Use of the dry‐weight‐rank method of botanical analysis in the eastern Transvaal Highveld

Abstract

The dry‐weight‐rank method of botanical analysis was tested in the highveld of the Eastern Transvaal and was found to be an efficient and accurate means of determining the botanical composition of veld herbage. Accuracy was increased by weighting ranks on the basis of quadrat yield, and by allocation of equal ranks to species with a similar contribution to yield within a quadrat. Although multipliers derived from local data gave the most accurate estimates, the gain in precision was only marginal as compared with estimates obtained with the use of the original multipliers proposed by ‘t Mannetje & Haydock (1963). The use of the latter is recommended. A regression relating accuracy of estimates of botanical composition to sample size was established. Possible applications of the method in studies on veld are briefly indicated.

Uittreksel

Die droë‐massa‐rangorde as ‘n metode van botaniese ontleding is in die Oos Transvaalse Hoeveld getoets en is bevind n doeltreffend en akkumte metode om botaniese samestelling van veld te bepaal. Akkuraatheid is verhoog deur beswaring van rangorde op basis van kwadraat opbrengste en deur die toekenning van dieselfde rangorde vir spesies met gelyke opbrengste in n kwadraat. Ten spyte daarvan dat koëffisente afgelei vanaf plaaslike data die mees akkumte beraming gegee het, was die verhoging in akkuraatheid gering in vergelyking met beraming vanaf die oorspronklike koëffisient soos voorgestel deur ‘t Mannetje & Haydock (1963). Die gebruik van laasgenoemde word aanbeveel. ‘n Regressie wat verband hou met die akkuraatheid van botaniese samestelling en steekproefgrootte is bereken. Moontlike toepassings van die metode in veldstudies word kortliks aangedui.