A CLOSED ECOSYSTEM
Knowledge that the pupils need before the lesson:
Before this lesson it might be a good idea to review the basics of photosyntesis with the pupils.
They need to know what factors affect plant growth (e.g. water, sunlight, carbondioxide and
nutrients) and how lack of one or many of these factors affect the plants. This lesson might also be
used as an introduction to photosyntesis, but in that case the pupils might not know exactly what a
plant needs to be able to grow (which might make it interesting).
Purpose of the lesson:
In this lesson the pupils will ”design” their own ecosystem. They will have to think about what
factors are important for their plants to be able to grow as much as possible.
Material:
A transparent glass jar with a lid. (It could be interesting to let one group of students use a glass jar
with tinted glass which would shut out more of the suns radiation.
Different types of soils:
Soil that is rich in humus, sandy soil, compost soil, the pupils may even bring soil from their own
garden (or greenhouses)
Different types of plants:
Seeds, succulents (e.g. small cactuses) or parts cut from plants (pupils may bring their own plants if
they wish)
The pupils may chose to add water and nutrients. If the lesson is in early autumn the pupils may add
earthworms (or some other invertebrate) to their ecosystem to produce carbondioxide.
What the pupils should do during the lesson:
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They will first make a plan of what “ingredients” to use in their ecosystem to make it thrive.
They will decide on what type of soil to use, what type of plants or seeds to use, how much
water they will add and they can also chose to add nutrients.
They will build their own ecosystem and write down the “recipe”. To be able to remember
what the ecosystem looked like they should take a picture of the ecosystem to add to their
final report.
The pupils will also write down a hypothesis on how well they think their ecosystem will
survive. They should consider what might go wrong and what they think will make their
ecosystem successful.
During the following months the pupils will make notes on a weekly basis on how their ecosystems
are growing and what changes are seen. If the project is started in autumn the pupils could watch
their ecosystems during the entire school year.
After a certain amount of time has passed (chosen by the teacher) the pupils will end their project
by comparing their ecosystem to those of other groups. The pupils will then summarize the project
by writing a final report, completed with pictures and the pupils own thoughts on how they could
have made their ecosystems more successful/what made their ecosystems successful compared to
their classmates ecosystems.
Below are two pictures of a closed ecosystem:
Växt med
rot
Stickling
Växtkompostmylla
Frön
Lecakulor och finsand
Picture taken on the first day
Picture taken five months later