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1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Working of deep-water minerals with sectored way

100%
Sukach M.
Teka Komisji Motoryzacji i Energetyki Rolnictwa
|
2014
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tom 14
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nr 4
2

Physicochemical properties of water retained in midfield bog pools

86%
Urban D., Grzywna A.
Teka Komisji Ochrony i Kształtowania Środowiska Przyrodniczego
|
2013
|
tom 10
3

Morphological variation of oospores in the population of Chara rudis A. Braun in a mesotrophic lake

86%
Boszke P., Bociag K.
Polish Journal of Ecology
|
2008
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tom 56
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nr 1
The morphological variation of Chara rudis A. Braun oospores was examined in a local population in a deep (43 m), hardwater (34 mg Ca dm–3) and mesotrophic (Ptot 0.095 mg P dm–3, SD 8 m) lake (NW Poland). Two variants of population density and three variants of depth were taken into account. Oospores are 712.8 ± 37.6 (600–817) μm long and 452.6 ± 34.2 (350–516) μm wide. They have 8–13 ridges. The outer membrane is slightly granulated. The isopolarity index (length/width × 100) is 158.4 ± 9.9 (140–190). The variation coefficient varies from 5% for oospore length to around 10% for fossa width. It was shown that the differences between oospores coming from individual depth and density variants are statistically significant. The biggest (733.21 ± 33.3 μm) oospores occurred on individuals growing at a depth of 3 m, while the smallest ones (673.3 ± 43.4 μm) at 5 m. The oospores from highly dense aggregations (> 50 individuals × 0.1 m–2) were much longer and wider than oospores from scattered (<10 individuals × 0.1 m–2) individuals. The observed intrapopulation variation of oospores can be regarded as a response to environmental changes along the depth gradient.
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
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tom 64
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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 long-term trend and temporal fluctuations of the sea level at the Polish Baltic coast

72%
Wisniewski B., Wolski T., Musielak S.
Oceanological and Hydrobiological Studies
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2011
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tom 40
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nr 2
6
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Transformation of statistical and spectral wave periods crossing a smooth low-crested structure

72%
Carevic D., Loncar G., Prsic M.
Oceanologia
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2012
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tom 54
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nr 1
We carried out experimental studies of a smooth submerged breakwater in a wave channel in order to study such a structure impacts on the changes of statistically and spectrally defined representative wave periods as waves cross it. We discuss the impact of relative submersion, i.e. the relationship between the breakwater crown submersion and the incoming significant wave length Rc/Ls−i, on the representative wave periods. The mean periods, estimated using statistical and spectral methods, were compared in front of and behind the breakwater: the two periods turned out to be identical. Based on the measurements of the spectral mean wave periods in front of and behind the breakwater, an empirical model is derived for estimating the reduction in mean spectral period for submerged and emerged smooth breakwaters.
7
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Wave-induced set-up and flow over shoals and coral reefs. Part 1. A simplified bottom geometry case

72%
Massel S. R., Brinkman R. M.
Oceanologia
|
2001
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tom 43
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nr 4
An analytical approach was used to model the wave-induced set-up and flow through simple shoal geometry when water depth is a linear function of the distance. Two different approaches were applied to parameterize the energy dissipation due to wave breaking. The resulting set-up height and flow velocity were determined and their dependence on the geometry of the shoal and offshore forcing was demonstrated. The extension of the solution to a more complicated bathymetry and verification against the experimental data will be given in the second part of the paper.
8

Response of riverine benthofauna associated with gravel-pebble bottom to impoundment - interhabitat comparison

72%
Tszydel M., Grzybkowska M., Kurzawski M., Kalisiak N.
Oceanological and Hydrobiological Studies
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2007
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tom 36
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nr Suppl.4
9

Free-living interstitial Plathelminthes of the Baltic Sea: diversity and abundance

58%
Urban-Malinga B.
Polish Journal of Ecology
|
2011
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tom 59
|
nr 3
Free-living Plathelminthes constitute an important component of meiobenthic communities in various marine benthic environments, but research focusing on this group is generally scarce. The current study investigated the free-living interstitial flatworms of the shallow sandy sublittoral zone of the southern Baltic coast. Sediment samples were taken at Hel Peninsula at water depths of 1.5 m and 7 m, and the plathelminths were identified alive to the species level. In total, 22 species were identified. The majority of the species belonged to Kalyptorhynchia and Proseriata, but Acoela recently moved from Plathelminthes into their own phyllum and represented by Mecynostomidae, was the most numerous group. The average total plathelminth densities ranged between 6 and 74 ind. 10 cm–2. The vertical distribution of the plathelminth fauna in the sediments was usually limited to the upper 3–4 cm, except for acoels which penetrated deeper into the sediment layers. The role of both sediment water saturation and oxygen availability appeared to be the main factors limiting flatworm occurrence in the sediments investigated in this study.
10

Predation on artificial nests imitating the broods of two rallid species: the influence of habitat features

58%
Chibowski P., Brzezinski M., Jedlikowski J.
Polish Journal of Ecology
|
2015
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tom 63
|
nr 4
We tested the influence of nest concealment (vegetation type, density and height), water depth and nest distance from the bank on predation rates upon simulated nests of the water rail (Rallus aquaticus) and the little crake (Porzana parva). Broods of both rallids were simulated by real and wax-filled quail (Coturnix coturnix) eggs coloured typically for each species. Three grades of nest concealment were used: uncovered nests located on wooden floating boards, nests hidden in littoral vegetation and nests hidden under a plastic mesh covered with plants, which made them invisible from the air. Concealment proved to have a stronger impact on the fate of artificial nests than water depth; 95% of the nests on boards were depredated after one week of exposure. Nests attached to a peg at water level and hidden in vegetation had survival rates of 18 and 22%, after three weeks of exposure in two experiment repetitions. In 2012, we found significant differences between survival rates of nests located in different types of vegetation after the first week of the experiment: nests in bulrush (Typha spp.) had a higher survival rate than nests in sedge (Carex spp.) and common reed (Phragmites australis), and nests in sedge had a better survival rate than nests in reed. Those differences disappeared after the end of the experiment. In 2013, nests located in sedge (Carex spp.) had a better survival rate than nests located in bulrush (Typha spp.) or the common reed (Phragmites australis). Covering nests with plastic mesh and plants increased nest survival up to 38% after a three-week-long exposure period. Potential nest predators were monitored: mammals (mustelids and rodents) using live traps and birds by observation of their hunting activity. Filling quail eggshells with wax allowed us to identify the marsh harrier (Circus aeruginosus) as the main nest predator — in 67% of depredated nests, wax eggs carried marks of a raptor beak. American mink (Neovison vison) and the water vole (Arvicola amhibius), though abundant in the study area, were not important nest predators, as only a few bite marks of these mammals were recorded.
11

Chlorophylls c in bottom sediments as markers of diatom biomass in the southern Baltic Sea

58%
Kowalewska G., Witkowski A., Toma B.
Oceanologia
|
1996
|
tom 38
|
nr 2
12

Badania morfometryczne wydm piaszczystych o prostej linii szczytu zaobserwowanych na dnie ujsciowego odcinka rzeki Raby

51%
Slowik-Opoka E., Radecki-Pawlik A.
Acta Scientiarum Polonorum. Formatio Circumiectus
|
2007
|
tom 06
|
nr 1
43-54
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