19.6 Succession

Question 1

What is succession

Answer 1

The term used to describe changes, over time, in the species that occupy a particular area

Question 2

How does succession take place

Answer 2

In a series of stages, at each stage new species colonise the area and these may change the environment

Question 3

How may a species change an environment

Answer 3

1. Make it less suitable for the existing species

2. More suitable for other speces with different adaptation

Question 4

What is the first stage of succession

Answer 4

1. Colonisation of an inhospitable environment by a pioneer species

Question 5

What features may pioneer species have that makes them suit colonisation

Answer 5

1. Asexual reproduction so a single organism can rapidly multiply to build up a population
2. The production of vast quantities of wind-dispersed seeds or spores, so they can reach isolated situations like volcanic islands
3. Rapid germination of seeds upon arrival so they do not require a period of dormancy
4. The ability to photosynthesis, as light is normally available but other food stores are not.
5. The ability to fix nitrogen from the atmosphere, because, even if there is soil, it has few or no nutrients
6. Tolerance to extreme conditions

Question 6

What is a climax community

Answer 6

The final stage of succession. It remains stable over a long period of time.

It is where the state comprises a balanced equilibrium of species with few, if any, new species replacing those that have become established

Question 7

What are the common features that emerge during any succession

Answer 7

1. The abiotic environment becomes less hostile
2. A greater number and variety of habitats and niches emerge
3. The greater number of habitats increases biodiversity
4. More complex food webs leading to increased biomass

Question 8

What determines a climax community

Answer 8

Climate

could be forest or rainforest, depending on climate

Question 9

What is another type of succession

Answer 9

Secondary succession. When land that has already sustained life if suddenly altered. This may be man made (logging) or natural (forest fire)

Question 10

Why is it when rapid succession occurs does a return to a climax community happen quicker

Answer 10

Because soil already exists in which spores and seeds often remain alive in the soil

Question 11

Succession diagram

Answer 11

barren land -> primary colonisers -> secondary colonisers -> tertiary colonisers -> scrubland -> Climax species