scholarly journals Temperature drives local contributions to beta diversity in mountain streams: Stochastic and deterministic processes

2019 ◽  
Vol 29 (3) ◽  
pp. 420-432 ◽  
Author(s):  
Jianjun Wang ◽  
Pierre Legendre ◽  
Janne Soininen ◽  
Chih‐Fu Yeh ◽  
Emily Graham ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Mountain Streams ◽  
Deterministic Processes

Partitioning and drivers of aquatic-insect beta diversity in mountain streams

2021 ◽  
Author(s):  
Pitágoras da Conceição Bispo ◽  
Ciro C. Zanini Branco ◽  
Marcos Carneiro Novaes ◽  
Lucas S. M. Costa ◽  
Elisa Yokoyama ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Aquatic Insect ◽  
Mountain Streams

Assembly patterns of the rhizosphere microbiome along the longitudinal root axis of maize (Zea mays L.)

2021 ◽  
Author(s):  
Lioba Rüger ◽  
Feng Kai ◽  
Dumack Kenneth ◽  
Chen Yan ◽  
Sun Ruibo ◽  
...  
Keyword(s):  
Zea Mays ◽  
Plant Species ◽  
Community Assembly ◽  
Beta Diversity ◽  
Zea Mays L ◽  
Soil Microbial Communities ◽  
Bulk Soil ◽  
Rhizosphere Microbiome ◽  
Deterministic Processes ◽  
Root Axis

<p>This study was conducted within the framework of the DFG project SPP2089 “Rhizosphere Spatiotemporal Organization – a Key to Rhizosphere Functions”.</p><p>Different plant species select for individual subsets of bulk soil microbial communities within root systems. The fast variability of root environments implies that roots constitute highly dynamic habitats. Rapid root elongation, combined with widely varying quality and quantity of rhizodeposition between different root regions, lead to continuously changing conditions for colonizing microorganisms. As the microbiome concept implies a rather static outcome of the microbial assembly, it raises the question as to where and how the dynamic transition of a microbial bulk soil community into a plant species-specific rhizosphere microbiome is taking place.</p><p>To investigate the assembly of communities of prokaryotes and their microbial predators (Cercozoa, Rhizaria; protists) along the longitudinal root axis of maize (Zea mays L.), plants were grown in an agricultural loamy soil. Rhizosphere soil was sampled at distinct locations along roots. Diversity and co-occurrence of rhizosphere microbiota along the root axis were tracked by high-throughput sequencing, diversity measures and network analyses.</p><p>High variation in beta diversity at root tips and the root hair zone indicated substantial randomness of community assembly. Deterministic processes of community assembly were revealed by low variability of beta diversity, changes in network topology, and the appearance of regular phylogenetic co-occurrence patterns in bipartite networks between prokaryotes and their microbial predators. Deterministic processes were most robust in regions with fully developed lateral roots, suggesting that a consistent rhizosphere microbiome finally assembled. For the targeted improvement of microbiome function, such knowledge on the processes of microbiome assembly on roots and its temporal and spatial variability is of crucial importance.</p>

scholarly journals The relative importance of stochastic and deterministic processes on bryophyte community assembly changes with scale

2021 ◽  
Author(s):  
Nagore Medina ◽  
Joaquin Calatayud ◽  
Richard Ladle ◽  
Francisco Lara ◽  
Isabel Draper ◽  
...  
Keyword(s):  
Species Composition ◽  
Beta Diversity ◽  
Environmental Gradients ◽  
Geographic Distance ◽  
Small Scale ◽  
Stochastic Effects ◽  
Network Analyses ◽  
Biogeographic Region ◽  
Deterministic Processes ◽  
The Impact

Studies focused on the drivers of change in species composition often fail to integrate several aspects of beta diversity and scale. Here, we assess the impact of species pool, environmental gradients, geographic distance, and spatial scale on the diversity of epiphytic bryophytes. We identify biogeographic modules of co-occurring species using network analyses. For each biogeographic unit we study the effects of environment, abundance structure of the community and geographic distance on beta diversity. We analyse two aspects of beta diversity related to different scales of analysis: between-forests dissimilarity in species composition and within-forests heterogeneity in species composition. We show that the structuring of the communities is a by-product of niche-related and stochastic processes. The balance of these processes changes with biogeographic region and scale, neutral stochastic effects are more significant in the most favourable regions and for small-scale within-forest heterogeneity

Scale sensitivity of environmental effects on the temporal beta diversity of fishes in tropical coastal lagoons

