In a cotton field, however farmers deliberately create
a species-poor low biodiverse environment where only
one plant type lives. The soil is deplenished of soil
organisms due to repeated tillage operations and pesticides,
the insect life is largely killed off by pesticides and weeds
are killed by herbicides. The cotton field is begging
for chaotic conditions from pest attack due to low
biodiversity and is consequently unstable.
We tend to comment on what we can see redwoods or
cotton when there is a lot more there. We tend to see
the world as we are rather than as it is.
> To: sgh1@cornell.edu
> Cc: gale-sinex@aae.wisc.edu, sanet-mg@amani.ces.ncsu.edu
> Date: Sun, 17 Nov 1996 18:06:25 PST
> Subject: the more diversity the better?
> From: jvworstell@juno.com (James V. Worstell)
> Are there any ecologists on this list who can discuss "positive feedback
> switches"? Many plant species change their environment to make it more
> suitable for themselves and in so doing decrease diversity--Coastal
> redwoods being a primary example cited by many. An extreme example:
> Sphagnum spp create "monocultural" bogs from ponds--almost eliminating
> diversity and helping more of their species survive. Many ecologists
> see stability as associated with lack of diversity. Where ecosystems
> are regularly disturbed, diversity is usually far higher, according to
> the studies of Reice and others. Extreme diversity and disturbed,
> chaotic physical conditions go hand in hand in nature. Many (or can we
> say most?) species fight such extreme diversity by creating a stable
> environment more conducive to their kind. Diversity increases as
> stability decreases.
>
> While decrying the pesticide-laced Illinois cornfield or Mississippi
> cotton field, one need not make the inferential leap to "the more
> diversity, the better."
>
> If these species had listservs they'd probably not say "diversity is bad"
>
Preston Sullivan
Technical Specialist
ATTRA Program