1. What services do ecosystems provide? How do humans affect ecosystems?
Humans & Ecosystems
What services do ecosystems provide?
How do humans affect ecosystems?

2. The Human System
This graph shows how much grain it takes to make one pound of each kind of meat.
If we did not eat beef then we could feed 3 times as many people on Earth.

3. The Human System

4. Violations of the First Principle of Ecosystem Sustainability
Excessive use of fossil fuels.
Feeding largely on the third trophic level.
Use of coal or nuclear power.
Use of agricultural land to produce meats.

5. Violations of the Second Principle of Ecosystem Sustainability
Lack of recycling.
Excessive use of fertilizers.
Destruction of tropical rain forests.
Nutrient overcharge into aquatic ecosystems.
Production and use of nonbiodegradable compounds.

6. Ecosystems respond to Disturbance
Disturbance An event caused by physical, chemical or biological agents that results in changes in population size or community composition

8. Watershed Studies Watershed
All of an area of land in a given landscape that drains into a specific stream, river, lake or wetland or larger body of water.

10. Resistance v. Resilience
Resistance is a measure of how much a disturbance can affect its flow of energy and matter
Resilience the rate at which an ecosystem returns to its original state after a disturbance
Restoration Ecology is a new scientific discipline that is interested in restoring damages ecosystems.

11. Intermediate disturbance hypothesis
Ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels.
WHY????

13. Ecosystems provide valuable services
Instrumental Services:
Provisions are goods that humans can use directly. (examples?)
Regulating services provided by natural systems help regulate environmental conditions. (examples?)
Support systems are services that natural systems provide (e.g. pollination, natural filters, pest control)

14. Ecosystem Services and Functions
Gas, climate and water regulation
Water supply
Erosion control
Soil formation
Pollination
Biological control

15. Ecosystem Services and Functions
Food production
Recreation
Raw materials
Nutrient cycling
Waste treatment

16. Intrinsic Values of Ecosystems
The Resilience of an ecosystem ensures that it will continue to provide benefits to humans—but this depends greatly on species diversity
Cultural Services are part of the aesthetic benefits to many people. (examples??)