2020 ◽  
Author(s):  
E Martins Camara ◽  
Tubino Andrade Andrade-Tub ◽  
T Pontes Franco ◽  
LN dos Santos ◽  
AFGN dos Santos ◽  
...  
Keyword(s):  
Environmental Effects ◽  
Beta Diversity ◽  
Coastal Lagoons ◽  
Scale Sensitivity ◽  
Temporal Beta Diversity

Kyiv park "Nivki" and "Teremki" forests and ecological analysis of their habitats

2014 ◽  
Vol 25 (3-4) ◽  
pp. 53-68
Author(s):  
I. V. Goncharenko ◽  
H. M. Holyk
Keyword(s):  
Standard Deviation ◽  
Species Composition ◽  
Human Impact ◽  
Soil Nitrogen ◽  
Beta Diversity ◽  
Plant Cover ◽  
Alpha Diversity ◽  
Light Regime ◽  
Individual Species ◽  
Anthropogenic Pressure

Cenotic diversity and leading ecological factors of its floristic differentiation were studied on an example of two areas – Kyiv parks "Nivki" and "Teremki". It is shown that in megalopolis the Galeobdoloni-Carpinetum impatientosum parviflorae subassociation is formed under anthropogenic pressure on the typical ecotope of near-Dnieper hornbeam oak forests on fresh gray-forest soils. The degree of anthropogenic transformation of cenofloras can be estimated by the number of species of Robinietea and Galio-Urticetea classes, as well as neophytes and cultivars. Phytoindication for hemeroby index may be also used in calculation. We propose the modified index of biotic dispersion (normalized by alpha-diversity) for the estimation of ecophytocenotic range (beta-diversity) of releves series. We found that alpha-diversity initially increases (due to the invasion of antropophytes) at low level of antropogenic pressure, then it decreases (due to the loss of aboriginal species) secondarily with increasing of human impact. Also we found that beta-diversity (differential diversity) decreases, increasing homogeneity of plant cover, under the influence of anthropogenic factor. Vegetation classification was completed by a new original method of cluster analysis, designated as DRSA («distance-ranked sorting assembling»). The classification quality is suggested to be validated on the "seriation" diagram, which is а distance matrix between objects with gradient filling. Dark diagonal blocks confirm clusters’ density (intracluster compactness), uncolored off-diagonal blocks are evidence in favor of clusters’ isolation (intercluster distinctness). In addition, distinction of clusters (syntaxa) in ordination area suggests their independence. For phytoindication we propose to include only species with more than 10% constancy. Furthermore, for the description of syntaxonomic amplitude we suggest to use 25%-75% interquartile scope instead of mean and standard deviation. It is shown that comparative analysis of syntaxa for each ecofactor is convenient to carry out by using violin (bulb) plots. A new approach to the phytoindication of syntaxa, designated as R-phytoindication, was proposed for our study. In this case, the ecofactor values, calculated for individual releves, are not taken into account, however, the composition of cenoflora with species constancies is used that helps us to minimize for phytoindication the influence of non-typical species. We suggested a syntaxon’s amplitude to be described by more robust statistics: for the optimum of amplitude (central tendency) – by a median (instead of arithmetic mean), and for the range of tolerance – by an interquartile scope (instead of standard deviation). We assesses amplitudes of syntaxa by phytoindication method for moisture (Hd), acidity (Rc), soil nitrogen content (Nt), wetting variability (vHd), light regime (Lc), salt regime (Sl). We revealed no significant differences on these ecofactors among ecotopes of our syntaxa, that proved the variant syntaxonomic rank for all syntaxa. We found that the core of species composition of our phytocenoses consists of plants with moderate requirements for moisture, soil nitrogen, light and salt regime. We prove that the leading factor of syntaxonomic differentiation is hidden anthropogenic, which is not subject to direct measurement. But we detect that hidden factor of "human pressure" was correlated with phytoindication parameters (variables) that can be measured "directly" by species composition of plant communities. The most correlated factors were ecofactors of soil nitrogen, wetting variability, light regime and hemeroby. The last one is the most indicative empirically for the assessment of "human impact". We establish that there is a concept of «hemeroby of phytocenosis» (tolerance to human impact), which can be calculated approximately as the mean or the median of hemeroby scores of individual species which are present in it.

