- Types of ecosystems
- Natural resources
- Pressures on ecosystems


[SLIDE 1]

The Earth's land includes various types of ecosystems such as:
- mountain and polar
- forests and woodlands
- inland rivers and wetlands
- drylands
- cultivated
- urban parks and gardens
- coastal
- island
- marine

Each of these ecosystems provides natural goods as well as services. Benefits that come from these natural ecosystems include a huge range of products and services including air quality regulation, biofuels, carbon sequestration, climate regulation, cultural heritage, disease regulation and medicines, dyes, education, erosion control, fiber, flood regulation, food, fresh and drinking water, fuelwood and timber, nutrient cycling, pest regulation, pollution regulation, recreation, ecotourism, aesthetic values, sediment retention and transport, waste processing and water regulation.


[SLIDE 2]

Ecosystems offer tremendous natural resources that we use and need on a daily basis. Our foods come from ecosystems even if we live in very urban areas. Natural resources include natural ecosystems and the biota in them. Most of the time, resources are considered only in terms of monetary or economic benefit. However, ecological value and capital extend far beyond this.

A public good is something that is not used up as people use it and which cannot be effectively limited by charging money, such as breathing air. A forest that is cut down, for example, can provide immediate economic benefit to the person or group that owns the land on which the forest stood. However, it also results in long-term loss for regulating and supporting services.


[SLIDE 3]

As the human population continues to rise, pressures on ecosystems to provide enough resources increase. More people means more food, more fuel, more wood, more water and more medicine.

The Millennium Ecosystem Assessment revealed that 15 of 24 vital services provided by ecosystems were in decline, 4 were competing against others and 4 were in a stable state. This pattern is unsustainable for growing human populations. The natural functions of the Earth are strained by human activity so much that the lives of future generations cannot be guaranteed without protecting the healthy ecosystems that will support them.