Phenolic compounds in the leaves of ecotypes of three graminoides in the semi-arid grasslands of southern Africa

The percentage of phenolic containing cells (PCC) and total phenolics in the leaves of different ecotypes of three ecological important grass species were determined during cultivation under uniform environmental conditions. Results obtained clearly indicate that ecotypes of these species exhibit a significant degree of variation with regard to percentage PCC and total phenolics. Furthermore, no anti-herbivory function can be assigned to phenolic compounds in these species, as ecotypes with Decreaser-species ecological status (highly palatable) have higher levels of total phenolics, compared with other less palatable ecotypes with lower levels of total phenolics. Percentage PCC and total phenolics represent two of various ecological important characteristics to be used in conjunction with other ecological characters to construct a usable, special purpose classification system. This system will assist rangeland ecologists in identifying functional ecotypes within grass species, thus facilitating the understanding and interpretation of vegetation dynamic models and rangeland condition assessments.