Populations Flashcards
1
Q
How does succession occur?
A
- Pioneer species colonise the inhospitable environment
- Lichens die and decompose, releasing nutrients into the soil which changes the abiotic environment so other organisms are introduced
- Continued weathering and erosion of rock builds up more soil
- Competition and succession continues
2
Q
What effects does succession produce?
A
- Less hostile environments
- Greater variety of habitats
- More complex food webs and increased biomass
3
Q
Why does secondary succession take place more quickly?
A
Because seeds still remain in the soil and animals will migrate from the surrounding areas
4
Q
What is the UK climax community?
A
Oak woodland
5
Q
Why should we conserve?
A
- Other species have occupied the Earth longer than us and we should respect living things
- Living organisms contain a variety of genes from which we can make other substances
- Variety enriches our lives and inspires us
6
Q
Why is bare rock initially colonised?
A
- A glacier retreats and deposits rock
- Sand is piled into dunes
- Volcanoes erupt and deposit lava
- Mud is deposited at river estuaries
