The Laurentian Forest in spring

Spring is a joyous time, decked out in the bright colours of the many flowers and the soft greens of young shoots.

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


The Laurentian Forest in Summer

In summer, the green of the foliage becomes more intense, and few flowers bloom in the shady underbrush.

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


The Laurentian Forest in Fall

In fall, the leaves turn yellow, orange and red before dropping and carpeting the ground.

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


The Laurentian Forest in Winter

In winter, a few conifers keep their dark green coats and break the monotony of the bare landscape.

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


The relative length of day and night (or “photoperiod”) is the main factor that regulates the changes from one season to the next.

At the Biodôme, it is the natural light entering through the skylights and in particular the light from the artificial lighting system that determines the photoperiod.

In fall, the days become shorter until December 21, the shortest day of the year. Then they begin to lengthen, until we reach the longest day of the year, June 21.
The relative length of day and night (or “photoperiod”) is the main factor that regulates the changes from one season to the next.

At the Biodôme, it is the natural light entering through the skylights and in particular the light from the artificial lighting system that determines the photoperiod.

In fall, the days become shorter until December 21, the shortest day of the year. Then they begin to lengthen, until we reach the longest day of the year, June 21.

© Biodôme de Montréal, 2005. All rights reserved

Lighting System

Lighting system at the Biodôme.

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


Changing temperatures also influence biological cycles from one season to the next. Cold fall nights, combined with the reduced light, provoke the phenomena that cause leaves to change colours.

In the Biodôme’s Laurentian Forest, the temperature also varies with the seasons, but never drops below zero — to keep the pipes from freezing and for visitors’ comfort. The leaves at the Biodôme do not turn such vibrant colours as in the actual Laurentians, perhaps because it never gets extremely cold here and because the soil acidity is different.

We begin raising the temperature as of March 1, to cause spring to arrive earlier than in nature. We also increase the photoperiod by ten minutes a day throughout March.
Changing temperatures also influence biological cycles from one season to the next. Cold fall nights, combined with the reduced light, provoke the phenomena that cause leaves to change colours.

In the Biodôme’s Laurentian Forest, the temperature also varies with the seasons, but never drops below zero — to keep the pipes from freezing and for visitors’ comfort. The leaves at the Biodôme do not turn such vibrant colours as in the actual Laurentians, perhaps because it never gets extremely cold here and because the soil acidity is different.

We begin raising the temperature as of March 1, to cause spring to arrive earlier than in nature. We also increase the photoperiod by ten minutes a day throughout March.

© Biodôme de Montréal, 2005. All rights reserved

The plants in the undergrowth of the Laurentian Forest are subject to very changeable light and temperature conditions, depending on the season.
Image: undergrowth in spring
undergrowth in spring

In spring the soil begins to warm up, and the plants beneath the spreading trees take advantage of the heat and abundant light to grow, accumulate reserves, bloom and produce berries.

Once summer comes, the trees blocks much of the sunlight. The plants have finished flowering. Along with their flowers and fruit, some plants also lose their foliage, leaving nothing more than a bulb or rhizomes in the soil.

The reserves stored in the bulb or rhizomes allow the plant to survive and even to grow in the soil until springtime rolls around again.
The plants in the undergrowth of the Laurentian Forest are subject to very changeable light and temperature conditions, depending on the season.
Image: undergrowth in spring
undergrowth in spring

In spring the soil begins to warm up, and the plants beneath the spreading trees take advantage of the heat and abundant light to grow, accumulate reserves, bloom and produce berries.

Once summer comes, the trees blocks much of the sunlight. The plants have finished flowering. Along with their flowers and fruit, some plants also lose their foliage, leaving nothing more than a bulb or rhizomes in the soil.

The reserves stored in the bulb or rhizomes allow the plant to survive and even to grow in the soil until springtime rolls around again.

© Biodôme de Montréal, 2005. All rights reserved

Undergrowth in Spring

Undergrowth in Spring

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


Undergrowth in Summer

Undergrowth in Summer

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


Undergrowth in Winter

Undergrowth in Winter

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


A Bud in Spring

In the spring, budburst occurs once it stays mild overnight. In the Laurentians, north of Montréal, this phenomenon occurs in May. It happens earlier at the Biodôme, in late March and early April, since we begin raising the temperature sooner than in nature to bring on an early spring

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


Leaves in Summer

Trees produce their buds during the summer, when their leaves have reached their maximum size. This is why you can already see buds on the trees when the leaves drop in the fall.

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


Branch in Winter

In winter, the trees are dormant, and the cells of the buds can withstand the severe cold.

Biodôme de Montréal

© Biodôme de Montréal, 2005. All rights reserved


Learning Objectives

The learner will:
  • Learn more about the ecosystems in the Americas;
  • Observe the diversity that each ecosystem offers regarding the flora, fauna as well as climate;
  • Identify the elements that shape different ecosystems, such as vegetation, wildlife, soil, etc.;
  • Develop different causes and consequences of human actions on ecosystems (from grade 4);
  • Formulate and justify possible solutions on issues, such as global warming, in order to preserve our ecosystems and biodiversity on Earth (from grade 6)

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