The network of Unesco World Biosphere Reserves, with 13 new additions just announced, makes up a vast reservoir of the planet's biodiversity.
It was only when I learned a couple of years ago that Mont Ste-Hilaire, near Montreal, was one of the 15 World Biosphere Reserves in Canada, that I set out to discover more about this system. Suffice to say that I have spent a few hours over several different occasions, looking at the Unesco website linked above and, in short, I still have not gained a concise understanding of how this system works.
I guess the overriding factor in play is that, since the system is worldwide, it is impossible to either impose or agree on worldwide standards, other than certain generalities. Obviously the countries of the world are so diverse in financial means, in values, priorities, cultural outlook, infrastructure, etc., that there would be little hope of creating an easily defined biosphere reserve system.
What I have understood so far is that the system is designed to encourage awareness and preservation of the great biodiversity on the planet. What we see in practice is that, for example, the 15 biosphere reserves designated so far in Canada encompass only a mere sliver of the biodiversity in Canada. So, although 564 reserves worldwide might seem like a lot, and indeed, many of them are impressive, even mind-blowing in their rich natural endowments, we can only assume that the network to-date only scratches the surface of what needs to be put in place. At least, the existence of the network of World Biosphere Reserves gives us some assurance that our indispensable biodiversity is at least on the radar.
What I find the best way to browse the world biosphere is this link, one of a few different ways to approach it.