TESTATE AMEBAS (PROTOZOA) AS INDICATORS OF DRAINAGE IN A FORESTED MIRE, NORTHERN ONTARIO, CANADA

Testate amoebae (Protozoa) were examined in a Picea mariana forested mire in northern Ontario, Canada to assess the use of testate amoebae as environmental bioindicators of drainage. Habitat types included Picea mariana trees, Ericaceae shrubs, and Sphagnum mosses. Several of the species or species groups recorded in the study area, emerged as showing significant differences in abundance between control and drained microsites. Significant differences were recorded between control and drained microsites for Cyclopyxis arcelloides-type Assulina muscorum and Centropyxis aerophila-type in certain site types. In other site types Cyclopyxis arcelloides. Trinema lineare, and Centropyxis aerophila-type, decreased in abundance with drainage whereas Assulina muscorum and Corythion dubium increased in abundance with drainage. This study demonstrates for the first time that alterations in the soil microenvironment from drainage are reflected almost immediately by the abundance of certain species of testate amoebae, some of which increase in number, whereas other decrease in number. Testate amoebae may, therefore, be used to monitor environmental effects of drainage in peatland forestry.