🚀 go-pugleaf

At 05:09 AM 1/19/98 GMT, Jim Heath wrote:
>As you might guess, I've had no trouble finding
>arguments in *favour* of biodiversity. But are there
>professional voices urging caution? For some fundamental
>biological reasons?
>

The discussion is really one of semantics, but I'll offer a real world
example of a sort. The California Flora is comprised of some 3500 species
and has been invaded by approx. 1050 species in the past 230 years while
very few species have been lost.  Biodiversity, using the layman's
definition which is the only one that really matters, has increased
dramatically.  (In truth, it is species richness that has increased.)  At
the same time, many habitats have been compromised, particularly lowland and
wetland habitats.  Some 99% of the native grasslands have been type
converted to Mediterranean annual grasslands, and so on.

So, in general, biodiversity has increased, and not just in the plant world
either, but no one would argue that native California is the better for it.
Although problematic when writing for the casual reader, it would be better
to differentiate between increased species richness via the homogenization
of the world's flora and the smaller scale mosaic qualities that natural
environments tend to have which promote true biodiversity.

Given the recent research on biodiversity and stability, I think it will be
difficult to find good example of negative effects of biodiversity when
using an accurate definition of the term.

All the best,
Andy


Andrew R. Dyer
Department of Biology
University of Michigan, Ann Arbor, MI 48109
and
Mitrani Center for Desert Ecology        Precise
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