TABLE CONTENTS

Long-term Changes in Soil Nematode Communities under the Impact of
Fertilizers
Gruzdeva, L., E. Matveeva & T. Kovalenko
Institute of Biology, Karelian Research Centre, Russian Academy of Sciences, Pushkinskaya St 11,
Petrozavodsk, 185910, Republic of Karelia, Russia
Changes taking place in the communities of soil nematodes of an artificially sown meadow
under the impact of annually applied mineral fertilizers have been studied in a field
experiment for nine years. Changes in the species composition, eco-trophic community
structure, and the number of nematodes from different genera depend on the fertilizer
applied. The application of mineral fertilizers had a more pronounced effect on the nematode
community in the plots without background manuring; the soil manuring weakened the
mineral fertilizer effect. The most significant changes in the soil nematode numbers were
observed for the trophic groups of bacterial feeders and plant feeders during the first 5-6
years of the experiment. The population of bacterial feeders increased in response to the
increasing rates (from 60 to 180 kg/ha annually) of the complete mineral fertilizer NPK and
nitrogen-containing fertilizers. The population of plant feeders increased in response to the
potassium fertilizers. The spectra of nematode genera sensitive to NPK and to the particular
nutrients have been identified with the use of parameters, including the maturity index of
nematode communities, the biotope preferences of the particular nematode genera, and the
general pattern of nematode habitats. It was found that the nematode community structure
stabilized by the seventh--ninth year of the succession; after this, the effect of annual
application of mineral fertilizers on the nematode community structure was not very
significant. The results obtained can be used to assess the effect of mineral fertilizers on the
soil fauna and to suggest optimum application rates of mineral fertilizers ensuring the
sustainable development of meadow herbs.
Effect of Cadmium and Lead Salts on Soil Nematodes
Suschuk, A.A., L.I. Gruzdeva & E. Matveeva
Institute of Biology, Karelian Research Centre, Russian Academy of Sciences, Pushkinskaya St 11,
Petrozavodsk, 185910, Republic of Karelia, Russia
Sensitivity of soil nematodes from 15 genera extracted from spruce forest at different
concentrations CdSO 4 (1.5, 3.0, 6.0 mg/l) and PbSO 4 (16, 32, 64 mg/l) was studied under
laboratory conditions. Toxicity of Cd and Pb was estimated on mortality of individuals.
Distilled water was used as control. In water 50% of nematodes died in 11 days, the majority
of taxa passed away in 16 days. Representatives of Plectus and Eudorylaimus were the most
sensitive to such environmental conditions; their death was registered in 7 and 11 days
respectively.
Nematodes from genera Plectus, Eudorylaimus and Tylenholaimus were the most sensible to
Cd (mortality were observed in 2 days). Representatives of Aphelenchoides, Rhabditis and
Acrobeloides showed a high resistance. They survived up to 15 days (dose 1.5 mg/l). With
increasing cadmium dose up to 3.0 and 6.0 mg/l death of nematodes was registered in 9 and 8
days respectively.
The first ones who responded earlier to Pb (in 3 days) were nematodes from genera
Metateratocephalus, Teratocephalus, Eudorylaimus. Representatives of genus Plectus lost
5 th International Congress of Nematology, 2008 268