7C Succession

Question 1

Define primary succession

Answer 1

Succession that happens on land that’s been newly formed or exposed

Question 2

Define secondary succession

Answer 2

Succession that happens on land that has been cleared from all the plants

Question 3

How does primary succession occur

Answer 3

When species colonise a new area, seeds and sores or blown in by the wind and begin to grow. The first species to colonise an area the pioneer species

The abiotic conditions are hostile and therefore only pioneer survive because they are adapted to cope in the harsh conditions

The pioneer species change the abiotic conditions as they die and microorganisms decompose the dead organic matter this forms soil

This make conditions less hostile so new organisms with different adaptations can move in, these then die and are decomposed adding more organic matter making the soil deeper and richer in minerals so larger plants can start to grow which retains more water

Some new species may change the environment making it less suitable for the previous species

Question 4

Define pioneer species

Answer 4

The first species to colonise an area

Question 5

How does secondary succession occur

Answer 5

It happens in the same was as primary succession but as there is already a layer of soil it starts at a later stage. The pioneer species are larger plants

At each stage different plants and animals that are better adapted for the improved conditions move in, outcompete the ones already there and become the dominant species in the ecosystem

As succession goes on the ecosystem becomes more complex, new species move in alongside existing ones so biodiversity increases

The final stage is the climax community where the ecosystem is supporting the largest and most complex community of plants and animals it can

Question 6

Define climax community

Answer 6

When the ecosystem is supporting the largest and most complex community of plants and animals it can

Question 7

What is the climax community for a particular climate called

Answer 7

its climatic climax

Question 8

In a temperate climate what species are there

Answer 8

Large trees due to the plentiful amount of water and mild temperatures

Question 9

In a polar climate what species are there

Answer 9

Herbs and shrubs only due to the lack of water, low temperatures and big changes between seasons

Question 10

How can human activities prevent conservation

Answer 10

A regularly mown grassy field won’t develop shrubs and trees even if the ecosystem could support them as the growing points are cut off by the lawn mower so larger plants can’t establish themself

The longer the interval between mowing the further succession can progress and the more biodiversity increases

Question 11

Define conservation

Answer 11

the protection and management of ecosystems

Question 12

What does conservation sometimes involve

Answer 12

preventing succession

Question 13

Ways to manage succession to conserve the moorland ecosystem

Answer 13

Animals are allowed to graze on the land- the animals eat the growing points which stops plants from establishing themselves and helps keep vegetation low

Managed fires are lit, after the fires secondary succession will occur the pioneer species are the ones being conserved. Larger species take longer to grow back and will be removed again next time the moor is burnt