scholarly journals A relationship between species richness and evenness that depends on specific relative abundance distribution

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4951
Author(s):  
Qiang Su
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Strong Correlation ◽  
Statistical Analyses ◽  
Abundance Distribution ◽  
Raw Data ◽  
Fractal Distribution ◽  
The Relationship ◽  
Rank Abundance

Although many ecologists focus on the relationship between species richness (S) and evenness (E), conflicts between observation and theory are difficult to reconcile. Empirical S–E relationships were not consistent, while relationships show strong correlation between S and E. Since E essentially depended on the relative abundance distribution (RAD), the hypothesis of this paper was that the S–E relationship should be determined by RAD. Theoretical S–E relationships for various RADs have already been reported, but they were rarely assessed by the raw data. This study constructed S–E relationships for a specific RAD, which indicated that if the community had a fractal distribution of rank abundance, E would decrease with S, and the S–E relationship would be unique for a given RAD. Such theoretical expectations were supported by three datasets with 82 samples, which suggested that the S–E relationship were controlled by RAD and inconsistent S–E relationships in statistical analyses could be accounted for by the variation of underlying RAD model between communities. From the perspective of RAD, it could be too early to split the diversity into S and E only based on the S–E relationship in statistical analyses.

Does the Mesh Size of the Plankton Net Affect the Result of Statistical Analyses of the Relationship Between the Copepod Community and Water Masses?

Crustaceana ◽  
2011 ◽  
Vol 84 (9) ◽  
pp. 1069-1083 ◽  
Author(s):  
Chun-Ming Shin ◽  
Kuo-Ping Chiang ◽  
Chih-Jung Wu
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Mesh Size ◽  
Water Masses ◽  
Statistical Analyses ◽  
The East China Sea ◽  
Copepod Community ◽  
The Difference ◽  
The Relationship ◽  
Net Affect

AbstractWe examined if the results of statistical analyses of the relationship between copepod communities and water masses would be affected by the mesh size of the plankton net, by comparing abundance and species composition of copepods in plankton samples collected by plankton nets of different mesh sizes. Our samples were collected during the summer of 2006 in the East China Sea (ECS) by plankton nets with mesh sizes of 100 and 330 μm. The abundance of copepods collected by the 100 μm-mesh plankton net was about two orders of magnitude higher than that collected by the 330 μm-mesh plankton net. The difference in abundance was mainly due to the loss of small-sized copepods in the samples collected by the plankton net with the larger mesh. Species richness was higher in samples collected by the 100 μm-mesh net and Piélou's evenness was generally higher in samples collected by the 330 μm-mesh net. Although species composition of copepods varied in samples collected by plankton nets with different mesh sizes, the statistical analysis of the relationship between the copepod community and the water masses in these samples appeared not to be affected.

scholarly journals mobsim: An R package for the simulation and measurement of biodiversity across spatial scales

2017 ◽  
Author(s):  
Felix May ◽  
Katharina Gerstner ◽  
Dan McGlinn ◽  
Xiao Xiao ◽  
Jonathan M. Chase
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Spatial Scales ◽  
R Package ◽  
Spatial Aggregation ◽  
Abundance Distribution ◽  
Real World Data ◽  
Ecological Processes ◽  
Biodiversity Patterns ◽  
Richness Estimators

Abstract1. Estimating biodiversity and its changes in space and time poses serious methodological challenges. First, there has been a long debate on how to quantify biodiversity, and second, measurements of biodiversity change are scale-dependent. Therefore comparisons of biodiversity metrics between communities are ideally carried out across scales. Simulation can be used to study the utility of biodiversity metrics across scales, but most approaches are system specific and plagued by large parameter spaces and therefore cumbersome to use and interpret. However, realistic spatial biodiversity patterns can be generated without reference to ecological processes, which suggests a simple simulation framework could provide an important tool for ecologists.2. Here, we present the R package mobsim that allows users to simulate the abundances and the spatial distribution of individuals of different species. Users can define key properties of communities, including the total numbers of individuals and species, the relative abundance distribution, and the degree of spatial aggregation. Furthermore, the package provides functions that derive biodiversity patterns from simulated communities, or from observed data, as well as functions that simulate different sampling designs.3. We show several example applications of the package. First, we illustrate how species rarefaction and accumulation curves can be used to disentangle changes in the fundamental biodiversity components: (i) total abundance, (ii) relative abundance distribution, (iii) and species aggregation. Second, we demonstrate how mobsim can be used to assess the performance of species-richness estimators. The latter indicates how spatial aggregation challenges classical non-spatial species-richness estimators.4. mobsim allows the simulation and analysis of a large range of biodiversity scenarios and sampling designs in an efficient and comprehensive way. The simplicity and control provided by the package can also make it a useful didactic tool. The combination of controlled simulations and their analysis will facilitate a more rigorous interpretation of real world data that exhibit sampling effects and scale-dependence.

