Biological studies of some tussock-grassland soils

Abstract

Summary The microfauna occurring in cultures of three tussock-grassland soils has been examined through three seasons. All three soils had a typical grassland fauna. Of the two major protozoan groups studied, the rhizopods and the ciliates, the ciliate fauna was in each case larger than the rhizopod fauna and the populations also appeared to be higher. The rhizopod fauna was similar in the three soils, but a number of ciliate species were confined to the soil with a high base status. The average incidence of the protozoan species was characteristic for each soil type and was slightly higher in the tussock zone than in the inter-tussock zone. The distribution of the rest of the fauna was generally similar in the three soils. Neither moisture nor food appeared to be limiting factors and the most favourable ecological conditions obtained in the soil with the lowest rainfall and the poorest plant cover.