Search results for "Taxonomic rank"
showing 10 items of 45 documents
New challenges in anostracan research: old issues, new perspectives and hot topics
2017
We present a summary of responses to our call among scientists working on Anostraca to commemorate the late Professor Graziella Mura, a pioneer of modern studies on this group of animals. Colleagues from all over the world promptly answered and contributed their works among which we selected the fourteen papers published in the Hydrobiologia Special Volume âNew Challenges in anostracan research: a tribute to Graziella Muraâ. Although Anostraca are widespread globally, they are among the least known taxonomic groups. Although some biogeographical data are available for some species and higher taxa, we are still far from a clear understanding of the phylogeny, ecology and biogeography of …
Comparative analysis of abundance–occupancy relationships for species at risk at both broad taxonomic and spatial scales
2015
The abundance–occupancy relationship is one of the most well-examined relationships in ecology. At the species level, a positive association has been widely documented. However, until recently, research on the nature of this relationship at broad taxonomic and spatial scales has been limited. Here, we perform a comparative analysis of 12 taxonomic groups across a large spatial scale (Canada), using data on Canadian species at risk: amphibians, arthropods, birds, freshwater fishes, lichens, marine fishes, marine mammals, molluscs, mosses, reptiles, terrestrial mammals, and vascular plants. We find a significantly positive relationship in all taxonomic groups with the exception of freshwater…
The Global Naturalized Alien Flora (GloNAF) database.
2019
This dataset provides the Global Naturalized Alien Flora (GloNAF) database, ver-sion 1.2. Glo NAF represents a data compendium on th e occurrence and identit y of naturalizedalien vascular plant taxa across geographic regions (e.g. countries, states, provinces, districts,islands) around the globe. The dataset includes 13,939 taxa and covers 1,029 regions (including381 islands). The dataset is based on 210 data sources. For each ta x on-b y-region combination, wepr ovide information on whether the tax on is consider ed to be naturalized in the specific region(i.e. has established self-sustaining popula tions in the wild). Non-native taxa are marked as“alien”, when it is not clear whether the…
Aggregation patterns of helminth populations in the introduced fish, Liza haematocheilus (Teleostei: Mugilidae): disentangling host–parasite relation…
2018
International audience; A number of hypotheses exist to explain aggregated distributions, but they have seldom been used to investigate differences in parasite spatial distribution between native and introduced hosts. We applied two aggregation models, the negative binomial distribution and Taylor's power law, to study the aggregation patterns of helminth populations from Liza haematocheilus across its native (Sea of Japan) and introduced (Sea of Azov) distribution ranges. In accordance with the enemy release hypothesis, we predicted that parasite populations in the introduced host range would be less aggregated than in the native host area, because aggregation is tightly constrained by abu…
Tree species identity and diversity drive fungal richness and community composition along an elevational gradient in a Mediterranean ecosystem
2017
Ecological and taxonomic knowledge is important for conservation and utilization of biodiversity. Biodiversity and ecology of fungi in Mediterranean ecosystems is poorly understood. Here, we examined the diversity and spatial dis- tribution of fungi along an elevational gradient in a Mediterranean ecosystem, using DNA metabarcoding. This study provides novel information about diversity of all eco- logical and taxonomic groups of fungi along an elevational gradient in a Mediterranean ecosystem. Our analyses revealed that among all biotic and abiotic variables tested, host species identity is the main driver of the fungal richness and fungal community composition. Fungal richness was strongly…
Determinants and Congruence of Species Richness Patterns across Multiple Taxonomic Groups on a Regional Scale
2012
Applying multiple generalized regression models, we studied spatial patterns in species richness for different taxonomic groups (amphibians, reptiles, grasshoppers, plants, mosses) within the German federal state Rhineland-Palatinate (RP). We aimed (1) to detect their centres of richness, (2) to rate the influence of climatic and land-use parameters on spatial patterns, and (3) to test whether patterns are congruent between taxonomic groups in RP. Centres of species richness differed between taxonomic groups and overall richness was the highest in the valleys of large rivers and in different areas of southern RP. Climatic parameters strongly correlated with richness in all taxa whereas land…
Hot spots, indicator taxa, complementarity and optimal networks of taiga
2000
If hot spots for different taxa coincide, priority-setting surveys in a region could be carried out more cheaply by focusing on indicator taxa. Several previous studies show that hot spots of different taxa rarely coincide. However, in tropical areas indicator taxa may be used in selecting complementary networks to represent biodiversity as a whole. We studied beetles (Coleoptera), Heteroptera, polypores or bracket fungi (Polyporaceae) and vascular plants of old growth boreal taiga forests. Optimal networks for Heteroptera maximized the high overall species richness of beetles and vascular plants, but these networks were least favourable options for polypores. Polypores are an important gro…
Investigating bacterial populations in styrene-degrading biofilters by 16S rDNA tag pyrosequencing
2014
Microbial biofilms are essential components in the elimination of pollutants within biofilters, yet still little is known regarding the complex relationships between microbial community structure and biodegradation function within these engineered ecosystems. To further explore this relationship, 16S rDNA tag pyrosequencing was applied to samples taken at four time points from a styrene-degrading biofilter undergoing variable operating conditions. Changes in microbial structure were observed between different stages of biofilter operation, and the level of styrene concentration was revealed to be a critical factor affecting these changes. Bacterial genera Azoarcus and Pseudomonas were among…
A review of the Entocytheridae (Ostracoda) of the world: updated bibliographic and species checklists and global georeferenced database, with insight…
2014
The creation of biodiversity datasets freely available for the scientific community is a valuable task to stimulate global research on biodiversity. Among others, the Global Biodiversity Information Facility (GBIF) is a remarkable resource providing free online access to biodiversity data on many diverse taxonomic groups (including Ostracoda) from both terrestrial and marine ecosystems. More specific databases for Ostracoda georeferenced data have been built (e.g., NACODe and OMEGA), some with freely available data. However, the Entocytheridae, a family of ostracods living commensal on other crustaceans, with 220 living species, representing the third non-marine ostracod family in number of…
Human experts vs. machines in taxa recognition
2020
The step of expert taxa recognition currently slows down the response time of many bioassessments. Shifting to quicker and cheaper state-of-the-art machine learning approaches is still met with expert scepticism towards the ability and logic of machines. In our study, we investigate both the differences in accuracy and in the identification logic of taxonomic experts and machines. We propose a systematic approach utilizing deep Convolutional Neural Nets with the transfer learning paradigm and extensively evaluate it over a multi-pose taxonomic dataset with hierarchical labels specifically created for this comparison. We also study the prediction accuracy on different ranks of taxonomic hier…