Spatial and bathymetric trends in composition and taxonomic diversity of Polychaeta (Annelida) assemblages from the deep Southern Gulf of California

2021 ◽  
Author(s):  
Araceli Jaquelín Mercado-Santiago ◽  
Pablo Hernández-Alcántara ◽  
Vivianne Solís-Weiss
Keyword(s):  
Species Richness ◽  
Gulf Of California ◽  
Taxonomic Diversity ◽  
Assemblage Structure ◽  
Geographic Position ◽  
Far Eastern

The deepsea fauna from the southern Gulf of California is currently poorly known, with only 193 species reported to date. The aim of this study was to analyze the composition, density, species richness, and taxonomic diversity (Δ) of the deepsea polychaetes of this region. Fifteen stations (238–2900 m depth) were sampled in 2012 and 2013. Eighty-four species from 58 genera and 26 families were identified. Density ranged from 4.76 to 42.86 ind 0.1m−2 and was not significantly correlated with depth; species richness ranged from 2 to 17 species per station, the lowest (2–6 species) occurring between depths of 651 and 915 m. Four assemblages were identified associated with depth (RANOSIM = 0.43, P = 0.002) and geographic position (RANOSIM = 0.56, P = 0.001): Prionospio elhersi–Subadyte mexicana–Syllis alternata (<350 m depth) and Aricidea sp. A–Ninoe jessicae (600–1000 m) in the western gulf; Onuphis similis–Aricidea (Acmira) simplex (1300–1600 m) and Aglaophamus paucilamellata–Sthenolepis spargens (>1200 m) in the middle gulf; stations 14A and 2A, sharing only their position at the far eastern gulf, remained isolated from any other assemblage. The highest diversity was found at 1300–1600 m (Δ = 86.1) and at >2000 m (Δ = 83–98) but decreased to Δ = 61.85 at 600–1000 m. The assemblage structure based on genera and family levels were similar to those based on species (Rho > 0.6), suggesting that either of the former two could be suitable surrogates for monitoring changes at the studied depths.

Biogeographic and latitudinal patterns of demersal fishes in the Mexican Pacific

2014 ◽  
Vol 95 (2) ◽  
pp. 411-422 ◽  
Author(s):  
Deivis S. Palacios-Salgado ◽  
V.H. Cruz-Escalona ◽  
M.J. Zetina-Rejón ◽  
F. Arreguín-Sánchez ◽  
J.T. Nieto-Navarro
Keyword(s):  
Species Richness ◽  
Gulf Of California ◽  
Taxonomic Diversity ◽  
Wide Distribution ◽  
Taxonomic Composition ◽  
Mexican Pacific ◽  
Distribution Ranges ◽  
Tropical Conditions ◽  
Gulf Of Tehuantepec ◽  
Latitudinal Patterns

Latitudinal patterns of composition, biogeographic affinity and indicators of taxonomic diversity are described for the by-catch fish community in five typical shrimping areas in the Mexican Pacific (Upper Gulf of California, Sinaloa-Nayarit, Jalisco-Colima, Michoacán-Guerrero and Gulf of Tehuantepec). The taxonomic composition included two classes, 20 orders, 65 families, 147 genera and 292 species. The family Sciaenidae was the best represented with 33 species, whereas at the genus level, Anchoa was represented with eight species. A high percentage of the species showed wide distribution ranges (30.2% for Cortez Province ~ Panamic Province; 21.3% for San Diego Province ~ Panamic Province); nevertheless, each ecosystem included a characteristic combination of species, apparently related to the physiographic conditions of the ecosystems. Species richness showed a pronounced decrease from the Upper Gulf of California, which has warm-temperate features, to the Gulf of Tehuantepec, which has tropical conditions; this is an opposite trend to that observed in the taxonomic diversity indicators, suggesting that a taxonomic redundancy was present in tropical areas and higher taxonomic diversity was present in the Upper Gulf of California, despite the lower species richness. This is explained by the prevailing environmental conditions and isolation processes generated during the formation of the Gulf of California.

scholarly journals Do carabids (Coleoptera: Carabidae) and chironomids (Diptera: Chironomidae) exhibit similar diversity and distributional patterns along a spatio-temporal gradient on a glacier foreland?

