Abiotic factors - data
Non-living elements of an ecosystem, such as climate, temperature, water, and soil type. factors are non-living. They include light intensity, temperature and moisture levels. The abundance and distribution of living organisms in an The living organisms in a particular area, together with the non-living components of the environment. are affected by abiotic factors.
The effect of abiotic factors on organisms
A shingle beach has small stones instead of fine sand. Plant seeds can lodge between the small stones and start to grow, particularly at the top of the shore away from the waves. Two students set up a A line created, for instance, with a tape measure, along which sampling occurs. along a shingle beach. They started at top of the beach and worked towards the sea. Every five metres they placed a A square frame of known area used for sampling the abundance and distribution of slow or non-moving organisms. on the beach and measured the height of all the plants found in each quadrat. They found the mean of this data; their results are presented in a graph below.
Question
What conclusions can you draw from this data about the mean plant height? Use numbers in your answer. [2 marks]
The average height of plants falls from 60 cm at the top of the shore to less than 10 cm after 25 metres [1 mark]. After this no plants were found [1 mark].
They also recorded the depth of the soil (an abiotic factor).
| Distance from top of shore (m) | Soil depth (cm) |
| 0 | 16 |
| 5 | 13 |
| 10 | 14 |
| 15 | 7 |
| 20 | 5 |
| 25 | 1 |
| 30 | 0 |
| 35 | 0 |
| 40 | 0 |
| Distance from top of shore (m) | 0 |
|---|---|
| Soil depth (cm) | 16 |
| Distance from top of shore (m) | 5 |
|---|---|
| Soil depth (cm) | 13 |
| Distance from top of shore (m) | 10 |
|---|---|
| Soil depth (cm) | 14 |
| Distance from top of shore (m) | 15 |
|---|---|
| Soil depth (cm) | 7 |
| Distance from top of shore (m) | 20 |
|---|---|
| Soil depth (cm) | 5 |
| Distance from top of shore (m) | 25 |
|---|---|
| Soil depth (cm) | 1 |
| Distance from top of shore (m) | 30 |
|---|---|
| Soil depth (cm) | 0 |
| Distance from top of shore (m) | 35 |
|---|---|
| Soil depth (cm) | 0 |
| Distance from top of shore (m) | 40 |
|---|---|
| Soil depth (cm) | 0 |
Question
What conclusions can you draw from this data? Use numbers in your answer. [2 marks]
The soil depth decreases from 16 cm at the top of the shore to 1 cm after 25 metres down it [1 mark]. Beyond this there was no soil [1 mark].
Question
What conclusion can you draw from the number of plants and the depth of soil? [1 mark]
As the depth of soil decreased so did the average height of plants.
Hint - It would be incorrect to state that the soil depth controlled the growth of plants unless you had further evidence.
More guides on this topic
- What happens during photosynthesis? - OCR 21st Century
- How do producers get the substances they need? - OCR 21st Century
- How do producers transport the substances they need?
- How are organisms in an ecosystem interdependent? - OCR 21st Century
- How are levels maintained within an ecosystem? - OCR 21st Century
