Succession and ecosystems Flashcards
What is primary succession?
Occurs on an area of land that has been newly formed like bare rock
No soil
What is secondary succession?
Occurs where soil is present
Give examples which would create primary succession
Volcanoes erupting and depositing lava
Formation of sand dunes
Silt and mud deposited at river estuaries
Glaciers retreating depositing rubble
What is each stage of succession called?
A seral stage
What is the order of the communities?
Pioneer community
Intermediate community
Climax community
List five adaptations of a pioneer community
1) Produce a large quality of seeds or spores
2) Seeds that germinate rapidly
3) Ability to photosynthesis
4) Tolerance to extreme environments
5) Ability to fix nitrogen
What supports the secondary colonisers?
Humus
What is the plagioclimax?
When succession is stopped artificially, the final stage of succession
Give examples of deflated succession
1) Grazing in agriculture
2) Removing existing vegetation to plant crops
3) Burning as a means of forrest clearance
What two factors change the abundance of organisms?
Immigration and births increase the number of individuals
Emigration and deaths decrease the number of individuals
Estimated number of population = Number of individuals ÷ area of sample
.
Estimated population size = no first sample x no second sample ÷ number of recaptured marked individuals
.
What is conservation?
The maintenance of biodiversity through human action or management
What is preservation?
Protection of an area by restricting or banning human interference
What are the three main reasons for conservation?
Economic
Social
Ethical
