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Plant Biology
Reforesting Boucherville
On Grosbois Island, east of the Boucherville Islands National
Park, a veritable open-air laboratory was set up in the spring
of 2004. In three sections of a former cornfield, botanists Étienne
Laliberté and Alain Cogliastro of Université de
Montréal planted close to 1,300 trees last May. Small
shoots of bur oak, American ash, silver maple and Eastern
cottonwood are being closely watched. Reforestation strategies
in this area, as well as in the whole Saint Lawrence plain,
could benefit from the knowledge gained at the park.
“By the fall of 2005, we should be able to identify
the most suitable strains for reforestation operations, and
especially, what techniques to use,” explains Alain
Cogliastro, an associate professor in the Plant Biology Research
Institute of the Biology Department. “The goal is not
to reproduce the forest as it was before Christopher Columbus,
but to quickly produce a functional forest. We want to give
nature a hand,” notes Étienne Laliberté,
who is devoting his master’s thesis to this project.
The difficulty the biologists are facing have forced them
to be creative. Solidago, quack grass, and thistle quickly
colonized the soil when farmers abandoned the land in 2001.
These invading species have left little room for species
that normally make up a forest. That’s what makes the
specialists’ work so promising. “The conventional
reforestation technique involves running a bulldozer through
it or spraying herbicides. Because we are in a national park,
we could not work this way,” Mr. Cogliastro notes.
Ecological approaches were tested on plantations that had
been divided into three parts. In the first, the stems were
planted inside canvas sleeves; in the second, an exclosure
of sticks was constructed, and the third was left wild. A
third of the trees were planted in a canvas cylinder that
lets light through, but not rodents; another third is protected
from big mammals that might browse on the foliage, and the
remaining third serves as a control culture.
If those fields had ears, they would have heard pretty
positive expressions from the observers. The botanists found
the young ashes performed better than the oaks, and the plants
are apparently stronger in exclosures than in sleeves. One
researcher, leaning over a plant in perfect health, says: “This
maple grew close to 20 cm in a few weeks. Good news.” But
a healthy scepticism is in order: it will all be analyzed
scientifically at the end of the growing season, and further
studies will be done next year, as well as in years to come.
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