Monday, April 28, 2008

Worm & Anti-worm Tanks

One of the projects that some groups did other than the decomposition chambers are the worm and anti-worm tanks. This was also to see which tank would rot faster.
This is the Worm tank (the tank with the earthworms):














And this is the Anti-worm tank:














The differences that can be easily seen are that the layers of the worm tank are more shallow than the anti-worm tank, as well as the anti-worm tank decomposing more slower than the worm tank. This is the result I expected, because worms are a decomposer themselves, and with the extra decomposers, the worm tank rots more faster than the anti-worm tank.

This is the result:

Worm tank before - Total = 15cm; leaf layer = 25cm; compost layer = 17cm; soil layer = 5cm.

Worm tank after - Total = 15cm; leaf layer = 15m; compost layer = 9.5 cm; soil layer = 5.3cm.

Anti-worm before: Total = 26cm; leaf layer = 26cm; compost layer = 19cm; soil layer = 5cm.

Anti-worm after: Total = 19cm; leaf layer = 19cm; compost layer = 15cm; soil layer = 5cm.

Or, if you’re more visual, here are the results as a graph:

The reason why the soil layer in the worm tank has increased is because of the worms; worm poo is like good quality soil. The anti-worm tank doesn't have any worms, so the soil layer didn't increase. Worms eat compost more better than leaves, so that's why the leaf layer didn't decrease and only the compost layer decreased and the soil layer increased (because of the poo). Leaves are big, so they're a bit too hard to digest (even worms & bacteria are picky sometimes). Even if there aren't any decomposers seen, there are still some bacteria which can help in the decomposition process, so that's why the anti-worm tanks have decreased layers too, but not as much as worms.

This is my last science post for Riolu's blog world, I guess. T.T so sad...

The Food Pyramid (Biomass Pyramid)

A biomass pyramid is another way to show which organism eats what. So it's kind of like a food web, but a biomass pyramid shows the energy flow too (I'll explain how this works).
A biomass pyramid looks like a pyramid for a start (or a triangle at least) and is divided into the amount of consumers (e.g. 4 for a chimpanzee's biomass pyramid; Fruits- insects- chimps- leopards). The layer at the very bottom is mainly the producers (plants). The reason why the layers get smaller as it goes to the top, is because of the amount of population of an organism needed to sustain the amount of energy for the organism (predator) above. E.g. 2 chimps are needed to feed 1 crocodile.