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The influence of emergent macrophytes (dominated by Phragmites australis (Cav.) Trin. ex Steud.) on the species composition, richness and abundance of epiphytic midges (Diptera: Chironomidae) was studied in five shallow lakes of eastern Poland during three seasons (May, July and October) of 2001. The lakes represented three states: clear (macrophyte dominated), intermediate (phytoplankton-macrophyte dominated) and turbid (phytoplankton dominated). The trophic status of lake strongly affected the assemblages of chironomids living on the surfaces of common reed. Habitat conditions regulated mostly densities and relative abundance of midge taxa and did not have any significant influence on the number of taxa. The Canonical Correspondence Analysis of epiphytic fauna showed the significance of 5 environmental variables: Secchi disc visibility, dissolved oxygen, reed density, concentration of total phosphorous and epiphytic chlorophyll-a. The analysis separated epiphytic midges into two groups. The first group included taxa limited by low oxygen content and water transparency and corresponds with clear state habitats. To the second group belong taxa typical of eutrophic waters with densities determined by the concentrations of total phosphorous and chlorophyll-a, common in lakes of intermediate state and in particular of turbid state.
The study investigated the effect of microhabitat (emergent/submerged macrophytes) within lakes of different status (transparent/cloudy water) on the diversity and distribution of chironomid assemblages. Field and laboratory studies were undertaken bimonthly, from January to November 2008, in two shallow lakes of Polesie Lubelskie (eastern Poland), transparent water and cloudy water lake. The main objectives of the study were to compare the density and taxonomic richness of chironomids associated with emergent and submerged macrophytes within lakes of extremely different environmental conditions and to recognize the most important variables affected chironomid distribution between microhabitats within lakes. In transparent water lake, number of chironomid taxa varied between 12 (emergent macrophytes) and 18 taxa (submerged macrophytes) and was significantly higher than in cloudy water lake, 6 and 8 taxa, respectively. Mean abundance of chironomids associated with emergent macrophytes was higher in cloudy water lake. The opposite relation was observed on submerged macrophytes. The PCA analysis showed visible distinction of chironomid assemblages between microhabitats and lake types. The results of RDA led to determine the significant variables (Monte-Carlo permutation test) affected chironomid distribution. In both, transparent and cloudy water lake, the significant variables responsible for chironomids distinction between microhabitats were density and biomass of macrophytes, biomass of periphytic algae and pH. Moreover, nutrients, N-NO3 (transparent water lake) and P-PO4 (cloudy water lake), showed the significant influence.
The importance of water soldier (Stratiotes aloides L.) as a colonization substratum for epiphytic and mining fauna has been investigated in the shallow, eutrophic lake in East Poland. Samples were taken in May, July and October in 2000–2001. Studies focused on abundance and species diversity of phytophilous fauna of Stratiotes aloides, in particular on the relation between epiphytic and mining organisms and their seasonal changes. The studied zoocenosis differed significantly in terms of density and taxa number. In all studied seasons fauna inhabiting Stratiotes aloides showed higher abundance and species diversity than mining invertebrates. Both zoocenosis were predominated by Chironomidae larvae. The percentage of midges in epiphytic fauna decreased slightly during vegetation period, the mining fauna showed the opposite pattern. Epiphytic Chironomidae were dominated by four taxa (Dicrotendipes sp., Glyptotendipes sp., Paratanytarsus austriacus, Psectrocladius sp.). The mining fauna was represented mainly by Glyptotendipes sp. larvae. Density and biomass of epiphytic fauna showed the positive correlation with water soldier biomass.
This study aimed to determine the species spectrum and abundance of zoopleuston in five small water bodies in different types of peatlands in Roztocze National Park in 2012. The highest number of taxa and density occurred in transitional bogs. The results of DCA analysis showed distinct grouping of zoopleuston communities, depending on bog type. The studied group of organisms had a strong gradient depending on the bog type correlated with the concentration of chlorophyll-a, suspension, and concentrations of inorganic nutrients in the habitat.
Our study investigates the role of Sphagnum mosses as habitat for chironomid larvae with regard to peatbog type (raised bog, transitional bog, fen). Samples were collected within Roztocze National Park (eastern Poland) from May to October 2012 with two monthly intervals. Studied peatbog types differ significantly in terms of density and domination structure of Sphagnum-associated chironomids. The results of CCA analysis indicated that pH, N-NO₃, and chlorophyll-a are significant for chironomid distribution between peatbog types. Moreover, chironomid assemblages were affected by environmental factors specific for a given peatbog type. Temperature and chlorophyll-a determined the chironomid assemblage in raised bogs. Water level, temperature, and total phosphorous were significant for chironomid structure in transitional bogs, whereas conductivity affected chironomids associated with Sphagnum in fens. Sphagnum mosses in transitional bogs were the preferred habitat for larval chironomids in this study. In transitional bogs chironomid density was the highest and typical, macrophyte-associated taxa, larvae of Psectrocladius sordidellus gr. (Zetterstedt, 1838), Cricotopus sylvestris gr. (Fabricius, 1794), and Glyptotendipes sp., were dominant. In raised bogs and fens, pelophilous taxa, larvae of Chironomus sp., and Procladius sp. showed higher abundances.
The influence of submerged macrophytes on composition, abundance and distribution of epiphytic and benthic chironomids was investigated in five lakes differing in the development of vegetation cover. Studied lakes represented three types, classified according to the concept of Alternative Stable States as: macrophyte dominated MD (dense vegetation), phytoplankton-macrophyte dominated PMD (sparse, patchy vegetation) and phytoplankton dominated PD (lack of submerged vegetation). Both zoocenosis responded differently to the changes in macrophyte cover. The density and biomass of benthic midges (density and biomass per m² of bottom surface) were visibly higher in the patchy vegetated lakes; the abundance of epiphytic chironomids did not show any regularity. The species composition of epiphytic chironomids differed visibly between particular lake types, changed with the decrease of macrophyte cover. The composition of benthic midges was similar in all lake types. The studies showed a strong dependence of the proportion of epiphytic to benthic chironomids on the cover of macrophytes. In MD lakes the phytophilous midges were more abundant than benthic; in PMD lakes we observed the opposite pattern.
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