scholarly journals Effects of invasion level of Prosopis juliflora on native species diversity and regeneration in Afar region, Northeast Ethiopia

2021 ◽  
Author(s):  
Wakshum Shiferaw
Keyword(s):  
Species Diversity ◽  
Native Species ◽  
Diversity Index ◽  
Woody Species ◽  
Prosopis Juliflora ◽  
Shannon Diversity Index ◽  
Shannon Diversity ◽  
Afar Region ◽  
Native Woody Species ◽  
Grazing Lands

AbstractThe study aimed to assess (i) the effects of Prosopis juliflora invasion on the diversity of plant species, and floristic composition at Awash Fentale and the Amibara districts of the Afar region and (ii) the effects of P. juliflora invasion on the regeneration potential of native woody species. Sample collection was performed in habitats of P. juliflora thicket, P. juliflora mixed with native species stands, non-invaded woodlands, and open grazing lands. A stratified random sampling technique was used for data collection. Among species of plants, the highest proportion of species, 87 (27.4%), was recorded under non-invaded woodlands, but the lowest proportion of species, 70 (22%), was recorded under open grazing lands. The invasion level of P. juliflora caused significantly reduced Shannon diversity index. The mean values of Shannon diversity index and species richness under P. juliflora mixed with native species (H’=2.22, R=14) and non-invaded woodlands (H’=2.23, R=13) were significantly higher than P. juliflora thicket (H’=1.96, R=12) and open grazing lands (H’=1.84, R=10). In this study, 102 trees ha-1native woody species were recorded under P. juliflora thicket, but 1252 trees ha-1native species were recorded under non-invaded woodlands. If the present effects of the invasion of P. juliflora on native species diversity were to continue coupled with a drier climate, plant diversity of the Afar flora region will be highly affected. As a result the ecosystem services will be under threat. Thus, the participation of all stakeholders and multidisciplinary research approaches should be designed for the management of invaded rangelands to reverse the situation.

Impacts of Prosopis juliflora on Native Species Diversity and Regeneration in Afar Region

2018 ◽  
Author(s):  
Wakshum Shiferaw ◽  
Sebsebe Demissew ◽  
Tamrat Bekele ◽  
Ermias Aynekulu
Keyword(s):  
Species Diversity ◽  
Native Species ◽  
Prosopis Juliflora ◽  
Afar Region

scholarly journals The system of faunacomponents conception and its application to qualify the degree of naturalness of fish assemblages

2007 ◽  
pp. 93-101
Author(s):  
Péter Sály
Keyword(s):  
Species Richness ◽  
Endemic Species ◽  
Native Species ◽  
Fish Assemblages ◽  
Diversity Index ◽  
Shannon Diversity Index ◽  
Human Influence ◽  
Shannon Diversity ◽  
Biogeographic Regions ◽  
Special Case

The increase of species richness in communities of natural biogeographic regions in an anthropogenic way can be expressed as biogeographic pollution. Where there is contaminated fauna, one must investigate how this occured. I studied how the members of Hungarian fishfauna could be present resident and have managed to workout a so-called system of fauna component conception which is suitable for this requirement.The expression of ’faunacomponent’ includes other expressions. That kind of species belong to a certain faunacomponent that reached the studied area in the same way. Species reached the studied area without an anthropogenious contribution are qualified as native fauna components. These kind of species are endemic species, occasional species and settlers. In contrast to native faunacomponents, some kind of human influence is always detectable in connection with the way reached the studied area by non-native species. Accordingly, group of non-native species includes directly or indirectly facilitated settlers, species that are introduced accidentally and those introduced intentionally. It is obvious that classifying a given species could be construed solely in connection with a certain area.Applying Shannon diversity index I have initiated the assemblage natural index (ANI) in order to show a way how to use the system of faunacomponent conception in practice. ANI refers to the degree of naturalness of faunistical samples. If ANI > 1 it means there are not any non-native species and ANI < 1 it means there are some non-native species in the sample respectively. In the latter case ANI decreases proportionally with the number of non-native species and specimens. In that special case when only one specimen of only one non-native species can be found in the faunistical sample ANI = 1.

