Book 17, Question 33
Why Does a Fallen Leaf Disappear in Just a Few Weeks?
A fallen leaf disappears in just a few weeks because decomposers like fungi, bacteria and termites work very fast in the warm, wet rainforest.
In the warm, wet air of the rainforest, decomposers work very quickly. Fungi, bacteria, termites, and other tiny animals break down dead leaves into simple nutrients that plants can use again. In a cooler forest, a leaf might last a year or more, but in a rainforest it can be gone in weeks!
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Quick answers
How much breaks down in a year?
At most of the sites, more than 95 percent of the leaf material was gone within a year.
Do small animals help?
Keeping small animals like mites and springtails out cut the breakdown speed in half, on average.
Source: UMN
More fun facts
- Scientists tested how fast dead leaves break down in 23 tropical forests in 14 countries.
- At most of the sites, more than 95 percent of the leaf material was gone within a year.
- They put the same plant materials, including bay leaves, in small mesh bags, called litterbags, and checked how much was left over time.
- Some bags had tiny holes that let in only bacteria, fungi and very small creatures.
- Other bags had bigger 2 mm holes that also let in small animals like mites, springtails and some earthworms.
- Keeping those small animals out cut the breakdown speed in half, on average.
- Leaves broke down faster in forests that got more rain each year.
Sources: UMN
Questions kids ask
How much rain did the test forests get?
Yearly rainfall at the sites ranged from 760 to 5,797 mm.