Succession

Question 1

Define succession

Answer 1

The changes which occur over time in the species that occupy a particular area.

Question 2

What is the first stage of succession?

Answer 2

The colonisation of an inhospitable environment by organisms called pioneer species.

Question 3

What features do pioneer species often have that suit them to colonisation?

Answer 3

1. The production of vast quantities of wind-dispersed seeds or spores
2. Rapid germination of seeds on arrival -> eliminates period of dormancy
3. Ability to photosynthesise -> light is normally available but other food is not
4. Ability to fix nitrogen from the atmosphere -> soil will have few or no nutrients
5. Tolerance to extreme conditions

Question 4

What are the common features of succession?

Answer 4

1. the non-living environment becomes less hostile
2. a greater number and variety of habitats
3. increased biodiversity
4. more complex food webs
5. increased biomass

Question 5

What does succession do to sudden alteration begin with?

Answer 5

Spores and seeds that remained alive in the soil, influx of animals and plants through dispersal and migration from surrounding areas.

Question 6

Climax communities

Answer 6

are in stable equilibrium with the prevailing climate -> determined by the main abiotic factor

Question 7

Conservation

Answer 7

The management of the Earth’s natural resources in such a way that maximum use of them can be made in the future.

Question 8

The main reasons for conservation are:

Answer 8

1. Ethical
2. Economic -> long-term productivity is greater if ecosystems are maintained in their natural balanced state
3. Cultural and aesthetic -> Habitats and organisms enrich our lives.

Question 9

Why is managing succession necessary?

Answer 9

Many species that existed in earlier stages are no longer present in the climax community due to succession removing their habitat or out-competition by other species.