Diversity of nematodes in the yellow-necked field mouseApodemus flavicollisfrom the Peripannonic region of Serbia

2014 ◽  
Vol 90 (1) ◽  
pp. 14-20 ◽  
Author(s):  
B. Čabrilo ◽  
V.M. Jovanović ◽  
O. Bjelić-Čabrilo ◽  
I. Budinski ◽  
J. Blagojević ◽  
...  
Keyword(s):  
Species Richness ◽  
Generalized Linear Models ◽  
Linear Models ◽  
Alpha Diversity ◽  
Nematode Species ◽  
Diversity Indices ◽  
Taxonomic Distinctness ◽  
Field Mouse ◽  
Apodemus Flavicollis ◽  
Longitudinal Gradient

AbstractUp to six nematode species were identified from 86 specimens of the yellow-necked field mouseApodemus flavicollisfrom three mountainous localities known as Avala, Cer and Liškovac in Serbia. The highest prevalence of infection of 97% was recorded from Mt. Avala. Only one nematode species,Syphacia frederici, occurred in all three localities. There was complete overlap in nematode species from Mts. Avala and Liškovac, whereas the taxonomic distinctness of Mt. Cer was seen in the presence of the insect-transmitted speciesRictularia proni. Locality was a statistically significant factor in all the best-fitted generalized linear models of variation in abundances. The highest level of both species richness and parasite alpha diversity (Shannon'sH= 1.47) was found in the easternmost Mt. Liškovac, whereas the diversity indices were lowest for the westernmost Mt. Cer (Shannon'sH= 0.48). In view of this geographical difference, the beta diversity indices were calculated along a west to east longitudinal gradient.

Forty years of dietary studies on barn owl (Tyto alba) reveal long term trends in diversity metrics of small mammal prey

2018 ◽  
Vol 68 (2) ◽  
pp. 129-146 ◽  
Author(s):  
Giuliano Milana ◽  
Luca Luiselli ◽  
Giovanni Amori
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Negative Correlation ◽  
Linear Models ◽  
Prey Availability ◽  
Diversity Indices ◽  
Barn Owl ◽  
Tyto Alba ◽  
Local Conditions ◽  
Over Time

AbstractThe diet of predators is influenced by local conditions (e.g., characteristics of habitat and microhabitat, seasonality, prey availability) and therefore tends to change across time. In this paper, the diet composition of the barn owl (Tyto alba) in Italy was studied using a meta-analysis of 47 articles (covering 212 independent sites, with multiple surveys for some sites, thus giving a total of 290 datasets) between 1972 and 2012. General Linear Models were used to assess the effects of year and study site on four distinct diversity indices (species richness, dominance, Shannon-Weaver diversity and equitability). The year of data collection was a factor used in all analyses. Year had a greater effect than study site on all diversity indices, but the effect was not significant for the evenness and the species richness. However, dietary dominance increased significantly over the years, the Shannon-Weaver index of diversity decreased significantly over time, and equitability also decreased significantly over time. The relative abundance of various species of rodents did not increase/decrease progressively over the years, although there were inter-annual fluctuations. On the other hand, the relative abundance of insectivores tended to decrease with time, and there was a significantly negative correlation between year and the frequency of consumption of Sorex spp. and a marginally significant negative correlation for Crocidura leucodon.

Protection status as determinant of carbon stock drivers in Cerrado sensu stricto

2020 ◽  
Vol 13 (3) ◽  
pp. 361-368
Author(s):  
Kelly Marianne Guimarães Pereira ◽  
Natielle Gomes Cordeiro ◽  
Marcela de Castro Nunes Santos Terra ◽  
Marcela Venelli Pyles ◽  
Christian Dias Cabacinha ◽  
...  
Keyword(s):  
Species Richness ◽  
Seed Size ◽  
Generalized Linear Models ◽  
Protected Area ◽  
Linear Models ◽  
Control Area ◽  
Carbon Stocks ◽  
Maximum Diameter ◽  
Functional Richness ◽  
Functional Dispersion

