SPATIAL VARIATIONS IN RARITY IN THE AEGEAN TENEBRIONID BEETLES (Coleoptera, Tenebrionidae)

Three measures of species rarity were calculated to investigate possible spatial patterns of variation in tenebrionid community rarity on the Aegean islands. For each species rarity was evaluated as geographic distribution (mean incidence of species on islands in the archipelago), ecological tolerance (total area of the islands occupied) and population density (number of decades of species’ records from 1870 to 2000). In addition, Kattan’s index of vulnerability was computed. These rarity and vulnerability measures were used to construct analogous indexes at community level. Plotting species richness on island coordinates, produced a map where richness decreased in the centre of the archipelago, reaching highest values on peripheral islands. Geographic rarity increased from the centre of the archipelago to periphery. By contrast, ecological tolerance and population density show the following pattern: islands located very close to the Anatolian mainland, as well as those that are clumped, host the most eurytopic and abundant species, while remote southern islands have ecologically specialized faunas with low population density. Vulnerability (i.e. the reverse of Kattan’s index applied to communities) decreased in remote islands, which are usually also the smallest. As a whole the tenebrionid beetles on the Aegean Islands constitute threatened faunal assemblages of great ‘rarity’ under several dimensions, and some islands are especially rich in rare species, deserving special attention in conservation efforts.

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

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s002531540800146x ◽

2008 ◽

Vol 88 (5) ◽

pp. 931-940 ◽

Cited By ~ 3

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.

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Avifauna of Saurashtra University Campus, Rajkot, Gujarat, India

Journal of Threatened Taxa ◽

10.11609/jott.5113.12.13.16764-16774 ◽

2020 ◽

Vol 12 (13) ◽

pp. 16764-16774

Author(s):

Varsha Trivedi ◽

Sanjay Vaghela

Keyword(s):

Species Richness ◽

Population Density ◽

Population Size ◽

Rare Species ◽

Bird Species ◽

Species Density ◽

Ecological Indices ◽

University Campus ◽

High Species Richness ◽

Line Transects

We examined the avifauna of Saurashtra University Campus (SUC), Rajkot, Gujarat from July to December 2017. The study area was divided into four sections: North (N), East (E), South (S) and West (W) and surveyed over 18 visits (four line transects/visit). We recorded a total of 82 bird species from 67 genera, 40 families and 16 orders. Of these 57 species were terrestrial and 25 aquatic. By population size the most abundant birds were members of Columbidae (28%), Sturnidae (13%), and Charadridae (8%). Seventy per cent of birds observed (n=7665) were classed as very common and 2% (n=261) as very rare. Species density (S/N = 3.39) and population density (n/N = 196) were at their maximum in December. Ecological indices on temporal base reveal high species richness and Simpson diversity (1/D =17.0 and 1-D= 0.942) in August and November and Shannon diversity was high (H’=3.275) in November during study period.

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Energetic and ecological constraints on population density of reef fishes

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.2186 ◽

2016 ◽

Vol 283 (1823) ◽

pp. 20152186 ◽

Cited By ~ 19

Author(s):

D. R. Barneche ◽

M. Kulbicki ◽

S. R. Floeter ◽

A. M. Friedlander ◽

A. P. Allen

Keyword(s):

Species Richness ◽

Body Size ◽

Population Density ◽

Species Interactions ◽

Spatial Scales ◽

Small Body ◽

Reef Fishes ◽

Abundant Species ◽

Global Scale ◽

Ecological Constraints

Population ecology has classically focused on pairwise species interactions, hindering the description of general patterns and processes of population abundance at large spatial scales. Here we use the metabolic theory of ecology as a framework to formulate and test a model that yields predictions linking population density to the physiological constraints of body size and temperature on individual metabolism, and the ecological constraints of trophic structure and species richness on energy partitioning among species. Our model was tested by applying Bayesian quantile regression to a comprehensive reef-fish community database, from which we extracted density data for 5609 populations spread across 49 sites around the world. Our results indicate that population density declines markedly with increases in community species richness and that, after accounting for richness, energetic constraints are manifested most strongly for the most abundant species, which generally are of small body size and occupy lower trophic groups. Overall, our findings suggest that, at the global scale, factors associated with community species richness are the major drivers of variation in population density. Given that populations of species-rich tropical systems exhibit markedly lower maximum densities, they may be particularly susceptible to stochastic extinction.

