RE: NANFA-- Report on America's Biodiversity

Bruce Stallsmith (
Sat, 31 Aug 2002 11:58:29 -0400

You hit on one of the $64 questions of ecology and conservation biology.
There is a huge literature of different models looking at the area lost vs.
species lost relationship you describe. The exact numbers one can find
depend on what taxa you're looking at in my experience; i.e. as you say,
freshwater mussels and vascular plants in eastern North America have been
much harder hit by reduced quality habitat than many mammals or insects,
although this isn't an absolute rule. Many of the modelers have based their
work on field observations in the tropics, especially in Amazonia and Costa
Rica, both because these are areas of imperilled high biodiversity and
because it's relatively easy and pleasant to work there. Since we've already
deforested most of North America at least once, it's hard to exactly
reconstruct what we started with and what we've lost, and how the loss of
habitat has exactly affected biodiversity. And as a personal observation,
biodiversity research in North America has only recently become as "sexy" as
going to an exotic setting. So we all know anecdotally that there's been a
lot of damage in N.A., but exact numbers and relationships are still being
put together.

--Bruce Stallsmith
Huntsville, AL, US of A

>From: "Crail, Todd" <>
>To: <>
>Subject: RE: NANFA-- Report on America's Biodiversity
>Date: Fri, 30 Aug 2002 22:42:51 -0400
>Perhaps this is something you can address Bruce, or anyone else for that
>matter :) The EO Wilson publications that I've read, he's always honed in
>on the fact that a 90% habitat reduction equals a 50% diversity loss. As
>well, the flip side is, a 90% gain in potential habitat equals a 50% gain
>in diversity.
>In Ohio, as an example, it's claimed we've lost 95% of our historical
>wetland areas and the remaining river and riffle habitat have been
>completely changed by daming and cropland siltation (which I've seen enough
>to believe this isn't far fetched). However, it's a pretty short list of
>extinctions and extirpations. I'd say that vascular plants and freshwater
>mussels have taken the largest hit with birds coming in a distant third.
>Does the equation loose weight as you move further away from the equator?
>Or are the current long lists of endangered, threatened, concern accurate
>examples of "living dead" unless action is taken in our current
>In other words, has Industrialization only had it's effects here long
>enough with the adaptability of the species that live here... That it's not
>gone to full fruition such as it would when an Amazonian rainforest or
>Micronesian mountain forest had the canopy ripped off and the thin layer of
>soil gone immediately?
>Just kinda wondering. Perhaps this is a question to just wonder under the
>stars :)
>Any thoughts greatly appreciated,
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