scholarly journals Spatial distribution of the macrozoobenthos in the Solís Grande Stream estuary (Canelones-Maldonado, Uruguay)

2001 ◽  
Vol 61 (3) ◽  
pp. 409-420 ◽  
Author(s):  
P. MUNIZ ◽  
N. VENTURINI
Keyword(s):  
Cluster Analysis ◽  
Spatial Distribution ◽  
Species Richness ◽  
Spatial Patterns ◽  
Fine Sand ◽  
Present Species ◽  
Multivariate Techniques ◽  
Natural Factors ◽  
Mean Diameter ◽  
Variation Explained

The analysis of 24 quantitative macrobenthic samples taken from the Solís Grande Stream estuary yielded 10 species from a total of 4,446 individuals. It was verified that both species richness and diversity was lower than those recorded in nearby regions with similar environmental conditions. In contrast with other studies, a marked dominance of any of the present species was not verified. All the species recorded correspond to typical estuarine organisms. Abundance data were analysed with multivariate techniques and the results showed a relationship with salinity, mean diameter and the percentage of fine sand. According to the cluster analysis and the canonical correspondence analysis (CCA) four groups of stations were defined. The partition out of total variation of the species data showed that the amount of variation explained by the space alone was low. Spatial patterns observed and their possible causes are analysed and discussed in relation to the natural factors that acts in this coastal ecosystem.

scholarly journals Fish community assessment with eDNA metabarcoding: effects of sampling design and bioinformatic filtering

2017 ◽  
Vol 74 (9) ◽  
pp. 1362-1374 ◽  
Author(s):  
Nathan T. Evans ◽  
Yiyuan Li ◽  
Mark A. Renshaw ◽  
Brett P. Olds ◽  
Kristy Deiner ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Spatial Resolution ◽  
Spatial Patterns ◽  
Water Body ◽  
Fish Community ◽  
Sampling Design ◽  
Environmental Dna ◽  
Body Type ◽  
Multiple Samples

Species richness is a metric of biodiversity that represents the number of species present in a community. Traditional fisheries assessments that rely on capture of organisms often underestimate true species richness. Environmental DNA (eDNA) metabarcoding is an alternative tool that infers species richness by collecting and sequencing DNA present in the ecosystem. Our objective was to determine how spatial distribution of samples and “bioinformatic stringency” affected eDNA-metabarcoding estimates of species richness compared with capture-based estimates in a 2.2 ha reservoir. When bioinformatic criteria required species to be detected only in a single sample, eDNA metabarcoding detected all species captured with traditional methods plus an additional 11 noncaptured species. However, when we required species to be detected with multiple markers and in multiple samples, eDNA metabarcoding detected only seven of the captured species. Our analysis of the spatial patterns of species detection indicated that eDNA was distributed relatively homogeneously throughout the reservoir, except near the inflowing stream. We suggest that interpretation of eDNA metabarcoding data must consider the potential effects of water body type, spatial resolution, and bioinformatic stringency.

scholarly journals Stages of spatial dispersion of the COVID-19 epidemic in Poland in the first six months (4 March-20 September, 2020).

2021 ◽  
Vol 94 (3) ◽  
pp. 305-324
Author(s):  
Przemysław Śleszyński
Keyword(s):  
Time Series ◽  
Cluster Analysis ◽  
Spatial Distribution ◽  
Population Density ◽  
Spatial Patterns ◽  
Concentration Index ◽  
Spatial Dispersion ◽  
First Case ◽  
And Cluster Analysis ◽  
Day By Day

The article is a continuation of research published by the author elsewhere (Śleszyński, 2020). The elaboration presents the regularity of spatial distribution of infections during the first six months after the detection of SARS-CoV-2 coronovirus in Poland under strong lockdown conditions. The main aim is to try to determine the basic temporal-spatial patterns and to answer the questions: to what extent the phenomenon was ordered and to what extent it was chaotic, whether there are any particular features of spread, whether the infection is concentrated or dispersed and whether the spreading factors in Poland are similar to those observed in other countries. Day by day data were used according to the counties collected in Rogalski’s team (2020). The data were aggregated to weekly periods (7 days) and then the regularity of spatial distribution was searched for using the cartogram method, time series shifts, rope correlation between the intensity of infections in different periods, Herfindahl-Hirschman concentration index (HHI) and cluster analysis. A spatial typology of infection development in the population was also performed. Among other things, it was shown that during the first period (about 100 days after the first case), the infections became more and more spatially concentrated and then dispersed. Differences were also shown in relation to the spread of the infection compared to observations from other countries, i.e. no relation to population density and level of urbanization.

