Subject: Re: NANFA-L-- Riparian Vegetation was "Creek Chubs?"
From: Mark (nanfa-in-jonahsaquarium.com)
Date: Tue Nov 30 2004 - 11:48:31 CST
At 10:55 PM -0500 11/28/04, Todd D. Crail wrote:
>Tough part will be when I approach the Metroparks and tell them "If
>you want to foster historic biodiversity, you need to cut down
>cooridors along the ditches going through your properties. There's
>not enough energy to create habitat with these trees and compromised
>light in this historic prairie region, not to mention an aquatic
>community that needs a highly productive sun-light driven habitat
>that can be burning off all those fertilizer BEFORE they get into
>the mainstems. You're actually hindering biodiversity and
>contributing to urban stream compromise by _having_ the trees."
>...Did I mention I have a 100 yard segment of ditch,-in-full
>sunlight, that's populated by 8 species of fish, a host of invert
>biodiversity, completely isolated in the center of the Oak Openings,
>which has thick forested canopy on both ends of the open segment...
>Which once under the trees, _all_ the animals disappear? Nice root
>wads, treelitter, and not a living thing present besides bacteria.
Um... I need a little more info. If there are trees now, why are
they surviving? Is this not land that was historically forested?
I'm not disputing that open stretches increase light, temperature,
and nutrient inputs and yield a more "productive" system in terms of
numbers of aquatic organisms. But is that really beneficial, if the
natural processes would otherwise lead to a forested and less
"productive" system? Sure, if we are going fishing, we want to see
lots of fish. But just because we want it, doesn't mean we should
have it. That's the same arguement that lead to the stocking of
carp, trout, bass, bluegill, etc, to the possible detriment of native
species.
By the way, I made a similar observation to yours last winter in
Wayne County Ohio. There were _many_ more fish and fish species in a
_open_ stretch of headwater than in a wooded stretch within 100 yards
of it. I attributed this to warmer water in the open stretch. I
also speculated that the species assembly was very different in the
open stretch than it would have been before that land was cleared.
The other question is whether the increased nutrient inputs in
"prairie" or non-forested stretches have a negative impact on the
watershed as a whole. I mean negative in terms of altering the
existing or previous nutrient balance and species assembly. Or can
you show that nutrient runoff from cleared-but-vegetated or prairie
stretches are no greater than those in forested areas?
-- Mark Conejo Creek drainage California USA<))>< /----------------------------------------------------------------------- / This is the discussion list of the North American Native Fishes / Association (NANFA). Comments made on this list do not necessarily / reflect the beliefs or goals of NANFA. For more information about NANFA, / visit http://www.nanfa.org . Please make sure all posts to nanfa-l are / consistent with the guidelines as per / http://www.nanfa.org/archive/nanfa/guidelines.html. To subscribe, / unsubscribe, or get help, visit the NANFA email list home page and / archive-in-http://www.nanfa.org/archive/nanfa/.
: Fri Dec 31 2004 - 12:42:56 CST