Skógræktarritið - 15.05.2001, Blaðsíða 81

their own and others trial and
error experiences. On familiar
territory, foresters have a con-
siderable advantage in having
training and experience in deter-
mining the forest potential of
prospective planting sites. But
in new territory, especially in
areas with a harsh climate and
where there is little experience
with tree planting, foresters
have little more to draw upon
than their intuition. This situa-
tion has confronted the author
over the years that he has tack-
led tree planting, mostly with
great success, so much so that
he was asked to explain and give
recommendations on how he
would proceed to reforest the
man-made barrens on the
Avalon Peninsula. The author's
basic tricks of the trade, many of
them quite unorthodox, are
described in a CD and 262 page
book Planting Trees on tfie Avalon
Peninsula, containing roughly 600
photographs and illustrations.
The following is a sinopsis of
that publication.
PART I: PLANTATIONS
This section describes the results
of some of the plantations estab-
lished by the Government of
Newfoundland between 1938-52
in Conception Bay North, Tilton,
Marysvale, and small plantations
established between 1970-1990
by various government, volunteer
and private citizen's organiza-
tions. Environmental influences
affecting tree growth and regen-
eration in plantations are also
described.
The Avalon has an insular cli-
mate, best described as Cool-
Temperate or Oceanic Boreal.
General climate statistics are
based mainly on one station at
St. John's Airport, which does not
give much useful data about how
climate and weather affect tree
growth.
A better approach is to express
the relationship between forests
and atmosphere in terms of the
energy cascade. In the late 1980's
early 1990’s energy fluxes were
measured on planting sites at
Glenwood in central Newfound-
land, in the experimental nursery
at Pasadena and a clearcut near
St. Georges in western New-
foundland. The energy flux mea-
surement technology was trans-
ferred to Gunnarsholt, south lce-
land where it's capabilities were
expanded and it is now part of
the extensive EUROFLUX net-
work. While measurements of
energy fluxes do not give a direct
assessment of potential plant
growth per se, they do, neverthe-
less, give foresters an insight of
how daily fluctuations of such
variables as solar radiation, eva-
potranspiration and soil heat flux
influence tree growth on cold
and warm days, respectively.
Given that the Avalon has a cool-
temperate climate, its energy
cascade is capable of supporting
much more highly productive
forests than currently exist. This
conclusion is reinforced by the
fact that, even on barren sites,
plantations have generally far
outgrown local natural 'forests'
by a factor of as much as 20:1.
PART 2: PHYSICAL ENVIRON-
MENT
Wind is the most limiting factor
reducing survival and growth of
both natural woodlands and
plantations alike. Wind flows in
very organized patterns. From a
silvicultural standpoint, coming
to grips with the pervasive wind
is a seemingly impossible task. It
is especially difficult to visualize
what patterns wind will create far
into the life of a plantation. The
best insight by far is to study the
short-term and long-term impact
of wind on planations, forest and
individual trees. For example,
clues as to the prevailing pat-
terns of wind can be inferred
from patterns of tree growth on
the shores of sea coasts, lakes,
broad rivers and even across
Fig. I. Spirity Cove wave forest shows
the effects of helical roll vortices.
Ölduskógur sýnir áfirif lágréttra skrúfvinda.
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