🚀 go-pugleaf

In article <23ekknINNgmk@cascade.cs.ubc.ca> pope@cs.ubc.ca (Art Pope) writes:
>A week or so ago I warned that reforestation was a tricky subject -- in
>part because of the definitions used for terms like "reforestation".
_____________
Reforestation is easily a tricky subject should the terms
reforestation and planting be mixed.
In order to bring the subject closer to some conclusion, I will summarize
as follows:

In B.C., planted area exceeded cut area by 6,281 ha in 1991-92.
(from MOF Annual Report)

In B.C., regeneration is ensured on all sites harvested today, 50 percent
of which planting is the regeneration method.
(From Art's last post where he quotes the MOF again)

So, all sites are regenerated and the MOF is making headway on backlogged
NSR.  But, Art goes on to say:

>However, planting is just a poor substitute for natural reseeding, made
>necessary by clearcutting. Once a site has been clearcut, planting is
>often the only way to get trees growing on it again (during our present
>civilization). And, of course, only 19 or so "commercially" valuable tree
>species are candidates for planting -- the other hundreds of species
>disturbed by the clearcuts are just on their own.
_____________
1. Planting is not made necessary by clearcutting.  Planting is chosen as a
regeneration method in order to speed up the regeneration time or to
achieve a desired species mix.  Other types of forest disturbance, such as
intense wildfire or bug kill, may easily result in identical
natural regeneration lags as would be experienced with clearcutting.

2. Clearcutting does not hamper natural regeneration; the subsequent
effects do and these effects again can easily result from fire or bug
kill.  Invasion by brush at low elevations on the coast or late snow melt
at higher elevations can easily shade out intolerant species.  Frost
pockets in interior valleys and mechanical damage by cattle are examples
as well.  Planting helps offset these problems, as well as brush control
and cutblock location.  In some cases, clearcutting is an inappropriate
harvest method altogether, wheras in others natural regeneration is so
thick that the forest must be severely spaced.

3. There are hundreds of species of plants that will not survive unless
forests are disturbed, such as fireweed, lupine, alder and Sitka Spruce.
Many tree species have relatively heavy seeds that do not move very far,
while most herbs and shrubs are well adapted to spreading their seeds.  It
is believed that Noble Fir was a native tree to BC prior to the last ice
age, when the ranges of all plants moved southwards with the advancing
ice.  Since Noble Fir has a heavy seed it has only moved back to
Washington State. 


On the subject of "recreating" forests, Art says:

>Finally, taganov@unixg.ubc.ca (Robert Edgar Froese) says:
>
>> Forests almost always grow back after clearcutting, and should grow back
>> without exception if managed properly and if clearcutting is applied
>> appropriately.
>
>Yes, some sort of forest almost always does grow back. Let's not fool
>ourselves, though, by pretending that the second growth has the same
>qualities as the original. The destroyed forest is not recreated.
_____________
If Art is simply stating the obvious, he is correct; however if one
visits a forest and comes back 5 years or 100 years later it will not be the
same either.  This is a gross oversimplification of reality.

Forests get disturbed, and disturbance by man is but one form, although
the dominant one in managed forests.  Forests are not static; they
continuously change.  Forests of similar type may evolve down different paths
following disturbance, governed by the same random, or intentional,
processes that caused their disturbance.  This path may be broken by
subsequent disturbance, or it may end in a self replacing state, often
called "old growth".  Forests are not "recreated" subsequent to
disturbance, yet given an amount of time appropriate to a particular area
and degree of disturbance forests will regain the essential qualities of
the pre-disturbance ("original") forest.

Is there any room in Art's definition of a forest for disturbance on a
scale greater than "one tree at a time?"  Furthermore, is disturbance by
man in any way acceptable under the definition of Forest, or must all
disturbance be outside of man?


-- 
Robert Froese  VE7MOQ
taganov biogeocoenose approach                  "Clearcutting is not a Crime"
taganov@unixg.ubc.ca