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EN
There are 150 meteorite craters worldwide, however, their aggregations are rarely noted. The nature reserve ‘Meteoryt Morasko’ in Poland with fishless meteorite ponds was analyzed as a unique ecosystem for biological analysis of invertebrate interactions. The aim of the study was to recognize the main environmental drivers of cladoceran and copepod community structure from among biotic (competitors and predators) and abiotic factors (i.e. oxygen and pH level) in the spring season. The abundance of small cladocerans (Alonella excisa and Chydorus sphaericus) was the highest at the end of the spring season, i.e. in June, while large species (Daphnia pulex and Simocephalus exspinosus) were most abundant in May. Both size groups of Cladocera were negatively affected by invertebrate predators (Chaoborus crystallinus and carnivorous copepods), which are known to play an important role in structuring cladoceran communities due to the fishless character of the studied ponds. No negative effect of those predators was found for Copepoda, however, nauplii density was reduced by competitors (Aedes communis larvae and ostracods). The temporary character of the examined ponds, oxygen depletion and low pH of water in the shallowest pond resulted in the abundant occurrence of cladoceran males, whose high densities are usually observed in autumn.
EN
The aim of the study was to determine whether biometric features of plants collected from single-species phytocoenoses developing in ponds can be used to describe habitat conditions of these water bodies. The biometric measurements were carried out in 148 field small water bodies at a total of 198 sites. The length of plants, their dry biomass, and volume of plant shoots were analyzed, converted to 1000 dm3 of water. The biometric measurements showed very large differences in individual parameters of different macrophyte species. The biggest differences were found in the length of elodeids and helophytes (from 1 cm to > 900 cm), regardless of trophic conditions. Although the Polish flora is dominated by plants having a wide ecological range, there are species whose parameters correspond to specific habitat fertility. The highest biometric parameters were found for Ceratophyllum submersum, Sparganium erectum, Typha latifolia and Schoenoplectus lacustris in ponds characterized by increased trophic conditions. In contrast, Myriophyllum spp. alone showed a negative correlation with trophic state indices. The trophic effect on the studied parameters becomes more apparent for species with optima in fertile water bodies. The parameters of Ceratophyllum submersum can be considered as the trophic state index (TSI).
EN
This study analyzed the chemistry and structure of planktonic fauna communities in small water bodies located within agricultural areas of different levels of anthropogenic transformation in the Wielkopolska region. Distance from farm buildings was a decisive factor when choosing the bodies of water for this study. A distinctive feature of the chemical characteristics of the examined water bodies was a high concentration of biogenic substances. The presence of biologically available mineral elements stimulated the development of algae, which was reflected in high concentrations of chlorophyll. High trophic conditions in the waters of the investigated ponds were also confirmed when analyzing the zooplankton community structure.
EN
The results of investigations performed in Lake Wielkowiejskie showed the influence of macrophyte architecture, understood as plant density, on the structure of plankton communities as well as the habitat preferences of particular species in both seasonal and spatial aspects.
EN
Different morphological features of particular water bodies, physical and chemical factors of their waters and sediments will have an impact on the development of specific aquatic vegetation types, which in turn will affect the creation of specific communities of plankton organisms. Therefore the aim of this study was to analyse the quantity and quality changes of macrophyte structure in relation to the lowering of the water level. Furthermore, the relationship between zooplankton community densities and environmental parameters was studied. Another aspect of the study was to investigate the similarity of the zooplankton communities of particular sampling stations in the three examined seasons. The study was carried out on Dąbrówka water body, a shallow and macrophyte-dominated pond, situated 10 km west of Poznań, Wielkopolska region, western Poland. The examination was conducted in the three seasons: spring, summer and autumn. The results revealed that during one vegetative period, including three seasons – spring, summer and autumn, three different layouts of aquatic vegetation were obtained, which reflected a significant transformation in the macrophyte cover. Along with the lowering of the water level the structural changes, especially in the case of submerged vegetation were recorded, which in each season was represented by different dominating species. Only three significant correlations between zooplankton densities and environmental factors observed. Negative relationship concerned total nitrogen and two positive related to biometric parameters of the macrophyte habitat (plant biomass plant stem volume). The plant biomass was a predictor of cladoceran abundance and plant stem volume referred to rotifers, which may reflect the complexity of the aquatic plant habitat, indirectly relating to the effectiveness of the macrophyte stand as anti-predator refuge. The analysis of the similarity of the zooplankton communities of particular sampling stations in the three examined seasons did not reveal any clear relationship, either in relation to a particular season or a sampling station. The participation of eutrophic species was highest in the spring and lowest during the autumn season. The open water zone possessed the highest participation of these species compared to the macrophyte zones.
