scholarly journals Do arthropod assemblages fit the grassland and savanna biomes of South Africa?

2016 ◽  
Vol Volume 112 (Number 9/10) ◽  
Author(s):  
Monique Botha ◽  
Stefan J. Siebert ◽  
Johnnie van den Berg ◽  
◽  
◽  
...  
Keyword(s):  
South Africa ◽  
Multidimensional Scaling ◽  
Vegetation Structure ◽  
Species Assemblages ◽  
Trophic Groups ◽  
Arthropod Communities ◽  
Arthropod Species ◽  
Scaling Analyses ◽  
Suction Sampling ◽  
Functional Assemblages

Abstract The long-standing tradition of classifying South Africa’s biogeographical area into biomes is commonly linked to vegetation structure and climate. Because arthropod communities are often governed by both these factors, it can be expected that arthropod communities would fit the biomes. To test this hypothesis, we considered how well arthropod species assemblages fit South Africa’s grassy biomes. Arthropod assemblages were sampled from six localities across the grassland and savanna biomes by means of suction sampling, to determine whether the two biomes have distinctive arthropod assemblages. Arthropod samples of these biomes clustered separately in multidimensional scaling analyses. Within biomes, arthropod assemblages were more distinctive for savanna localities than grassland. Arthropod samples of the two biomes clustered together when trophic groups were considered separately, suggesting some similarity in functional assemblages. Dissimilarity was greatest between biomes for phytophagous and predacious trophic groups, with most pronounced differentiation between biomes at sub-escarpment localities. Our results indicate that different arthropod assemblages do fit the grassy biomes to some extent, but the pattern is not as clear as it is for plant species.

scholarly journals Diversity patterns of plants and arthropods in soybean agro-ecosystems in the Grassland Biome of South Africa

2020 ◽  
Vol 21 (12) ◽  
Author(s):  
Paul Duvel Janse van Rensburg ◽  
Stefan John Siebert ◽  
Tlou Masehela ◽  
Suria Ellis ◽  
Johnnie Van den Berg
Keyword(s):  
South Africa ◽  
Species Composition ◽  
Plant Species ◽  
Species Assemblages ◽  
Line Transect ◽  
Field Boundary ◽  
Alien Plant ◽  
Diversity Patterns ◽  
Arthropod Species ◽  
Grassland Biome

Abstract. Janse van Rensburg PD, Siebert SJ, Masehela T, Ellis S, Van den Berg J. 2020. Diversity patterns of plants and arthropods in soybean agroecosystems in the grassland biome of South Africa. Biodiversitas 21: 5559-5570. Soybean is widely cultivated in the grassland biome of South Africa (ca.  800 000 ha per annum). Yet the possible effects that large-scale cultivation of soybean has on biodiversity in adjacent habitat are not fully understood. This study aimed to describe the plant and arthropod species assemblages and diversity patterns within these soybean agroecosystems. Surveys were conducted inside soybean fields, field boundaries (transition zones between soybean fields and adjacent habitat), and adjacent pasture. An adapted D-vac was used to sample arthropods in the different zones, while plant surveys were conducted by means of fixed width (2 m) line transect. A total of 320 plant species (4910 specimens) and 373 arthropod morpho-species (9216 specimens) were recorded. Soybean fields had significantly lower plant and arthropod diversity than the adjacent habitats. Plant species diversity was similar in the field boundary and adjacent pasture. Significantly higher species richness and abundance of arthropods were found in the boundary than the pasture. These results show that the cultivation of soybean and the associated agricultural practices had no adverse effects on biodiversity patterns in the adjacent habitats. However, the boundary dominated by alien plant species did contain a significantly different plant species composition from the pasture. This difference was also mirrored by unique assemblages of arthropods. This suggests that disturbance resulting from soybean cultivation contributed to species losses and gains that maintained diversity in the field boundary but changed its plant and arthropod species composition. No effect was found in the pasture beyond the boundary (> 50 m). High diversity, but unique species assemblages of plants and arthropods in the boundary and pasture suggest that these habitats may have important conservation value in soybean agroecosystems by supporting ecosystem functions and services.

scholarly journals 'n Multidimensionele skaleringstudie van personeelkonsultantgroepe in Suid Afrika

