I had not considered how bees effect pastures and grazing:
The future of New Zealand's pastoral farming industry, not just honey production, is under a huge threat from the varroa bee mite. In the North Island, if the pastoral industry does not start to do something about the loss of bees for clover pollination now, in 10 years it will be in crisis, says East Coast beekeeper Bill Savage. "The feral colonies that hill-country farmers relied on for clover pollination are gone from this region and in about 10 years there will be a huge problem." Without clover, nitrogen is not being fixed to grow the grass. Free nitrogen fertiliser from clover is the key competitive advantage that the pastoral industry, the backbone of New Zealand's economy, has over the rest of the world.