Smaller Zooplankton Species are not Superior in Exploitative Competition: A Comment on Persson

1987 ◽  
Vol 129 (6) ◽  
pp. 928-931 ◽  
Author(s):  
Jan Bengtsson
Keyword(s):  
Exploitative Competition ◽  
Zooplankton Species

scholarly journals High honeybee abundances reduce wild bee abundances on flowers in the city of Munich

Oecologia ◽  
2021 ◽  
Author(s):  
Susanne S. Renner ◽  
Marie Sophie Graf ◽  
Zoe Hentschel ◽  
Helen Krause ◽  
Andreas Fleischmann
Keyword(s):  
Apis Mellifera ◽  
Adjacent Area ◽  
Exploitative Competition ◽  
Wild Bees ◽  
European Cities ◽  
Urban Garden ◽  
Wild Bee ◽  
June July ◽  
The City ◽  
Clear Support

AbstractThe increase in managed honeybees (Apis mellifera) in many European cities has unknown effects on the densities of wild bees through competition. To investigate this, we monitored honeybees and non-honeybees from 01 April to 31 July 2019 and 2020 at 29 species of plants representing diverse taxonomic and floral-functional types in a large urban garden in the city of Munich in which the same plant species were cultivated in both years. No bee hives were present in the focal garden, and all bee hives in the adjacent area were closely monitored by interviewing the relevant bee keepers in both 2019 and 2020. Honeybee numbers were similar in April of both years, but increased from May to July 2020 compared to 2019. The higher densities correlated with a significant increase in shifts from wild bee to honeybee visits in May/June/July, while visitor spectra in April 2019 and 2020 remained the same. Most of the species that experienced a shift to honeybee visits in 2020 were visited mostly or exclusively for their nectar. There were no shifts towards increased wild bee visits in any species. These results from a flower-rich garden have implications for the discussion of whether urban bee keeping might negatively impact wild bees. We found clear support that high honeybee densities result in exploitative competition at numerous types of flowers.

Crustacean zooplankton species richness: single- and multiple-year estimates

1998 ◽  
Vol 55 (7) ◽  
pp. 1573-1582 ◽  
Author(s):  
Shelley E Arnott ◽  
John J Magnuson ◽  
Norman D Yan
Keyword(s):  
Spatial Scales ◽  
Species Pool ◽  
Crustacean Zooplankton ◽  
Zooplankton Species ◽  
Asymptotic Approach ◽  
Sampling Programme ◽  
Temporal And Spatial ◽  
Shield Lakes ◽  
The Relationship ◽  
Temporal Extent

Richness estimates are dependent on the spatial and temporal extent of the sampling programme and the method used to predict richness. We assessed crustacean zooplankton richness in eight Canadian Shield lakes at different temporal and spatial scales using three methods of estimation: cumulative, asymptotic, and Chao's index. Percent species detected increased with the number of spatial, intraannual, or interannual samples taken. Single samples detected 50% of the annual species pool and 33% of the total estimated species pool. This suggests that previous estimates of zooplankton richness, based on single samples in individual lakes, are too low. Our richness estimates for individual lakes approach the total number of zooplankton found in some regions of Canada, suggesting that each lake has most taxa at some time, the majority being very rare. Single-year richness estimates provided poor predictions of multiple-year richness. The relationship between richness and environmental variables was dependent on the method of estimation and the number of samples used. We conclude that richness should be treated as an "index" rather than an absolute and sampling efforts should be standardized. We recommend an asymptotic approach to estimate zooplankton richness because the number of samples taken influenced it less.

Evolution and intraspecific exploitative competition I. One-locus theory for small additive gene effects

1980 ◽  
Vol 18 (3) ◽  
pp. 297-313 ◽  
Author(s):  
Freddy Bugge Christiansen ◽  
Volker Loeschcke
Keyword(s):  
Exploitative Competition ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Additive Gene ◽  
Small Additive

scholarly journals Comparative study of the zooplankton composition of six lacustrine ecosystems in Central Brazil during the dry season

2000 ◽  
Vol 60 (1) ◽  
pp. 101-111 ◽  
Author(s):  
F. L. do R. M. STARLING
Keyword(s):  
Zooplankton Community ◽  
Federal District ◽  
Dry Season ◽  
Zooplankton Species ◽  
Waste Stabilisation Ponds ◽  
Central Brazil ◽  
Morphometric Features ◽  
Santa Maria ◽  
Sørensen Index

Zooplankton community from six lacustrine ecosystems located in Federal District (Central Brazil) was studied based on samples collected during the dry season (July to September). A total of 71 taxa were recorded: 44 rotifers, 17 cladocerans and 10 copepods. The highest number of zooplankton species was recorded in oligotrophic Bonita Pond (32 species) and the lowest number in hypertrophic waste stabilisation ponds (7 species). This tendency of decreasing the diversity with increasing trophic level was consistent with a cluster analysis of the samples based on Sorensen index of similarity. From the overall similarity dendrogram, two groups of ecosystems were distinguished: one containing the natural ponds Bonita and Formosa and the other comprising the reservoirs Santa Maria, Descoberto and Paranoá. The role of morphometric features in determining the zooplankton community in such lacustrine ecosystems was also discussed.

Relative importance of colonist quantity, quality, and arrival frequency to the extinction of two zooplankton species

Oecologia ◽  
2017 ◽  
Vol 184 (2) ◽  
pp. 441-452 ◽  
Author(s):  
James S. Sinclair ◽  
Shelley E. Arnott
Keyword(s):  
Relative Importance ◽  
Zooplankton Species

scholarly journals Considerations on the biochemical composition of some freshwater zooplankton species.

1999 ◽  
Vol 58 (1) ◽  
pp. 58 ◽  
Author(s):  
Nicoletta RICCARDI ◽  
Monica MANGONI
Keyword(s):  
Biochemical Composition ◽  
Zooplankton Species ◽  
Freshwater Zooplankton

Is Daphnia magna an ecologically representative zooplankton species in toxicity tests?

1995 ◽  
Vol 90 (2) ◽  
pp. 263-267 ◽  
Author(s):  
Sanna Koivisto
Keyword(s):  
Daphnia Magna ◽  
Toxicity Tests ◽  
Zooplankton Species
Sign in / Sign up

Export Citation Format

Share Document