I am wondering, do extreme environments mean less biodiversity?

I had the following idea; an extreme environment requires specialised organisms. So in an extreme environment, you would have a small range of species because they all need to be specialised.

However, in an environment that is conducive to growth of organisms (i.e. not extreme), a wider range of organisms would be able to grow as they don't need to be specialised and thus there would be more biodiversity.

Is this a logical idea? Is there any literature that could back this up?

Thanks
Oliver

Extreme environments do seem to have less biodiversity, but I suppose it depends on what you consider "extreme".

In any case, perhaps a good way to think about this is to start by thinking about species niches (the range of conditions they can live in, which might be narrow or broad), and the amount available niche space. It's generally thought that niche spaces cannot overlap too much, because one species would outcompete another and drive it to extinction. In a certain amount of niche space you could fit a small number of "generalists" or many "specialists".

You can think about whether extreme environments have a small amount of available niche space or a lot. Does a desert have more niche space than a rainforest? What about an acidic lake vs. the ocean? I'm not sure "extremeness" necessarily translates well to niche space.

To develop these ideas further you could do some research on "niche partitioning", "species packing", "niche space", "community assembly rules".

This site is a good starting point: http://canadianbiodiversity.mcgill.ca/e … /index.htm