EN
Hydromacrophyte habitats, which can differ in a multiplicity of biometric parameters, are among the most important factors affecting zooplankton community structure. The main goal of this work was to determine the impact of plant habitat parameters expressed by density, biomass, and plant volume along with chemical features on the composition and dynamics of rotifer and crustacean communities. A number of small water bodies of different origin (12) located in different catchment areas of the Wielkopolska region were analyzed. It was found that helophytes and nymphaeids had the highest biomass and the lowest stem density, while elodeids were of the lowest biomass and the greatest stem density. Similarity analysis confirmed this distribution of biometric parameters among particular ecological groups of macrophytes. The greatest numbers of zooplankton were noted among vegetated zones, which supports the idea of zooplankton using macrophytes as anti-predator refuge. Based on the study of a total of 23 plant stands, it was found that macrophyte biomass and the density of the plant habitat were the strongest predictors of three biometric parameters of zooplankton abundance.
EN
The main aim of this study was to analyze the diel distribution of zooplankton communities within the zones of Nymphaea albae, Myriophyllum verticillatum, and Typha angustifolia, and, compared to that, in the open water area of a lake. It also aimed to analyze the relationship between zooplankton densities and the concentration of physicochemical factors and chlorophyll a content. A total of 149 zooplankton taxa were noted, and, despite the narrow range of the research in the analyzed lake, some rare species were noted, among which two - Colurella sinistra and Lecane inopinata – were recorded for the first time among Polish fauna. The rush zone was taxonomically the richest, while the open water area was the poorest. The highest number of individuals was observed in the Myriophyllum bed, while the lowest was noted in the zone dominated by Nymphaea alba. The highest densities of zooplankton occurred at dusk, while the lowest occurred during the day, irrespective of the sampling station. Because Lake Wielkowiejskie is a shallow and macrophyte-dominated water body, the differences in the diurnal distribution of zooplankton communities may suggest horizontal migrations between the pelagic zone and the phytolittoral, as well as between particular macrophyte stands. A positive correlation between the densities of some zooplankters and the concentration of chlorophyll a was found, while a negative relationship with the concentration of nitrites was recorded for Lecane quadridentata and Alonella nana.
EN
The main aim of the study was to analyze diurnal changes in the composition and dynamics of the cladoceran community among three stations located along a horizontal transect that included the central part of a Myriophyllum verticillatum bed at the perimeter of a macrophyte stand and the open water zone of neighboring vegetated stations. Typically littoral species distinctly dominated the material examined. Ceriodaphnia quadrangula significantly influenced the total crustacean community. The maximum abundance of littoral species was noted in the middle part of the plant stand while the minimum was in the open water. These species revealed a similar pattern of diurnal distribution, irrespective of the station, with the highest numbers at night and the lowest during the day and morning. A similar pattern of diurnal distribution was also observed for pelagic species that exhibited significant differences in the open water zone between the day (the lowest numbers) and night (the highest) samplings. It was suggested that the diurnal distribution of cladoceran representatives between the macrophyte bed and the open water zone of Lake Wielkowiejskie might have been influenced by young fish predation (pelagic species) and by typical adaptations of particular species to living within the heterogeneous habitat of a macrophyte stand (littoral species).
