The development of the ecological index method for assessing veld condition in the Karoo

Abstract

The results of a previous study were used for the development of the Ecological Index Method (EIM) of veld condition assessment in the karoo areas. The EIM makes use of a veld benchmark, which must be previously identified and characterised on each topographical unit in each Reasonably Homogenous Farming Area. As a result of the process of retrogression of the veld in the karoo areas, five different ecological groups of plants are identified, namely, Decreasers, Increasers II (a), Increasers II (b), Increasers II (c) and Invaders, A relative index value is allocated to each ecological group. The operation of the EIM is illustrated by the use of the data of four sites in different veld condition classes on the same topographical unit in the Grassridge Basin Area. A rapid method of veld condition assessment with the EIM for extensive surveys is also proposed.

Keywords: development|ecological index methods|methods|assessment techniques|veld condition|Karoo|benchmarks|topographical variables|homogenous farming areas|veld|ecological niches|plants|decreasers|Increasers|Invaders|indices|evaluations|species lists