Objectives:

To construct a biome that incorporates the interrelationships that exist among biotic and abiotic components in the forest ecosystem.

Lesson Information:

	Grade Level	11
	Subject	Biology 20
	Curriculum Correlation	Agricultural Botany of Saskatchewan, food webs
	CEL's	Critical and Creative Thinking, Communication.
	Duration	2 hours
	Group Size	class, small groups
	Setting	indoors
	Vocabulary	biotic, abiotic, ecosystem, biosphere, biome.

Activities:

• Needs of a Forest Biome

Materials:

Paper, pencils, drawing and model building materials, copies of the background information on Biosphere II.

Background Information:

A forest is a highly complex, constantly changing environment made up of a variety of living (biotic) and non-living (abiotic) things. Just as each individual part of a tree is vital to the life and growth of a single tree, so all components of the forest community are essential to its health and well-being.

The abiotic components of a forest include water, nutrients, rocks, sunlight, and air. The biotic components include wildlife, trees, shrubs, wild flowers, ferns, mosses, lichens, fungi, and microscopic soil organisms. All plant and animal life is interdependent and one part of nature is always providing for the habitat needs of another.

The forest ecosystem embodies this principle of interdependence. For example, on the most basic level, trees need water and nutrients to create their own food, and in turn trees provide food (their fruits and seeds) for animals. On a more complex and far-reaching level, tree roots and tissues absorb and gradually release a great deal of water. Some of this water is used by the tree to create its own food, but the majority is released into the earth's atmosphere, cooling the air and contributing to the hydrologic cycle. This water is eventually returned to earth in the form of precipitation, which is needed by all life to survive.

The interactions between biotic and abiotic components in forest ecosystems are numerous and fascinating. They demonstrate the interdependence of life and help us understand the importance of caring for and managing the precious forest resource.

Notes:

1. This activity is based on an experimental closed environment in rural Arizona, called Biosphere II. In this experimental station, scientists tried to successfully recreate complete natural ecosystems, including several forest biomes (a biome is an ecological community of plants and animals extending over a large area, e.g.. the boreal forest biome comprises tall conifer formations; the temperate forest biome is a mixture of deciduous and coniferous trees). The scientists lived in the closed environment for two years.

2. Numerous experiments were conducted in Biosphere II in an attempt to increase our understanding of the importance of habitat and of some of the complex interactions and interdependencies in nature. These concepts are building blocks in the study of forest ecosystems.

Resources:

l. Atlantic Science Curriculum Project. SciencePlus 7 and SciencePlus 8. Toronto: Harcourt Brace Jovanovich, 1988 for help with designing experiments.

2. Biosphere, a 57-minute film about two large river ecosystems 10 000 km apart (the Mackenzie and the Amazon) and how they are linked within the biosphere. NFB: No. 106C 0084 033. Available from your local NFB film office, or through many public libraries and educational film libraries. Quote the film title and film number when ordering.

3. Myers, Dr. Norman, ed. Gaia, An Atlas of Planet Management. New York: Anchor Press/ Doubleday. 1984.

Related Internet Links:

• Saskatchewan Education Evergreen Curriculum

• Canadian Forests