Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 16

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  community composition
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Distribution of microbial-selected populations in Lake North Mamry by fluorescent in situ hybridization

100%
Skowronska A.
Polish Journal of Environmental Studies
|
2007
|
tom 16
|
nr 1
Fluorescent in situ hybridization (FISH) with rRNA -targeted oligonucleotide probes has become one of the major techniques in environmental microbiology, allowing rapid and reliable definition of prokaryotes and quantification of population sizes. The aim was to demonstrate the applicability of the FISH method to study bacterioplankton composition in North Mamry Lake, and to follow the dynamics of two populations of common bacteria. We analyzed the phylogenetic composition of free-living bacterioplankton assemblage using oligonucleotide probes specific for Bacteria as well as for β-Proteobacteria and Cytophaga-Flavobacterium groups. Up to 53% of bacteria detected with DA PI could be detected via FISH by applying the universal bacterial probe for domain Bacteria (Eub338). Percentage of Cytophaga-Flavobacterium cluster did not exceed 20%. Members of the β –Proteobacteria appeared to be the most abundant group.
2

The effect of habitat in biasing fish abundance and species richness estimates when using various sampling methods in streams

86%
Bayley P. B., Dowling D. C.
Polskie Archiwum Hydrobiologii
|
1993
|
tom 40
|
nr 1
3

Emergence phenology and microhabitat distribution of aquatic Diptera community at the outlets of barrage lakes: effects of temperature, substrate and current velocity

72%
Cmrlec K., Ivkovic M., Semnicki P., Mihaljevic Z.
Polish Journal of Ecology
|
2013
|
tom 61
|
nr 1
True flies (Diptera, Insecta) are one of the most important groups of aquatic insects in respect of the number of families and abundance of individuals. The goals of this study were to determine emergence patterns and the main ecological factors that influence dipteran family abundance and emergence at barrage lake outlets. Differences in abundance and variations between microhabitats were examined. The study was carried out in Plitvice Lakes National Park (Dinaric karst region, Croatia) at outlets of three barrage lakes. On each site several microhabitats, which differ in substrate and water velocity were selected. The selected substrates were moss on tufa, particulate tufa with detritus, pebbles and silt. Sampling of dipteran adults was conducted at the end of every month during 2007/2008 with 6 emergence traps placed at each site. Simuliidae and Chironomidae were the most abundant families among the 13 families present. Temperature influenced the start of emergence and the duration of flight period. All three lake outlets differed in abundance of individuals, especially the lowest barrage lake outlet which can be contributed to the lowest levels of organic seston and highest rates of tufa deposition. For Chironomidae, Simuliidae and aquatic Empididae statistically significant positive correlation between abundance and current velocity was observed. The least favoured substrate for all Diptera families was silt, while moss was the preferred one.
4

Potholes of mountain river as biodiversity spots: structure and dynamics of the benthic invertebrate community

72%
Ren H., Yuan X., Yue J., Wang X., Liu H.
Polish Journal of Ecology
|
2016
|
tom 64
|
nr 1
Temporary freshwater rock pools, as special, small-sized and isolated habitats, provide ideal systems for studying island biogeography and ecological theories and processes. In this study, a total of 70 potholes of mountain rivers were sampled during the four seasons from November 2013 to October 2014 to assess the structure of the benthic invertebrate community and to identify the relationships between habitat characteristics and the community composition. Pothole area ranged from approximately 0.01 to 0.39 m², and pothole depth ranged from 0.03 to 0.74 m. Forty-three taxa belonging to 37 families and 16 orders were collected from the potholes. The highest numbers of benthic invertebrate taxa were observed in summer and the highest average number of taxa per pothole (8.5) was observed in autumn. The diversity was the highest in spring, and the average densities of benthic invertebrates were highest in autumn. Large potholes supported more taxa than small ones and significant relationships between richness and pothole area, richness and water volume were observed. The results of Redundancy Analysis show that the community composition of benthic invertebrates in the potholes was closely correlated with water temperature, pothole area and water depth. Our results indicate that benthic invertebrate communities in river potholes are mainly structured by water depth, pothole area and water volume. The seasonal changes are also an important factor determining the presence/absence of certain taxa.
5

A contribution to the knowledge of Arctic zooplankton diurnal variability [Kongsfjorden, Svalbard]

