Biological studies of some tussock-grassland soils

Abstract

A marked resemblance has been found between the ecology of the major groups of algae in the soil of three tussock grasslands and the occurrence of these groups in the soils of other temperate countries. The algal growth has been greatest on Omarama soil from near Alexandra where Bacillariophyceae (diatoms) and Cyanophyceae (blue-green algae) were associated with a high pH and a high concentration of nutrient salts. The poorest algal growth occurred on Tekoa soil from Bealey where the higher vegetation had relatively recently changed from forest to grassland. Chlorophyceae (green algae), particularly the desmids, were common on Taupo soil from Waiouru. In all samples the algae were almost confined to the surface layers of the soil but considerable growth developed when soil from a depth of 1 1/4 in. (3 cm) was cultured, suggesting the presence of dormant cells in the lower layers of the soil.