The impact of grazing on pollinators and pollination

The effects of livestock grazing on plant-animal interactions such as pollination processes have rarely been studied. Since plant diversity and flower occurrence can be substantially reduced by grazing, presumably associated insect assemblages are also affected. In our study, along with flower availability insect abundance as well as species diversity was diminished under heavy grazing. However, trapping methods can be biased. Colour traps for example compete with fl owers for the attraction of pollinators. The observed reduction of fruit set in the investigated plant species apparently did not result from pollination limitation since seed production was fairly similar for all species. For two closely investigated species, even more fl owers remained un-pollinated under low grazing pressure. Obviously, the site with a long grazing history still supports a vivid pollinator community