Publications

Scientific publications

T.J. Hokkanen, L. Gruzdeva and E. Matveeva.
Nematode fauna in different biotopes in finnish and Russian Karelia
// Biodiversity of Fennoscandia (diversity, human impact, nature conservation). Petrozavodsk: Karelian Research Centre of RAS, 1997.
In 1994 a multi-disciplinary study was started in Tohmaj(rvi (North Karelia, Finland), to clarify the complex effects of grazing on ecological processes and species diversity in forest pastures and semi-natural meadows.

Tohmajrvi experiment was performed in three paddocks: 1) a semi-natural meadow abandoned from intensive used for several years before, 2) a mixed forest with a section of planted birch, and 3) a birch - spruce forest including a more moist and peaty section. Each paddock was sampled from three sections, each one of which included an adjacent fenced control area (12 x 12 m) and a grazed area. Together 18 plots were sampled, 5 individual cores of soil from each. Each soil core was divided vertically in two - the one part for soil analysis (H2O, pH, organic matter, total carbon, total nitrogen) and the other part for nematode analysis (species, feeding group, number of individuals). All soil cores were treated individually.

In this paper we present some results of soilborne Nematode fauna from the Tohmajrvi experiment forest and meadow pastures sampled in 1995, after about 1.5 yrs of grazing. Also a comparison of the species composition between less intensively used meadows from Tolvaj(rvi region (Republic of Karelia, Russian Federation) and, is presented. Total number of species in all studied biotopes was practically the same (including Tolvaj(rvi results). In individual samples the number of nematodes varied from less than 100 per 100 g of soil to over 8000 per 100 g of soil. The number of species (including also in some cases groups) in individual samples at Tohmaj(rvi varied from 8 to 29, but the differences between the treatments were not statistically significant. In Tohmaj (rvi meadow the number of bacterial feeders greatly exceeded that of hyphal feeders, being also the greatest of all feeding groups. In forested biotopes hyphal feeders were much more common, and the distribution of nematodes in the feeding groups was more even than in meadow. The number of predators was in all cases low.
Last modified: November 20, 2006