scholarly journals Maintenance of Intraspecific Diversity in Response to Species Competition and Nutrient Fluctuations

2022 ◽  
Vol 10 (1) ◽  
pp. 113
Author(s):  
Jorin Hamer ◽  
Birte Matthiessen ◽  
Silvia Pulina ◽  
Giannina S. I. Hattich
Keyword(s):  
Diversity Index ◽  
Context Dependency ◽  
Intraspecific Diversity ◽  
Substantial Part ◽  
Evolutionary Potential ◽  
Species Sorting ◽  
Specific Effects ◽  
Phytoplankton Communities ◽  
Genotype Diversity ◽  
Species Specific

Intraspecific diversity is a substantial part of biodiversity, yet little is known about its maintenance. Understanding mechanisms of intraspecific diversity shifts provides realistic detail about how phytoplankton communities evolve to new environmental conditions, a process especially important in times of climate change. Here, we aimed to identify factors that maintain genotype diversity and link the observed diversity change to measured phytoplankton morpho-functional traits Vmax and cell size of the species and genotypes. In an experimental setup, the two phytoplankton species Emiliania huxleyi and Chaetoceros affinis, each consisting of nine genotypes, were cultivated separately and together under different fluctuation and nutrient regimes. Their genotype composition was assessed after 49 and 91 days, and Shannon’s diversity index was calculated on the genotype level. We found that a higher intraspecific diversity can be maintained in the presence of a competitor, provided it has a substantial proportion to total biovolume. Both fluctuation and nutrient regime showed species-specific effects and especially structured genotype sorting of C. affinis. While we could relate species sorting with the measured traits, genotype diversity shifts could only be partly explained. The observed context dependency of genotype maintenance suggests that the evolutionary potential could be better understood, if studied in more natural settings including fluctuations and competition.

The species-specific effects of sublethal concentrations of cadmium on freshwater phytoplankton communities in a Canadian Shield lake

1985 ◽  
Vol 63 (11) ◽  
pp. 1997-2003 ◽  
Author(s):  
Danny C. Reinke ◽  
Frank DeNoyelles Jr.
Keyword(s):  
Cadmium Concentration ◽  
Continuous Cultures ◽  
Experimental Lakes Area ◽  
Batch Cultures ◽  
Freshwater Phytoplankton ◽  
Specific Effects ◽  
Cell Counts ◽  
Phytoplankton Communities ◽  
Species Specific

The species-specific responses of natural phytoplankton communities to low cadmium concentrations were measured in Lake 239 (Experimental Lakes Area, northwestern Ontario). Both in situ and laboratory 5-L continuous-flow cultures, and 5-L and 100-mL cultures were used. Asterionella formosa, Dinobryon sertularia, and Dinobryon bavaricum showed dramatic negative sensitivity to low cadmium concentrations (5–100 μg/L), while Rhabdoderma gorskii and Elakatothrix sp. consistently increased in numbers at the same cadmium concentrations. In all experiments, some species exhibited no apparent effect to cadmium addition as measured by cell counts. The "bottle effect" of each technique was evaluated by comparing the community similarity valves of the control cultures to the lake samples and showed the in situ continuous cultures to be most similar to the lake followed by the laboratory continuous cultures, the in situ 5-L batch cultures, the 5-L laboratory cultures, and the 100-mL batch cultures. Replicate cadmium cultures, all techniques, were more similar to each other than the lake samples. The similarity of the cadmium cultures to the lake sample or control cultures decreased with increased cadmium concentration and incubation time.

