1. How is waste produced and recycled in ecosystems?
Waste in Ecosystems
How is waste produced and recycled in ecosystems?
Starter:
Consider wild animals, plants and humans.
Make a list of the waste that each of the 3 produces.
Too easy? What happens to the waste?

2. Waste
Animal Plant Human

3. Waste Animal Plant Human Faeces Petal Skin?(snakes) Fruit
Dead bio matter
Dead animals
Urine
Petal
Fruit
Dead plants
Leaves

4. This is Autumn..

5. A few months later
What has happened? Why and by what ?

6. Decomposition
Think – Pair – Share – how do these four organisms contribute to the decomposition of Dead Organic Matter.

7. I lay my eggs in pellets of dung and my larvae eat the dung, Yummy!
We use the carbon molecules cellulose and starch, to get energy from respiration. We release Carbon dioxide into the atmosphere
I eat soil and leaves and the soil grinds up the leaves in my stomach. Then my enzymes can digest them. Delish!
I lay my eggs in pellets of dung and my larvae eat the dung, Yummy!

8. Nitrogen – one of the most annoying and important chemicals on Earth.
Why is nitrogen important? Why is it so annoying?

9. Have a look at this diagram.
Annotate me on the board.

10. Task – 6 mark question.
Explain in detail how nitrogen is cycled through an ecosystem. (6 marks)

11. Why is there so much waste?
Plants produce a lot of waste. What do they produce lots of that seems wasteful?

12. Animals and excesses

13. Stable Ecosystems
Most ecosystems are very stable so MOST of the biomass and chemicals in the ecosystem are constantly recycled. Q: Why are ecosystems not usually “closed loops”? Give some examples of reasons that might stop an ecosystem being closed loop. E.g. Rivers carry branches away from the ecosystem.

14. Plenary
Describe briefly what a closed loop ecosystem is and they it is hard to achieve.