Abstract Aims Natural vegetation plays an important role in global carbon cycling and storage. Thus, the Cerrado (Brazilian savannah) is considered a carbon sink because of its intrinsic characteristics. Our aim was to evaluate how the aboveground biomass and biodiversity relationship change between three Cerrado remnants with different protection status: a ‘control area’ (Legal Reserve area), a protected area (PA) and a non-protected area (Non-PA). Methods All three studied fragments are situated in northern Minas Gerais state, Brazil. We estimated the aboveground carbon stocks based on the forest inventory. We also measured three dimensions of biodiversity metrics for each plot: functional trait dominance, taxonomic diversity and functional diversity. The following functional traits were evaluated for the species: wood density, maximum diameter and seed size. We carried out generalized linear models seeking to evaluate how carbon stocks, community-weighted mean (CWM) trait values, species richness and diversity, and functional diversity indices differ among the remnants. Important Findings The Cerrado areas without protection status had lower carbon stocks, species richness, species diversity, functional richness and functional dispersion, whereas both PA and Non-PA had lower CWM maximum diameter and seed size compared with the Legal Reserve control area. Generalized linear models showed that carbon stocks, species and functional richness metrics were correlated within and across sites, and thus, species richness could serve as a good proxy for functional richness and carbon stocks. The carbon stocks were positively driven by species richness and CWM maximum diameter, while they were negatively driven by functional dispersion. Functional richness, species diversity and CWM seed size appeared in the set of best models, but with no significant direct effect on carbon stocks. Thus, we concluded that absence of protection in the Cerrado areas decreases both species richness and carbon stocks.

Spatial patterns of meiofauna and diversity of nematode species assemblages in the Uvea lagoon (Loyalty Islands, South Pacific)

2008 ◽  
Vol 88 (5) ◽  
pp. 931-940 ◽  
Author(s):  
Y. Guo ◽  
M.-N. Helleouet ◽  
G. Boucher
Keyword(s):  
Species Richness ◽  
Spatial Patterns ◽  
Environmental Parameters ◽  
Nematode Species ◽  
Abundant Species ◽  
Diversity Indices ◽  
Species Assemblages ◽  
Leeward Side ◽  
Local Composition ◽  
Total Species Richness

Meiofauna assemblages were investigated at 15 stations on triplicated samples in the Uvea Atoll (Loyalty Islands) in relation to 9 selected environmental parameters. Spatial patterns and variability of meiofauna density were quantified according to location, macrofauna and nematode species assemblages. Meiofauna was dominated by ciliates and nematodes. Densities of total meiofauna and of most of the meiofauna taxa were significantly higher in the back reef North Pléiades stations than the leeward side of the Island. The highest correlation between biotic patterns and environmental parameters that best explains the pattern was with sediment thickness and to a lesser extent organic matter, C/N ratio and depth. One hundred and thirty-four nematode species were identified with four dominant species Chromadora macrolaimoides, an undescribed species of Bolbonema, Daptonema svalbardense and Prochromadorella septempapillata. Three significantly different nematode species assemblages were detected in two of the previously described macrofauna assemblages by cluster analysis and multidimensional scaling methods suggesting that nematodes are more sensible ecological indicators than macrofauna. Diversity indices based on dominance were not significantly different among the three nematode species assemblages but indices based on species richness and rarefaction were significantly higher leeward of Uvea Island. Estimates of total species richness showed no sign of stabilizing with sample size. However, rare species stabilized very quickly, whereas abundant species were added with increasing sampling coverage, indicating a high spatial variability of the local composition of nematodes.

scholarly journals Functional Diversity in Ferns Is Driven by Species Richness Rather Than by Environmental Constraints

2021 ◽  
Vol 11 ◽  
Author(s):  
Daniela Aros-Mualin ◽  
Sarah Noben ◽  
Dirk N. Karger ◽  
César I. Carvajal-Hernández ◽  
Laura Salazar ◽  
...  
Keyword(s):  
Species Richness ◽  
Functional Diversity ◽  
Environmental Conditions ◽  
Linear Models ◽  
Environmental Filtering ◽  
Diversity Indices ◽  
Resource Acquisition ◽  
Climate Data ◽  
Acquisition Strategies ◽  
Functional Diversity Indices

