Ciliates in Sphagnum Peatlands: Vertical Micro-Distribution, and Relationships of Species Assemblages with Environmental Parameters

摘要

The distribution of ciliates living among different species of mosses (Sphagnum angustifolium, S. cuspidatum, S. flexuosum, S. magellanicum, Polytrichum strictum, and P. commune) in eastern Poland Sphagnum peatlands is described. The highest species richness (23-35 taxa) occurred in hollows dominated by S. angustifolium, S. flexuosum, and S. palustre. Decidedly lower numbers of taxa (7-10) were observed in hummocks dominated by S. magellanicum and Polytrichum. The greatest abundance of ciliates was found in micro-sites dominated by S. flexuosum (25-30 individuals (ind./g), while the lowest was found in sites dominated by Polytrichum (4-6 ind./g). Likewise, independent of the species of mosses, micro-vertical differentiation of these protozoa was found. The number of species and abundance significantly increased at the deepest sampling depth. The upper sampling of mosses (0-5 cm) was dominated by mixotrophic taxa, whereas the deeper sampling level (5-10 cm) showed increases in the proportions of bacterivore species. In peatlands, the factors limiting the occurrence of ciliates are physical and chemical suitability — mainly the total organic carbon content and depth of water table (DWT), but also somewhat lower levels of pH and the species of moss.In turn, an increase in pH also increased the role of nutrients. Such factors have a significant effect on the occurrence of ciliates. The abundances of ciliates in spring and autumn were positively correlated with the concentration of organic matter independent of the species of moss; however, in summer, the influence of pH and DWT increased. http://zoolstud.sinica.edu.tw/Journals/48.1/33.pdf