Degradation gradient as a basis for monitoring the ephemeral Omatako floodplains of central Namibia.

Abstract

A group of Herero cattle farmers initiated a community grazing trial within a floodplain of the ephemeral Omatako River in central Namibia. A degradation model was constructed from measurements of various characteristics, for determining changes in wetland condition. Species data for Canonical Correspondence Analysis (CANOCO) came from the nearest perennial grass, if present within 5m of the sample point, otherwise from the nearest annual grass. The first ordination axis indicates a degradation gradient, with perennial grass species towards one extreme and annual grasses towards the other. The second axis appears to reflect a moisture gradient, although it was not measured.