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Population density, activity centres, and pandemic: Visualizing clusters of COVID-19 cases in Hong Kong

Environment and Planning A Economy and Space ◽

10.1177/0308518x211012700 ◽

2021 ◽

pp. 0308518X2110127

Author(s):

Jiangping Zhou ◽

Sam KS Ho ◽

Shuyu Lei ◽

Valarie CK Pang

Keyword(s):

Hong Kong ◽

Population Density ◽

Spatial Patterns ◽

Number Of Clusters ◽

The Third ◽

General Number

The impacts of coronavirus disease 2019 (COVID-19) on society and economy are wide-ranging, long-lasting, and global. The experience of multiple countries or regions in fighting the pandemic indicates that there could be multiple COVID-19 surges, where a growing number of cases can be observed in the more recent surge(s). Were COVID-19 cases and clusters of cases (across surges) randomly distributed in spaces? Did population density and activity centres influence clusters of cases and associated venues? Based on information on the associated venues of the four surges of COVID-19 cases between January 2020 and February 2021 as well as population density, visuals were made to distinguish the relationships between population density, activity centres, and clusters of cases in Hong Kong. Different spatial patterns were observed across the four surges: fewer cases were observed in the first surge with a more evenly distributed pattern of clusters; the second surge as compared to the first surge saw a wider distribution and an increase in the number/layer of clusters; compared to the second surge, the third surge suffered from many more cases but saw a decrease in the general number of clusters; and compared to the previous three surges, the fourth surge had the largest number of cases, yet even fewer clusters were observed, where several clusters are again concentrated in specific areas similar to the previous surge. Across the four surges, a few locales could see recurrent clusters of cases and a few communities were without cases.

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Sheep nemabiome diversity and its response to anthelmintic treatment in Swedish sheep herds

Parasites & Vectors ◽

10.1186/s13071-021-04602-y ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Peter Halvarsson ◽

Johan Höglund

Keyword(s):

Species Richness ◽

Diversity Index ◽

Nematode Species ◽

Abundant Species ◽

Anthelmintic Treatment ◽

Host Age ◽

Larval Culture ◽

Nematode Parasites ◽

South Central ◽

Nematode Diversity

Abstract Background A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.

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Mountain definitions and their consequences

Alpine Botany ◽

10.1007/s00035-021-00265-8 ◽

2021 ◽

Author(s):

Christian Körner ◽

Davnah Urbach ◽

Jens Paulsen

Keyword(s):

Species Richness ◽

Population Density ◽

Climatic Change ◽

Plant Species ◽

Human Population ◽

Short Communication ◽

Plant Species Richness ◽

Mountainous Terrain ◽

Human Population Density

AbstractMountains are rugged structures in the landscape that are difficult to delineate. Given that they host an overproportional fraction of biodiversity of high ecological and conservational value, conventions on what is mountainous and what not are in need. This short communication aims at explaining the differences among various popular mountain definitions. Defining mountainous terrain is key for global assessments of plant species richness in mountains and their likely responses to climatic change, as well as for assessing the human population density in and around mountainous terrain.

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Toward a better understanding of the subtropical Atlantic Forest in the state of Santa Catarina, Brazil: tree sampling accuracy, species richness and frequency of rare species

Acta Botanica Brasilica ◽

10.1590/0102-33062014abb3146 ◽

2014 ◽

Vol 28 (3) ◽

pp. 382-391 ◽

Cited By ~ 4

Author(s):

Vanessa Leite Rezende ◽

Pedro V. Eisenlohr ◽

André Luís de Gasper ◽

Alexander Christian Vibrans ◽

Ary Teixeira de Oliveira-Filho

Keyword(s):

Species Richness ◽

Atlantic Forest ◽

Rare Species ◽

The State ◽

Santa Catarina

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Bird and mammal conservation in Gaoligongshan Region and Jingdong County, Yunnan, China: patterns of species richness and nature reserves

Oryx ◽

10.1046/j.1365-3008.2000.00131.x ◽

2000 ◽

Vol 34 (4) ◽

pp. 275-286 ◽

Cited By ~ 6

Author(s):

Daoying Lan ◽

Robin Dunbar

Keyword(s):

Species Richness ◽

Population Density ◽

Human Population ◽

Yunnan Province ◽

Nature Reserve ◽

Present Situation ◽

Primary Forest ◽

Mammal Conservation ◽

Latitudinal Patterns ◽

Conservation Of Biodiversity

AbstractElevational and latitudinal patterns of species richness for birds and mammals were compared with human population density in relation to nature reserve designation in two areas of Yunnan Province, China. Results suggest that species richness is not the same for the two areas. In Gaoligongshan Region, species richness is inversely correlated with elevation and altitude, while reserve designation is positively correlated with elevation and latitude. In Jingdong County, reserve designations are positively correlated with elevation, but species richness shows no clear trends. In general, the present situation is strongly influenced by human activities. It appears that reserve designation is mismatched with species richness in Gaoligongshan Region, while there is a better fit between the two in Jingdong County. In both areas, however, it appeared that reserves were located primarily in order to reduce conflict with humans rather than to maximize conservation of biodiversity, probably because humans were responsible for forest—especially primary forest—destruction and degradation in the low-lying areas.

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