EN
The aim of the study was to evaluate the trophic conditions of the waters of twelve small ponds based on the analysis of their physical and chemical parameters according to Carlson's Trophic State Index and OECD. Great differentiation in the trophic status of ponds located in different varieties of landscape was observed and ranged from mesotrophic to weak eutrophic conditions in mid-forest ponds and clay-pits, eutrophic conditions in pastoral ponds, and hypertrophic conditions in urban water bodies. Throughout the analysis, a number of limitations in the classification methods of trophic conditions in the examined water bodies were noted. The specific problems were the shallow depth of ponds, which often corresponded with the depth of the Secchi di
EN
The composition and dynamics of zooplankton (Rotifera, Crustacea) communities were studied in a dystrophic lake (Drawieński National Park, northern Poland). The investigated lake was a typical mid-forest lake of a small area (ca. 0.65 ha) but relatively deep (Z[max] = 6.8m) and covered with a peat (Sphagnum sp.) mat. The study was made in the shallow part of the lake (Z = 0.5 m). Zooplankton was collected twice in August 2004, in triplicate subsamples, taken from three stations (1. under the peat mat, 2. the transitional zone between the peat mat and open water area and 3. open water zone) from two different sites within the same lake. The distance between sampling stations within a transect was ca. 1.5 m. The whole area under study was not greater than 10 m[^2]. Therefore the results concern the very small-scale distribution of zooplankton. The aim of the study was to find out whether spatial segregation of the zooplankton community and the dominating species between the Sphagnum mat and open water zone as well as in the transitional zone between both zones takes place in a dystrophic lake and whether the moss mat can be considered as an anti-predator refuge. Both the species number and zooplankton densities differed between the stations along a transect, being the highest (40 zooplankton species and mean 150 ind 1[^-1] for the whole zooplankton community) in the peat mat and lowest (12 species and 72 ind 1[^-1]) in the open water zone. Humic-water species constituted 24% of the species composition of rotifer and 14% of the crustacean community. Cladocerans prevailed numerically over rotifers. Dominating species - Bdelloidae, Keratella cochlearis Gosse, Polyarthra vulgaris (Carlin), Synchaeta pectinata Ehrenberg, Trichocerca insignis Carlin, Alonella excisa (Fischer), Ceriodaphnia quadrangula (O.F. Muller) - revealed a differentiated pattern of spatial distribution. The mean Shannon-Weaver biodiversity index of zooplankton was not notably high and amounted to 1.45. The highest values were found in the peat mat (mean - 1.76 for rotifers and 0.67 for crustaceans), while the lowest values were found in the open water (0.99 and 0.36 respectively). These results suggest that in the site connected with Sphagnum moss in a humic lake more diverse and abundant zooplankton occurs in relation to other habitats. The differences in zooplankton distribution between the peat mat and the open water zone of the dystrophic lake seems to be affected by biological interactions which relate to predator presence, both vertebrate and invertebrate, and competition between large cladocerans and smaller rotifers. Due to the dominance of larger forms of zooplankton it may be supposed that invertebrate predators may have a more pronounced effect. The habitat within the Sphagnum moss can be considered as a predictable refugium.
