The causes of southern African spatial patterns in species richness: speciation, extinction and dispersal in the Danthonioideae (Poaceae)

2015 ◽  
Vol 42 (5) ◽  
pp. 914-924 ◽  
Author(s):  
H. Peter Linder ◽  
Yanis Bouchenak-Khelladi
Keyword(s):  
Species Richness ◽  
Spatial Patterns

The role of time and species identities in spatial patterns of species richness and conservation

2016 ◽  
Vol 30 (5) ◽  
pp. 1080-1088 ◽  
Author(s):  
Judi E. Hewitt ◽  
Simon F. Thrush ◽  
Kari E. Ellingsen
Keyword(s):  
Species Richness ◽  
Spatial Patterns

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.

Metabolic asymmetry and the global diversity of marine predators

Science ◽  
2019 ◽  
Vol 363 (6425) ◽  
pp. eaat4220 ◽  
Author(s):  
John M. Grady ◽  
Brian S. Maitner ◽  
Ara S. Winter ◽  
Kristin Kaschner ◽  
Derek P. Tittensor ◽  
...  
Keyword(s):  
Species Richness ◽  
Spatial Patterns ◽  
Marine Mammals ◽  
Phylogenetic Diversity ◽  
Latitudinal Gradient ◽  
Latitudinal Gradients ◽  
Competitive Interactions ◽  
Marine Predators ◽  
Theoretical Predictions ◽  
The Tropics

Species richness of marine mammals and birds is highest in cold, temperate seas—a conspicuous exception to the general latitudinal gradient of decreasing diversity from the tropics to the poles. We compiled a comprehensive dataset for 998 species of sharks, fish, reptiles, mammals, and birds to identify and quantify inverse latitudinal gradients in diversity, and derived a theory to explain these patterns. We found that richness, phylogenetic diversity, and abundance of marine predators diverge systematically with thermoregulatory strategy and water temperature, reflecting metabolic differences between endotherms and ectotherms that drive trophic and competitive interactions. Spatial patterns of foraging support theoretical predictions, with total prey consumption by mammals increasing by a factor of 80 from the equator to the poles after controlling for productivity.

Null models and spatial patterns of species richness in South American birds of prey

2002 ◽  
Vol 5 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Jose Alexandre Felizola Diniz-Filho ◽  
Carlos Eduardo Ramos de Sant'Ana ◽  
Marcia Christianne de Souza ◽  
Thiago F. L. V. B. Rangel
Keyword(s):  
Species Richness ◽  
Spatial Patterns ◽  
Null Models ◽  
Birds Of Prey ◽  
South American

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

2008 ◽  
Vol 88 (5) ◽  
pp. 931-940 ◽  
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.

scholarly journals Determinants and Congruence of Species Richness Patterns across Multiple Taxonomic Groups on a Regional Scale

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Jörn Buse ◽  
Eva Maria Griebeler
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Spatial Patterns ◽  
Regional Scale ◽  
External Validation ◽  
Federal State ◽  
Strongly Correlated ◽  
Richness Patterns ◽  
Taxonomic Groups ◽  
German Federal State

Applying multiple generalized regression models, we studied spatial patterns in species richness for different taxonomic groups (amphibians, reptiles, grasshoppers, plants, mosses) within the German federal state Rhineland-Palatinate (RP). We aimed (1) to detect their centres of richness, (2) to rate the influence of climatic and land-use parameters on spatial patterns, and (3) to test whether patterns are congruent between taxonomic groups in RP. Centres of species richness differed between taxonomic groups and overall richness was the highest in the valleys of large rivers and in different areas of southern RP. Climatic parameters strongly correlated with richness in all taxa whereas land use was less significant. Spatial richness patterns of all groups were to a certain extent congruent but differed between group pairs. The number of grasshoppers strongly correlated with the number of plants and with overall species richness. An external validation corroborated the generality of our species richness models.

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.

Factors shaping alien plant species richness spatial patterns across Natura 2000 Special Areas of Conservation of Greece

2017 ◽  
Vol 601-602 ◽  
pp. 461-468 ◽  
Author(s):  
Panayiotis G. Dimitrakopoulos ◽  
Sotirios Koukoulas ◽  
Alexandros Galanidis ◽  
Pinelopi Delipetrou ◽  
Dimitris Gounaridis ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Spatial Patterns ◽  
Natura 2000 ◽  
Plant Species Richness ◽  
Alien Plant Species ◽  
Alien Plant ◽  
Of Greece

The structural characteristics and climatic and human impacts of deciduous oak forests in China

2021 ◽  
Author(s):  
Guoping Chen ◽  
Qiong Cai ◽  
Wenjing Fang ◽  
Yuhao Feng ◽  
Jiangling Zhu ◽  
...  
Keyword(s):  
Species Richness ◽  
Spatial Patterns ◽  
Tree Species ◽  
Structural Characteristics ◽  
Tree Height ◽  
Oak Forests ◽  
Oak Forest ◽  
Stem Density ◽  
Shrub Species ◽  
The Mean

Abstract Aims Deciduous oak forest is one of the typical vegetation types in temperate and subtropical mountain zones in China. However, the patterns and determinants of the structural characteristics of these forests remain poorly understood. Methods We investigated 682 oak forest plots across China to characterize the community structures of the oak forests and analyze the underlying factors controlling their spatial patterns. Important Findings Across all plots, the overall mean values were 13.7 cm, 10.0 m, 1468 stems/ha, and 24.3 m 2/ha for the diameter at breast height (DBH), height, stem density and total basal areas (TBA) of trees, respectively. The average species richness was 6 species/600 m 2, 10 species/100 m 2, and 4 species/1 m 2 for the tree, shrub and herb layers, respectively. As latitude increased, the mean tree height, stem density, TBA, tree species richness and shrub species richness decreased, and the mean DBH did not show a significant trend, while species richness of herbs increased significantly. Climatic and anthropogenic variables could explain more variations in mean DBH, mean tree height, TBA, tree species richness, shrub species richness than those in stem density and herb species richness. Further analysis showed that precipitation-related climatic factors were major factors shaping the spatial patterns of community structures. Our findings provide a basis for recognizing the biogeographic patterns of oak forest structures and their responses to global change in China.

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