative contribution of mortality components. The relative speed of compositional shift increased with increasing temperature change rates in deciduous forests but decreased with increasing warming rates in evergreen forests. These new concepts provide a way to identify novel and high-resolution temporal patterns in communities.

scholarly journals Individual-based multiple-unit dissimilarity: novel indices for assessing temporal variability in community composition

2021 ◽  
Author(s):  
Ryosuke Nakadai
Keyword(s):  
Community Composition ◽  
Beta Diversity ◽  
Temporal Dynamics ◽  
Diversity Indices ◽  
Barro Colorado Island ◽  
Forest Monitoring ◽  
List Type ◽  
Wide Range ◽  
Multiple Unit ◽  
Temporal Beta Diversity

AbstractBeta-diversity was originally defined spatially, i.e., as variation in community composition among sites in a region. However, the concept of beta-diversity has since been expanded to temporal contexts. This is referred to as “temporal beta-diversity”, and most approaches are simply an extension of spatial beta-diversity.The persistence and turnover of individuals over time is a unique feature of temporal beta-diversity. Nakadai (2020) introduced the “individual-based beta-diversity” concept, and provided novel indices to evaluate individual turnover and compositional shift by comparing individual turnover between two periods at a given site. However, the proposed individual-based indices are applicable only to pairwise dissimilarity, not to multiple-temporal (or more generally, multiple-unit) dissimilarity.Here, individual-based beta-diversity indices are extended to multiple-unit cases.To demonstrate the usage the properties of these indices compared to average pairwise measures, I applied them to a dataset for a permanent 50-ha forest dynamics plot on Barro Colorado Island in Panama.Information regarding “individuals” is generally missing from community ecology and biodiversity studies of temporal dynamics. In this context, the method proposed here is expected to be useful for addressing a wide range of research questions regarding temporal changes in biodiversity, especially studies using individual-tracked forest monitoring data.

scholarly journals How robust are popular beta diversity indices to sampling error?

Ecosphere ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. e02100 ◽  
Author(s):  
P. Jason Schroeder ◽  
David G. Jenkins
Keyword(s):  
Beta Diversity ◽  
Sampling Error ◽  
Diversity Indices

scholarly journals Beta-diversity partitioning: methods, applications and perspectives

2017 ◽  
Vol 25 (5) ◽  
pp. 464-480 ◽  
Author(s):  
Xingfeng Si ◽  
◽  
Yuhao Zhao ◽  
Chuanwu Chen ◽  
Peng Ren ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Diversity Partitioning ◽  
Partitioning Methods
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