Aquatic and semi aquatic Hemiptera community of Sonebeel, the largest wetland of Assam, northeastern India

2018 ◽  
Vol 10 (13) ◽  
pp. 12792-12799
Author(s):  
Anupama Saha ◽  
Susmita Gupta
Keyword(s):  
Species Richness ◽  
Pest Control ◽  
Relative Abundance ◽  
Species Distribution ◽  
Diversity Indices ◽  
Environmental Data ◽  
Northeastern India ◽  
Ecological Roles

Aquatic and semiaquatic Hemiptera bugs play significant ecological roles, and they are important indicators and pest control agents.  Little information is currently available concerning its populations in southern Assam.  This study assessed hemipterans in four sites of Sonebeel, the largest wetland in Assam (3458.12 ha at full storage level), situated in Karimganj District.  The major inflow and outflow of the wetland are the rivers Singla and Kachua, respectively (the Kachua drains into the Kushiyara River).  Samples were trapped with pond nets and were seasonally recorded.  This study recorded a total of 28 species of aquatic and semiaquatic hemipterans belonging to 20 genera under nine families.  Population, geographical and environmental data (e.g., rainfall) were used to assess the relative abundance of species, species richness and different diversity indices, and species distribution. 

scholarly journals Association of bisphenol A with puberty timing: a meta-analysis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hui Meng ◽  
Yunping Zhou ◽  
Yunxia Jiang
Keyword(s):  
Bisphenol A ◽  
Confidence Intervals ◽  
Random Effects ◽  
Strong Correlation ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Random Effects Models ◽  
Study Heterogeneity ◽  
The Relationship ◽  
Prevalence Ratios

AbstractObjectivesThe results of existing studies on bisphenol A (BPA) and puberty timing did not reach a consensus. Thereby we performed this meta-analytic study to explore the association between BPA exposure in urine and puberty timing.MethodsMeta-analysis of the pooled odds ratios (OR), prevalence ratios (PR) or hazards ratios (HR) with 95% confidence intervals (CI) were calculated and estimated using fixed-effects or random-effects models based on between-study heterogeneity.ResultsA total of 10 studies involving 5621 subjects were finally included. The meta-analysis showed that BPA exposure was weakly associated with thelarche (PR: 0.96, 95% CI: 0.93–0.99), while no association was found between BPA exposure and menarche (HR: 0.99, 95% CI: 0.89–1.12; OR: 1.02, 95% CI: 0.73–1.43), and pubarche (OR: 1.00, 95% CI: 0.79–1.26; PR: 1.00, 95% CI: 0.95–1.05).ConclusionsThere was no strong correlation between BPA exposure and puberty timing. Further studies with large sample sizes are needed to verify the relationship between BPA and puberty timing.

Genetic variations of SCNA7 and blood pressure potassium interaction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Delgado ◽  
M Delgado-Lelievre ◽  
D Lelievre ◽  
A Delgado-Almeida
Keyword(s):  
Blood Pressure ◽  
Strong Correlation ◽  
Genetic Variations ◽  
Sodium Potassium ◽  
Blood Institute ◽  
Urine Creatinine ◽  
National Heart Lung ◽  
Gated Channel ◽  
K Concentration ◽  
The Relationship