Biogeographical regionalisation of Colombia: a revised area taxonomy

Phytotaxa ◽  
2021 ◽  
Vol 484 (3) ◽  
pp. 247-260
Author(s):  
CARLOS E. GONZÁLEZ-OROZCO
Keyword(s):  
Cluster Analysis ◽  
Species Richness ◽  
Plant Species ◽  
Spatial Patterns ◽  
Species Turnover ◽  
Land Plants ◽  
Geospatial Analyses ◽  
Areas Of Endemism ◽  
Biogeographic Regions ◽  
Definition Of

This study proposes a biogeographical regionalisation of Colombia based on geospatial analyses of plant species turnover and a revised area taxonomy. The spatial patterns of species turnover are calculated for 20,342 plant species in continental Colombia with distributions estimated from 271,568 georeferenced records aggregated to 414 (~50 km) grid cells across Colombia. The proposed biogeographic regions are defined by applying an agglomerative cluster analysis using a matrix of pairwise Simpson’s beta (bsim) dissimilarity values. Three main centres of species richness and 25 areas of endemism were identified across Colombia, complementing the definition of regionalisation. Biogeographical regionalisation comprises two dominions (Pacific and Boreal Brazilian), six provinces (Chocó-Darién, Guajira, Magdalena, Paramo, Sabana and Imerí) and thirty-five districts. The revised area taxonomy provides an updated and objective biogeographical classification for Colombia and is the first biogeographic regionalisation exclusively based on the taxic distributional overlap of Colombia´s land plants.

scholarly journals DISTRIBUCION ESPACIAL DE LA TAXOCENOSIS ANNELIDA-MOLLUSCA EN LA PLATAFORMA CONTINENTAL DEL GOLFO DE SALAMANCA, CARIBE COLOMBIANO

2016 ◽  
Vol 22 ◽  
Author(s):  
Angela Guzmán Alvis ◽  
Juan Manuel Díaz
Keyword(s):  
Cluster Analysis ◽  
Spatial Distribution ◽  
Continental Shelf ◽  
Fine Sand ◽  
Sediment Type ◽  
Biological Features ◽  
Analysis Of Similarity ◽  
Muddy Bottom ◽  
Abundance And Diversity

A preliminary characterization of macrozoobenthic assemblages on the continental shelf off southwestern Santa Marta, Colombian Caribbean, is made on the basis of bottom samples taken at 17 stations, in depths between 15 and 100 m. Only families of the most abundant groups, Mollusca and Polychaeta, were taken into account for the analysis. Cluster analysis of similarity between stations and between families revealed the ocurrence of three assemblages, whose spatial distribution is related with sediment type, depth, and some biological features: one assemblage is found on bottoms with fine to very fine sand and muds at dephts between 15 and 60 m, showing the greater abundances and families diversity; the second assemblage is found at about 60 m depth in muddy bottom; a last assemblage inhabits also muddy bottom below 100 m depth and exhibits the lowest numbers of abundance and diversity.

scholarly journals The subtidal macrobenthos in the mesohaline part of the Schelde Estuary (Belgium): influenced by man?

2000 ◽  
Vol 80 (4) ◽  
pp. 587-597 ◽  
Author(s):  
Tom Ysebaert ◽  
Liesbeth De Neve ◽  
Patrick Meire
Keyword(s):  
Grain Size ◽  
Species Richness ◽  
Indicator Species ◽  
Dry Weight ◽  
Fine Sand ◽  
Sediment Type ◽  
Multivariate Techniques ◽  
Surface Deposit ◽  
Hard Substrates ◽  
Schelde Estuary