72%
Walkusz W., Kwasniewski S., Dmoch K., Beszczynska-Moller A.
Polish Polar Research
|
2007
|
tom 28
|
nr 1
Zooplankton was investigated at fixed site in 24 hours in Kongsfjorden, a glacial fjord situated on the west coast of Spitsbergen (Svalbard) (79°N, 12°E), in order to unveil the level of diurnal variability in community composition and abundance. Parallel to zooplankton study water temperature and salinity were measured while information on local tides and winds was obtained from external sources. Observed changes did not exceed the range of variability regarded intrinsic, resulting from the nature of plankton. Because of this low variability we are of the opinion that the data presented can be regarded a valid measure of the natural heterogeneity of zooplankton communities in hydrologically dynamic Arctic coastal waters in summer. The observed changes in zooplankton were primarily induced by the complex dynamics of the fjord's water masses. In spite of importance of tidal forcing, the variability in zooplankton did not demonstrate similar temporal fluctuations due to modification of the water movement by other irregular forces (local wind). Also, we have not found any indication of diel vertical migration in coastal water in the Arctic under the condition of midnight sun.
6

Structure of benthic fish assemblages under intense exploitation in the Gulf of Gdansk

72%
Psuty-Lipska I.
Bulletin of the Sea Fisheries Institute
|
2001
|
nr 3
7

Composition of a small mammal community studied by three comparative methods

72%
Luisselli L., Capizzi D.
Acta Theriologica
|
1996
|
tom 41
|
nr 4
Small mammal community composition of a Mediterranean area of central Italy was studied by comparing three different methods: (1) live-trapping, (2) owl pellet analysis and (3) snake gut analysis. All the methods employed provided useful data on both species composition and abundance in the field, although live-trapping and analysis of Tyto alba pellets allowed the detection of the higher number of small mammal species. When live-trapping is used, it seems necessary to place traps in every environmental type available in the study area.
8

Are community composition and abundance of psammon Rotifera related to grain-size structure of beach sand in lakes?

72%
Ejsmont-Karabin J.
Polish Journal of Ecology
|
2004
|
tom 52
|
nr 3
The aim of the study was to test the hypothesis that the size distribution of sand grains in lake beach should affect the species composition, densities and body-size structure of psammon communities of Rotifera. Studies were carried out in hydro-, hygro- and euarenal zones of 38 beaches (5 to 50 m long and 1 to 10 m wide) in 16 lakes of different trophic status and morphometry (Masurian Lakeland, Poland). Porosity has no impact on psammon rotifer numbers as well as body-size of animals does not seem to play a significant role in species preference to different size classes of sand grains. However, the significant correlations were found between the rotifer numbers and the share of grain size fraction 0.25–1.00 mm (positive) and the share of the largest (i.e. >1 mm) fraction (negative). The psammobionts generally are more related to the grain size fraction 0.5–1.0 mm than the psammoxenes and psammophiles. Although particular rotifer species prefer different grain size fractions, bdelloids are the only group of Rotifera preferring the smallest (<0.125 mm) grain fraction.
9

Inorganic phosphorus and nitrogen modify composition and diversity of microbial communities in water of mesotrophic lake

58%
Chrost R. J., Adamczewski T., Kalinowska K., Skowronska A.
Polish Journal of Microbiology
|
2009
|
tom 58
|
nr 1
77-90
The effects of inorganic nutrients (N, P) enrichment of mesotrophic lake water on changes in bacterial and protistan (heterotrophic nanoflagellates and ciliates) communities compositions were studied in the mesocosm experiment. Phosphorus (PO₄³⁻) and nitrogen (NH₄⁺) alone and in combination were added to three types of experimental mesocosms. Mesocosms results suggested that simultaneous addition of P and N stimulated phytoplankton growth and production rates of bacterial biomass its turnover rate. Strong positive correlations between chlorophyll a and bacterial secondary production rates suggested that bacteria were mainly controlled by organic substrates released in course of phytoplankton photosynthesis. Both nutrients increased distinctly protistan biomass and resulted in the shift in ciliate community composition from algivorous to large omnivorous species. The response of bacterial numbers and biomass to nutrients addition was less evident. However, intensive grazing caused their dynamic changes. Fluorescence in situ hybridization (FISH) revealed only small changes in bacterial taxonomic composition. There was an apparent shift in dominance from Cytophaga-Flavobacterium to the Alphaproteobacteria group in the mesocosm with simultaneous addition of P and N, which positively related to increased abundance of bacterivorous protists. Experiment demonstrated that inorganic N and P nutrients directly influenced the bottom-down control of microbial communities, which had a crucial effect on morphological diversity of bacteria.
10

