Distribution patterns of molluscan fauna in seagrass beds in the Ensenada de O Grove (Galicia, north-western Spain)

2012 ◽  
Vol 93 (3) ◽  
pp. 619-630 ◽  
Author(s):  
P. Quintas ◽  
J. Moreira ◽  
J.S. Troncoso
Keyword(s):  
Species Richness ◽  
Outer Part ◽  
Distribution Patterns ◽  
Abundant Species ◽  
Seagrass Beds ◽  
Muddy Sand ◽  
Molluscan Fauna ◽  
Western Spain ◽  
Scaling Analyses ◽  
North Western

The distribution and composition of molluscan assemblages of seagrass beds in the Ensenada de O Grove (north-western Spain), are described in this paper. The studied bottoms were mostly muddy and colonized predominantly by Zostera marina L., Z. noltei Hornemann, or by both species. Molluscan fauna was dominated by gastropods and bivalves, in terms of both species richness and abundance. A total of 7641 individuals belonging to 68 taxa was identified. The most abundant species were the gastropods Peringia ulvae, Retusa truncatula and Calyptraea chinensis and the bivalves Abra alba, Loripes lucinalis and Kurtiella bidentata. Cluster and multidimensional scaling analyses based on Bray–Curtis similarity coefficient showed two distinct faunal assemblages. Group A comprised intertidal sites colonized either by Z. noltei or by Z. marina and Z. noltei on muddy sand and sandy mud bottoms and subtidal sites exclusively colonized by Z. marina in the outer part of the inlet on muddy sand with the highest values of species richness and diversity. Group B consisted of sites characterized by low values of species diversity and a species composition typical of a ‘reduced Macoma community’. The sorting coefficient and the combination of gravel, sorting coefficient and carbonates content (BIOENV analyses) and the salinity of bottom water and depth (canonical correspondence analyses) were the most important abiotic variables in explaining the structure of the molluscan assemblage.

Invasion by the leguminous tree Acacia dealbata (Mimosaceae) reduces the native understorey plant species in different communities

2012 ◽  
Vol 60 (8) ◽  
pp. 669 ◽  
Author(s):  
Paula Lorenzo ◽  
Eva Pazos-Malvido ◽  
Margarita Rubido-Bará ◽  
Manuel J. Reigosa ◽  
Luís González
Keyword(s):  
Species Richness ◽  
Plant Density ◽  
Plant Cover ◽  
Community Type ◽  
Leguminous Tree ◽  
Acacia Dealbata ◽  
Total Plant ◽  
Western Spain ◽  
North Western ◽  
Understorey Plant

Acacia dealbata Link (Mimosaceae) is a woody leguminous tree introduced to Europe from Australia that has become a serious environmental problem in north-western Spain, where it forms dense monospecific patches threatening native-plant biodiversity. We describe the effects of invasion by A. dealbata on understorey plant composition in shrubland, oak- and pine-forest communities in north-western Spain. Plant species richness and composition, plant density and total plant cover were measured and compared among patches with different invasion status (invaded, transition and non-invaded patches) in each studied community. A clear effect of the community type and invasion on the understorey vegetation was observed. In general, composition of shrubland was different from that of oak and pine forests. We found significant effects of invasion status on species richness, plant density and total plant cover; values were significantly lower in invaded than non-invaded patches. Invasion by A. dealbata also was associated with changes in species composition. In total, eight native species, including the endemic Daboecia cantabrica (thuds) K. Koch, were confined to non-invaded patches and were replaced by other natives in invaded and transition patches. Our results suggest that although A. dealbata represented a serious threat to all of the study communities, the severity of the impact depended on the community type.

scholarly journals Rove beetles (Coleoptera: Staphylinidae) of a large pristine peat bog in Belarus Lake District

2018 ◽  
Vol 61 (2) ◽  
pp. 99-104
Author(s):  
Gennadi G. SUSHKO ◽  
Keyword(s):  
Species Richness ◽  
Abundant Species ◽  
The Other ◽  
Peat Bog ◽  
Lake District ◽  
Open Spaces ◽  
Rove Beetles ◽  
Moss Layer ◽  
High Species Richness ◽  
North Western

Species composition and diversity of the rove beetles were studied in main habitats of a large pristine peat bog in Belarus Lake District (North-Western Belarus). Very specific staphylinid assemblages were found. They were characterized by not high species richness and diversity. In these uneven assemblages, a very small number of species: Drusilla canaliculata (Fabricius, 1787), Philonthus cognatus Stephens, 1832, Staphylinus erythropterus Linnaeus, 1758, Ischnosoma splendidus (Gravenhorst, 1806) dominated, while the majority of recorded species were rare. Unlike other inhabitants of the moss layer among the highly abundant species of rove beetles, peat bog specialists were not found. The highest diversity and evenness had the rove beetles assemblages in open spaces. On the other hand, the differences in these assemblages were not high.