2018 ◽  
Author(s):  
Mauro Gobbi ◽  
Valeria Lencioni
Keyword(s):  
Species Richness ◽  
Species Turnover ◽  
Aquatic Insect ◽  
Taxonomic Diversity ◽  
Carabid Beetles ◽  
Species Assemblages ◽  
Glacier Foreland ◽  
Distributional Patterns ◽  
Glacier Front ◽  
Spatio Temporal

Carabid beetles and chironomid midges are two dominant cold-adapted taxa, respectively on glacier forefiel terrains and in glacial-stream rivers. Although their sensitivity to high altitude climate warming is well known, no studies compare the species assemblages exhibited in glacial systems. Our study compares diversity and distributional patterns of carabids and chironomids in the foreland of the receding Amola glacier in central-eastern Italian Alps. Carabids were sampled by pitfall traps; chironomids by kick sampling in sites located at the same distance from the glacier as the terrestrial ones. The distance from the glacier front was considered as a proxy for time since deglaciation since these variables are positively correlated. We tested if the distance from the glacier front affects: i) the species richness; ii) taxonomic diversity; and iii) species turnover. Carabid species richness and taxonomic diversity increased positively from recently deglaciated sites (those c. 160 m from the glacier front) to sites deglaciated more than 160yrs ago (those located >1300 m from glacier front). Species distributions along the glacier foreland were characterized by mutually exclusive species. Conversely, no pattern in chironomid species richness and turnover was observed. Interestingly, taxonomic diversity increased significantly: closely related species were found near the glacier front, while the most taxonomically diverse species assemblages were found distant from the glacier front. Increasing glacial retreat differently affect epigeic and aquatic insect taxa: carabids respond faster to glacier retreat than do chironomids, at least in species richness and species turnover patterns.

scholarly journals Untangling the positive association of phylogenetic, functional, and taxonomic diversity with alien bird species richness

Ecosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
A. Andrikou‐Charitidou ◽  
G. Boutsis ◽  
E. Karadimou ◽  
A. S. Kallimanis
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Positive Association ◽  
Taxonomic Diversity ◽  
Bird Species Richness

scholarly journals Ephemeroptera of Canada

ZooKeys ◽  
2019 ◽  
Vol 819 ◽  
pp. 211-225 ◽  
Author(s):  
Luke M. Jacobus
Keyword(s):  
Species Richness ◽  
Metropolitan Areas ◽  
Dna Barcode ◽  
Valid Species ◽  
Index Numbers ◽  
The Usa ◽  
Far Eastern

Thus far, 335 currently valid species in 82 genera and 21 families of mayflies (Ephemeroptera) have been documented from Canada, remarkably representing a little more than half of the combined species richness of Canada, Mexico and the USA. The current known species richness for Canada represents an increase of 11.3% as compared to that reported in 1979. Species richness is greatest in the families Heptageniidae (83), Baetidae (76) and Ephemerellidae (45). A total of 328 DNA Barcode Index Numbers (BINs) are available for Canadian mayfly species. The greatest net gains anticipated for future species tallies are for Baetidae (25), Heptageniidae (10) and Leptophlebiidae (10). A total of 66 more species overall is anticipated for Canada, with greatest gains potentially coming from lentic habitats across Canada and from far eastern and far western areas in general. However, even metropolitan areas should not be overlooked for the potential of discovery.

Temperature and vegetation complexity structure mixed-species flocks along a gradient of elevation in the tropical Andes

The Auk ◽  
2021 ◽  
Author(s):  
Flavia A Montaño-Centellas ◽  
Harrison H Jones
Keyword(s):  
Species Richness ◽  
Abiotic Stress ◽  
Environmental Gradients ◽  
Bird Community ◽  
Taxonomic Diversity ◽  
High Elevation ◽  
Tropical Andes ◽  
Mixed Species ◽  
Mixed Species Flocks ◽  
Species Flocks

