Life Science: Sustainability of Ecosystems
Unit Overview
The land in Saskatchewan supports agriculture, forestry, mining, and tourism. Choices made in those sectors have significant impacts on the lifestyles of all people in the province and on the health of our environment. Students should develop a greater understanding of how personal, social, economic, and political decisions influence our environment and how these choices are rooted in cultural understandings of our relationship with the natural environment. As students develop these understandings, they are better able to make informed decisions that enhance the sustainability of our world.
Students have previously studied habitats, communities, ecosystems, and the interactions within ecosystems as part of their life science studies. Students have examined the diversity of life in ecosystems and the cycling of matter and energy through a food web.
In this unit, students will examine sustainability of ecosystems from a systems perspective. Students will document biodiversity as an indicator of the health of ecosystems and investigate the characteristics of population dynamics, within the context of the carrying capacity and limiting factors of ecosystems. This approach provides students with opportunities to explore the interdependence of species and the relationships between organisms and their physical environment. The study of the physical environment will include consideration of the large scale cycling of elements (carbon, nitrogen, and oxygen) in biogeochemical cycles and the bioaccumulation of toxins in food chains and webs and the consequent effect on the sustainability of ecosystems.
Students are encouraged to develop an action plan that they or members of their community can undertake in order to maintain or enhance the sustainability of our environment at a local, regional, national, or international level.
K-12 Related Topics in Science
Saskatchewan Science Units (2005)
Grade 5 - Plant Structure and Function
Grade 5 - Communities and Ecosystems (Optional)
Grade 6 - Ecosystems
Grade 7 - The Basics of Life
Grade 7 - Saskatchewan - The Land
Grade 8 - Adaptation and Succession
Grade 8 - Plant Growth (Optional)
Grade 9 - Saskatchewan - The Environment
Grade 9 - Diversity of Life (Optional)
Biology 20 - Ecological Organization
Biology 20 - The Diversity of Life
Pan-Canadian Framework Units
Grade 1 - Needs and Characteristics of Living Things
Grade 2 - Animal Growth and Changes
Grade 2 - Air and Water in the Environment
Grade 3 - Plant Growth and Changes
Grade 3 - Exploring Soils
Grade 4 - Habitats and Communities
Grade 6 - Diversity of Life
Grade 7 - Interactions within Ecosystems
Grade 10 - Sustainability of ecosystems
Grade 11/12 - Matter and Energy for Life
Grade 11/12 - Evolution, Change, and Diversity
Grade 11/12 - Interactions Among Living Things
Key Questions
- What is sustainability?
- How does biodiversity indicate the health of an ecosystem?
- What natural factors affect the stability of an ecosystem?
- How do energy and matter flow through ecosystems?
- How do human activities affect the sustainability of an ecosystem?
- How can humans in general improve the sustainability of our ecosystems?
Key Concepts
A systems approach to studying ecological concepts highlights relationships and interdependencies among biotic and abiotic factors in ecosystems. Different cultures understand these relationships in different ways which can lead to differing perspectives on how best to adopt sustainable practices.
Sustainability is a paradigm or worldview that refers to the ability to meet the needs of the present generation without compromising the ability of future generations to meet their needs.
The dynamic nature of ecosystems is revealed through the study of interrelationships such as the flow of energy through an ecosystem. Plants and animals obtain their energy from the Sun, either directly or indirectly. Scientists represent the flow of energy using food webs, food chains, and pyramids of energy, numbers, and biomass.
Biodiversity, the measure of the number and variety of species in an ecosystem, is an indicator of the health of an ecosystem. The actual biodiversity of different types of ecosystems varies, even when those ecosystems are healthy. The change in population of a species may vary over time, due to both natural and human causes. Population dynamics is the study of these changes and the limiting factors that influence populations. Rapid population changes, such as the introduction of an invasive species or the extinction of a species due to bioaccumulation of toxins, may change the nature of interactions and interrelationships within an ecosystem.
The Earth is a closed system in which matter is neither created nor destroyed. Nutrients essential for life cycle through various geochemical cycles such as the carbon cycle, nitrogen cycle, and water cycle.
Suggested Themes
Teachers are strongly encouraged to use case studies of local ecosystems.