Decomposers

1. Decomposers BC Science Probe 7 Section 2.5 Pages 44-47

2. Decomposers • Earth is like a spaceship: • Once it has been launched, nothing more can be added to it. • Air and water must be recycled or the astronauts will die.

3. Decomposers • The same is true on Earth. • Life depends on the recycling of matter. • How does this work?

4. Decomposers • Food chains and food webs show how matter and energy move from one organism to another. • Decomposers are an important part of this cycle.

5. Decomposers • Decomposers break down their food and use up the last of the energy in the food chain. • At the same time, the release nutrients. • Nutrients are chemical substances that organisms need to grow and survive.

6. Decomposers • Nutrients can be released into the soil, water or air.

7. Decomposers • Then the nutrients can be taken up by plants and used again to help the plants grow.

8. Decomposers • Decomposers keep matter moving between the living and non-living parts of the ecosystem!

9. Decomposers • Even though decomposers are small, they do a lot of work. • Imagine what your yard, or the park would look like if years of grass clippings and fallen leaves were still in their original forms!

10. Decomposers • No decomposers = nutrients locked in dead plants. • Decomposers, like moulds and bacteria, break down matter and turn it into the nutrients that living things need every day.

12. Composting • Composting uses decomposers to break down kitchen waste or plant scraps.

13. Composting • In a compost ecosystem, small detrivores like earthworms, mites, grubs, insects and nematodes, chew, digest and mix the waste.

14. Composting • Then the decomposers like fungi and bacteria break down the waste more. • This makes the nutrients available to plants when you put the compost on a garden. • Kind of like a vitamin pill for a garden.

15. Dying Salmon • When salmon return from the ocean to their home stream, they reproduce then die. • Don’t be sad! • This helps to ensure the survival of the species.

16. Dying Salmon • Detrivores like gulls, eagles and bears eat a bunch of the dying and dead salmon.

17. Dying Salmon • The bacteria and fungi finish breaking down the dead fish and turn the tissue into a liquid. • This allows the nutrients from the salmon to dissolve in the stream.

18. Dying Salmon • In the spring, plankton are nourished by the nutrients in the stream and the salmon fry will eat the plankton.

19. Dying Salmon • The nutrients from the salmon either in the stream, or leftover from the ones the bears and wolves try to eat, also nourish the forest.