1988 ◽  
Vol 14 (2) ◽  
Author(s):  
C. C. Theron ◽  
L. C. De Jager
Keyword(s):  
South Africa ◽  
Multidimensional Scaling ◽  
Ideal Point ◽  
Stimulus Space

A multidimentional scaling study of personnel consultancy groups in South Africa. Ten 12x12 symetric dissimilarity matrices of inter personnel consultant comparisons were submitted to weigthed multidimensional scaling. Vector and ideal point models were used to relate preference and con- sultant attributes to the group stimulus space. Results indicate that the hypothetical ideal consultant differs significantly from existing consultancies and that there exists a partial incongruence between the attributes used spontaneously when comparing a number of consultancies and the critical consultant attributes identified in the literature. Recommendations for further research are made. Opsomming Tien 12x12 simmetriese dissimilariteitsmatrikse van interpersoneelkonsultante-beoordelings is onderwerp aan matriksgeweegde multidimensionele skating. Vektor n "ideal point" modelle is gebruik om voorkeur en konsultantattribute met die groepstimulusruimte in verband te bring. Resultate dui daarop dat die hipotetiese ideate konsultant betekenisvol verskil van bestaande konsultantaanbiedinge en dat daar 'n element van inkongruensie bestaan tussen die attribute wat spontaan na vore tree by onderlinge vergelyking van konsultantgroepe en die kritieke attribute soos deur die literatuur geidentifiseer. Aanbevelings vir verdere studie word gemaak.

scholarly journals The response of sward-dwelling arthropod communities to reduced grassland management intensity in pastures

2015 ◽  
Vol 54 (2) ◽  
pp. 107-120 ◽  
Author(s):  
Alvin J. Helden ◽  
Annette Anderson ◽  
John Finn ◽  
Gordon Purvis
Keyword(s):  
Community Structure ◽  
Grassland Management ◽  
Taxon Richness ◽  
Arthropod Communities ◽  
Pitfall Trapping ◽  
Management Intensity ◽  
Arthropod Biodiversity ◽  
Stocking Rates ◽  
Univariate Analyses ◽  
Suction Sampling

AbstractWe compared arthropod taxon richness, diversity and community structure of two replicated grassland husbandry experiments to investigate effects of reduced management intensity, as measured by nutrient input levels (390, 224 and 0 kg/ha per year N in one experiment, and 225 and 88 kg/ha per year N in another). Suction sampling was used to collect Araneae, Coleoptera, Hemiptera and Hymenoptera, with Araneae and Coleoptera also sampled with pitfall trapping. Univariate analyses found no significant differences in abundance and species density between treatments. However, with multivariate analysis, there were significant differences in arthropod community structure between treatments in both experiments.Reducing N input and associated stocking rates, as targeted by agri-environment schemes, can significantly alter arthropod communities but without increasing the number of species present. Other approaches that may be necessary to achieve substantial enhancement of sward arthropod biodiversity are suggested.

Structure and dynamics of arthropod communities in bat guano deposits in buildings

1981 ◽  
Vol 59 (2) ◽  
pp. 260-270 ◽  
Author(s):  
Robin Franklin Bernath ◽  
Thomas H. Kunz
Keyword(s):  
New Hampshire ◽  
Myotis Lucifugus ◽  
Arthropod Communities ◽  
Resource Base ◽  
Free Living ◽  
Structure And Dynamics ◽  
Arthropod Species ◽  
Little Brown Bat ◽  
Composition Structure ◽  
Bat Guano

This study characterizes the composition, structure, and dynamics of arthropod communities associated with bat guano deposits in buildings. Guano beneath three summer roosts of the little brown bat (Myotis lucifugus) in southern New Hampshire was sampled over a 1-year period.Twelve arthropod species are reported of which most are cosmopolitan associates of dried organic matter and stored products. Included are psocopterans, beetles, mites, hemipterans, a flea, and a pseudoscorpion. These taxa function as fungivores, sarcophages, predators, and ectoparasites.These simple arthropod communities exploit a seasonally rich resource produced by roosting bats. Nycteriglyphine mites were the first free-living colonizers of fresh guano deposits and were the most numerous arthropods throughout the year. Older guano deposits and those with the most diverse resource base generally supported the greatest number of species.Seasonal changes in communities included the presence of fleas only when bats were present, a greater number but lower diversity of other arthropod species when bats were present, and a more equitable distribution and abundance of species when bats were absent. Fresh, wet guano supported higher densities of fungivorous mites and flea larvae than did older, drier guano.