The macrobenthos of the subtidal, mesohaline zone of the Schelde Estuary (Belgium) was sampled in October 1996 and 1997 at 54 and 73 sampling locations respectively. Sediments ranged from silty to very coarse, with the dominant sediment type being silt (33% of all locations). Of the 35 macrobenthic species observed, only seven species occurred in more than 20% of the samples. The polychaete Heteromastus filiformis and Oligochaeta were most common. Multivariate techniques revealed three distinct communities, linked mainly with sedimentological factors: (1) a species-poor (nine species) community with a dominance of the amphipod Bathyporeia pilosa, a low mean abundance and biomass (86 ind m−2, 0.0189 g ash-free dry weight (AFDW) m−2), and a mean median grain size of 215±19 μm (fine sand); (2) a species-rich (22) community, with the small polychaete Polydora ligerica as indicator species, a relatively high mean abundance and biomass (2298 ind m−2, 1.395 g AFDW m−2, oysters excluded), a mean median grain size of 133±41 μm, and also the occurrence of sediments with hard substrates being characteristic for this community; (3) a community with an intermediate species richness (12), abundance and biomass (248 ind m−2, 0.249 g AFDW m−2), with H. filiformis and Oligochaeta as indicator species, and a median grain size of 76±9 μm. In the study area several typical brackish water species were observed (e.g. Polydora ligerica, Corophium lacustre, Gammarus salinus).Mean total abundance and biomass were very low, and the benthic communities appeared to be under stress, with a dominance of mainly small, subsurface deposit and surface deposit feeding opportunistic species. This is probably a combined effect of both natural physical and human-induced disturbance. Only sediments with hard substrates (e.g. rocks) seems to favour species richness, providing a shelter against physical disturbance.

scholarly journals Spatial Distribution of Lichens in Metrosideros excelsa in Northern New Zealand Urban Forests

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 170
Author(s):  
Gladys N. Benitez ◽  
Glenn D. Aguilar ◽  
Dan Blanchon
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
New Zealand ◽  
Lichen Species ◽  
Positive Correlation ◽  
Breast Height ◽  
Lichen Community ◽  
The North ◽  
The City ◽  
Lichen Flora

The spatial distribution of corticolous lichens on the iconic New Zealand pōhutukawa (Metrosideros excelsa) tree was investigated from a survey of urban parks and forests across the city of Auckland in the North Island of New Zealand. Lichens were identified from ten randomly selected trees at 20 sampling sites, with 10 sites classified as coastal and another 10 as inland sites. Lichen data were correlated with distance from sea, distance from major roads, distance from native forests, mean tree DBH (diameter at breast height) and the seven-year average of measured NO2 over the area. A total of 33 lichen species were found with coastal sites harboring significantly higher average lichen species per tree as well as higher site species richness. We found mild hotspots in two sites for average lichen species per tree and another two separate sites for species richness, with all hotspots at the coast. A positive correlation between lichen species richness and DBH was found. Sites in coastal locations were more similar to each other in terms of lichen community composition than they were to adjacent inland sites and some species were only found at coastal sites. The average number of lichen species per tree was negatively correlated with distance from the coast, suggesting that the characteristic lichen flora found on pōhutukawa may be reliant on coastal microclimates. There were no correlations with distance from major roads, and a slight positive correlation between NO2 levels and average lichen species per tree.

Spatial Patterns of Urban Innovation and Their Evolution from Perspectives of Capacity and Structure: Taking Shenzhen as an Example

2021 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Erjie Hu ◽  
Di Hu ◽  
Handong He
Keyword(s):  
Spatial Distribution ◽  
Spatial Pattern ◽  
Distribution Pattern ◽  
Spatial Patterns ◽  
Spillover Effect ◽  
Tertiary Industry ◽  
Innovation Capacity ◽  
Structure Index ◽  
Secondary Industry ◽  
Spatial Spillover Effect

Innovation is a key factor for a country’s overall national strength and core competitiveness. The spatial pattern of innovation reflects the regional differences of innovation development, which can provide guidance for the regional allocation of innovation resources. Most studies on the spatial pattern of innovation are at urban and above spatial scale, but studies at urban internal scale are insufficient. The precision and index of the spatial pattern of innovation in the city needs to be improved. This study proposes to divide spatial units based on geographic coordinates of patents, designs the innovation capability and innovation structure index of a spatial unit and their calculation methods, and then reveals the spatial patterns of innovation and their evolutionary characteristics in Shenzhen during 2000–2018. The results show that: (1) The pattern of innovation capacity of secondary industry exhibited a pronounced spatial spillover effect with a positive spatial correlation. The innovation capacity and innovation structure index of the secondary industry evolved in a similar manner; i.e., they gradually extended from the southwest area to the north over time, forming a tree-like distribution pattern with the central part of the southwest area as the “root” and the northwest and northeast areas as the “canopy”. (2) The pattern of innovation capacity of tertiary industry also had a significant spatial spillover effect with a positive spatial correlation. There were differences between the evolutions of innovation capacity and innovation structure index of tertiary industry. Specifically, its innovation capacity presented a triangular spatial distribution pattern with three groups in the central and eastern parts of the southwest area and the south-eastern part of the northwest area as the vertices, while its innovative structure showed a radial spatial distribution pattern with the southwestern part of the southwest area as the source and a gradually sparse distribution toward the northeast. (3) There were differences between the evolution modes of secondary and tertiary industries. Areas with high innovation capacity in the secondary industry tended to be more balanced, while areas with high innovation capacity in the tertiary industry did not necessarily have a balanced innovation structure. Through the method designed in this paper, the spatial pattern of urban innovation can be more precise and comprehensive revealed, and provide useful references for the development of urban innovation.