Functional traits determine how species interact with their abiotic and biotic environment. In turn, functional diversity describes how assemblages of species as a whole are adapted to their environment, which also determines how they might react to changing conditions. To fully understand functional diversity, it is fundamental to (a) disentangle the influences of environmental filtering and species richness from each other, (b) assess if the trait space saturates at high levels of species richness, and (c) understand how changes in species numbers affect the relative importance of the trait niche expansion and packing. In the present study, we determined functional diversity of fern assemblages by describing morphological traits related to resource acquisition along four tropical elevational transects with different environmental conditions and species richness. We used several functional diversity indices and their standardized effect size to consider different aspects of functional diversity. We contrasted these aspects of functional diversity with climate data and species richness using linear models and linear mixed models. Our results show that functional morphological trait diversity was primarily driven by species richness and only marginally by environmental conditions. Moreover, increasing species richness contributed progressively to packing of the morphological niche space, while at the same time decreasing morphological expansion until a saturation point was reached. Overall, our findings suggest that the density of co-occurring species is the fundamental driving force of morphological niche structure, and environmental conditions have only an indirect influence on fern resource acquisition strategies.

The importance and use of taxon sampling curves for comparative biodiversity research with forest arthropod assemblages

2005 ◽  
Vol 137 (1) ◽  
pp. 120-127 ◽  
Author(s):  
Christopher M. Buddle ◽  
Julien Beguin ◽  
Elise Bolduc ◽  
Alida Mercado ◽  
Tara E. Sackett ◽  
...  
Keyword(s):  
Species Richness ◽  
Alpha Diversity ◽  
Wiener Index ◽  
Diversity Indices ◽  
Taxon Sampling ◽  
Sampling Effort ◽  
Single Index ◽  
Arthropod Biodiversity ◽  
Forested Ecosystems ◽  
Number Of Individuals

AbstractFor over three decades, the importance of taxon sampling curves for comparative biodiversity studies has been repeatedly stated. However, many entomologists (both within Canada and worldwide) continue to publish studies without standardizing their data to take sampling effort into account. We present a case study to illustrate the importance of such standardization, using the collection of spiders (Araneae) by pitfall traps as model data. Data were analyzed using rarefaction to represent one example of a taxon sampling curve, and by a variety of traditional diversity indices to describe alpha diversity. Raw species richness and single-index diversity measures (Shannon–Wiener, Simpson's, and Fisher's α) provided contradictory results. Rarefied species richness standardized to the number of individuals collected enabled more accurate comparisons of diversity and revealed when sampling was insufficient. Focusing on arthropods occurring in forested ecosystems, we also examined the use of taxon sampling curves in current literature by reviewing 133 published articles from 14 journals. Only 26% of the published articles in our review used a taxon sampling curve, and raw species richness and the Shannon–Wiener index of diversity were the most commonly used estimates. There is clearly a need to modify how alpha diversity is measured and compared for arthropod biodiversity studies. We recommend the abandonment of both raw species richness and single-index measures of diversity, and reiterate the need to use rarefaction or a related technique that allows for meaningful comparisons of species richness while taking into account sampling effort.

Parasitism underground: determinants of helminth infections in two species of subterranean rodents (Octodontidae)

Parasitology ◽  
2010 ◽  
Vol 137 (10) ◽  
pp. 1569-1575 ◽  
Author(s):  
M. A. ROSSIN ◽  
A. I. MALIZIA ◽  
J. T. TIMI ◽  
R. POULIN
Keyword(s):  
Generalized Linear Models ◽  
Parasite Species ◽  
Linear Models ◽  
Nematode Species ◽  
Helminth Species ◽  
Subterranean Rodents ◽  
South American ◽  
Host Age ◽  
Wild Mammals ◽  
Helminth Infections