Multidimensional scaling analysis of psychopathy in male juveniles using the PCL: YV

2017 ◽  
Vol 7 (4) ◽  
pp. 262-279 ◽  
Author(s):  
Holly Ellingwood ◽  
Karla Emeno ◽  
Craig Bennell ◽  
Adelle Forth ◽  
David Kosson ◽  
...  
Keyword(s):  
Juvenile Offenders ◽  
Multidimensional Scaling ◽  
Factor Model ◽  
Future Research ◽  
Scaling Analysis ◽  
Content Type ◽  
Psychopathy Checklist ◽  
Juvenile Psychopathy ◽  
The Usa ◽  
Scaling Analyses

Purpose The purpose of this paper is to examine the structure of juvenile psychopathy, as measured by the Psychopathy Checklist: Youth Version (PCL: YV). Design/methodology/approach Using a sample of 2,042 male youths from the USA, Canada, and the UK, the study was a conceptual replication of Bishopp and Hare’s (2008) multidimensional scaling (MDS) analysis of adult male offenders assessed with the Psychopathy Checklist-Revised. Findings The scaling analyses generally replicated those obtained by Bishopp and Hare, providing support for a multidimensional, four-factor model of juvenile psychopathy similar to that obtained with adults. However, a small number of items fell outside their predicted regions. Slight differences in the structure of juvenile psychopathy were found for incarcerated and supervised samples of youth, with the four-factor model breaking down slightly for the supervised sample. Item misplacements may indicate that certain items on the PCL: YV are being misinterpreted, reflect different dimensions for different samples, or cannot be reliably measured. Future research should examine these possibilities, with special attention being paid to supervised samples. Originality/value To the authors’ knowledge, this is one of the first known attempts to use MDS analysis to examine the psychopathy structures that emerge for male juvenile offenders. The greater nuances afforded by using MDS offer a more comprehensive understanding of psychopathy between incarcerated and supervised youth using the PCL: YV.

Multidimensional scaling analyses of the perceived social structure of informal groups.

2001 ◽  
Vol 5 (3) ◽  
pp. 200-207 ◽  
Author(s):  
John B. Nezlek ◽  
Joy Austin-Lane ◽  
Cynthia H. Null
Keyword(s):  
Multidimensional Scaling ◽  
Social Structure ◽  
Scaling Analyses ◽  
Informal Groups

scholarly journals Message in a Bottle, Metabarcoding Enables Biodiversity Comparisons Across Ecoregions

2021 ◽  
Author(s):  
Dirk Steinke ◽  
Stephanie L deWaard ◽  
Jayme E Sones ◽  
Natalia V. Ivanova ◽  
Sean WJ Prosser ◽  
...  
Keyword(s):  
Species Composition ◽  
Large Scale ◽  
Spatial And Temporal Variation ◽  
Geographical Distance ◽  
Transient Species ◽  
Arthropod Communities ◽  
Biogeographic Patterns ◽  
Arthropod Species ◽  
Dna Metabarcoding ◽  
Basic Understanding

Background Traditional biomonitoring approaches have delivered a basic understanding of biodiversity, but they cannot support the large scale assessments required to manage and protect entire ecosystems. This study employed DNA metabarcoding to assess spatial and temporal variation in species richness and diversity in arthropod communities from 52 protected areas spanning three Canadian ecoregions. Results This study revealed the presence of 26,263 arthropod species in the three ecoregions and indicated that at least another 3,000 to 5,000 await detection. Results further demonstrate that communities are more similar within than between ecoregions, even after controlling for geographical distance. Overall alphadiversity declined from east to west, reflecting a gradient in habitat disturbance. Shifts in species composition were high at every site with turnover greater than nestedness, suggesting the presence of many transient species. Conclusions Differences in species composition among their arthropod communities confirm that ecoregions are a useful synoptic for biogeographic patterns and for structuring conservation efforts. The present results also demonstrate that metabarcoding enables large scale monitoring of shifts in species composition, making it possible to move beyond the biomass measurements that have been the key metric employed in prior efforts to track change in arthropod communities.

