Peat bogs contain a large amount of organic matter because dead plant material does not fully decompose.
Explain what is meant by the term decomposer.
Small insects called springtails feed on the dead organic matter in the peat bog. These springtails are then preyed upon by spiders. Use this information to draw a food chain for these organisms.
Scientists can measure the percentage of organic matter in soil. The method involves drying a sample of soil and then burning it to combust the organic material. The formula below is used to calculate the percentage of organic matter:
Percentage of organic matter=mass of dried soil−mass of burnt soilmass of dried soil×100 \text{Percentage of organic matter} = \frac{\text{mass of dried soil} - \text{mass of burnt soil}}{\text{mass of dried soil}} \times 100 Percentage of organic matter=mass of dried soilmass of dried soil−mass of burnt soil×100A trespasser entered a protected nature reserve through a peat bog. Soil samples were collected from the entrance of the nature reserve and from the boots of three suspects (X, Y, and Z).
| Soil from | Mass of dried soil in g\text{g}g | Mass of burnt soil in g\text{g}g | Percentage organic matter |
|---|---|---|---|
| Nature reserve entrance | 8 | 6 | 25 |
| Boot of Suspect X | 4 | 3 | 25 |
| Boot of Suspect Y | 4 | 3.6 | |
| Boot of Suspect Z | 4 | 3.2 | 20 |
Use the formula to calculate the percentage of organic matter in the soil from the boot of Suspect Y.
Which suspect is most likely to be the trespasser?
The suspect accused of being the trespasser claimed that the soil analysis was not reliable. Suggest one reason why the result may not be reliable.