scholarly journals On a Variational Definition for the Jensen-Shannon Symmetrization of Distances Based on the Information Radius

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 464
Author(s):  
Frank Nielsen
Keyword(s):  
Diversity Index ◽  
Diversity Indices ◽  
Shannon Diversity Index ◽  
Probability Measures ◽  
Variational Optimization ◽  
Shannon Diversity ◽  
Concept Of Information ◽  
Jensen Shannon Divergence

We generalize the Jensen-Shannon divergence and the Jensen-Shannon diversity index by considering a variational definition with respect to a generic mean, thereby extending the notion of Sibson’s information radius. The variational definition applies to any arbitrary distance and yields a new way to define a Jensen-Shannon symmetrization of distances. When the variational optimization is further constrained to belong to prescribed families of probability measures, we get relative Jensen-Shannon divergences and their equivalent Jensen-Shannon symmetrizations of distances that generalize the concept of information projections. Finally, we touch upon applications of these variational Jensen-Shannon divergences and diversity indices to clustering and quantization tasks of probability measures, including statistical mixtures.

scholarly journals Species richness and diversity in shrub savanna using ordinary kriging

2016 ◽  
Vol 51 (8) ◽  
pp. 958-966 ◽  
Author(s):  
Anderson Pedro Bernardina Batista ◽  
José Márcio de Mello ◽  
Marcel Régis Raimundo ◽  
Henrique Ferraço Scolforo ◽  
Aliny Aparecida dos Reis ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Spatial Dependence ◽  
Ordinary Kriging ◽  
Diversity Index ◽  
Spatial Models ◽  
Shannon Diversity Index ◽  
Shannon Diversity ◽  
Species Richness And Diversity ◽  
Number Of Species

Abstract: The objective of this work was to analyze the spatial distribution and the behavior of species richness and diversity in a shrub savanna fragment, in 2003 and 2014, using ordinary kriging, in the state of Minas Gerais, Brazil. In both evaluation years, the measurements were performed in a fragment with 236.85 hectares, in which individual trees were measured and identified across 40 plots (1,000 m2). Species richness was determined by the total number of species in each plot, and diversity by the Shannon diversity index. For the variogram study, spatial models were fitted and selected. Then, ordinary kriging was applied and the spatial distribution of the assessed variables was described. A strong spatial dependence was observed between species richness and diversity by the Shannon diversity index (<25% spatial dependence degree). Areas of low and high species diversity and richness were found in the shrub savanna fragment. Spatial distribution behavior shows relative stability regarding the number of species and the Shannon diversity index in the evaluated years.

scholarly journals A checklist of gilled mushrooms (Basidiomycota: Agaricomycetes) with diversity analysis in Hollongapar Gibbon Wildlife Sanctuary, Assam, India

2015 ◽  
Vol 7 (15) ◽  
pp. 8272 ◽  
Author(s):  
Girish Gogoi ◽  
Vipin Parkash
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
Abundant Species ◽  
Shannon Diversity Index ◽  
Diversity Analysis ◽  
Wildlife Sanctuary ◽  
Shannon Diversity ◽  
Number Of Species ◽  
Simpson Diversity Index ◽  
Richness Index

<p>Hollongapar Gibbon Wildlife Sanctuary is comprised of five distinct compartments.  A total of 138 species of gilled mushrooms belonging to 48 genera, 23 families, five orders of the class Agaricomycetes, division Basidiomycota, have been collected and analyzed. The order Agaricales was was found with the highest number of species (113), followed by Russulales (14), Polyporales (5), Cantharellales (4) and Boletales (2). The species <em>Coprinellus disseminatus </em>and <em>Megacollybia rodmani</em> have shown the highest (8.26) and the lowest density (0.05), respectively.  A total of 24 species, e.g., <em>Termitomyces albuminosus, Marasmius curreyi, Marasmiellus candidus, Leucocoprinus medioflavus, Mycena leaiana, Hygrocybe miniata, Collybia chrysoropha, Gymnopus confluens</em> were common with frequency percentage of 11.9, whereas <em>Megacollybia rodmani</em> with less frequency percentage (2.4) was found only in few quadrates of the sanctuary.  The highly abundant species were <em>Termitomyces medius</em> (91.7) and <em>Coprinellus disseminatus </em>(86.8), and less abundant species were <em>Psilocybe wayanadensis</em> (1.0) and <em>Lepiota</em> sp. (1.0) in the study site.  The order of the species richness index (<em>R</em>) compartment wise was 2&gt;3&gt;4&gt;5&gt;1. Both the Shannon diversity index and Simpson diversity index of agarics was maximum (1.88, 0.98) in compartment 2, whereas minimum (1.72, 0.95) in compartment 1 and 5, respectively.  Moreover, the compartment 2 was found very much similar with compartment 3 and very less similar with compartment 1.</p><div> </div>

