Original NZ mammal & forest (Was Re: Clear-cut)
bsandle at southern.co.nz
Wed Feb 9 00:57:28 EST 2000
In nz.politics Owen McShane <omcshane at wk.planet.gen.nz> wrote:
: DVK wrote:
:> Brian Sandle wrote:
:> > Bats are our only original mammals in NZ. What functions do they have?
:> The same as sheep (talk about modifying the natural landscape!) : )
: In this context it is unwise to talk of a species having a function. It
: implies there is some great watchmaker who has designed a system in
: which bats do this and dogs do this and lions do that. In fact bats or
: anything else occupy an ecological niche. And if they don't something
: else will. The new evolutionary science is trying to take more care with
: the use of such words. For two long our language has endorsed the great
: watchmaker view of the world or the idea that evolution is deterministic
: and driven to end up with humans at the top of some biological tree. We
: are simply on end of a branch of high complexity.
: Bats have no function. They just are. Similarly it is not the function
: of possums to top feed off our trees. They just do.
If something happening in the forest depends on that then it would be
their so-called function.
Since it seems to have been missed I repost here an example of
how systems have evolved in which organisms are dependent on others. I
think `function' may be a high school biology term:
From: Brian Sandle <bsandle at southern.co.nz>
Subject: Original NZ mammal & forest (Was Re: Clear-cut)
truffler1635 at my-deja.com wrote:
: In article <20000204234404.27004.00001460 at ng-cj1.aol.com>,
: gswoodsguy at aol.com (GSWoodsguy) wrote:
:> clear cutting is a vital part of timber harvesting. You thin a few
:> cut the remaining trees and replant. IMHO
: Thanks for your _opinion_. But forest management should have a little
: more basis than just opinion, don't you think?
: The problem with clearcutting is that regeneration is presumed, not
: proven. Most mycorrhizal fungi associated with most trees dies out
: within a year after clearcutting. Without mycorrhizal fungi, most trees
: The last issue of McIlvania has an interesting article on successional
: mycorrhizal on glaciers in Washington. The mycorrhizal fungi associated
: with nearly exposed rocky areas is nearly completely different from
: soils 50-100 years old, and considerably different from established old-
: growth trees at lower elevations. In other words, there appears to be a
: succession of mycorrhizal fungi as trees grow. And as soils grow.
: Since most mycorrhizal fungi have _not_ been cultivated (most haven't
: even been identified) it is impossible to grow trees. The best thing
: that can happen is planting seedlings and _hoping_ nature is still able
: to inoculate the mycorrhizal fungi necessary to keep the trees alive.
: Many essential mycorrhizal fungi are hypogeous (underground) truffles.
: The Northern Spotted owl is the best vector for dispersal of these
: fungi. The fungi are the major source of food for Northern flying
: squirrels and California Red-backed voles. Voles especially need to eat
: their own body weight in truffles to survive. To stay alive, a mature
: vole needs to eat 16 pounds of truffles per year. But voles probably
: don't travel further than 100 yards from where they are born.
: Northern Spotted owls eat many voles each day. The spores pass through
: both voles and owls without apparent harm, and germinate some distance
: away. A Northern Spotted owl flies up to 40 miles each day. Each time it
: regurgitates an owl pellet, or defecates, it essentially is dispersing
: hundreds of mycorrhizal fungi species. That's how truffles get spread in
: Clearcutting disrupts that cycle. Great Horned owls roost on the edges
: of clearcuts. When they see a Spotted owl, they try to overtake it and
: kill it. Most spotted owls are killed by Great Horned owls or other
: Widespread clearcuts are the reasons Northern Spotted owls are nearing
: extinction. Should the owls become extinct, old-growth forests may
: Daniel B. Wheeler
You claim, Owen, that something else will take over. What then?
Another interesting mechanism showing how organsims have evovled in
The Compost Connection Newsletter- May, 1997
The Compost Connection for Washington Agriculture. October
1997. Funded by a grant from the W.K. Kellogg Foundation.
No.5. Suppressing Plant Diseases...
Last modified on: 19-Jan-1999 - 22K bytes - in English
Recently, Ohio State University researchers demonstrated that the
beneficial microbes in compost and other decomposing organic matter
can activate certain disease-resistance systems in plants. When a
pathogen infects a plant, the plant mobilizes certain biochemical
defenses, but these are often too late to avoid the disease. Plants
grown in compost appear to have these systems already running and
this prevents the pathogen from causing disease. This mechanism,
called systemic acquired resistance, is somewhat pathogen specific,
but it opens the door for enhancing disease control through common
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