The influence of hydrology and water quality on phytoplankton community composition and biomass in a humoeutrophic reservoir, Siemianowka reservoir [Poland]

58%
Grabowska M., Gorniak A., Jekatierynczuk-Rudczyk E., Zielinski P.
International Journal of Ecohydrology and Hydrobiology
|
2003
|
tom 03
|
nr 2
185-196
11

Vascular ground flora in relation to topography, canopy structure and gap light regimes in a subtropical broadleaved forest (South China)

58%
Ou Y.-D., Su Z.-Y., Ke X.-D., Li Z.-K.
Polish Journal of Ecology
|
2012
|
tom 60
|
nr 3
We examined the influence of topogra phy, canopy structure and gap light environmental variables on the patterns of vascular ground flora (vascular plants less than 1 m in height excluding tree seedlings) in a subtropical broadleaved forest in S China, using field data obtained from a 4-ha permanent plot. Both topographic and canopy environmental conditions had a significant effect on community composition, species diversity and distribution of the vascular ground flora. However, topographic factors, especially slope position and aspect, had a greater influence as compared with canopy and understory light conditions. Both number of individuals and number of individuals per species of the ground flora varied significantly with different slope position, aspect, slope steepness and transmitted direct radiation, while species richness varied significantly under different slope position and canopy leaf area index (LAI) The effects of topographic and canopy environmental conditions on ground-flora composition and structure was further confirmed by Canonical Correspondence Analysis (CCA). Multi-response Permutation Procedures (MRPP) showed significant differences in the ground-flora species composition based on all the topographic, canopy structure and gap light variables. Species indicative of topographic, canopy structure and gap light regimes were identified with a significant indicator value (IV ≥ 35%) by Indicator Species Analysis (ISA), which indicated that certain species have their ecological preference for a particular environmental gradient.
12
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Ocean acidification and marine microorganisms: responses and consequences

58%
Das S., Mangwani N.
Oceanologia
|
2015
|
tom 57
|
nr 4
13
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Fish monogeneans from a shallow, eutrophic Oswin Lake in Poland

58%
Mierzejewska K., Wlasow T., Dzika E.
Wiadomości Parazytologiczne
|
2006
|
tom 52
|
nr 1
A study was carried out in a shallow, eutrophic Oświn Lake, within Seven Islands Reserve (north-eastern Poland), in order to determine the infection of fish with monogeneans as sensitive indicators of water quality. This paper presents comparative analysis of the occurrence of Monogenea in fishes from two, distinctly separated pools of the lake, differing in environmental conditions. The impact of fish size and sampling season on the infection parameters was also analyzed. Material and methods. In 1998 and 1999, a total of 1091 fish representing 8 dominant species were examined. Samples were collected four times a year (in May, July, August, and October) simultaneously from the eastern and western parts of the lake. Results. 16 species of Monogenea (and some unidentified specimeus) occurred in the fish examined, most of them from the Dactylogyridae family: Dactylogyrus sphyrna, D. auriculatus, D. intermedius, D. anchoratus, D. falcatus, D. tincae, D. wunderi, D. zandti, D. difformis, D. nanus, D. distinguendus, D. crucifer, D. caballeroi. Furthermore, Tetraonchus monenteron (Tetraonchidae), Gyrodactylus elegans (Gyrodactylidae), and Paradiplozoon megan (Diplozoidae) were detected. Monogenea occurred abundantly on the gills of pike, roach, rudd, white bream, carp bream and crucian carp, but rather sporadically in tench and perch. The highest species variety and diversity of monogenean guilds were detected in carp bream and roach. It was proved that D. crucifer and D. difformis were significantly more abundant in the western pool compared to the eastern one. Infection of fish with Dactylogyridae was season-dependent, contrary to the infection of pike with T. monenteron. Intensity of infection of white bream with D. sphyrna and roach with D. crucifer increased with fish body length; such a relationship did not appear for the other monogeneans and their hosts. Conclusion. Presence of common Monogenea in the fish examined, lack of rare species, poor diversity of monogenean guilds and relatively low infection rate could be connected with the low stability of the lake environment. Location-dependent occurrence of D. crucifer and D. difformis indicated that the exchange between fish groups from the eastern and western parts of the lake is limited.
14

The effects of release from cold stress on the community composition of terrestrial gymnamoebae: A laboratory-based ecological study simulating transition from winter to spring

58%
Anderson O. R.
Acta Protozoologica
|
2004
|
tom 43
|
nr 1
15

Ground beetles [Coleoptera: Carabidae] in anthropogenic grasslands in Germany: effects of management, habitat and landscape on diversity and community composition