SUMMARYPatterns of infection among hosts in a population are often driven by intrinsic host features such as age or sex, as well as by positive or negative interactions between parasite species. We investigated helminth parasitism in 2 South American rodent species,Ctenomys australisandC. talarum(Octodontidae), to determine whether the unusual solitary and subterranean nature of these hosts would impact their patterns of infection. We applied generalized linear models to infection data on a total of 7 helminth species (1 inC. australisand 6 inC. talarum). Host age and season of capture influenced infection levels in some of the helminth species, but none were influenced by host body condition. InC. talarum, 4 pairs of helminth species showed significant associations, either asymmetrical or symmetrical, and with 3 of the 4 being positive; strong inter-specific facilitation appears likely in 1 case. Also, we found that female hosts, especially non-pregnant ones, harboured heavier infections of 2 nematode species than male hosts. This is in sharp contrast to the general male-bias reported for most studies of nematodes in wild mammals, and we develop explanations for these results based on the unusual ecology of these subterranean rodents.

scholarly journals Ichthyofauna of the Mata de Itamacaoca, an urban protected area from the upper Munim River basin, Northern Brazilian Cerrado

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Elioenai da Silva Oliveira ◽  
Erick Cristofore Guimarães ◽  
Pâmella Silva de Brito ◽  
Lucas de Oliveira Vieira ◽  
Rafael Ferreira de Oliveira ◽  
...  
Keyword(s):  
Species Richness ◽  
River Basin ◽  
Fish Species ◽  
Fish Community ◽  
Linear Models ◽  
Anthropogenic Impacts ◽  
Sampling Site ◽  
Abundant Species ◽  
Diversity Indices ◽  
Alien Invasive Species

Abstract: The Munim River basin is one of the main river drainages of the Hydrological unit Maranhão, but there are few published studies which focus on ichthyological surveys and taxonomic work within this basin. The present study aims to provide a fish species inventory of the Mata da Itamacaoca, one of the few urban protected areas from the upper Munim River basin, comparing the ichthyofauna with other lists by conducted at the upper Munim River basin. A total of 42 collection expeditions were conducted, the sampling was conducted at five collecting sites distributed within the boundaries of Mata de Itamacaoca, upper Munim River basin. Diversity indices were calculated and generalised linear models (GLMs) were employed to assess differences in species richness, diversity and evenness depending on season and location in relation to the reservoir dam wall. In order to visualize fish community differences, non-metric multidimensional scaling (nMDS) and a one-way PERMANOVA was used to understand whether factors of site, season and location to the dam wall had an effect on fish community compositions. A total of six orders, 13 families, and 23 fish species were found, and the order with the highest species richness, considering all reaches, was Characiformes followed by Cichliformes. The most abundant species was Nannostomus beckfordi, while Pimelodella parnahybae and Hoplerythrinus unitaeniatus were the rarer species sampled. There were no alien invasive species collected within the study area. Species richness was significantly higher below the dam wall, but there were no other significant differences in diversity indices with regards to season or location. Fish community composition was significantly different above and below the dam wall and was significantly affected by sampling site. Season did not have an effect on fish community. This study corroborates other studies conducted in the Unidade Hidrológica Maranhão sensu Hubbert and Renno (2006), that the ichthyofaunal composition and taxonomy of species within this region face major data deficits, anthropogenic impacts, this study may be a baseline for comparing similar environments throughout the region.

scholarly journals Does plant diversity determine the diversity of the rhizosphere microbial community?

2021 ◽  
Author(s):  
Aleksei Zverev ◽  
Arina Kichko ◽  
Vasiliy Shapkin ◽  
Aleksandr Pinaev ◽  
Nikolay Provorov ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Mutual Influence ◽  
Plant Root ◽  
Alpha Diversity ◽  
Diversity Indices ◽  
Font Size ◽  
Community System ◽  
Highly Correlated ◽  
Rhizosphere Community

