THE DRY‐WEIGHT‐RANK METHOD FOR THE BOTANICAL ANALYSIS OF PASTURE

Abstract

A method is presented which gives an accurate estimate of the botanical composition of grassland on a dry‐weight basis, without the necessity of cutting and hand‐separating samples. In a number of quadrats an observer estimates which species take first, second, and third place in terms of dry‐weight. The data are tabulated to give the proportion of quadrats in which each species received first, second, and third place. These proportions are multiplied by 70·2, 21·1, and 8·7, respectively, and added to give the dry‐weight percentages of each species. The dry‐weight‐rank method was tested four times by comparing the results with those of hand‐separating cut samples. No great differences between the two methods were detected when exact rankings, obtained from hand‐separating, were used, and it was found that ranks could be estimated accurately, provided that sufficient training had been given to the observers.