scholarly journals Modeling Soil Erosion and Landscape Metric Analysis of River Catchments in Pulau Pinang, Malaysia

2020 ◽  
Vol 55 (3) ◽  
Author(s):  
Sumayyah Aimi Mohd Najib
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Soil Loss ◽  
Diversity Index ◽  
Land Use Changes ◽  
Shannon Diversity Index ◽  
Universal Soil Loss Equation ◽  
Data Sampling ◽  
Shannon Diversity ◽  
Soil Loss Equation

To determine the soil erosion in ungauged catchments, the author used 2 methods: Universal Soil Loss Equation model and sampling data. Sampling data were used to verify and validate data from model. Changing land use due to human activities will affect soil erosion. Land use has changed significantly during the last century in Pulau Pinang. The main rapid changes are related to agriculture, settlement, and urbanization. Because soil erosion depends on surface runoff, which is regulated by the structure of land use and brought about through changes in slope length, land-use changes are one of many factors influencing land degradation caused by erosion. The Universal Soil Loss Equation was used to estimate past soil erosion based on land uses from 1974 to 2012. Results indicated a significant increase in three land-use categories: forestry, built-up areas, and agriculture. Another method to evaluate land use changes in this study was by using landscape metrics analysis. The mean patch size of built-up area and forest increased, while agriculture land use decreased from 48.82 patches in 1974 to 22.46 patches in 2012. Soil erosion increased from an estimated 110.18 ton/km2/year in 1974 to an estimated 122.44 ton/km2/year in 2012. Soil erosion is highly related (R2 = 0.97) to the Shannon Diversity Index, which describes the diversity in land-use composition in river basins. The Shannon Diversity Index also increased between 1974 and 2012. The findings from this study can be used for future reference and for ungauged catchment research studies.

Exercise training-induced changes in the gut microbiota of Standardbred racehorses

2016 ◽  
Vol 12 (3) ◽  
pp. 119-130 ◽  
Author(s):  
A.H.D. Janabi ◽  
A.S. Biddle ◽  
D. Klein ◽  
K.H. McKeever
Keyword(s):  
Exercise Training ◽  
Gut Microbiota ◽  
Diversity Index ◽  
Training Group ◽  
The Body ◽  
Shannon Diversity Index ◽  
Training Period ◽  
Control Group ◽  
Shannon Diversity ◽  
Over Time

Exercise has a significant effect on different physiological systems in the body of human and animals. Only limited numbers of published studies in laboratory animals or humans have shown the effect of exercise on the gut microbiota, and no studies have shown this effect in horses. In this study, 8 horses (4 mares, 4 geldings) were exercise trained for 12 weeks, and 4 additional mares were used as a parallel seasonal control. To identify bacterial community changes over time for both groups, rectal faecal samples were collected, DNA was extracted, and the 16S rRNA gene (V3-V4) was sequenced using the Illumina Miseq platform. One-way ANOVA, Shannon diversity index, and Principal Coordinate Analysis (PCoA) were used to identify differences between and among samples. The exercise training group showed significant changes in the levels of Bacteroidetes, Proteobacteria, and Spirochaetes phyla (P<0.05), while there were no changes in the gut microbiota of the seasonal control group through the three months of the study (P>0.05). Moreover, with training two genera significantly changed in their relative abundance over time, namely Clostridium and Dysgonomonas (P<0.05). Dysgonomonas spp. was significantly changed in abundance during the exercise training period (P<0.05). Also Treponema spp. showed significant changes during the exercise training period (P<0.05). Shannon diversity index was decreased (P<0.05) in the exercise group at the beginning of the study, but then returned to pre-training levels. PCoA showed significant separation between time points of the exercise training group as far as the levels of genera and species (P<0.05) represented. Our results show that exercise training influences the gut microbiota, especially at the beginning of training.

