Free living protozoa and, in particular, testate amoebae are considered to be an important component of biodiversity of forest ecosystems. They take part in regulation of abudance of microorganisms, decomposition of plant resides, biogeochemical cycle of silica.
Objects of investigations are: the mountain soils of Sikhote- Alin (sea-coast of Japan sea), mountain and tundra soils of the nothern part of Okhotskoe sea, soils of Komandor Islands. More than 200 species, varietets and forms of testate amoebae were dicovered. The most part of dicovered species are found in all places.
A few species are found in mountain soils of conifer- deciduous ecosistems of Sikhote-Alin only - brown soils compose more than 50% of soils. 187 species, varieties and forms of testate amoebae belonging to 10 families and 26 genera were found. The important peculiarity of amoebae communities is the exceptional variety of Centropyxis (33 species and forms) and Nebela (22) genera, that is almost 30% of the total species variety. There are rather a lot of indeterminable amoebae (spp.) - - - 15,5%. This is, probably, connected to the variety of environmental conditions in this mountainous area. The large morphological variety of determinated species, also reflects the unique environmental conditions.
Almost all testate amoebae are common in others areas of Holarctic. The exceptions are Hoogenradia humicola, H. sp. and Distomatopyxis couillardi, which are known from Mediterranean and Canada areas of Holarctic and described from soils on Africa. Nebela caudata is also exception, it was found in Great Britain.
In soils what were formed under influence of permafrost was observed the decrease of specifical composition and density of testate amoebae (on 20-30 times less than in the European spruce forest of southern taiga). The list of protozoa isn't exceed 20- 30 species as a rule. The most of them are found in the layer of green mos. In the gydromorphic sites of Komandor Islands testate amoebae are isolated. The density of testate amoebae may reach maximum in the gley soils of southern taiga.
The morphological intraspecific measures of different species of testate amoebae are interest too. Some species, Schoenobornia humicola for example, are disintegrated on the different size groups. This fact wasn't noted formerly in the shortfrozen soils of Europe. Another part of speies have a clear morphological originality, for example Euglypha strigosa sensu stricto.
Anatoly Bobrov Department of Soil Science Moscow State University Moscow, Russia 119899 Phone: +7 (095) 243-1079 Fax: +7 (095) 939-0989 E-mail: anatoly@bobrov.soils.msu.su