Sucession

Question 1

Why are ecosystems dynamic

Answer 1

They’re constantly changing

Question 2

Define succession

Answer 2

An ecosystem changes over time

Question 3

What is primary succession

Answer 3

On land that’s newly formed or exposed exposed = bare rock

Eg. Volcano has just made new land. No soil or plants

Question 4

What is secondary succession

Answer 4

Land that’s been cleared to remove previous plants but soil remains
Eg. Deforestation

Question 5

Des I’ve how primary succession happens

Answer 5

1. Species colonise a new land surface = pioneer species
2. Seeds and pores are blown in the wind and grow
3. Abiotic = hostile
4. Pioneer species die and decompose forming humus
5. Abiotic = less hostile
6. New organisms can begun to grow
7. New species change the environment so it’s less suitable to the pioneer species

Question 6

Why can only pioneer species grow at the start

Answer 6

They specially adapted to cope with harsh conditions

Question 7

How does the death of pioneer species become less hostile

Answer 7

The decomposition forms humus
The basic soil allows better water retention
So more plants can grow with different adaptions
Forming deeper and richer soils
So Larger plants can grow

Question 8

What is the difference in the process of primary and secondary succession

Answer 8

Secondary already has soil so it starts at a later stage. So the pioneer species are larger

Question 9

How is competition involved in succession

Answer 9

At each stage better adapted plants out compete the current plants
And become the dominant species

Question 10

Why does biodiversity increase as succession goes on

Answer 10

The ecosystem becomes more complex and can support more orgs

Question 11

What is a climax community

Answer 11

The final stage of succession
The ecosystem is supporting the largest and most complex community it can
It won’t change

Question 12

Define climatic community

Answer 12

The climax community for a particular climate

Question 13

Why are trees in the climax community in temperate climates

Answer 13

High water availability
Mild temp
Not much change in seasons
Deep soils

Question 14

Why are shrubs In the climax community of polar climates

Answer 14

Low water availability
Low temp
Big changes In summer and winter
Poor soil quality

Question 15

What is plagioclimax

Answer 15

Human activities prevent succession ans stop the climax community being reached

Question 16

Define conservation

Answer 16

The protection and management of an ecosystem

Question 17

Give 2 ways to mange succession

Answer 17

1. Animal grazing

2. Managed fires

Question 18

How do lawn mowers stop a climax community

Answer 18

Cuts off growing points

Larger plants can’t get established

Question 19

How do grazing animals stop succession

Answer 19

Animals eat the growing points

Stopping trees establishing themselves

Question 20

How do managed fires stop succession

Answer 20

Secondary succession happens after

The pioneer species grows back but the land is burned again before the larger plants can establish themselves

Question 21

Give 4 conservation strategies

Answer 21

1. Seed banks for endangered species
2. Fishing quotas = limit the amount of fish allowed to be caught
3. Strict planning laws and regulations
4. Endangered species bred in captivity and retuned to the wild