Unit B: Sustainable Ecosystems and Human Activity
Chapter 3: Natural Ecosystems and Stewardship
Key Questions: Why is it necessary to keep ecosystems in balance?
Key Concepts:
- Natural ecosystems are valuable to humans.
Ecosystems are balanced but can change over time.
- Biodiversity describes the variety and amount of life in an ecosystem.
- Human activities can affect and threaten the sustainability of natural
ecosystems.
- Pollution of water, land, and air causes health and economic problems.
- Plant and animal resources should be used in a sustainable way
3.1: Benefits of Natural Ecosystems
pg. 78
Ecosystems Benefits
Ecosystems contribute a wide variety of benefits to us and the biosphere in
general. Some ecosystems are used for recreational activities and are
beautiful, but also supply food, lumber and medicine. Environmentally
ecosystems support climate, water and air pollutions, and oxygen supply, as
well as erosion control flood prevention and wildlife balance. For humans
the ecosystems supply jobs, tourism, and services.
Cultural Benefits
- recreation, education, and spirituality.
Products
- Terrestrial ecosystems provide wood, food, and medicines
- Plants provide the wood, dyes, fabrics, food, and medicines
- Animals provide leather, oil, bones, and beeswax.
Environmental Benefits
- Producing oxygen; oxygen comes from organisms that can
photosynthesize. 50 % come from ocean organisms. The by product of
photosynthesis is oxygen and glucose.
- Moderating Climate; plants in many different ecosystems (tropical
rainforests) take in carbon dioxide, which helps to control the green
house gas and the Earth’s temperature. Photosynthesis uses carbon
dioxide to make glucose.
- Filtering Pollutants; plants and certain other organisms can remove
and destroy harmful chemicals in the air, water, and soil.
Economic Benefits
- Forestry; 65 % of Ontario’s land is covered with forests. Forestry is a
$18 billion dollar industry. 80 000 people work within the industry,
and another 300 000 people have jobs related to forestry.
- Ecotourism; is the tourism to the ecology of an area, which creates
jobs; such as, hotels, restaurants, transportation services, arts
organizations and companies that organize global tours.
Other Benefits
- Prevents erosion and flooding. The roots of plants help to reduce the
erosion of soil by wind and water.
- Wetlands help to absorb and filter water, and remove pollutants.
Some Benefits of Ecosystems
Benefit
Examples
Cultural
Recreation, education, spirituality
Products
Lumber, food, medicine
Environmental
Climate moderation, water, air
purification, oxygen supply
Economic
Job opportunities, tourism products and
services
Other
Erosion reduction, food prevention,
balance of wildlife maintained
Valuing Ecosystems
Humans can have both positive and negative affects on ecosystems.
Public awareness can make it easier to maintain and protect areas and
species that live within an ecosystem as humans use the benefits and its
products.
Human damage:
- Campers, hikers and hunters may enter protect areas and harm
breeding grounds for both birds and animals.
- Litter increase pollutions, bacteria growth and harm wildlife.
- Carelessness with fire can impact air and water quality, as well as
harm plants and wildlife.
- Road construction and buildings disturb natural habitats. Vehicles
lead to an increase in air pollution.
Check Your Learning:
Questions 1 – 5, pg. 81
Wrap Up:
- Ecosystems provide us with many benefits including recreation, food,
medicine, and economic opportunities.
- Ecosystems help to protect us from some environmental threats.
- The benefits of an ecosystem are free and renewable.