scholarly journals Prevalence of Diarrhoeagenic Escherichia Coli and Associated Risk Factors in Dug Wells in Ile-Ife, Southwestern Nigeria

2021 ◽  
Author(s):  
Babatunde Odetoyin ◽  
Olawumi Ogundipe ◽  
Adebola Onanuga
Keyword(s):  
Risk Factors ◽  
Escherichia Coli ◽  
Drinking Water ◽  
Diversity Index ◽  
Shannon Diversity Index ◽  
Southwestern Nigeria ◽  
E Coli ◽  
Shannon Diversity ◽  
Dug Wells ◽  
Associated Risk Factors

Abstract BackgroundDiarrhoeagenic Escherichia coli (DEC) strains are common bacterial causes of morbidity and mortality in young children. Waterborne DEC could pose a potential health risk to humans through domestic use of contaminated water. However, epidemiological studies on DEC strains in drinking water are scarce in Nigeria. This study determined the prevalence, diversity and factors associated with the presence of DEC in dug wells in Ile-Ife, southwestern Nigeria.MethodsWe assessed 143 wells for safety by coliform count using the multiple tube technique. A standardized questionnaire was used to obtain relevant information about the wells and their owners. Contaminating isolates were identified as E. coli by amplifying their 16S rRNA gene. Five DEC pathotypes comprising enterotoxigenic E. coli (ETEC), enteroaggregative E. coli (EAEC) enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC) were detected using two sets of multiplex PCR assays. Isolates diversity was determined by (GTG)5 Repetitive element palindromic PCR and Shannon diversity index. Multivariate logistic regression analysis was used to identify associated risk factors. Results Fifty-eight (40.6%) wells were contaminated by diarrhoeagenic E. coli. Wells with dirty platforms, damaged by erosion and sited near septic tanks significantly harboured DEC (p<0.05). There was a preponderance of STEC among the isolates with nine isolates carrying multiple diarrhoeagenic genes and 10 (17.2%) wells contaminated by multiple DEC strains. The (GTG)5-PCR fingerprinting assigned all DEC strains into six clades, with an overall Shannon diversity index of 18.87. A diverse profile was obtained among and between the isolates recovered from different sources.ConclusionsThe presence of DEC strains in drinking water highlights the risk to human health associated with the use of untreated water. There was a high degree of genetic diversity among the isolates implying multiple sources of contamination. There is a need for periodic sanitation and inspection of wells for cracks to prevent seepages and possible outbreaks of waterborne diseases.

scholarly journals The spleen bacteriome of wild rodents and shrews from Marigat, Baringo County, Kenya

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12067
Author(s):  
Rehema Liyai ◽  
Gathii Kimita ◽  
Clement Masakhwe ◽  
David Abuom ◽  
Beth Mutai ◽  
...  
Keyword(s):  
16S Rrna ◽  
Bacterial Diversity ◽  
Small Mammals ◽  
Pathogenic Bacteria ◽  
Diversity Index ◽  
Shannon Diversity Index ◽  
Gene Sequences ◽  
16S Rrna Analysis ◽  
Shannon Diversity ◽  
Mitochondrial Cytochrome B

