Wyniki wyszukiwania - BazTech

1

Impact of habitat heterogeneity on the biodiversity and density of the zooplankton community in shallow wetlands (Upo wetlands, South Korea)

Choi J.-Y., Jeong K.-S., Kim S.-K., Joo G.-J.

Oceanological and Hydrobiological Studies

|

2016

|

Vol. 45, No. 4

485--492

EN

Macrophytes play a major role in the structuring of aquatic environments, and create diverse microhabitats. Therefore, these plants represent an important factor regulating the zooplankton biomass, taxonomic composition, and distribution in freshwater ecosystems. In the current study, we examined the effects of the structural heterogeneity provided by various macrophytes. We identified four habitat types in this study: (1) open water (without macrophytes), (2) the helophyte zone, (3) the pleustophyte zone, and (4) the mixed vegetation zone (containing pleustophytes, nymphaeids, and elodeids). We tested the hypothesis that complex habitat structures support large zooplankton assemblages. Specifically, we collected zooplankton samples from a total of 119 sampling points in the Upo Wetlands, South Korea, during the spring and autumn of 2009. The largest zooplankton assemblage was found in the mixed macrophyte zone, followed by the helophyte and pleustophyte zones. The pleustophyte zone supported larger zooplankton assemblages during autumn compared to spring. Differences in zooplankton assemblages were considered to be strongly related to seasonal variation in the development and growth of pleustophytes. However, two-way ANOVA revealed that seasons had no significant influence on the zooplankton density and diversity. Instead, different habitat types substantially determined zooplankton characteristics. In conclusion, we demonstrated that wetland areas with high macrophyte species diversity contribute toward higher zooplankton diversity.

2

Changes in the spatial structure of submerged macrophytes in Lake Rotcze (Łęczna-Włodawa Lakeland)

Lorens B., Sugier P.

Oceanological and Hydrobiological Studies

|

2010

|

Vol. 39, No.4

65-73

EN

The aim of this study is to present short-term changes in the spatial structure of water vegetation in Lake Rotcze. Field studies were carried out during the growing seasons of 2000 and 2005. The obtained results allowed to estimate the following parameters that characterize the spatial structure of macrophytes: species frequency in particular ecological groups, the average vegetation cover in these groups, the average cover of particular species, both in the whole reservoir and in different depth ranges, as well as the PVI (Percent Volume Infested) coefficient for ecological groups. The frequency and cover of some species and ecological groups of macrophytes changed during the study period.

3

Zooplankton community structure within various macrophyte stands of a small water body in relation to seasonal changes in water level

Kuczyńska-Kippen N., Nagengast B., Celewicz-Gołdyn S., Klimko M.

Oceanological and Hydrobiological Studies

|

2009

|

Vol. 38, No.3

125-133

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.