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Ecology of testate amoebae (Protists) in a Sphagnum-dominated peat bog and the relationship between species assemblages and environmental parameters

Niedźwiecki M., Mieczan T., Adamczuk M.

Oceanological and Hydrobiological Studies

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2016

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Vol. 45, No. 3

344--352

EN

Despite its ecological importance, little information is available regarding spatial and seasonal changes in the testate amoebae community in peat bogs. The objectives of this study were to examine the structure of communities and horizontal distribution of testate amoebae fauna, to improve the understanding of factors affecting the distribution of moss testate amoebae communities and to analyze the seasonal changes in testate amoebae communities in a Sphagnum-dominated peat bog (eastern Poland). A total of 45 testate amoebae species were identified in the samples. The highest species richness occurred in hollows dominated by Sphagnum angustifolium, much lower numbers of taxa were observed in hummocks dominated by Sphagnum magellanicum and Polytrichum. The Monte Carlo permutation test showed the significance of Ntot, temperature, pH, and the depth to the water table for the variability of testate amoebae in all microhabitats. Species found in spring samples were associated with the increased Ntot content. Species occurring in summer samples were associated with the increasing pH gradient and species developing in late spring and autumn preferred a greater depth to the water table.

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Distribution of testate amoebae along a gradient hummock-lawn-hollow in a Sphagnum-bog : potential implications for palaeoecological reconstructions

Portsmuth A., Avel-Niinemets E., Pensa M.

Polish Journal of Ecology

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2011

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Vol. 59, nr 3

551-566

EN

Testate amoebae consist of a group of protists producing protective external coats (tests), which potentially allows them to be used in palaeoecological studies. They are known to be good indicators of several ecological parameters such as water chemistry, moisture and water table level in substrate, and especially peat moisture. Because of their strong dependence on environmental variables it is assumed that each bog microform (e.g. hummock, hollow) is characterized by a different assemblage of testate amoebae. The distribution of testate amoebae assemblages in peat bog of north-eastern Estonia was studied along the gradient from hummock to hollow in the upper 30 cm of the peat layer along a transect of 10 m. The composition and abundance of testate amoebae communities were analyzed in the samples collected (peat sampler, 5 cm diameter) from each sample point (at a distance of 2.5 m from each other) from hummock to hollow. Indicatory species specific to certain bog microforms (representing a set of environmental variables) were found, as well as other species typical for individual environment variables such as depth, peat decomposition degree, and distance to water table or local vegetation. Data analysis showed that distinct bog microforms are better described by abundance of particular testate amoebae species in peat than by species proportions in total abundance of the assemblage. The frequency of occurrence of species with dry environment preference correlates well with arboreal and Calluna vulgaris pollen and high degree of decomposition of peat; it all indicates a dryer environment and possibly is referring to a hummock microform. Amphitrema flavum correlates well with Sphagnum; this correlation increases with the A. flavum shift downwards from Sphagnum up to 4 cm. Testate amoebae assemblages in different bog microforms, even within 10 m, are distinctly different. To pay attention to possible changes of bog microforms in time is therefore crucialfor reconstructing the palaeohydrological history of bogs.

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Vertical microzonation of testate amoebae and ciliates in peatbog waters in relation to physical and chemical parameters

Mieczan T.

Polish Journal of Ecology

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2010

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Vol. 58, nr 4

729-740

EN

Peatbogs have both horizontal and vertical differences in moisture, pH, light and nutrient availability. Micro-distribution of testate amoebae taxa has been observed along the Sphagnum stem but there is no data concerning the vertical micro-distribution of protozoa in water column under the peatbog surface and in the interstitial waters. The research was made in a small (ca 16 ha) peatbog complex in the eastern Poland. Vertical microzonation of testate amoebae and ciliates in relation to physical, chemical and biological parameters (peat porosity, temperature, dissolved oxygen, chlorophyll a, TN, TP, DOC and TOC) in Sphagnum hollows, mud bottom hollows and interstitial waters in peatbog were studied. Samples were taken once a month from April to November 2009 from three layers: free water mass up to 10 cm (FW), bottom water (BW) and interstitial, pore water - IW (water between particles of peat on depth 20-25 cm). During each sampling occasion 3 samples were collected from each site. At each type of micro-habitat and each sampling date water was sampled using a plexiglass core. The water column sampled from the top surface to the bottom was 25 cm high. Interstitial waters were collected from mini-piezometers located into the peat. Temperature, dissolved oxygen, conductivity, chlorophyll a and nutrients contents were always lower in interstitial water than in free and bottom waters. The highest numbers of testate amoebae and ciliates taxa occurred in the bottom water (31 and 13 taxa, respectively) and became much lower in interstitial water (17 and 5 taxa, respectively). The density and biomass of protozoa differed significantly between the studied layers, with the lowest numbers in the interstitial water and the highest in the bottom water. Ordination analysis indicated that chlorophyll a, TOC and TP can strongly regulate the abundance and species composition of protozoa. The RDA ordination showed that the testate amoebae species can be divided into three groups associated with: 1) free water mass, 2) bottom water and 3) interstitial water, while the ciliate species into two groups associated with: 1) interstitial water and 2) free water mass and bottom waters. The free water mass and bottom water were dominated by mixotrophic taxa, whereas the deepest layer showed the increase of the contribution of small, bacterivorous species. In all the examined micro-habitats the highest abundance and biomass of these microorganisms occurred in early spring and late autumn, while the lowest values were recorded in late summer.