The rhizosphere community represents an “ecological interface” between plant and soil, providing the plant with a number of advantages. Close connection and mutual influence in this communication allow to talk about the self-adjusting “plant-rhizosphere community” system, which should be be studied in connection. Diversity estimation is one of the ways of describing both bacterial and plant communities. Based on the literature, there are two assumptions of how the diversity of plant communities related to the diversity of bacterial communities: 1) an increase in the species richness of plants leads to an increase in the number of available micro-niches, and increasing of microbial diversity, 2) an increase in the species richness of plants is accompanied by the predominant development of bacteria from highly productive specific taxa and decreasing in the diversity of microorganisms. E xperimental studies show controversial results. We analyzed field sites (rye crop field and two fallow sites), using DNA isolation of both the plant root mass (followed by sequencing of the ITS1 region) and rhizosphere microorganisms (followed by sequencing of the 16s rDNA V4 region). This allowed us to 1) accurately determine the abundance and taxonomic position of plant communities; 2) extract information about both plant and microbial communities from the same sample. There was no correlation between alpha-diversity indices of plants and rhizosphere communities. Alpha-diversity connection should be explored in similar plant communities, such as synusia. We hypothesize, that the significant differences in plant abundances lead to significant changes in exudation profiles, and the loss of diversity connection. T he beta-diversity between rhizosphere communities and plant communities is highly correlated, in particular in terms of the abundance of taxa. This can be explained by a potential correlation (as reported in the literature) or by the presence of statistical artifacts. p { margin-bottom: 0.1in; direction: ltr; color: #000000; line-height: 115%; text-align: left; orphans: 2; widows: 2; background: transparent }p.western { font-family: "Liberation Serif", serif; font-size: 12pt; so-language: en-US }p.cjk { font-family: "Noto Serif CJK SC"; font-size: 12pt; so-language: zh-CN }p.ctl { font-family: "Lohit Devanagari"; font-size: 12pt; so-language: hi-IN }a:link { color: #000080; text-decoration: underline

scholarly journals Does plant diversity determine the diversity of the rhizosphere microbial community?

2021 ◽  
Author(s):  
Aleksei Zverev ◽  
Arina Kichko ◽  
Vasiliy Shapkin ◽  
Aleksandr Pinaev ◽  
Nikolay Provorov ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Mutual Influence ◽  
Plant Root ◽  
Alpha Diversity ◽  
Diversity Indices ◽  
Font Size ◽  
Community System ◽  
Highly Correlated ◽  
Rhizosphere Community

The rhizosphere community represents an “ecological interface” between plant and soil, providing the plant with a number of advantages. Close connection and mutual influence in this communication allow to talk about the self-adjusting “plant-rhizosphere community” system, which should be be studied in connection. Diversity estimation is one of the ways of describing both bacterial and plant communities. Based on the literature, there are two assumptions of how the diversity of plant communities related to the diversity of bacterial communities: 1) an increase in the species richness of plants leads to an increase in the number of available micro-niches, and increasing of microbial diversity, 2) an increase in the species richness of plants is accompanied by the predominant development of bacteria from highly productive specific taxa and decreasing in the diversity of microorganisms. E xperimental studies show controversial results. We analyzed field sites (rye crop field and two fallow sites), using DNA isolation of both the plant root mass (followed by sequencing of the ITS1 region) and rhizosphere microorganisms (followed by sequencing of the 16s rDNA V4 region). This allowed us to 1) accurately determine the abundance and taxonomic position of plant communities; 2) extract information about both plant and microbial communities from the same sample. There was no correlation between alpha-diversity indices of plants and rhizosphere communities. Alpha-diversity connection should be explored in similar plant communities, such as synusia. We hypothesize, that the significant differences in plant abundances lead to significant changes in exudation profiles, and the loss of diversity connection. T he beta-diversity between rhizosphere communities and plant communities is highly correlated, in particular in terms of the abundance of taxa. This can be explained by a potential correlation (as reported in the literature) or by the presence of statistical artifacts. p { margin-bottom: 0.1in; direction: ltr; color: #000000; line-height: 115%; text-align: left; orphans: 2; widows: 2; background: transparent }p.western { font-family: "Liberation Serif", serif; font-size: 12pt; so-language: en-US }p.cjk { font-family: "Noto Serif CJK SC"; font-size: 12pt; so-language: zh-CN }p.ctl { font-family: "Lohit Devanagari"; font-size: 12pt; so-language: hi-IN }a:link { color: #000080; text-decoration: underline

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