The Eastern Grassveld Region

Abstract

In the later stages of development a large number of species take part, the majority belonging to the tribe Andropogoneae, which includes Anthistiria imberbis (inSinde or Red Grass), the species which is usually dominant. When we compare these subsequent species with the pioneers, we notice many points of difference. The former are not so xerophytic, nor so deep-rooted. They form a closer mat over the surface of the soil, and thus prevent the run-off of water to a large extent. Their shallow spreading root systems obtain moisture first, before it is able to soak down to the lower levels, and this is partly why they are able to oust the pioneers. Light, however, is another factor of considerable importance. The seedlings of Anthistiria for instance, prefer to germinate in the shade of other herbage: It is particularly interesting to notice in mixed transitional grassland how young plants of Anthistiria almost invariably come up through the middle of a tuft of Aristida which gradually becomes smothered as the Anthistiria grows taller and shades it, and also forms a mass of roots immediately above those of Aristida. Aristida seedlings themselves, on the other hand, do not seem to tolerate shade. They usually germinate in the open spaces. The pioneer species therefore prepare the way — and it is a necessary preparation — for the establishment of the climax types.