scholarly journals Species richness and diversity in shrub savanna using ordinary kriging

2016 ◽  
Vol 51 (8) ◽  
pp. 958-966 ◽  
Author(s):  
Anderson Pedro Bernardina Batista ◽  
José Márcio de Mello ◽  
Marcel Régis Raimundo ◽  
Henrique Ferraço Scolforo ◽  
Aliny Aparecida dos Reis ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Spatial Dependence ◽  
Ordinary Kriging ◽  
Diversity Index ◽  
Spatial Models ◽  
Shannon Diversity Index ◽  
Shannon Diversity ◽  
Species Richness And Diversity ◽  
Number Of Species

Abstract: The objective of this work was to analyze the spatial distribution and the behavior of species richness and diversity in a shrub savanna fragment, in 2003 and 2014, using ordinary kriging, in the state of Minas Gerais, Brazil. In both evaluation years, the measurements were performed in a fragment with 236.85 hectares, in which individual trees were measured and identified across 40 plots (1,000 m2). Species richness was determined by the total number of species in each plot, and diversity by the Shannon diversity index. For the variogram study, spatial models were fitted and selected. Then, ordinary kriging was applied and the spatial distribution of the assessed variables was described. A strong spatial dependence was observed between species richness and diversity by the Shannon diversity index (<25% spatial dependence degree). Areas of low and high species diversity and richness were found in the shrub savanna fragment. Spatial distribution behavior shows relative stability regarding the number of species and the Shannon diversity index in the evaluated years.

scholarly journals Energy–water and seasonal variations in climate underlie the spatial distribution patterns of gymnosperm species richness in China

2020 ◽  
Vol 10 (17) ◽  
pp. 9474-9485
Author(s):  
Bikram Pandey ◽  
Janak R. Khatiwada ◽  
Lin Zhang ◽  
Kaiwen Pan ◽  
Mohammed A. Dakhil ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Seasonal Variations ◽  
Distribution Patterns ◽  
Spatial Distribution Patterns

scholarly journals Heavy metal distribution in sediments around the offshore tin mining area of Central Bangka Regency, Indonesia

2021 ◽  
Vol 926 (1) ◽  
pp. 012027
Author(s):  
Irvani ◽  
S Adibrata ◽  
M Yusuf ◽  
M Hudatwi ◽  
A Pamungkas
Keyword(s):  
Heavy Metals ◽  
Spatial Distribution ◽  
Active Surface ◽  
Fine Sand ◽  
Mining Area ◽  
Pollution Load Index ◽  
Coarse Sand ◽  
Sieve Analysis ◽  
Marine Animals ◽  
Type Composition

Abstract Vary heavy metals scattered in suspension loads and re-sedimentation from the tailing of the offshore-alluvial tin mining at Tanah Merah and its surroundings, Central Bangka Regency. Research is needed to determine the type, composition, spatial distribution of heavy metals, and potential pollution. The active surface-sediments were taken from shallow marine systematically around the offshore tin mining area in the east season. Geochemical analysis of sediment using x-ray fluorescence, coupled with minerals and sieve analysis, and support by spatial analysis. These sediments have dominant the sand-size (range very-fine sand to coarse sand) and silt, contained predominantly large quantities of quartz minerals and shell fragments of marine animals. The metals are in the following decreasing order: Cr>Zn>Pb>Ni>Cu>As>Co>Cd. The spatial distribution of heavy metals generally has a relatively south, east, and north position, with concentrations occurring along the coastline and showing the degradation composition towards the open sea. The marine sediments are uncontaminated to moderately contaminated by Cd and Pb, indicate both natural and anthropogenic enrichment, low the pollution load index (PLI), and have various potential ecological risks index (RI) (low to very high RI).

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