Effect of cattle stocking density on the botanical composition of an unfertilised mountain pasture

The effect of cattle stocking density on the botanical composition of an unfertilised mountain pasture was investigated during 6 years. Three stocking rates (SR) were tested: 1.8, 1.2 and 0.6 AU/ha on surfaces of 7.4, 11.1 and 22.3 ha, respectively. Rotational grazing was applied and 3 paddocks were assigned to each herd. Our results show that the botanical composition hardly underwent changes during the trial. In addition, we did not observe tree growth, even with a low stocking rate (0.6 AU/ha). The vegetation was more influenced by environmental factors (e.g. soil and climate) than the utilisation practices. The only tendency that could be related to the stocking rate was an indirect effect. Indeed, the low SR is characterised by a larger number of areas with high refusals. These areas show a proportion of grasses (especially red fescue) slightly more important, while legumes are less abundant. Even if they are not marked, these effects suggest that a low SR is not optimal to maintain on the long term a good botanical composition. Nevertheless, it is sufficient in order to avoid tree regeneration.