58%
Mayr S., Wolters V., Dauber J.
Wiadomości Entomologiczne
|
2007
|
tom 26
|
nr 3
Grasslands are of great importance for the conservation and maintenance of biodiversity in agricultural landscapes. In order to sustain grasslands and their associated biodiversity, we need to widen our knowledge of the role of grassland management and the amount of grassland cover in a landscape. The aim of our study was to correlate the variability of community composition and diversity of carabid beetles in anthropogenic grasslands with management, habitat conditions, landscape composition and plant species richness. Since the condition of grassland biodiversity is often solely evaluated on the basis of species richness of vascular plants, we also wanted to assess whether plants could indicate the diversity of carabid beetles in grasslands. Therefore, we sampled carabid beetles on 29 grassland sites with low to high management intensity and a great variation of abiotic conditions in Central Germany. The diversity of carabid beetles was the highest in grasslands of medium management intensity and was positively affected by a high cover of crops in the surrounding landscape. Both the landscape and soil moisture had an impact on activity density of carabids but depended on the trophic group of the beetles. There was no connection between plant species richness and carabid diversity. The results of our study suggest that plant species richness as a sole indicator of grassland biodiversity might not be sufficient. Nevertheless, moderate management intensity which supports high plant species richness can also increase carabid diversity. We therefore conclude that moderate management in-tensity is crucial to provide highest biodiversity of carabid beetles in grasslands. Due to landscape effects on carabid communities, we suggest that besides management of single fields, the composition and structure of the whole landscape should be taken into considera-tion in order to sustain a rich species pool of carabid beetles in agricultural landscapes.
16

Canopy leaf beetles and weevils in the Białowieza and Borecka Forests in Poland (Col., Chrysomeloidea, Curculionoidea)

51%
Sprick P., Floren A.
Polish Journal of Entomology
|
2007
|
tom 76
|
nr 2
In this study we present a faunistic overview of an investigation of arboreal phytophagous beetles collected from primeval forests and managed forests of Białowiea and Borecka Forests by insecticidal knock-down in 2001 and 2002. The whole dataset is based on 122 fogging samples and on stem eclector samples from 49 trees. In the area of Białowiea Forest 78 fogging samples from common oak (Quercus robur L.), 28 from spruce (Picea abies (L.) KARST.), 13 from hornbeam (Carpinus betulus L.) and 3 from different trees (Acer platanoides L., Populus tremula L., Pinus sylvestris L.) were taken. The samples from ancient woodland, primary forest sanctuaries, and different-aged managed forest stands revealed 129 phytophagous beetle species and 24458 individuals of the families Chrysomelidae, Bruchidae, Anthribidae, Rhynchitidae, Attelabidae, Apionidae, Nanophyidae, and Curculionidae. The stem eclector catches resulted in 32 species and 7077 individuals of Chrysomelidae, Anthribidae, Apionidae and Curculionidae. In the area of Borecka Forest 11 trees were fogged (3 Quercus robur L., 4 Picea abies, 3 Carpinus betulus and 1 Tilia cordata MILL.), resulting in 25 species and 1531 individuals. The following seven species,mainly collected by fogging, were previously not recorded from Białowiea forest: Zeugophora frontalis, Longitarsus curtus, Cryptocephalus nitidus, Crepidodera nitidula, Bruchidius marginalis, Acanthoscelides obtectus, and Phaeochrotes cinctus. Some rare species as Cryptocephalus querceti, Polydrusus flavipes, Anthonomus pinivorax, Magdalis fuscicornis, Magdalis exarata, Rhynchaenus pilosus, and Rhynchaenus hortorum were caught in medium or large numbers indicating that they preferably occur in the canopy. Full-winged specimens of Psylliodes cucullatus were found for the first time. Canopy communities were dominated by the feeding generalist Strophosoma capitatum (47.5% of all weevils, Anthribidae excluded) and other broad-nosed weevils of the genera Phyllobius und Polydrusus. Broad-nosed weevils represented 92.1% of the total weevil catch. Polydrusus flavipes proved to be a characteristic species of the wet oak forest, where it was abundant mainly on old oak trees. 36% of the weevil species, but only 13% of the leaf beetle species develop on the sampled trees (Quercus, Picea, and Carpinus). The remaining species develop on other forest trees (22% of the leaf beetles and 32% of the weevils), on herbs, low shrubs or in the open country (65% of the leaf beetles and 32% of the weevils); rarely sampled tree genera were not considered in this analysis.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.