Decomposition — Science definition
Defined in 2 courses:
- Biological breakdown and transformation of organic material into other matter stores and forms. (Science 6: Matter, Energy & Earth Systems)
- Breakdown of dead material by fungi, bacteria and small animals feeding on it, which returns carbon to the air and nutrients to the soil. (Life Science & Scientific Inquiry)
Where it is taught
- Cycling Matter Through Organisms & Environment — Ecosystems, Watersheds & Conservation, Science 6: Matter, Energy & Earth Systems, Grade 6
- Decomposition, Soil & Nutrient Availability — Ecosystems, Matter & Energy, Life Science & Scientific Inquiry, Grade 7
In use
The fast loop runs through photosynthesis, respiration and decomposition in days to decades.
Cycling Matter Through Organisms & Environment
Decomposition is a biological process carried out by living organisms, so anything that affects those organisms affects the rate — and that is the key to this unit, because it explains both why tropical soils and arctic soils behave so differently and why a compost heap works faster when you turn it.
Decomposition, Soil & Nutrient Availability
Questions using decomposition
Problem 1
- decomposition: Biological breakdown and transformation of organic material into other matter stores and forms.
- Decomposers make matter disappear.
- Recycling matter automatically recycles all usable energy.
- One illustrative result establishes every real condition and needs no further evidence.
Answer and explanation
decomposition: Biological breakdown and transformation of organic material into other matter stores and forms.
Biological breakdown and transformation of organic material into other matter stores and forms. Soil: 20 − 5 + 3 = 18 units. Plants: 8 + 5 − 2 = 11. Animals: 2 + 2 − 3 = 1. The total remains 30 units. These are simplified nutrient-account units, not a complete real decomposition pathway or energy total; actual stores and processes would be more detailed.
Problem 2
- Changed water content
- Correct units alone
- A stated interval alone
- A labeled table alone
Answer and explanation
Changed water content
Water differences affect wet mass independently of dry organic material loss.