1. Mission Update 1.What are some key components of a healthy ecosystem? What makes an ecosystem healthy? 3/22

2. A healthy ecosystem has: 1.Productivity – ability to increase biomass (mass of all living things) in an ecosystem 2.Resilience- ability to respond to a disturbance by resisting damage and/or recovering quickly. 3.Organization (biodiversity) – variety of living organisms in an ecosystem.

3. Productivity Primary Producers – making of new material from molecules such as H 2 O and CO 2. Photosynthesis is the main form of productivity. Examples include: plants, marine algae and some bacteria. Secondary producers – make material using primary producers. Examples include: animals, protists, fungi and many bacteria.

5. Resilience All ecosystems strive for a balance or equilibrium or homeostasis. How are the following human impacts affecting the homeostasis: Agriculture Deforestation Climate Change Overfishing Polluting/Wastes Removing soil nutrients, adding fertilizers, soil run-off (pollution), removal of weeds (lowering biodiversity), increase of 1 type of plant (lowering biodiversity), etc. Removing plants (lowering biodiversity), removing habitats of other animals, decreasing primary producers- therefore not lowering CO 2 in air, etc. We already know lots of examples of this Removing animals (lowering biodiversity), removing secondary producers, removing diet for other animals, etc. Ruining habitats for species in the polluted air, water, and land. Removing habitats and biomass for landfills, etc.

6. Resilience How well can an ecosystem bounce back from human and natural events? Hurricane Tornado Flooding Droughts Pollution Etc. If humans left the planet right now, how fast or how well would nature “take over”?

7. Organization/Biodiversity A healthy ecosystem needs a wide variety of species. Some are primary producers (like grass, trees, weeds, etc.) and some are consumers (like animals, fungi, bacteria, etc.) If there is a large variety of species, then the ecosystem will not collapse when one specie goes extinct. There must be a balance between producers and consumers (prey and predator).

10. Make a food web Make a food web that contains at least 2 producers and 10 or more consumers.

11. Now remove one specie from the web… what would/could happen?

12. Keystone Species A keystone specie is one that has a great influence on the ecosystem and without that species, the ecosystem could collapse or struggle to continue. Keystone species could be small micro-organisms to large predators

13. Are humans a keystone species? What could/might happen if all the humans immediately went extinct? What parts, if any, of the ecosystem do humans “keep in check”?