scholarly journals The role of reservoirs in changing the species composition of the ichthyofauna (on the example of the Kuibyshev reservoir)

2019 ◽  
Vol 288 ◽  
pp. 012058
Author(s):  
F M Shakirova ◽  
V Z Latypova ◽  
N Yu. Stepanova ◽  
V G Tereshchenko ◽  
O K Anokhina ◽  
...  
Keyword(s):  
Species Composition ◽  
Kuibyshev Reservoir

Long-term dynamics and destruction of marsh vegetation in the Kolokolkova Bay of the Barents Sea

2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Barents Sea ◽  
Mean Value ◽  
Marsh Vegetation ◽  
Composition And Structure ◽  
The Mean ◽  
Species Composition And Structure

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.

LANDSLIDE RISK MANAGEMENT IN THE COASTAL ZONE OF THE KUIBYSHEV RESERVOIR DUE THE DESIGN OF HIGH-SPEED LINE "MOSCOW-KAZAN"

2017 ◽  
Author(s):  
Nikolai Petrov ◽  
Nikolai Petrov ◽  
Inna Nikonorova ◽  
Inna Nikonorova ◽  
Vladimir Mashin ◽  
...  
Keyword(s):  
High Speed ◽  
Computational Models ◽  
Stable State ◽  
Landslide Risk ◽  
Kuibyshev Reservoir ◽  
Stepped Surface ◽  
The Stability ◽  
Landslide Slope ◽  
The Village

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.

scholarly journals The Species Composition and Seasonal Dynamics of Thrips (Thysanoptera) Populations on Maize (Zea Mays L.) in Southeastern Poland

2011 ◽  
Vol 51 (3) ◽  
pp. 210-216 ◽  
Author(s):  
Halina Kucharczyk ◽  
Paweł Bereś ◽  
Zbigniew Dąbrowski
Keyword(s):  
Zea Mays ◽  
Species Composition ◽  
Seasonal Dynamics ◽  
Food Source ◽  
Zea Mays L ◽  
Maize Plant ◽  
Seasonal Abundance ◽  
Immature Stages ◽  
Thrips Species

The Species Composition and Seasonal Dynamics of Thrips (Thysanoptera) Populations on Maize (Zea MaysL.) in Southeastern PolandThrips species composition and seasonal abundance was studied on maize crops during two seasons (2006-2007), in southeastern Poland. Altogether 21 species have been identified, among themFrankliniella tenuicornis(Uzel 1895) andHaplothrips aculeatus(Fabricius 1803) which are a graminicolous species and were eudominants, comprising 96.8% in 2006 and 82.0% in 2007 of all collected specimens. Other species occurred only in low numbers. The frequent and numerous presence ofF. tenuicornisspecies in their immature stages in the samples, confirmed the role of the maize plant as the host.H. aculeatusprobably chose maize as a food source and substitute plant for breeding.

scholarly journals Species Composition and Role of Anopheles Mosquitoes in Malaria Transmission Along Badagry Axis of Lagos Lagoon, Lagos, Nigeria

2010 ◽  
Vol 2 ◽  
pp. IJIS.S4698 ◽  
Author(s):  
I.O. Oyewole ◽  
C.A. Ibidapo ◽  
O.O. Okwa ◽  
A.O. Oduola ◽  
G.O. Adeoye ◽  
...  
Keyword(s):  
Species Composition ◽  
Malaria Transmission ◽  
Control Programme ◽  
Anopheles Mosquitoes ◽  
Vector Control Programme ◽  
Baseline Information ◽  
Falciparum Sporozoite ◽  
Lagos Lagoon ◽  
Sporozoite Infection

Three communities along Badagry axis of the Lagos lagoon were sampled for indoor resting Anopheles mosquitoes in order to determine their species composition, relative abundance, density and contribution to malaria transmission in the coastal ecosystem. A total of 1938 adult female Anopheles mosquitoes collected from 2005 to 2007 constituted three species viz Anopheles gambiae, An melas and An. nili. The Polymerase Chain Reaction (PCR)–-based tests indicated that more than three-fourth of the An. gambiae s.l (75.8%) population belongs to An. gambiae s.s the remaining were An. melas. Further analysis showed that all the An. gambiae s.s was the M form. ELISA-based analyses indicated that An. gambiae s.s and An. melas were the main vectors of malaria in this area with an overall P. falciparum sporozoite infection rate of 4.8% and 6.5% respectively. Both species also maintained relatively high EIR indicating their prominent roles in malaria transmission in the study area. All the An. nili tested were negative for P. falciparum sporozoite infection. This study provides baseline information for planning vector control programme relevant to reduction of malaria transmission in the coastal areas of Nigeria.

scholarly journals Lithology could affect benthic communities living below boulders