Density-dependent and species-specific effects on self-organization modulate the resistance of mussel bed ecosystems to hydrodynamic stress

2021 ◽  
Author(s):  
Gerardo I. Zardi ◽  
Katy Rebecca Nicastro ◽  
Christopher D. McQuaid ◽  
Monique de Jager ◽  
Johan van de Koppel ◽  
...  
Keyword(s):  
Self Organization ◽  
Mussel Bed ◽  
Hydrodynamic Stress ◽  
Density Dependent ◽  
Specific Effects ◽  
Species Specific

Variation in vegetation cover and seedling performance of tree species in a forest-savanna ecotone

2019 ◽  
Vol 35 (2) ◽  
pp. 74-82 ◽  
Author(s):  
Hamza Issifu ◽  
George K. D. Ametsitsi ◽  
Lana J. de Vries ◽  
Gloria Djaney Djagbletey ◽  
Stephen Adu-Bredu ◽  
...  
Keyword(s):  
Vegetation Cover ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Tree Cover ◽  
First Year ◽  
Transplant Experiment ◽  
Tree Seedling ◽  
Savanna Woodland ◽  
Specific Effects ◽  
Species Specific

AbstractDifferential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.

Bifidobacteria exert species-specific effects on constipation in BALB/c mice

2017 ◽  
Vol 8 (10) ◽  
pp. 3587-3600 ◽  
Author(s):  
Linlin Wang ◽  
Lujun Hu ◽  
Qi Xu ◽  
Tian Jiang ◽  
Shuguang Fang ◽  
...  
Keyword(s):  
Specific Effects ◽  
Species Specific

Edible bifidobacteria exerted species-specific effects in relieving constipation.

scholarly journals Species-Specific Effects of Ant Inhabitants on Bromeliad Nutrition

PLoS ONE ◽  
2016 ◽  
Vol 11 (3) ◽  
pp. e0152113 ◽  
Author(s):  
Ana Z. Gonçalves ◽  
Rafael S. Oliveira ◽  
Paulo S. Oliveira ◽  
Gustavo Q. Romero
Keyword(s):  
Specific Effects ◽  
Species Specific

Species-specific Effects of Nitromethylene Heterocycle Insecticides on Nicotinic Receptors in Locust Neurons and Mouse N1E-115 and BC3H1 Cells

1994 ◽  
Vol 22 (6) ◽  
pp. 454-461
Author(s):  
Marga Oortgiesen ◽  
Ruud Zwart ◽  
Henk P.M. Vijverberg
Keyword(s):  
Mammalian Cells ◽  
Neuroblastoma Cells ◽  
Receptor Subtypes ◽  
Inward Current ◽  
Specific Effects ◽  
Blocking Effects ◽  
Inward Currents ◽  
Species Specific ◽  
Ganglion Neurons

The effects of nitromethylene heterocycle (NMH) insecticides on subtypes of nicotinic acetylcholine (nACh) receptors were investigated in locust thoracic ganglion neurons, mouse N1E-115 neuroblastoma cells, and mouse BC3H1 muscle cells by using electrophysiological techniques. In locust neurons, all of the six NMH insecticides tested induced transient inward currents resembling nicotinic ACh-induced inward currents, while, in the continued presence of the NMH compounds, the ACh-induced inward current was blocked. The amplitude of the inward current and the blocking effects of the NMH insecticides were enhanced by concentrations between 0.1 and 10μM. Cross-desensitisation with the ACh-induced inward current confirmed that the NMH-induced inward current was governed by the activation of nACh receptors. Mammalian endplate type nACh receptors in BC3H1 cells and mammalian neuronal type nACh receptors in N1E-115 cells were much less sensitive to the NMH insecticides than the locust neuronal nACh receptors. At a concentration of 10μM, which blocked 80–100% of the ACh-induced inward current in locust neurons, NMH insecticides only partially blocked the ACh-induced inward currents mediated by the two subtypes of mammalian nACh receptors. NMH insecticides also failed to induce significant agonist effects in the mammalian cells at this concentration. The results provide a possible explanation for the selectively greater toxicity of NMH insecticides to insects than to vertebrates, at the level of nACh receptor subtypes and, hence, demonstrate that this in vitro approach is valuable for the investigation of species-specific interactions of compounds at their target site.

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