Regulation of the development and species dominance of summer phytoplankton in Lake Vesij�rvi: predictability of enclosure experiments

Hydrobiologia ◽  
1992 ◽  
Vol 243-244 (1) ◽  
pp. 303-310 ◽  
Author(s):  
Juha Keto ◽  
Jukka Horppila ◽  
Timo Kairesalo
Keyword(s):  
Species Dominance ◽  
Enclosure Experiments

Monoculture-based consumer-resource models predict species dominance in mixed batch cultures of dinoflagellates

Harmful Algae ◽  
2020 ◽  
Vol 99 ◽  
pp. 101921
Author(s):  
M. De Rijcke ◽  
J.M. Baert ◽  
N. Brion ◽  
M.B. Vandegehuchte ◽  
F. De Laender ◽  
...  
Keyword(s):  
Batch Cultures ◽  
Species Dominance ◽  
Consumer Resource ◽  
Mixed Batch

Tree species dominance in neotropical savanna aboveground biomass and productivity

2021 ◽  
Vol 496 ◽  
pp. 119430
Author(s):  
Marcela de Castro Nunes Santos Terra ◽  
Jamir Afonso do Prado-Júnior ◽  
Cléber Rodrigo de Souza ◽  
Luiz Otávio Rodrigues Pinto ◽  
Eduarda Martiniano de Oliveira Silveira ◽  
...  
Keyword(s):  
Aboveground Biomass ◽  
Tree Species ◽  
Neotropical Savanna ◽  
Species Dominance

scholarly journals Cytokine profiles and Lactobacillus species presence in pre-menopausal subjects with genital Mycoplasma genitalium or Ureaplasma urealyticum colonization

2021 ◽  
Vol 17 ◽  
pp. 174550652110091
Author(s):  
John Garza ◽  
Kushal Gandhi ◽  
Sarah Choi ◽  
Asley Sanchez ◽  
Gary Ventolini
Keyword(s):  
Ureaplasma Urealyticum ◽  
Mycoplasma Genitalium ◽  
Interleukin 12 ◽  
Lactobacillus Species ◽  
Control Group ◽  
Study Group ◽  
Species Dominance ◽  
Cytokine Profiles ◽  
Menopausal Women ◽  
Significant Difference

Background and Purpose: Lactobacilli play a vital role in protecting the vagina against pathogens. Cytokines are vital components of defense against infections in women. The genital mycoplasmas, Mycoplasma genitalium and Ureaplasma urealyticum, are associated with various infectious diseases in adults and infants. The objective of our study is to identify differences in cytokine profile and Lactobacillus species dominance between a study group of non-pregnant pre-menopausal women with genital M. genitalium or U. urealyticum colonization and a control group of non-pregnant pre-menopausal women without genital M. genitalium or U. urealyticum colonization. Methods: A real-time polymerase chain reaction was performed to measure Lactobacillus species in vaginal swab samples. Cytokine analysis was performed using multiplex immunoassay techniques. Analysis of variance confirmed a significant difference in cytokine profiles between patient groups, with t-tests identifying the most significantly different cytokines. Categorical data analysis identified significant patterns of relative Lactobacillus species dominance in the study group. Results: Lactobacillus iners was the predominant Lactobacillus species in the control group ( p = 0.005). There were no dominant Lactobacillus species observed in the study group. Vascular endothelial growth factor A ( p = 0.002), interleukin-8 ( p = 0.001), and interleukin-1β ( p = 0.049) were expressed significantly higher in the study group, whereas interleukin-1 receptor antagonist ( p < 0.001), interleukin-10 ( p = 0.001), interleukin-12 ( p = 0.002), and interferon-γ ( p = 0.022) were expressed higher in the control group. Association matrices for cytokines were significantly different between two groups ( p < 0.001), with mostly negative associations in the control group and mostly positive associations in the study group. Conclusion: Cytokine levels, their associations, and the patterns of Lactobacillus species dominance are observed to significantly diverge on the basis of M. genitalium and U. urealyticum colonization among non-pregnant pre-menopausal women.

scholarly journals Female butterflies prefer males bearing bright iridescent ornamentation

2007 ◽  
Vol 274 (1613) ◽  
pp. 1043-1047 ◽  
Author(s):  
Darrell J Kemp
Keyword(s):  
Mate Choice ◽  
Driving Force ◽  
Female Mate Choice ◽  
Sex Recognition ◽  
Female Mate ◽  
Wing Colour ◽  
Enclosure Experiments ◽  
Colour Patterns

Butterflies are among nature's most colourful animals, and provide a living showcase for how extremely bright, chromatic and iridescent coloration can be generated by complex optical mechanisms. The gross characteristics of male butterfly colour patterns are understood to function for species and/or sex recognition, but it is not known whether female mate choice promotes visual exaggeration of this coloration. Here I show that females of the sexually dichromatic species Hypolimnas bolina prefer conspecific males that possess bright iridescent blue/ultraviolet dorsal ornamentation. In separate field and enclosure experiments, using both dramatic and graded wing colour manipulations, I demonstrate that a moderate qualitative reduction in signal brightness and chromaticity has the same consequences as removing the signal entirely. These findings validate a long-held hypothesis, and argue for the importance of intra- versus interspecific selection as the driving force behind the exaggeration of bright, iridescent butterfly colour patterns.