2020 ◽  
Vol 100 (6) ◽  
pp. 879-888
Author(s):  
M. Canessa ◽  
G. Bavestrello ◽  
E. Trainito ◽  
A. Navone ◽  
R. Cattaneo-Vietti
Keyword(s):  
Species Composition ◽  
Mediterranean Sea ◽  
Mineral Composition ◽  
Benthic Communities ◽  
Direct Influence ◽  
Biological Interactions ◽  
Physical Constraints ◽  
Free Face ◽  
Unstable Surface

AbstractStructure and diversity of sessile zoobenthic assemblages seem to be driven not only by chemical-physical constraints and biological interactions but also by substrate lithology and its surface features. Nevertheless, broadly distributed crustose epilithic corallines could mask the role of substrate on animal settling. To evaluate the direct influence of different rocky substrates, occurrence and coverage of several sessile species, growing on the dark (i.e. coralline-free) face of sublittoral limestone and granite boulders were compared in the Tavolara MPA (Mediterranean Sea). The analysis of photographic samples demonstrated significant differences in terms of species composition and coverage, according to lithology. Moreover, limestone boulders were widely bare, while the cover per cent was almost total on granite. The leading cause of observed patterns could be the different level of dissolution of the two types of rocks, due to their different mineral composition and textural characteristics. Limestone has previously been shown to have higher dissolution compared with granite, and consequently, a more unstable surface. Our results suggest that, in dark habitats, the absence of the crustose coralline layer allows more rock dissolution and consequent lower stability of the limestone compared with granite, which, in turn, reduces the zoobenthos colonization.

Influence of Chemical Diversity in Determining Lichen Communities Structure along an Altitudinal Gradient in the Chopta Tungnath, Western Himalaya

2017 ◽  
Vol 3 (01) ◽  
pp. 07-13
Author(s):  
Vertika Shukla ◽  
Rajesh Bajpai ◽  
Manoj Semwal ◽  
D. K. Upreti
Keyword(s):  
Species Diversity ◽  
Secondary Metabolites ◽  
Species Composition ◽  
Altitudinal Gradient ◽  
Western Himalaya ◽  
Chemical Diversity ◽  
Lichen Diversity ◽  
Lichen Community ◽  
High Precipitation

In recent years there has been growing interest in the study on lichen diversity with relation to altitudinal gradient and anthropogenic disturbances , as changes in lichen community composition may indicate air quality and microclimatic changes. The altitudinal data of species diversity and its subsequent changes with respect to time and space may provide vital information regarding impact of air pollution and/or climate change at regional or global scales. Chopta-Tungnath and adjoining areas of Garhwal Himalaya provide habitat and ecological variation with range of altitude lying between 300 to 3000 m. Out of the 116 species of lichens known from the studied area, the highest species diversity was observed between altitudes 1800 to 2100 m. Lichen communities occurring between 600–1800 m were dominated by members of Physciaceae, while Parmeliaceae were most common above 1800 m. Altitude beyond 2100 m experiences high precipitation, varying temperature conditions and increased incident UV radiation, which are responsible for controlling the variability in lichen diversity to a great extent in the region. The diversity of secondary metabolites in lichen species and consequent changes in species composition at various altitudes indicate the association of secondary chemicals in conferring the lichens resistance to biotic and abiotic stresses. The correlations of lichen diversity, secondary metabolites and the altitudes at which the lichens are growing, present suggestive role of secondary metabolites in determining species composition and sustainability in different environmental conditions.

Testing the enemies hypothesis in forest stands: the important role of tree species composition

Oecologia ◽  
2004 ◽  
Vol 142 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Janne Riihimäki ◽  
Pekka Kaitaniemi ◽  
Julia Koricheva ◽  
Harri Vehviläinen
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Forest Stands ◽  
Tree Species Composition ◽  
Enemies Hypothesis

Zooplankton of the St. Lawrence Great Lakes — Species Composition, Distribution, and Abundance

1974 ◽  
Vol 31 (5) ◽  
pp. 783-794 ◽  
Author(s):  
N. H. F. Watson
Keyword(s):  
Species Composition ◽  
Great Lakes ◽  
Lake Erie ◽  
Dry Weight ◽  
Individual Species ◽  
Composition Distribution ◽  
Free Weight ◽  
Sampling Intervals ◽  
Peak Abundance

