New Forest Service policies take a big step backward
Daniel B. Wheeler
dwheeler at ipns.com
Tue Apr 23 10:06:04 EST 2002
"Bob Weinberger" <forestry at eoni.com> wrote in message news:<uc918etasdio96 at corp.supernews.com>...
> All of the container nurseries I have dealt with over at least the last 15
> years inoculate their growing medium with appropriate mycorrhizae.
15 varieities is not much, especially when most of those varieties are
Glomus varieties. There are about 70 species of Glomus associated with
almost all known plant life on earth. Trees, however, are associated
with only two which produce fruiting bodies similar to truffles. The
rest are largely found in health soils in most places on earth. They
are dispersed by earth worms and other soil-building micro-organisms.
> Some of the best growing plantations I have seen here in the Inland NW are
> those on land that had been in agricultural production for upwards of 50
> years before being replanted to trees. The ones I am most familiar with
> were in wheat production. If the mycorrhizae only survive a few months
> after timber harvest, these sites were certainly barren of (tree associated)
Glomus species will keep a tree alive. Barely. And wheat is associated
with several species. Perhaps old wheat fields are easier for creeping
voles (meadow mice) to bring new mycorrhizal fungi into the area.
Almost all voles eat a wide variety of foods, including truffle-like
fungi associated with forbes and some shrubs or trees.
> While more recent old field reclamation utilized seedlings
> that had been innoculated w/ mycorrhizae, those planted in the mid to late
> 50's almost certainly were not.
> The plantations planted in the late 50's , that I am familiar with, are
> producing 1 1/2 to 2 times the growth of wild stands in the same general
> area on equal sites.
That may be because they were still receiving the benefits of what
used to be a fairly intact ecosystem, Bob. Probably there were more
small mammals dispersing mycorrhizal fungi at that time. Chris Maser
points this out in several of his books. But he also says that over
time (he quotes a 200-year timespan) mycorrhizae are depleted.
Especially where short-term rotation logging takes place.
> Some possible reasons for this increased growth in the likely absence of
> mycorrhizae (at least in the early years of the stand's life):
> 1. Residual effect of any fertilizer that was used in the wheat operation.
> 2. Virtually no vegetative competition early in the trees' lives .
I'd say that was a key point.
> 3. If the beneficial mycorrhizae had died out, so also may have negative
> agents such as pathogens and parasitic nematodes.
Unlikely if there were still elements of humus in the soil, and humus
is pretty important for tree growth as well.
> 4. Possibly superior gentic traits in the planted stock ( unlikely though,
> since seed collections in the 50's usually involved robbing squirrel
Ironically, you may have hit on something here, Bob. Squirrels are
known mycophagists, and may have inoculated their caches with their
> > > Try 2 cords.
> > Actually I was referencing only the stem. But you are correct that the
> > total biomass more closely totals 2 cords.
> I believe what was being referred to here is the fact that the most commonly
> used cord to mbf ratio is 2 cords/1mbf.
I suppose that depends on the size of the tree and the amount of waste
generated during sawing. A single 8-foot diameter log 4 feet long
should produce close to 1mbf. Smaller diameter material has
considerably more waste due to wood curvature. But even chips and
sawdust waste are now being used in lumber creation (particle board
comes to mind) so I'm not sure that figure still applies.
Daniel B. Wheeler
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