Abstract Mixed-species flocks constitute community modules that can help test mechanisms driving changes to community composition across environmental gradients. Here, we examined elevational patterns of flock diversity (species richness, taxonomic diversity, species, and guild composition) and asked if these patterns were reflections of the full bird community at a given elevation (open-membership hypothesis), or if they were instead structured by environmental variables. We surveyed both the overall avian community and mixed-species flocks across an undisturbed elevational gradient (~1,350–3,550 m) in the Bolivian Andes. We then tested for the role of temperature (a surrogate for abiotic stress), resource diversity (arthropods, fruits), and foraging niche diversity (vegetation vertical complexity) in structuring these patterns. Patterns for the overall and flocking communities were similar, supporting our open-membership hypothesis that Andean flocks represent dynamic, unstructured aggregations. Membership openness and the resulting flock composition, however, also varied with elevation in response to temperature and vegetation complexity. We found a mid-elevation peak in flock species richness, size, and Shannon’s diversity at ~2,300 m. The transition of flocking behavior toward a more open-membership system at this elevation may explain a similar peak in the proportion of insectivores joining flocks. At high elevations, increasing abiotic stress and decreasing fruit diversity led more generalist, gregarious tanagers (Thraupidae) to join flocks, resulting in larger yet more even flocks alongside a loss of vegetation structure. At lower elevations, flock species richness increased with greater vegetation complexity, but a greater diversity of foraging niches resulted in flocks that were more segregated into separate canopy and understory sub-types. This segregation likely results from increased costs of interspecific competition and activity matching (i.e., constraints on movement and foraging rate) for insectivores. Mid-elevation flocks (~2,300 m) seemed, therefore, to benefit from both the open-membership composition of high-elevation flocks and the high vegetation complexity of mid- and low-elevation forests.

scholarly journals Plant Taxonomic Diversity Better Explains Soil Fungal and Bacterial Diversity than Functional Diversity in Restored Forest Ecosystems

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 479 ◽  
Author(s):  
Hanif ◽  
Guo ◽  
Moniruzzaman ◽  
He ◽  
Yu ◽  
...  
Keyword(s):  
Species Richness ◽  
Microbial Diversity ◽  
Soil Properties ◽  
Bacterial Diversity ◽  
Functional Diversity ◽  
Forest Ecosystems ◽  
Taxonomic Diversity ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
Bacterial Richness

Plant attributes have direct and indirect effects on soil microbes via plant inputs and plant-mediated soil changes. However, whether plant taxonomic and functional diversities can explain the soil microbial diversity of restored forest ecosystems remains elusive. Here, we tested the linkage between plant attributes and soil microbial communities in four restored forests (Acacia species, Eucalyptus species, mixed coniferous species, mixed native species). The trait-based approaches were applied for plant properties and high-throughput Illumina sequencing was applied for fungal and bacterial diversity. The total number of soil microbial operational taxonomic units (OTUs) varied among the four forests. The highest richness of fungal OTUs was found in the Acacia forest. However, bacterial OTUs were highest in the Eucalyptus forest. Species richness was positively and significantly related to fungal and bacterial richness. Plant taxonomic diversity (species richness and species diversity) explained more of the soil microbial diversity than the functional diversity and soil properties. Prediction of fungal richness was better than that of bacterial richness. In addition, root traits explained more variation than the leaf traits. Overall, plant taxonomic diversity played a more important role than plant functional diversity and soil properties in shaping the soil microbial diversity of the four forests.

Taxonomic diversity estimation using rarefaction

Paleobiology ◽  
1975 ◽  
Vol 1 (4) ◽  
pp. 333-342 ◽  
Author(s):  
David M. Raup
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Sample Size ◽  
Fossil Record ◽  
World Wide ◽  
Taxonomic Diversity ◽  
Early Jurassic ◽  
Late Triassic ◽  
Geologic Time ◽  
Large Samples

Benthic ecologists have successfully applied rarefaction techniques to the problem of compensating for the effect of sample size on apparent species diversity (= species richness). The same method can be used in studies of diversity at higher taxonomic levels (families and orders) in the fossil record where samples represent world-wide distributions of species or genera over long periods of geologic time.Application of rarefaction to several large samples of post-Paleozoic echinoids (totaling 7,911 species) confirms the utility of the method. Rarefaction shows that the observed increase in the number of echinoid families since the Paleozoic is real in the sense that it cannot be explained solely by the increase in numbers of preserved species. There has been no statistically significant increase in the number of families since mid-Cretaceous, however. At the order level, echinoid diversity may have been nearly constant since late Triassic or early Jurassic.

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