The Effect of Edaphic Factors on the Similarity of Parasitic Nematodes in the Soil Sampled in Nurseries of Ornamental Trees and Shrubs

The largest faunistic similarity of nematodes was found in soils sampled in coniferous nurseries where arborvitae (Thuja occidentalis - Cupressaceae), spruces (Picea spp. - Pinaceae) and pines (Pinus spp. - Pi-naceae) were grown. In soil sampled from deciduous tree and shrub nurseries, similar species composition of parasitic nematodes was found in stands of oaks (Quercus spp. - Fagaceae), black locusts (Robiniapseudo-acacia - Fabaceae) and maples (Acer spp. - Sapindaceae). In soils, especially the light and medium, from stands of coniferous and deciduous trees and shrubs, Aphelenchus avenae was often isolated. Bitylenchus dubius occurred in both types of nurseries, particularly in light soils. The largest faunistic similarities between nematodes isolated from places of growth of coniferous and deciduous plants were recorded in soils of loamy sand and sandy loam. The most abundant nematode species and the greatest similarity in species of plant parasitic nematodes were observed in soils with neutral pH or slightly acidic. Aphelenchus avenae was found in soil samples collected from both coniferous and deciduous plants, with no relation to soil acidity.