Evaluation of natural pastures : Quantitative criteria for assessing condition in the themeda veld of the orange free state

Abstract

There is a need for objective standards of veld condition assessment in South Africa. The alternative practical criteria of condition are examined and their field application is evaluated. Examples of quality, productivity and acceptability ratings are quoted from local research. A simple score sheet is suggested.

The selection and use of ecological benchmark sites are proposed and interpretation of scoresheet results relative to benchmarks is explained. The requirements of a meaningful field assessment procedure are considered. The definition of “desirable species” on the basis of perenniality, productivity and acceptability, is compared with the uses of the concepts of “climax” and “decreaser” species.

Uittreksel

Die behoefte van objektiewe standaarde vir bepaling van veld toestand in Suid‐Afrika word beklemtoon. Die alternatiewe praktiese maatstawwe, van toestand is ondersoek en hul toepassing in die veld is geevalueer. Voorbeelde van die produktiwiteit, kwaliteit en smaaklikheid van plaaslike grasse word as basis van beoordeling aangebied. ‘n Eenvoudige telkaart is voorgestel.

Die uitkenning en gebruik van “ekologiese verwysingspunte” (benchmark sites) is voorgestel en die interpretasie van telkaart resultate relatief tot verwysingspunte is bespreek. Die eienskappe van beteken‐isvolle veldprosedures vir toestandbepaling is oorweeg. Die definisie van “gewensde spesies” op die basis van meerjarigheid, produktiwiteit en smaaklikheid, word vergelyk met die begrippe van “klimaks” en “verminderende “ spesies.

Notes

New address: Department Primary Industries, Charleville, Qld., Australia

Permanent address: Department of Primary Industries, Brisbane, Qld., Australia.