An ecosystem to rediscover with each passing season
In nature, this kind of northern ecosystem, a mixed forest where deciduous and coniferous trees mingle, occurs in both North American and Asia at similar latitudes. An ecosystem that awakens, blossoms, changes colour and sleeps in time with the seasons, the Laurentian Maple Forest illustrates how living things can adapt to great variations in climate.
The Biodôme's Laurentian Maple Forest consists of hardwoods and conifers. You can see a variety of land and aquatic habitats dotting its 1,518 m², whose denizens are often most active at night.
Just as in nature, changes in temperature and light cause plants to become dormant toward the end of the summer. The leaves change colour and drop off in the fall, and in the spring, the cycle starts again as plants sprout anew. In fact, spring actually comes slightly ahead of time in the Biodôme's Laurentian Maple Forest!
Land and water habitats dot the landscape, like those one might see when climbing down a mountain in La Mauricie Park: a yellow birch/sugar maple grove, a mountain lake and stream, an area flooded by a beaver dam, a white birch/aspen stand, a swamp, a yellow birch/balsam fir stand... Grooves on the rocks attest to the passage of the glaciers that covered almost all of Québec 10,000 years ago.
Conditions in the Biodôme's Laurentian Maple Forest change considerably from one season to the next, to reflect the actual conditions outside. The temperature reaches 23°C at the height of the summer, and gradually falls to 4°C at night (12°C in daytime) to induce plant dormancy. The lighting is also shortened, to encourage this plant “winter,” which lasts 8 to 12 weeks. Relative humidity ranges from 45% to 90%.
In the Biodôme, you can observe both hardwoods, including sugar maples and white birches, and conifers such as firs and white spruces, occurring naturally in the Laurentians, in habitats specifically suited to their growth.
In the spring, bulbs flower before the first shoots appear on the trees. In the fall, the maple leaves turn to splendid reds and yellows and soon carpet the ground. The plants all go into dormancy.
In nature, plant growth slows or stops altogether at the end of the summer, as the days shorten. At the same time, trees form more wood and store up food. Then the leaves begin to fall, as plants become dormant. At this point, even if they were exposed to warmer conditions and more light, they would not begin to grow again.
How long a plant remains dormant depends on its species and where it grows. But our plants definitely need a fairly long period of cold temperatures before they are ready to reawaken in the spring.
As this dormancy period ends, plants wait for the proper conditions for “bud burst.” Temperatures of 4ºC to 10ºC are generally sufficient to coax them out of dormancy. In Québec, the dormancy period is considered to end in March, but the persistent low temperatures delay bud burst until May.
All this is to say that Nature leaves the Biodôme just enough leeway to manufacture “real” seasons in the Laurentian Maple Forest, through careful control of photoperiods and temperatures.
Based on an article in Quatre-Temps magazine, vol. 76, no. 2.
The different terrestrial and aquatic habitats are populated by animals that are generally more active at night. Among the inhabitants of this ecosystem are dozens of species of fish, along with amphibians, reptiles, birds and mammals such as beavers, porcupines, otters and lynx.