EN
The research on the distribution of species of the Lecane genus among different types of macrophytes (including rushes, nymphaeids and two zones of submerged macrophytes) in comparison with open water was carried out for three years in a shallow lake (Lake Budzyńskie, western Poland; an area - 17.4 ha, maximum depth - 2.7 m and a mean depth - 1.4 m) in order to determine the possibility of their competition and of co-existence. The distinct species of submerged macrophytes create separate vegetation beds and patches in the lake. The size of a particular macrophyte bed did not exceed the area of 5 m. Zooplankton samples were collected between 1997 and 1999 (from April to October, at about 2-week intervals) in the shallow part (approx. 1m deep) of a lake. Nymphaeids were only sampled during the 1998 and 1999. Samples were taken at each site using a plexiglass core sampler ([the empty set] 50-mm). Subsamples of a volume of about 1.5 l from the surface layer (0-1.5 m) were sampled from randomly chosen places within each macrophyte patch. Six Lecane species were analysed (Lecane bulla (Gosse), L. closterocerca (Schmarda), L. flexilis (Gosse), L. furcata (Murray), L. luna (Miiller) and L. lunaris (Ehrenberg)). L. bulla dominated at most of the examined stations each year. Detailed seasonal analysis of the abundance of particular species of the Lecane genus in most cases revealed the replacement character of their occurrence. The sudden increase in the numbers of one species caused a simultaneous decrease of another within the same macrophyte stand. A distinct replacement pattern was observed for L. bulla, which was replaced by L. closterocerca or L. luna and for another two pairs of species (L. closterocerca with L. furcata and L. flexilis with L. luna). At the same time, pairs of species such as L. closterocerca-L. lunaris (statistically positive correlation was found in the case of Chara bed - r[s] = 0.70; P = 0.007), L. flexilis-L furcata (within Typha - r[s]= 0.58; P = 0.048) and also L. luna-L. furcata (in the Myriophyllum bed - r[s]= 0.80; P = 0.001) exhibited a similar pattern of seasonal changes without, however, revealing the exchange occurrence between each other. The pattern of species replacement within a genus is an example of the competitive exclusion of closely related species. The nature of the seasonal distribution of species of the Lecane genus, replacing each other over a period of time, may be connected with the niche overlap of particular species, which results in time segregation. Exploitative competition cannot be excluded when describing such behaviour.
EN
The examination of the composition and dynamics of periphytic communities took place in three lakes of similar morphometry . Lake Wielkowiejskie, Budzyńskie and Dębiniec, situated in the Wielkopolska region, (Western Poland). These lakes are typical macrophyte-dominated, shallow and polymictic water bodies. Periphyton was collected from two macrophyte-covered stations, including the rush vegetation station (Typha angustifolia L.) and the stonewort stand (Chara tomentosa L.) in each examined lake. The material was sampled three times in 2003, including the spring (April), summer (July) and autumn (September) seasons, from the same parts of the lakes.The aim of the study was to find out whether there is an influence of particular macrophyte species, differing spatially and morphologically and representing two different ecological types of aquatic vegetation, on the development of particular periphytic species. There was also an attempt at answering the question of what is more important in the structuring of the periphytic communities - the specific architecture of the macrophyte substratum or the physical-chemical features of a particular lake? The concentrations of chlorophyll a, TN, TP and TOC in water were higher in the Chara beds compared with theTypha stations in most cases. The Shannon-Weaver biodiversity index of periphytic algae revealed very high values in all lakes and amounted in the Typha and Chara stands to the mean values 4.68 and 3.87 respectively in Wielkowiejskie Lake, 3.32 and 4.39 in Budzyńskie Lake and 3.08 and 3.91 in Dębiniec Lake. Furthermore, the standardized index of evenness exhibited the greatest differentiation in the Typha station with the highest (0.76) in Wielkowiejskie and the lowest (0.52) in Dębiniec Lake The analysis of the growth-forms of periphytic communities showed slightly higher diversity of slowly moving and stalked diatoms in most cases at the Chara stations of all studied lakes. The similarity between periphytic communities in the Typha and Chara stands of the examined lakes, compared using the Ward method and Euclidean distance measure, revealed a stronger relationship within a particular habitat but not a lake. The clearest pattern of similarity grouping a particular habitat was obtained for the summer period, when macrophytes reached their optimum. The Jaccard similarity index confirmed the differentiation of both examined habitats, reaching the mean value of 0.34. Based on the biomass of single periphytic species, habitat selectivity for seven species was found. Significantly higher biomass was obtained in the case of the rush zone for only one algae species - Eunotia lunaris (Ehr.) Grun. In the Chara bed six species revealed significantly higher biomasses - Cosmarium regnelli Wille, Oocystis marssonii Lemm., Ulotrix zonata (Weber et Moor) Kutz., Scenedesmus acuminatus (Lagerh.) Chod., Merismopedia elegans A. Braun and Phacus orbicularis Hubner. The habitat preference of periphytic communities to different macrophyte species may be due to the environmental factors, including the specific architecture of a particular macrophyte substrate such as density or texture of the plant surface. Furthermore, seasonality, as well as physical-chemical parameters may structure periphytic communities within the littoral zone of lakes.