EVALUATION OF MOUNTAIN AREA AS NON-POINT SOURCE OF NITROGEN FOR SETO INLAND SEA: THE NORTHERN SHIKOKU REGION, JAPAN

2017 ◽  
Author(s):  
Shohei Morisawa ◽  
Shohei Morisawa ◽  
Yukio Komai ◽  
Yukio Komai ◽  
Takao Kunimatsu ◽  
...  
Keyword(s):  
Average Concentration ◽  
Point Sources ◽  
Seto Inland Sea ◽  
Mountain Streams ◽  
Unit Load ◽  
Mountain Areas ◽  
Mountain Area ◽  
The Seto Inland Sea ◽  
Unit Load Method ◽  
Important Position

The northern Shikoku region is located in the Western part of Japan and faces towards the Seto Inland Sea. The forest area, which is one of the non-point sources in the Seto Inland Sea watershed, occupies 75% of the land use in the watershed of the northern Shikoku region. The amount of loadings of nutrients and COD in the Seto Inland Sea has been estimated by the unit load method but actually the data has not been investigated. It is however, necessary to know the real concentration of nitrogen in mountain streams to evaluate the role which is the mountain area plays as non-point sources. Therefore, more water samples of mountain streams in the watershed need to be taken and the concentrations of nitrogen analyzed. The mountain streams in the northern Shikoku area were investigated from April, 2015 to November, 2015. The number of sampling sites was 283, in addition to the past data by Kunimatsu et al. The average concentration of nitrate nitrogen in Ehime, Kagawa, and Tokushima was 0.61mg/L, 0.78mg/L and 0.34mg/L, respectively. The environmental standard range for nitrogen in the Seto Inland Sea is from between less than 0.2mg/L and less than 1mg/L. Therefore, the average concentration of nitrogen in these regions was over category II, and those of mountain streams in Kagawa Prefecture exceeded category III. About 20% of mountain streams were more than 1mg/L. It has become clear that mountain areas occupy an important position as non-point sources for the Seto Inland Sea.

A review of beta diversity studies

2010 ◽  
Vol 18 (4) ◽  
pp. 323 ◽  
Author(s):  
Chen Shengbin ◽  
Ouyang Zhiyun ◽  
Xu Weihua ◽  
Xiao Yi
Keyword(s):  
Beta Diversity ◽  
Diversity Studies

scholarly journals Alpha and beta diversity of birds along elevational vegetation zones on the southern slope of Altai Mountains: Implication for conservation

2019 ◽  
Vol 19 ◽  
pp. e00643 ◽  
Author(s):  
Na Li ◽  
Hongjun Chu ◽  
Yingjie Qi ◽  
Chunwang Li ◽  
Xiaoge Ping ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Altai Mountains ◽  
Southern Slope ◽  
Alpha And Beta Diversity ◽  
Vegetation Zones

scholarly journals Effects of Polyphenols in Tea (Camellia sinensis sp.) on the Modulation of Gut Microbiota in Human Trials and Animal Studies

2021 ◽  
Vol 12 (2) ◽  
pp. 202-216
Author(s):  
Mus Azza Suhana Khairudin ◽  
Abbe Maleyki Mhd Jalil ◽  
Napisah Hussin
Keyword(s):  
Gut Microbiota ◽  
Beta Diversity ◽  
Animal Studies ◽  
Tea Polyphenols ◽  
Microbiota Composition ◽  
Polyphenol Compounds ◽  
Human Trials ◽  
Diet Induced Obesity ◽  
Different Types ◽  
Meta Analyses

A diet high in polyphenols is associated with a diversified gut microbiome. Tea is the second most consumed beverage in the world, after water. The health benefits of tea might be attributed to the presence of polyphenol compounds such as flavonoids (e.g., catechins and epicatechins), theaflavins, and tannins. Although many studies have been conducted on tea, little is known of its effects on the trillions of gut microbiota. Hence, this review aimed to systematically study the effect of tea polyphenols on the stimulation or suppression of gut microbiota in humans and animals. It was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Articles were retrieved from PubMed and Scopus databases, and data were extracted from 6 human trials and 15 animal studies. Overall, large variations were observed in terms of microbiota composition between humans and animals. A more consistent pattern of diversified microbiota was observed in animal studies. Tea alleviated the gut microbiota imbalance caused by high-fat diet-induced obesity, diabetes, and ultraviolet-induced damage. The overall changes in microbiota composition measured by beta diversity analysis showed that tea had shifted the microbiota from the pattern seen in animals that received tea-free intervention. In humans, a prebiotic-like effect was observed toward the gut microbiota, but these results appeared in lower-quality studies. The beta diversity in human microbiota remains intact despite tea intervention; supplementation with different teas affects different types of bacterial taxa in the gut. These studies suggest that tea polyphenols may have a prebiotic effect in disease-induced animals and in a limited number of human interventions. Further intervention is needed to identify the mechanisms of action underlying the effects of tea on gut microbiota.

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