Recent studies of zooplankton of the St. Lawrence Great Lakes have concentrated on a broad synoptic coverage of sampling stations and repeated cruises throughout a growing season. This has resulted in a considerable amount of detail about seasonal changes in species composition, total numbers, and vertical and horizontal distributions. Investigators have treated the data to show differences in distribution over the lakes on a cruise and cruise mean averages for each lake, often weighted by area to provide relative abundance figures over the season and between lakes.Maximum numbers were observed in Lake Erie (225,000/m3). Considerably fewer organisms were found in periods of peak abundance in Lake Ontario (55,000/m3) and Lake Huron (22,000/m3). No firm estimates are available for Lake Superior but numbers from one cruise (8000/m3) indicate still lower values there. Biomass estimates (either as ash-free weight of material from planktonnet hauls or from conversions of numbers to biomass from dry weight factors for individual species) are highest for Lake Erie, but reflect the larger size of organisms in the other lakes, especially Huron and Superior.Species distributions are now reasonably well known for crustaceans, except in one or two taxa of the cladocerans Daphnia and Bosmina whose variability should be investigated more fully. Recent studies have been made on the rotifers, but their numbers, distribution, and ecological role is not fully defined. Similarly, the distribution and role of protozoan groups have been largely ignored.Several computer techniques are suggested for the handling and analysis of the large quantities of data generated on lakewide surveys including community coefficients and cluster analyses. More attention should be given to determining sampling intervals to obtain information which can precisely detect changes in abundance from year to year, and better population dynamics and production data are needed to relate zooplankton stocks to eutrophication.

scholarly journals The double role of pigmentation and convolute leaves in community assemblage of Amazonian epiphytic Lejeuneaceae

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5921 ◽  
Author(s):  
Sylvia Mota de Oliveira
Keyword(s):  
Species Composition ◽  
Vertical Gradient ◽  
Carbon Gain ◽  
Life Strategy ◽  
Character State ◽  
Amazon Forest ◽  
Reproduction Mode ◽  
High Dispersal ◽  
Dark Pigmentation

Background Epiphytic bryophyte communities in the Amazon forest show a vertical gradient in species composition along the trunk of the host trees. The investigation of species traits related to this pattern has focused on the physiology of selected taxa with a clear preference for one of the extremes of the gradient. Although some species are indeed only found on the tree base or in the outer canopy, the vertical gradient is composed mainly by the variation in the abundances of species with a broader occurrence along the height zones. Therefore, this study approaches the differences among community assemblages, rather than among species, to test the role of morphological and dispersal traits on the establishment of the vertical gradient in species composition. Methods A character state matrix was built for 104 species of the family Lejeuneaceae recorded as epiphytes in the Amazonian terra firme forests, and six binary traits supposed to influence species occurrence: dark pigmentation on leaves; ability to convolute leaves when drying; possession of thickened cell walls; reproduction mode (monoicous or dioicous); occurrence of asexual reproduction; and facultative epiphyllous habit. Based on a previous dataset on community composition along the vertical gradient, trait occurrences in random draws of the metacommunity was compared to trait occurrences in field data, in order to detect significant deviations in the different height zones. Results Four out of the six traits tested showed significantly higher or lower occurrence in the species composition of canopy and/or understory communities. Traits related to high dispersal ability did not vary much along the vertical gradient; although facultative epiphylls were overrepresented on tree base. Dark pigmentation and convolute leaves were significantly more frequent in the canopy communities, but also significantly less frequent in communities at the base of the tree. Discussion Dark pigmentation and convolute leaves seem to be advantageous for the establishment in the canopy zones. They may, respectively, prevent light damage and allow longer periods of photosynthesis. Interestingly, these traits occur randomly along the trunk, but are wiped out of communities on the tree base. In the relatively deep shade of the first meters of the understory, they possibly hamper net carbon gain, the first by darkening the leaf surface and the second by delaying desiccation—which can be damaging under high temperatures and low light. The fact that production of asexual propagules is not overrepresented in the most dynamic microenvironment along the gradient, the canopy, challenges current views of bryophyte life strategy theory.

scholarly journals Effects of the availability of floral resources and neighboring plants on nectar robbery in a specialized pollination system

2021 ◽  
Author(s):  
Júlia Mendonça Almeida ◽  
Caio César Corrêa Missagia ◽  
Maria Alice Santos Alves
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Floral Resources ◽  
Floral Display ◽  
Nectar Robbing ◽  
Mixed Species ◽  
Individual Level ◽  
Nectar Foraging ◽  
Nectar Robbery

Abstract Many plants pollinated by nectar-foraging animals have to maintain a balance between legitimate visitor attraction strategies and mechanisms that minimize illegitimate visits. This study investigated how floral display and neighboring species composition influences nectar robbing in the tropical ornithophilous herb Heliconia spathocircinata. We tested the role of inflorescence display, flower abundance, and neighboring species in the reduction of nectar robbing in H. spathocircinata. Our results indicate that nectar robbing hummingbird activity was higher in moderately large inflorescence displays and that the frequency of nectar robbing in H. spathocircinata decreases with increased flower abundance and the presence of neighboring plant species. Neighboring non-ornithophilous plants decreased the frequency of nectar robbing in H. spathocircinata flowers to a greater extent than ornithophilous ones. These results suggest that nectar robbing hummingbirds are attracted to similar conditions that attract legitimate visitors, and that spatial aggregation and mixed-species displays may represent a mechanism to dilute nectar robbing effects at an individual level.

Sign in / Sign up

Export Citation Format

Share Document