EN
The aim of this examination was to study the impact of the physical parameters, understood as spatial and morphological features, of two macrophyte habitats created by Chara tomentosa and Typha angustifolia on the Rotifera and Crustacea communities of three shallow lakes with extensive macrophyte cover. There were 161 zooplankton species in total identified from three lakes, with over 60% of species common among all lakes. Species richness varied between the sampling stations, with lowest values within the open water zone and highest among macrophyte stands. Significant differences in zooplankton densities between particular stations for all groups of zooplankton were observed, with the highest values within the most diverse and complex habitat – the Chara bed. Furthermore, the distribution of pelagic species between particular stations differed significantly in the case of copepods, with the highest abundance also in the stonewort beds.
EN
Vertical distribution of chosen species of Rotifera was studied in Piaseczno Lake, during a water stagnation period, in the summer of 2004. Environmental factors, such as temperature, dissolved oxygen and water transparency in the whole water column were measured. The presence of a total of 45 species of Rotifera was found. The analysis of the diel vertical distribution of the examined species of rotifer communities revealed differentiated models. Diel vertical migrations were observed in the case of Gastropus stylifer, Asplanchna priodonta and Trichocerca similis. The remaining species (Kellicottia longispina, Polyarthra dolichopter and P. vulgaris) did not undergo migrations, they remained within a certain water layer throughout the day and night. These differences in the diel behaviour of particular species of rotifers may be mostly dependent on particular ecological requirements and different forms of predation caused by invertebrate and young fish predators.
EN
Diel vertical distribution of Crustacean communities was studied in Piaseczno Lake, in the water stagnate period, in the summer of 2004. Additionally, temperature, dissolved oxygen and water transparency in the whole water column were measured. The presence of a total of 30 species of crustaceans was found. Vertical distribution of both cladocerans and copepods was uneven and the highest numbers of individuals was noticed in the epilimnion. In the case of the larval stages of Copepoda the highest abundances were recorded in the metalimnion. Diel vertical migrations were observed only for three species - Diaphanosoma brachyurum, Daphnia hyalina and Mesocyclops oithonoides. Species which remained in the surface layers of water were cladocerans such as Daphnia cucullata, Chydorus sphaericus and Bosmina longirostris, while the rest of the species revealed an equal pattern of distribution in the water column. Diversified vertical distribution and diel vertical migrations of crustacean zooplankton ware probably caused by intense pressure of predators, mainly planktivorous fish present in great numbers in the examined water body, as well as the seeking of optimal life conditions in the pelagic zone of Piaseczno Lake (Jezioro Piaseczno).
EN
The examined Lake Lubaskie Duze covering the area of 41.5 ha is a dimictic lake a mean depth of 12 m (max. depth 16 m). The systematic observations of phyto- and zooplankton changes together with the selected physico-chemical parameters of water which were carried out for this lake during 1991-1996 showed its mesotrophic character declining towards eutrophy . In 1996, the research was expanded to the analyses of the plankton dynamics in the zones of rushes and submerged vegetation. The purpose of this research was to examine qualitative and quantitative changes of plankton inhabiting various habitats. The samples were collected along the transect starting from rushes to the area of open water (pelagic zone). The sampling was performe at four stations: station 1 - zone of rushes, community of reed and cattail; station 2 - zone of open water area between stations 1 and 3; station 3 - zone of submerged vegetation, community of hornwort; station 4 - open water (pelagic zone). Taking into consideration the spatial distribution of plankton, the differences in the taxonomic groups inhabiting the zones along the transect were noted. In the zone of submerged vegetation, the higher species diversity and greater numbers of specimens were observed than in the zone of rushes.
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