Background There is a global increase in reports of emerging diseases, some of which have emerged as spillover events from wild animals. The spleen is a major phagocytic organ and can therefore be probed for systemic microbiome. This study assessed bacterial diversity in the spleen of wild caught small mammals so as to evaluate their utility as surveillance tools for monitoring bacteria in an ecosystem shared with humans. Methods Fifty-four small mammals (rodents and shrews) were trapped from different sites in Marigat, Baringo County, Kenya. To characterize their bacteriome, DNA was extracted from their spleens and the V3–V4 regions of the 16S rRNA amplified and then sequenced on Illumina MiSeq. A non-target control sample was used to track laboratory contaminants. Sequence data was analyzed with Mothur v1.35, and taxomy determined using the SILVA database. The Shannon diversity index was used to estimate bacterial diversity in each animal and then aggregated to genus level before computing the means. Animal species within the rodents and shrews were identified by amplification of mitochondrial cytochrome b (cytb) gene followed by Sanger sequencing. CLC workbench was used to assemble the cytb gene sequences, after which their phylogenetic placements were determined by querying them against the GenBank nucleotide database. Results cytb gene sequences were generated for 49/54 mammalian samples: 38 rodents (Rodentia) and 11 shrews (Eulipotyphyla). Within the order Rodentia, 21 Acomys, eight Mastomys, six Arvicanthis and three Rattus were identified. In the order Eulipotyphyla, 11 Crucidura were identified. Bacteria characterization revealed 17 phyla that grouped into 182 genera. Of the phyla, Proteobacteria was the most abundant (67.9%). Other phyla included Actinobacteria (16.5%), Firmicutes (5.5%), Chlamydiae (3.8%), Chloroflexi (2.6%) and Bacteroidetes (1.3%) among others. Of the potentially pathogenic bacteria, Bartonella was the most abundant (45.6%), followed by Anaplasma (8.0%), Methylobacterium (3.5%), Delftia (3.8%), Coxiella (2.6%), Bradyrhizobium (1.6%) and Acinetobacter (1.1%). Other less abundant (<1%) and potentially pathogenic included Ehrlichia, Rickettsia, Leptospira, Borrelia, Brucella, Chlamydia and Streptococcus. By Shannon diversity index, Acomys spleens carried more diverse bacteria (mean Shannon diversity index of 2.86, p = 0.008) compared to 1.77 for Crocidura, 1.44 for Rattus, 1.40 for Arvicathis and 0.60 for Mastomys. Conclusion This study examined systemic bacteria that are filtered by the spleen and the findings underscore the utility of 16S rRNA deep sequencing in characterizing complex microbiota that are potentially relevant to one health issues. An inherent problem with the V3-V4 region of 16S rRNA is the inability to classify bacteria reliably beyond the genera. Future studies should utilize the newer long read methods of 16S rRNA analysis that can delimit the species composition.

scholarly journals Diversity and Abundance of Insects at the Campus of Higher Polytechnic Institute of Manica, Mozambique

2021 ◽  
pp. 34-39
Author(s):  
António C. Manhice
Keyword(s):  
Relative Abundance ◽  
Diversity Index ◽  
Polytechnic Institute ◽  
Shannon Diversity Index ◽  
Sampling Techniques ◽  
Insect Diversity ◽  
Pitfall Traps ◽  
Shannon Diversity ◽  
Diversity Sampling

The aim of this study was to assess insect diversity and abundance at the Campus of Higher Polytechnic Institute of Manica, Mozambique. Collection of insects was carried out by pitfall traps a long linear transects and sweep nets during 21 days of October 2019. Data were analyzed using descriptive statistical and Shannon diversity index. A total of 1780 individuals of insects belonging to 8 orders, 15 families and 27 species were collected. Highest relative abundance was observed in Hymenoptera order (92.64%), and the least were Blattodea (2.70%), Diptera (2.13%), Coleoptera (0.82%), Orthoptera (1.52%), Phasmatodea (0.06%), Mantodea (0.28%) and Hemiptera (0.11%). The abundant specie was Crematogaster peringueyi (Hymenoptera) with 89.83% follwed by Macrotermes natalensis (Blattodea) and Chrysonmya chloropyga (Diptera) with 2.47% and 1.63% respectively. Higher insect diversity was observed in Orthoptera order (Shannon, H'=1.76), while the orders Coleoptera, Diptera, Hymenoptera, Blattodea, Phasmatodea, Hemiptera, had the lowest diversity (Shannon, H'<1). Further work need to be done in the study area, expanding the duration of the study and applying diversity sampling techniques.

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