Bees don't pollinate 100% of our plants, no. I made a really rushed comment earlier before scooting off to grab my dinner and realised when coming back to the thread that i'd given the impression that bees are responsible for everything we eat - sorry!
I found this extract in CBC news, quoting a couple of different sources.
"About 35 per cent of the world's crop production is dependent on pollinators such as bees, birds and bats, scientists estimated in the Proceedings of the Royal Society B: Biological Sciences in 2006.
Another study the same year found many wild plants around the world weren't getting pollinated enough, especially those in areas with a lot of species, such as tropical jungles. The authors of the study published in Proceedings of the Natural Academy of Sciences said some could be at risk of extinction as a result.
It's not just a problem in the tropics either ? the diversity of bees and the flowers they pollinate have both declined significantly in Britain and the Netherlands over 25 years, reported a 2006 study"
Thing is, many bird and bat species, and quite a lot of other insects, are also in decline so the overall picture for pollinators isn't good. Plus, there are many cases where one plant is adapted for one pollinator and if that animals goes, then so will the plant. The main trouble is that ecosystems are really complicated places. You can mess with them to a certain extent but then you do one last thing and the whole thing collapses, and it's difficult to know where the cut-off line is. We know bees are in trouble, we know that in the British ecosytem they play an important role, so it's a good idea to start looking out for them as if we lose them, we may not know the full implications of this until it is far too late.