L. Forró szerk.: Miscellanea Zoologica Hungarica 13. 2000 (Budapest, 2000)
Szabó, A.: A contribution to the Ciliata (Protozoa) fauna of chernozem soils
Materials and methods Sampling was carried out in a high productivity chernozem soil, located 15 km to the south of the main road no. 33 between Hajdúszoboszló and Nagyhegyes settlements. Samples were taken from a dug soil profile from layers of 0-10, 10-20, 20-40, 40-60, 60-80 and 80-100 cm with three replications. After a careful mixing of the sub-samples taken from the same depth they (altogether about 1 kg each) were carried to the laboratory in sterile boxes. The homogenised samples were dried on roomtemperature for 8-10 days. During the quantitative analysis of soil samples the culture-dilution method was used. Our method is based on the dilution technique of Varga Telegdy-Kováts (1953), and also that of Singh (1955) with certain modifications, but incorporates several elements of modifications introduced by BrunbergNielsen (1968) and Buitkamp (1979). In our opinion this method can be successfully used for the biological analysis of all soil types. In the course of the quantitative analysis of soil samples the culture method has been modified, by which the starting mass of the dry soil used was increased to 5x10 g (Buitkamp 1979, Foissner 1981, used 8x3 g soil). To the sub-samples 40-40 ml of a 1:5, Protozoon-free soil extractum was added respectively, by which the drastic destroying influence of distilled water can be eliminated. After a careful shaking of samples a dilution series of 8 (1/5-1/640) samples was made, from each of them 10 repetitions were used. One ml suspension was taken for the repetitions, which were injected into plankton tubes containing non-nutrient agar. During the analysis the volume of the samples processed has been increased from 0.05 ml to 1 ml. These modifications increased significantly the objectivity of the statistical method used, and errors deriving from the aggregated appearance of cysts could be avoided (Gellért 1957, Stout 1962). In this way we tried to avoid errors deriving from random sampling. From each sample 5x80 cultures were set up. Culture tubes were incubated on 21 °C for 6 days (Buitkamp 1979). Processing of data was based on the VIII/2. Table of Fisher & Yates (1963) and on the formula (ind/g) of Brunberg-Nielsen (1968). Foissner (1987) has published his widely used method for the same purpose in 1987, which is accepted, but our studies were started earlier with another processing method. In order to keep the comparability of our data we have consequently applied the above described method during the long term studies. After heat treatment — on 58 °C for 45 minutes — the number of cysts was determined from the soil samples, making the determination of the actual number of species and individuals possible. For the qualitative analysis of the samples cultures were set up in every case (Foissner 1987). 50 g of the air-dry soil sample was put into a crystallizing cup in a step-like pattern. To wet the soil samples Protozoon-free, 1:5 soil extractum was used. Samples were examined on days 2, 4, 6, 10, 14 and 21 and the appearing species were recorded an each occasion. In order to support the identification of species, the wet silvering method of Klein (1926), the core staining method of Feulgen, the silvering method of Chatton & Lwoff (1936) and the protargol method modified by Wilbert (1975) were used. The estimated biomass of Ciliata in the soils was calculated by the formula of Pussard (1967, 1971) and given in g/ha. The average mass of solonetz soils was considered to be 1.45 g/cm 3 . Volume of Ciliata has been calculated by the Simpson-formula (Czorik 1968) and using the method of Buitkamp (1979 and also pers. comm.). The body of the organisms has been compared to simple geometric bodies. The density of the protoplasm has been considered to be 1. Identification was based on studies by Borror (1972), Buitkamp (1977a, b), Buitkamp Wilbert (1974), Foissner (1979, 1981a, b, 1984), Kahl (1930-1935), Hemberger (1982) and Stiller (1971, 1974). The nomenclature of Ciliata follows Corliss (1979).