Distribution Patterns and Climatic Explanations of Species Richness of Vascular Plants in Xinjiang, China

2011 ◽  
Vol 28 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Li-ping LI ◽  
Nurbay Abdusalih ◽  
Shao-peng WANG ◽  
Zhi-heng WANG ◽  
Zhi-yao TANG
Keyword(s):  
Species Richness ◽  
Vascular Plants ◽  
Distribution Patterns

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

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.

scholarly journals Deep-Water Cartilaginous Fishes in the Central Mediterranean Sea: Comparison between Geographic Areas with Two Low Impact Tools for Sampling

2021 ◽  
Vol 9 (7) ◽  
pp. 686
Author(s):  
Angela Carluccio ◽  
Francesca Capezzuto ◽  
Porzia Maiorano ◽  
Letizia Sion ◽  
Gianfranco D’Onghia
Keyword(s):  
Adriatic Sea ◽  
Fish Habitat ◽  
Conservation Status ◽  
Abundant Species ◽  
Cartilaginous Fish ◽  
Fish Diversity ◽  
Ionian Sea ◽  
Central Mediterranean ◽  
The North ◽  
North Western

Baited lander represents a low impact technique, an alternative to the traditional trawl sampling for collecting data on fish diversity and abundance, especially for threatened species such as Chondrichthyes living in sensitive habitats. In this study, distribution and abundance of cartilaginous fish were compared between two geographic areas, the southern Adriatic Sea and the north-western Ionian Sea, with two low impact sampling gears, an experimental bottom longline and a baited lander. Species diversity was evaluated by applying ecological indices and difference in mean abundances were tested using multivariate analysis. A total of 13 species of cartilaginous fish were collected. Significant differences in the assemblage recorded in the same area using different sampling tools were detected and no significant differences were detected among different areas explored with the same method. Using longline, the most abundant species collected in both areas was Galeus melastomus, while using lander, the most observed species were Dalatias licha in the southern Adriatic Sea and Hexanchus griseus in the north-western Ionian Sea. According to IUCN classification, of the 13 species collected, 2 are near threatened and 5 are threatened. A better governance of sensitive habitats coinciding with the essential fish habitat for these species would ensure them a better conservation status.

Pollens of honeys from north-western Spain

1991 ◽  
Vol 30 (2) ◽  
pp. 69-73 ◽  
Author(s):  
M V Jato ◽  
A Sala-Llinares ◽  
M I Iglesias ◽  
M Suarez-Cervera
Keyword(s):  
Western Spain ◽  
North Western

scholarly journals Lack of detectable genetic isolation in the cyclic rodent Microtus arvalis despite large landscape fragmentation owing to transportation infrastructures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Julio C. Dominguez ◽  
María Calero-Riestra ◽  
Pedro P. Olea ◽  
Juan E. Malo ◽  
Christopher P. Burridge ◽  
...  
Keyword(s):  
Population Density ◽  
Mixed Models ◽  
Landscape Fragmentation ◽  
Microtus Arvalis ◽  
Density Peaks ◽  
Genetic Patterns ◽  
Large Fluctuations ◽  
Genetic Impact ◽  
Western Spain ◽  
North Western

AbstractAlthough roads are widely seen as dispersal barriers, their genetic consequences for animals that experience large fluctuations in population density are poorly documented. We developed a spatially paired experimental design to assess the genetic impacts of roads on cyclic voles (Microtus arvalis) during a high-density phase in North-Western Spain. We compared genetic patterns from 15 paired plots bisected by three different barrier types, using linear mixed models and computing effect sizes to assess the importance of each type, and the influence of road features like width or the age of the infrastructure. Evidence of effects by roads on genetic diversity and differentiation were lacking. We speculate that the recurrent (each 3–5 generations) episodes of massive dispersal associated with population density peaks can homogenize populations and mitigate the possible genetic impact of landscape fragmentation by roads. This study highlights the importance of developing spatially replicated experimental designs that allow us to consider the large natural spatial variation in genetic parameters. More generally, these results contribute to our understanding of the not well explored effects of habitat fragmentation on dispersal in species showing “boom-bust” dynamics.

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