scholarly journals Molecular identification and diversity of adult arthropod carrion community collected from pig and sheep carcasses within the same locality during different stages of decomposition in the KwaZulu-Natal province of South Africa

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12500
Author(s):  
Danisile Tembe ◽  
Mokgadi Pulane Malatji ◽  
Samson Mukaratirwa
Keyword(s):  
South Africa ◽  
Molecular Identification ◽  
Warm Season ◽  
Cold Season ◽  
Beetle Species ◽  
Molecular Analyses ◽  
Arthropod Species ◽  
Kwazulu Natal ◽  
The Difference ◽  
Pig Carcasses

The current study aimed at molecular identification and comparing the diversity of arthropods communities between pig and sheep carcasses during the cold and warm season in KwaZulu-Natal province of South Africa. Adult arthropods found on and around the carcasses were collected using either fly traps or forceps. Molecular analyses confirmed the identification of twelve arthropod species collected from both sheep and pig carcasses during the cold season. Results showed that 11 of 12 arthropod species were common in both sheep and pig carcasses, with exception to Onthophagus vacca (Coleoptera: Scarabaeidae) (Linnaeus, 1767) and Atherigona soccata (Diptera: Muscidae) (Rondani, 1871) species which were unique to sheep and pig carcasses respectively. However, during the warm season, the sheep carcass attracted more arthropod (n = 13) species as compared to the pig carcass. The difference in the obtained arthropod was due to the presence of O. vacca which was also unique to the sheep carcass during this season. Furthermore, there was an addition of a beetle species Hycleus lunatus (Coleoptera: Meloidae) (Pallas, 1782), which was collected from both sheep and pig carcasses but unique to the warm season. The pig carcass attracted more dipteran flies during both warm (n = 1,519) and cold season (n = 779) as compared to sheep carcass during the warm (n = 511) and cold season (n = 229). In contrast, coleopterans were more abundant on the sheep carcass during the warm season (n = 391) and cold season (n = 135) as compared to the pig carcass in both warm season (n = 261) and cold season (n = 114). In overall, more flies and beetles were collected on both sheep and pig carcasses during the warm season, and this further highlight that temperature influenced the observed difference in the abundance of collected arthropod between seasons.

Associated cultivated plants in tomato cropping systems structure arthropod communities and increase the Helicoverpa armigera regulation

2019 ◽  
Vol 109 (6) ◽  
pp. 733-740
Author(s):  
A.G. Dassou ◽  
S.D. Vodouhè ◽  
A. Bokonon-Ganta ◽  
G. Goergen ◽  
A. Chailleux ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Cropping Systems ◽  
Cropping System ◽  
Cultivated Plants ◽  
Generalist Predators ◽  
Mixed Cropping ◽  
Trophic Groups ◽  
Arthropod Communities ◽  
Pests And Diseases ◽  
Helicoverpa Armígera

AbstractCultivating plant mixtures is expected to provide a higher productivity and a better control of pests and diseases. The structure of the arthropod community is a major driver of the magnitude of natural pest regulations.With the aim of optimizing pest management, a study was carried out to determine the effect of the cropping system type (tomato mono-cropping vs. mixed-cropping) on the diversity and abundance of arthropods from three trophic groups (herbivores, omnivores, predators) and the abundance of Helicoverpa armigera. Therefore, the diversity of cultivated plants and arthropod communities was assessed within tomato fields from 30 farmer's fields randomly selected in South of Benin. Results showed that the arthropod abundance was significantly higher in mixed-cropping systems compared with mono-cropping systems, although the crop type did not alter significantly the arthropod diversity, evenness, and richness. At the level of taxa, the abundances of generalist predators including ants (Pheidole spp., and Paltothyreus tarsatus) and spiders (Araneus spp. and Erigone sp.) were significantly higher in mixed fields than in mono-crop fields. Then, the abundances of omnivore-predator trophic groups have a negative significant effect on the H. armigera abundance. This study allowed better understanding of how plant diversity associated to tomato fields structures arthropod's food webs to finally enhance the ecological management of H. armigera.

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