Abundance of leafminers and leaf area loss by chewing herbivores in hybrids between Quercus crispula and Quercus dentata

2004 ◽  
Vol 34 (12) ◽  
pp. 2501-2507 ◽  
Author(s):  
Takahide A Ishida ◽  
Kouhei Hattori ◽  
Masahito T Kimura
Keyword(s):  
Leaf Area ◽  
Parental Species ◽  
Quercus Crispula ◽  
Species Dominance ◽  
Area Loss ◽  
Early Instar ◽  
Sap Feeding ◽  
Leaf Area Loss ◽  
Quercus Dentata ◽  
Northern Japan

We examined responses of phytophagous insects to hybrids between Quercus crispula Blume and Quercus dentata Thunberg in a natural population in northern Japan. The abundance of leafminers and leaf area loss by chewing insects in hybrids were intermediate between those in the parental species (additive mode), close to those of either of the parental species (dominance mode), or similar to those of both parental species (no difference). Hybrids were neither more susceptible nor resistant to the insect herbivores we monitored. In Phyllonorycter (Gracillariidae) species, which are specialized to either of the parental oak species, the mortality of sap-feeding early instar larvae did not differ between hybrids and the parental species. The abundance of four leafminer taxa was correlated with environmental conditions (i.e., distance from the coastal edge of the forest or the timing of budbreak) as well as genetic factors.

scholarly journals Struktur Komunitas Fitoplankton di Perairan Pesisir Pulau Siantan Kabupaten Kepulauan Anambas Provinsi Kepulauan Riau

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Lani Puspita ◽  
Notowinarto Notowinarto ◽  
Rudi Gunawan
Keyword(s):  
Community Structure ◽  
Coastal Area ◽  
Diversity Index ◽  
Natural Food ◽  
Species Dominance ◽  
Sampling Locations ◽  
Level Data ◽  
Dominance Level ◽  
Index Value ◽  
Sampling Times

Phytoplankton as a producers  and natural food for fish have an important role in aquatic ecosystems, thus indirectly affecting the availability of fish catches. The research was conducted at Siantan Island Coastal Area Anambas Islands District Riau Islands Province. This coastal area is one of the fishing grounds in Anambas Island. This study aims to analyze the community structure of phytoplankton at Siantan Island Coastal Area Anambas Islands District Riau Islands Province. Sampling was conducted during March and April 2012. Community structure parameters analyzed include Species Diversity Level, Species Uniformity Level, and Species Dominance Level. Data were analyzed spatially and temporally. Similarity between the sampling locations was conduted by Multivariate Analysis - Cluster. Results of data analysis showed that the phytoplankton of Bacillariophyceae Class found in the most abundant amount. Diversity Index Value indicates that the level of phytoplankton plankton community in a state of moderate. Species Uniformity Index Value and Species Dominance Index Value indicates that phytoplankton in the three sampling locations are generally in a state of uniform and no one dominates. All three sampling locations have relatively the same condition and between sampling times (morning, afternoon, and evening) are also not very different condition. Keywords: phytoplankton, coastal, Anambas Islands  

scholarly journals Year-to-year crop shifts promote weed diversity in tropical permanent rainfed cultivation

2020 ◽  
Author(s):  
Margot Neyret ◽  
Anneke de Rouw ◽  
Nathalie Colbach ◽  
Henri Robain ◽  
Bounsamay Soulileuth ◽  
...  
Keyword(s):  
Upland Rice ◽  
Centella Asiatica ◽  
Shannon Index ◽  
Species Number ◽  
List Type ◽  
Herbaceous Species ◽  
Frequent Change ◽  
Young Tree ◽  
Species Dominance ◽  
Density And Biomass

AbstractIn the past decades, the expansion and modernisation of agriculture in the mountainous areas of Southeast Asia has had severe impacts on biodiversity, as the once species-rich forests were turned into homogeneous fields receiving ample external inputs. A common feature of permanent cropping with annual crops is the frequent change of crop choice, depending on market opportunities or other motives. However, the precise effect of crop shifts on weeds in tropical areas is largely unknown. In this study, we investigated the short-term effect of crop sequences on the diversity of weed communities in smallholder fields in Northern Thailand. Crop choices were upland rice, maize, fallow and young tree plantations with or without intercrop. We counted the number of crop shifts and the number of crops involved during a 3-years period preceding weed sampling. We showed that the number of crop shifts did not affect weed density and biomass. However, herbaceous species number and diversity (measured as Shannon index) increased by 36% and 46% respectively, while herbaceous species dominance decreased by 38%, in fields with yearly crop shifts compared to fields with no shifts in the previous three years. The effect of a particular crop on diversity, or the effect of intercropping with young trees, was weaker. It was likely due to the more variable resources (especially light) in fields with two crop shifts, allowing species with different niches to co-exist. Crop type and frequent crop shifts did not affect shrub and tree species number, diversity or dominance. Some species were strongly associated with fields with no crop shift in the sequence (e.g. the tree Antidesma velutinosum) or to fields with two crop shifts in the sequence (e.g. the herb Centella asiatica, the C4 grass Digitaria radicosa). Overall, this study showed that in this agronomical system, maintaining yearly crop shifts does not significantly affect weed abundance, but supports in-field plant species diversity, which is likely to impact the services provisioned by tropical mountainous agro-ecosystemsHighlightsFrequent crop shifts in a crop sequence increased weed richness and diversity.Crop shifts had a stronger effect on weed richness and diversity than the current crop.The number of crop shifts did not affect weed biomass and density.Graphical abstract

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