Structure of White Clover Populations and Plants in Pastures Grazed by Beef Cattle

Seasonal variation in the structure of white clover (Trifolium repens) populations and the morphology of individual plants was studied in permanent pastures grazed by beef bulls. Three grazing regimes were applied: set stocking with 5.0 bulls/ha and rotational grazing with either, 5.0 or 7 .5 bulls/ha, Management had little effect on the structure of the plants or the stolon branching structure of the population. On average, 45% of the plants were of 2nd order; this value remained relatively constant throughout the year. The proportion of 1st-order plants increased ��nd the proportion of plants of 3rd- and highCl' order decreased in spring when fragmentation of plants occurred. Dry weights of plants and plant parts were higher in summer, with no difference between grazing regimes. Average plant density was estimated at 1280 plants/m'. Seasonal trends in plant and population structure were similar to those recorded in other studies under sheep grazing. Differences between managements in plant morphology recorded under sheep grazing were not apparent here; this is attributed to the grazing of cattle in the present study being less selective than that of sheep in previous studies.