scholarly journals A further examination of two new taxonomic distinctness measures

1997 ◽  
Vol 154 ◽  
pp. 303-306 ◽  
Author(s):  
PJ Somerfield ◽  
F Olsgard ◽  
MR Carr
Keyword(s):  
Taxonomic Distinctness

scholarly journals The hypoxia that developed in a microtidal estuary following an extreme storm produced dramatic changes in the benthos

2016 ◽  
Vol 67 (3) ◽  
pp. 327 ◽  
Author(s):  
James R. Tweedley ◽  
Chris S. Hallett ◽  
Richard M. Warwick ◽  
K. Robert Clarke ◽  
Ian C. Potter
Keyword(s):  
Species Composition ◽  
Environmental Stress ◽  
Benthic Macroinvertebrates ◽  
Total Density ◽  
Taxonomic Distinctness ◽  
Residence Times ◽  
Number Of Species ◽  
Environmental Perturbations ◽  
Extreme Storm ◽  
Evenness Index

Runoff from an extreme storm on 22 March 2010 led, during the next 3 months, to the formation of a pronounced halocline and underlying hypoxia in the upper reaches of the microtidal Swan–Canning Estuary. Benthic macroinvertebrates were sampled between January 2010 and October 2011 at five sites along 10km of this region. By mid-April, the number of species, total density, Simpson’s evenness index and taxonomic distinctness had declined markedly, crustaceans had disappeared and the densities of annelids and molluscs had declined slightly. These faunal attributes (except Simpson’s index) and species composition did not recover until after the end of the hypoxia. The survival of annelids and loss of crustaceans in this period reflects different sensitivities of these taxa to severe environmental stress. The results emphasise that microtidal estuaries with long residence times are highly vulnerable to the effects of environmental perturbations, particularly during warmer periods of the year.

Increasing variation in taxonomic distinctness reveals clusters of specialists in the deep sea

Ecography ◽  
2010 ◽  
Vol 34 (2) ◽  
pp. 306-317 ◽  
Author(s):  
Vincent Zintzen ◽  
Marti J. Anderson ◽  
Clive D. Roberts ◽  
Carol E. Diebel
Keyword(s):  
Deep Sea ◽  
Taxonomic Distinctness

scholarly journals Assemblage of Insects on Medicinal Plants: An Insight from ICIMOD Herbal Garden in Godavari of Lalitpur, Nepal

2019 ◽  
Vol 24 (1) ◽  
pp. 34-41
Author(s):  
Daya Ram Bhusal ◽  
Sweta Shrestha ◽  
Kishor Chandra Ghimire
Keyword(s):  
Medicinal Plants ◽  
Taxonomic Distinctness ◽  
Temperature Dependent ◽  
Insect Communities ◽  
Rauvolfia Serpentina ◽  
Mentha Spicata ◽  
Zanthoxylum Armatum ◽  
Four Seasons ◽  
Collecting Techniques ◽  
Mountain Development

Present study was conducted within the herbal garden of International Centre for Integrated Mountain Development (ICIMOD) in Godawari of Kathmandu valley to explore the insect communities in medicinal plants. Five medicinal plants, viz. Rauvolfia serpentina (= Sarpagandha), Urtica dioca (= Sissnu), Zanthoxylum armatum (= Timur), Valeriana jatamansii (= Sungandhawal) and Mentha spicata (= Pudina) were selected for the study. Insects were randomly sampled during four seasons from September 2017 to June 2018 using different collecting techniques, like hand picking, pit-fall traps, net-sweeping and stem beating. A total of 869 insects individuals belonging to 42 different genera were collected and identified. It was found that the abundance of insects was high during spring season (299 insects comprising 35 % of collected species), followed by summer (255 insects comprising 29 % of collected species) and winter (219 insects comprising 25 % of collected species) seasons, and low during autumn season (96 insects comprising 11 % of collected species). It was further found that the abundance of insect species was temperature-dependent, but was independent of relative humidity. The maximum indicator species were present on M. spicata. Taxonomic distinctness (delta+) of insects was high on V. jatamansii, but low on U. dioca.

scholarly journals Zooplankton community structure in the Yellow Sea and East China Sea in autumn

2015 ◽  
Vol 63 (4) ◽  
pp. 455-468 ◽  
Author(s):  
Hongju Chen ◽  
Guangxing Liu
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
East China Sea ◽  
Yellow Sea ◽  
Zooplankton Community ◽  
The Yellow Sea ◽  
East China ◽  
Taxonomic Distinctness ◽  
Zooplankton Community Structure ◽  
China Sea

Abstract Study on zooplankton spatial distribution is essential for understanding food web dynamics in marine ecosystems and fishery management. Here we elucidated the composition and distribution of large mesozooplankton on the continental shelf of the Yellow Sea and East China Sea, and explored the zooplankton community structure in these water masses. Sixty vertical hauls (bottom or 200 m in deep water to surface) using a ring net (diameter 0.8 m, 505-μm mesh) were exploited in November 2007. The biogeographic patterns of zooplankton communities were investigated using multivariate analysis methods; copepod biodiversity was analyzed using univariate indices. Copepods and protozoans were dominate in the communities. Based on the species composition, we divided the study areas into six station groups. Significant differences in zooplankton assemblages were detected between the Yellow Sea and East China Sea. Species richness was higher in East China Sea groups than those in Yellow Sea, whereas taxonomic distinctness was higher in Yellow Sea than in East China Sea. There was a clear relationship between the species composition and water mass group.