Abstract Introduction The sodium voltage-gated channel alpha subunit 7 (SCN7A) has been associated to renal Na regulation and hypertension. This study explores the relationship between blood pressure (BP) and urinary overnight Na/K ratio (UONaK) in hypertensives (HT) and normotensive (NT) subjects from from National Heart, Lung and Blood Institute funded, Family Blood Pressure Program (FBPP) that were genotyped for 3 SNPs for SCN7A: CV2161217, CV 356958 and CV433036. Hypothesis Genetic variations in the SCNA7 are differently associated to BP and UONaK in HT and NT. Methods 1,749 subjects genotyped for SCN7A SNPs CV2161217, CV 356958 and CV433036 were analyzed from FBPP. Subjects with diastolic BP (DBP) ≥80 or systolic BP (SBP) ≥130 mmHg were classified HTN; subjects with SBP <130 and DBP <80 mmHg were classified as NT. UONAK was calculated by dividing overnight Na by K concentration. Correlation analysis done with partial variables (use of antihypertensive drug, use of diuretics, overnight urine creatinine). Results For the CV2161217, HTN group (n=1,030), 52% had C/C, 39% C/T and 9% T/T. In NT group (n=719), 52% had C/C, 38% C/T and 10% T/T. In the HT group, subjects with CC genotype showed strong correlation between DBP and UONaK (Fig 1a) while no significant correlation with SBP. Those with CT genotype maintained the correlation between SBP and UONaK (r=0.10, p=0.03) with no correlation with SBP. The TT showed no correlation between UONaK and SBP or DBP. In the NT, subjects with TT genotype showed strong correlation between DBP and UONaK (Fig 1b) and with SB (r=0.256, p=0.03). Those with CT or TT genotypes showed no correlation between UONaK and SBP or DBP. Similar finding were obtained for CV356958 SNP; no similar association was observed in the CV433036 SNP. Conclusions Subjects with the genetic variations in the SCNA7, such as CV2161217 and CV 356958 SNPs, showed significant correlation between blood pressure and overnight urinary sodium potassium. This finding could have important implications in non dipping status observed in some hypertensive patients. Funding Acknowledgement Type of funding source: None

scholarly journals Relationships between resource availability and elevation vary between metrics creating gradients of nutritional complexity

Oecologia ◽  
2021 ◽  
Vol 195 (1) ◽  
pp. 213-223
Author(s):  
Mark A. Lee ◽  
Grace Burger ◽  
Emma R. Green ◽  
Pepijn W. Kooij
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Resource Availability ◽  
Plant Biomass ◽  
Plant Species Richness ◽  
Mineral Contents ◽  
Nutritive Values ◽  
Animal Community ◽  
Nutritional Chemistry ◽  
The Relationship

AbstractPlant and animal community composition changes at higher elevations on mountains. Plant and animal species richness generally declines with elevation, but the shape of the relationship differs between taxa. There are several proposed mechanisms, including the productivity hypotheses; that declines in available plant biomass confers fewer resources to consumers, thus supporting fewer species. We investigated resource availability as we ascended three aspects of Helvellyn mountain, UK, measuring several plant nutritive metrics, plant species richness and biomass. We observed a linear decline in plant species richness as we ascended the mountain but there was a unimodal relationship between plant biomass and elevation. Generally, the highest biomass values at mid-elevations were associated with the lowest nutritive values, except mineral contents which declined with elevation. Intra-specific and inter-specific increases in nutritive values nearer the top and bottom of the mountain indicated that physiological, phenological and compositional mechanisms may have played a role. The shape of the relationship between resource availability and elevation was different depending on the metric. Many consumers actively select or avoid plants based on their nutritive values and the abundances of consumer taxa vary in their relationships with elevation. Consideration of multiple nutritive metrics and of the nutritional requirements of the consumer may provide a greater understanding of changes to plant and animal communities at higher elevations. We propose a novel hypothesis for explaining elevational diversity gradients, which warrants further study; the ‘nutritional complexity hypothesis’, where consumer species coexist due to greater variation in the nutritional chemistry of plants.

scholarly journals Roles of Spatial Scale and Rarity on the Relationship between Butterfly Species Richness and Human Density in South Africa

PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0124327 ◽  
Author(s):  
Silvia Mecenero ◽  
Res Altwegg ◽  
Jonathan F. Colville ◽  
Colin M. Beale
Keyword(s):  
South Africa ◽  
Species Richness ◽  
Spatial Scale ◽  
Butterfly Species ◽  
The Relationship ◽  
Human Density

scholarly journals Structure of three subtropical bat assemblages (Chiroptera) in the Andean rainforests of Argentina

Mammalia ◽  
2016 ◽  
Vol 80 (1) ◽  
Author(s):  
Mariano S. Sánchez
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Seasonal Changes ◽  
Common Species ◽  
Guild Structure ◽  
Trophic Guild ◽  
Long Tail ◽  
Mist Net ◽  
Yungas Forests

AbstractI evaluated bat assemblages in terms of species richness, relative abundance, trophic guild structure, and seasonal changes at three sites along of the Southern Yungas forests. A total of 854 individuals were captured, representing 25 species of three families, with an effort of 27,138 m of mist net opened per hour. Subtropical assemblages showed a similar structure to those from tropical landmark, with a dominance of frugivorous Phyllostomid; in addition, a few species were abundant, followed by a long tail of less common species. However, subtropical sites differed due to the dominance of the genus

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