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Effect of vegetation patchiness and site factors on distribution and diversity of testate amoebae and ciliates in peatbogs

Mieczan T.

Polish Journal of Ecology

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2010

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Vol. 58, nr 1

135-144

EN

Testate amoebae and ciliates are common inhabitants of moist soils, lakes and peatbogs. These microorganisms are important consumers of bacteria, flagellates and algae; they also participate in transformation of the organic matter and nutrient regeneration. The complexity of micro-environmental conditions present in peatbogs and the challenges associated with the proper sampling may partly explain the fact that these microorganisms are still much less studied than other components of the ecosystem. The influence of emergent and submerged plants on community composition, abundance and biomass of testate amoebae and ciliates were investigated in two peatbogs in the eastern Poland. The raised and carbonate bogs selected for this study were considered to be representative of the bogs of the region and contained a broad diversity of habitats. Samples were collected in patches of Sphagnum angustifolium (C.C.O. Jensen ex Russow), Sphagnum cuspidatum Ehrh. ex Hoffm., Sphagnum palustre L., belts of Phragmites australis (Car.), Typha latifolia L., Carex acutiformis Ehrhart., Calliergonella cuspidata (Hedw.) and beds of Utricularia sp. Sampling was done on a monthly basis from April to November. At each plant patch (microhabitat) and each sampling date the water was sampled using a plexiglass core (length 1.0 m, [Radius]50 mm). Comparison of the species number, abundance and biomass (estimated in C organic units) of testate amoebae and ciliates between Sphagnum patches did not show statistically significant differences. The significant differences were noted in patches of plants in carbonate peatbog. The highest species number (40-46) was found in the Utricularia and Calliergonella, and the lowest richness (26-20) in the Typha, Phragmites and Carex. The density and biomass of protozoa communities, increase together with the abundance and the level of the complicated spatial structure of the plants. Based on differences in plant structure, two groups of habitats with similar patterns of size-related testate amoebae and ciliate distribution were distinguished. The first group consisted of three vegetated zones of smooth stem structure (Phragmites, Typha and Carex), the second group comprised plant species, which were more complex (Sphagnum, Utricularia and Calliergonella). In the redundancy analysis, water level, pH, concentration of TP, chlorophyll a and TOC together explain 45% of the variation in the species distribution data. The contribution of conductivity, dissolved oxygen TN and DOC was not (or marginally) statistically significant.

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Species composition of testate amoebae (Protists) and environmental parameters in a Sphagnum peatland

Lamentowicz Ł., Gąbka M., Lamentowicz M.

Polish Journal of Ecology

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2007

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Vol. 55, nr 4

749-759

EN

The research was made on the largest (ca 500 ha) peatland complex in the western Poland ("Chlebowo" mire) (N 52[degrees] 44'14.3" E 16[degrees]45'20.7"), that exists under considerable anthropogenic pressure. Species composition of testate amoebae in selected microhabitats was described. The fundamental environmental factors influencing the structure of assemblages were determined. Twenty four samples were taken from 10 sites (Sphagnum lawn, hollow and hummock) dominated by Sphagnum and brown mosses. Each of them was analysed in relation to its taxonomical composition. Nine environmental parameters (acidity (pH), conductivity colour, NH4[^+], NO3[^-], PO4[^3-], SO4[^2-], Ca[^2+] and [Mg[^2]) were measured in the field and laboratory. Thirty two testate amoebae species of 13 genera were identified within the 24 sites. In most of the sites species composition was dominated by Hyalosphenia papilio Leidy, Cyclopyxis arcelloides Leidy and Hyalosphenia elegans Leidy, however the most numerous were Amphitrema flavum Archer, Hyalosphenia papilio Leidy and Cyclopyxis arcelloides Leidy. The particular parameters, i.e. pH, depth to the water table (DWT) and So4[^2-] content significantly explained the species variability. Multivariate analyses showed that species tend to group especially along the pH gradient; to a smaller extent along the DWT and SO 4[^2-], together with pH.

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Epiphytic Protozoa (testate amoebae and ciliates) associated with Sphagnum in peatbogs: relationship to chemical parameters

