Ordination of land types in the Karoo Region into reasonably homogeneous farming areas based on vegetation and environmental factors.

Abstract

The 291 preliminary land types in the Karoo Region formed the basis for the demarcation of the 144 Reasonably Homogeneous Farming Areas (RHFAs). The land types were firstly reduced to 23 Floristic Climatic Regions (FCRs) according to character species for certain macroclimatic conditions. The character species were identified by means of computer classification and ordination techniques (PHYTOTAB, TWINSPAN and DECORANA). About 22 soils forms and numerous soil series were found in the Karoo Region. Based on differences in the inherent veld production potential and erodibility of the different soils, as well as differences in slope nine Veld Soil Potential Classes (VSPCs) were synthesised. The land types in each of the FCRs were, lastly, consolidated according to their similarity in terms of macroclimate and dominant topographical units and VSPCs, into RHFAs.Language: English

Keywords: Character species; classification; Computer classification; decorana; Environment; environmental factors; FCRs; floristic climatic regions; Homogeneous farming areas; karoo; Karoo Region; land types; ordination; Ordination techniques; phytotab; production; production potential; Reasonably Homogeneous Farming Areas; RHFAs; slope; soil series; soils; south africa; technique; twinspan; vegetation; veld soil potential classes; VSPCs