scholarly journals Climate Change and Species Invasion Drive Decadal Variation in Fish Fauna in the Min River, China

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1558
Author(s):  
Weide Deng ◽  
Li Lin ◽  
Xiaoxia Huang ◽  
Te-Yu Liao ◽  
Bin Kang
Keyword(s):  
Environmental Changes ◽  
Fish Fauna ◽  
Habitat Diversity ◽  
Influential Factor ◽  
Taxonomic Distinctness ◽  
Decadal Variation ◽  
Human Disturbances ◽  
Min River ◽  
Trade Offs ◽  
Ecological Protection

Freshwater fishes are threatened by increasing environmental changes and human disturbances. The Min River, the largest river in Southeastern China, contains unique fish fauna for the Oriental realm. Due to environmental changes brought by forty years of economic growth, fish numbers have dramatically declined. The average taxonomic distinctness in the 1970s was significantly higher than that in 2015, while no significant differences were found in the variation in taxonomic distinctness between the two periods. Due to the river network and habitat diversity, fish fauna composition showed significant spatial differences but lower variation than the decadal variation. Precipitation was determined to be the most influential factor in determining the spatial pattern of fish fauna, followed by temperature. Species introduced for aquaculture have invaded the endemic fish community after escape and should be reconsidered in the trade-offs between economic development and ecological protection.

Can land use indicate wetland floristic quality and taxonomic distinctness?

2017 ◽  
Vol 78 ◽  
pp. 331-339 ◽  
Author(s):  
Suneeti K. Jog ◽  
Jason T. Bried ◽  
Xiao Feng ◽  
Andrew R. Dzialowski ◽  
Monica Papeş ◽  
...  
Keyword(s):  
Land Use ◽  
Taxonomic Distinctness ◽  
Floristic Quality

scholarly journals Reticulation, divergence, and the phylogeography–phylogenetics continuum

2016 ◽  
Vol 113 (29) ◽  
pp. 8025-8032 ◽  
Author(s):  
Scott V. Edwards ◽  
Sally Potter ◽  
C. Jonathan Schmitt ◽  
Jason G. Bragg ◽  
Craig Moritz
Keyword(s):  
Demographic History ◽  
Nuclear Gene ◽  
Speciation Analysis ◽  
Taxonomic Distinctness ◽  
Gene Trees ◽  
Next Generation ◽  
Comparative Phylogeography ◽  
Demographic Models ◽  
Fast Evolution ◽  
Generation Sequencing

Phylogeography, and its extensions into comparative phylogeography, have their roots in the layering of gene trees across geography, a paradigm that was greatly facilitated by the nonrecombining, fast evolution provided by animal mtDNA. As phylogeography moves into the era of next-generation sequencing, the specter of reticulation at several levels—within loci and genomes in the form of recombination and across populations and species in the form of introgression—has raised its head with a prominence even greater than glimpsed during the nuclear gene PCR era. Here we explore the theme of reticulation in comparative phylogeography, speciation analysis, and phylogenomics, and ask how the centrality of gene trees has fared in the next-generation era. To frame these issues, we first provide a snapshot of multilocus phylogeographic studies across the Carpentarian Barrier, a prominent biogeographic barrier dividing faunas spanning the monsoon tropics in northern Australia. We find that divergence across this barrier is evident in most species, but is heterogeneous in time and demographic history, often reflecting the taxonomic distinctness of lineages spanning it. We then discuss a variety of forces generating reticulate patterns in phylogeography, including introgression, contact zones, and the potential selection-driven outliers on next-generation molecular markers. We emphasize the continued need for demographic models incorporating reticulation at the level of genomes and populations, and conclude that gene trees, whether explicit or implicit, should continue to play a role in the future of phylogeography.

scholarly journals Large-scale patterns in the community structure and biodiversity of freeliving nematodes in the Bohai Sea, China

2001 ◽  
Vol 81 (5) ◽  
pp. 755-763 ◽  
Author(s):  
Y. Guo ◽  
P.J. Somerfield ◽  
R.M. Warwick ◽  
Z. Zhang
Keyword(s):  
Community Structure ◽  
Environmental Variables ◽  
Large Scale ◽  
Bohai Sea ◽  
Yellow River ◽  
River Mouth ◽  
Sediment Surface ◽  
Similar Species ◽  
Taxonomic Distinctness ◽  
The Bohai Sea

Freeliving marine nematodes were sampled on two occasions from an extensive grid of 20 stations in the Bohai Sea and its approaches. Differences within stations between sampling periods were small, resulting from small changes in abundance of dominant species. Differences between stations were significant, and were used to cluster stations into groups with similar species composition. These station groupings revealed a weak faunal gradient leading from the mouth of the Huanghe (Yellow River) to the Bohai Strait. Analyses relating faunal composition to environmental variables showed that there were significant differences in environmental variables between faunally-defined groups of stations. The variables most closely correlated with community structure were silt/clay and sand, depth, phaeopigment concentrations below the sediment surface, organic content and arsenic. These reflect natural processes within the Bohai Sea. A suite of univariate measures were related to distance from the river mouth, with a major discontinuity about 120 km into the Bohai Sea. Comparison of values of the biodiversity measures average taxonomic distinctness (Δ+) and variation in taxonomic distinctness (Λ+) suggest that the meiobenthos of the Bohai Sea as a whole is not under major pollution stress.

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