Mieczan Tomasz

Polish Journal of Ecology

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2007

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Vol. 55, nr 1

79-90

EN

The composition and abundance of microorganisms (testate amoebae and ciliates) dwelling in the water in the patches of Sphagnum palustre L. in three peatbogs with different pH values of the Poleski National Park (Eastern Poland) and their relationship to chemical parameters were studied. From April to October 2005 from each peatbog twice a month, eight samples were collected by washing 10 g of a wet mass of plant material in 50 ml of distilled water. A total of 11 testate amoebae taxa and 32 ciliate taxa occurred among Sphagnum palustre. Testate amoebae and ciliates richness and abundance were significantly greater (33 taxa and> 15 ind. g[^-1], respectively) in low pH (4.5) peatbog. Generally, the moss dwelling testacean fauna was dominated by cosmopolitan and ubiquitous taxa. Only four testate amoebae taxa (Arcella vulgaris, Assulina muscurum, Hyalosphenia sp. and Euglypha sp.) showed a clear preference for a low pH. Ciliate communities were dominated by Colpodea, Cyrtophorida, Scuticociliatida and Suctorida. In all peatbogs bacterivorous protozoa occurred in the highest numbers (up to 60%), while algivorous and mixotrophic in the lowest (range from 3 to 10%). Moisture conditions appeared to play a key role in determining the distribution pattern of testacean communities, while pH and the content of total organic carbon in water correlated positively with the total numbers or biomass of testate amoebae and ciliates.

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Historia rozwoju dwóch torfowisk mszarnych w Borach Tucholskich

Lamentowicz M., Obremska M., Mitchell Edward A.D.

Przegląd Geologiczny

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2006

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Vol. 54, nr 1

76-80

EN

Our research confirmed the value of kettle-hole mires for reconstructing Holocene environmental changes. The multi-proxy approach in which three palaeoecological methods were used (analyses of testate amoebae, plant macrofossils and pollen) improved the interpretation potential. We studied two Sphagnum mires situated in Tuchola Pinewoods (N Poland). In Tuchola mire 9000 years of environmental changes (groundwater level and pH) were recorded. Water table changes inferred from Tuchola mire show patterns similar to regional hydrological changes recorded in Polish lakes and mires as well as in other European sites. Jelenia Wyspa mire recorded changes in local vegetation and palaeohydrology during the last 1500 years. A rise in the groundwater table, caused by deforestation in the catchment area, allowed Sphagnum to expand. Consequently, the peatland evolved into an oligotrophic mire dominated by peat mosses. Approx. 200 years ago water pH increased and subsequently decreased, the lowest value being associated with the deforestation maximum. Furthermore, the planting of pine probably also caused an acidification of Jelenia Wyspa mire.

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Testate amoebae (protists) as palaeoenvironmental indicators in peatlands

Lamentowicz M., Mitchell E. A. D.

Polish Geological Institute Special Papers

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2005

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Vol. 16

58--64

EN

Testate amoebae (or testaceans, Testacea, Arcellaceans) are unicellular eukaryotic organisms living in freshwater or most terrestrial habitats such as soils, mosses, lakes, rivers, as well as brackish habitats such as estuaries. They are very abundant in Sphagnum mosses, where they live in the top part of mosses and the oxygenated part of the peat. The tests (shells) of Testacea are well preserved in peat and to a lesser extent in lake sediments. Efforts should be concentrated on constructing reliable regional transfer functions (mathematical representation of relation of species to environmental variables - presence of particular taxa in fossil material is the function of past environmental parameters), as they exist for some world areas, and there is a complete lack of them for central Europe. Polish data are exceptionally important because Poland is under several contrasted climatic influences - from oceanic to continental. The comparison of our data on climatic tendencies with those from Western Europe and the rest of the world will show how similar or different the responses of Polish peatlands might be. The paper has three aims: (a) to present the need for ecological studies on testate amoebae in Central Europe, (b) to show the potential of reconstruction of past environment on the basis of multiproxy studies that include testate amoebae as an integral part of the palaeoecology toolbox and (c) to put our research efforts on testate amoebae in Poland in a more global perspective.

PL

Ameby skorupkowe (Testacea) to jednokomórkowe organizmy, które żyją w środowiskach słodkowodnych, w większości siedlisk lądowych (glebie, mszakach, jeziorach, rzekach) oraz w siedliskach słonawych (np. w ujściowych partiach rzek). Testacea występują licznie w mchach torfowcach (Sphagnum), gdzie zasiedlają ich górną część oraz natleniony stropowy fragment torfu. Skorupki ameb dobrze zachowują sie w torfie oraz w mniejszym stopniu w osadach jeziornych. Główny wysiłek powinien być skoncentrowany na budowaniu regionalnych funkcji transferu (transfer function; matematyczny obraz relacji organizmu w stosunku do środowiska -obecność poszczególnych taksonów w materiale kopalnym jest funkcją przeszłych parametrów środowiskowych). Dla kilku obszarów już one powstały, ale brak tego rodzaju danych dla centralnej części Europy. Polskie dane są wyjątkowo istotne, ponieważ obszar ten znajduje się pod wpływem różnych wpływów klimatycznych - od klimatu oceanicznego do kontynentalnego. Porównanie naszych danych z informacjami z innych stanowisk w Europie i na świecie może wykazać, w jak odmienny sposób reagują polskie torfowiska na zmiany klimatyczne. Artykuł ma trzy cele: (a) zaprezentowanie potrzeby badań ekologii ameb skorupkowych w Europie centralnej, (b) przedstawienie potencjału rekonstrukcji paleośrodowisk na bazie wielu wskaźników, gdzie ameby skorupkowe stanowią integralną część metod badań paleoekologii i (c) zaprezentowanie naszych badań nad Testacea w Polsce w szerszej, globalnej perspektywie.