The Rural Voice, 1990-03, Page 34FARM AND FOREST
A necessary relationship:
by Cathy Laird
BACK IN 1979 AT THE
Royal Winter Fair in Toronto,
Ian MacLachlan received the
Grand Champion Award for his
maple syrup. He and his wife,
Lorraine, were producing 1,200
to 1,500 gallons of syrup annual-
ly from their 75 acres of sugar
bush. They were also buying
bulk syrup and repacking it for
wholesale and retail customers.
"In 1980," MacLachlan says,
"the trees in the sugar bush were
beginning to die at an increasing
rate. From 1982 to 1985, we lost
600 trees, and the annual produc-
tion of syrup dropped 20 per
cent."
"In 1984-85, we were fight-
ing a losing battle against forest
decline, so we reluctantly de-
cided to get out of the syrup
business."
Today, though few people
realize it, the MacLachlans'
experience is too common in too
many parts of North America,
and "forest decline" is felling the
maple syrup business in Quebec.
"My concern," adds
MacLachlan, "has gone beyond
the producing sugar bush of
North America. The whole
deciduous forest of the northern
hemisphere is falling apart."
Maple trees — those vibrant
Canadian landmarks — are
shallow -rooted and susceptible to both
airborne pollutants and acid rain. But,
MacLachlan says, "there hasn't been a
tree die yet directly from acid rain.
Trees in decline are like human beings
with AIDS, who die of pneumonia or
another secondary infection. The soil
is leached, the root systems are weak-
ened, the foliage is damaged. Then
other problems such as fungi, natural
diseases, pests, and/or drought find it
much easier to push the trees over the
brink."
Trees can adapt and survive against
"My concern,"says Ian MacLachlan, "has gone
beyond the producing sugar bush of North
America. The whole deciduous forest of the
northern hemisphere is falling apart."
natural predators on their own, adds
MacLachlan, a former president of the
Ontario Maple Syrup Producers Asso-
ciation. "Unfortunately, the increased
loads of airborne pollutants are upping
the balance against survival."
Statistics make the die -back
obvious. Comparing the growth of
trees in Ontario between 1900 and
1940 to the rate of tree growth from
1940 to 1980, provincial researchers
have found that there was an average
12 per cent decrease in growth in the
more recent period.
Indeed, forest die -back
appears to be increasing. There
seems to be a critical point at
which pollution impairs the
ability of trees to grow. The
result is a widespread and ever-
growing number of "bodies"
throughout forests and along
roads, lanes, and fencerows.
Signs of deterioration
include stunted leaves, pale or
brown leaves (around the edges
in particular), dead top branches
with peeling bark, an early
change of colour (orange leaves
in July), and bare twigs. The
following list of Tree Cate-
gories is used widely today:
1. Normal trees: Foliage
full size and rich in colour. No
dead twigs or branches.
2. Foliage abnormally small,
curled, thin, yellowish, or other-
wise weak in appearance, but not
conspicuously so. No dead
twigs or branches.
3. A tree similar to number
2, except that is has a number of
dead or bare twigs in the top of
the crown. Such bare twigs are
perhaps in a dying state, and
hence represent one of the early
symptoms of die -back.
THE POINT OF NO RETURN:
Generally, trees with the symp-
toms listed below will die.
4. Trees with dead branches
for no apparent reason, but such
branches constitute less than half the
crown. A "branch" should be at least
3 or 4 feet long and there should be
two or three dead branches before the
tree is placed in this class.
5. Trees with more than half the
crown dead.
6. Crown dead, except for small
adventitious branches, usually to be
found at the base of the crown.
(Mader and Thompson, 1969)
In response to increasing concern
over the welfare of trees, a small
30 THE RURAL VOICE