ecological succession

Question 1

primary succession

Answer 1

• no previous plant life

- larva flows, beaches

Question 2

secondary succession

Answer 2

• disturbances remove some or all species

- soil remains

Question 3

community structure

Answer 3

• not static
• determined by succession
• disturbances :
• physical disasters
• humans or animals
• climate change
• competitive interactions

Question 4

pioneer species

Answer 4

• early successional
• little competition for space and resources
• hardy
• establish rapidly
• spores and seeds can disperse over long distances
• do not grow in shade
• grow up, stabilise and enrich soil
• alter the amount of light available by providing shade

Question 5

primary succession

Answer 5

• lichens
• do not need soil to survive
• they form soil
• add small amounts of organic matter
• mosses and other simple plants follow
• ferns, grasses begin to grow as the soil develops
• faunal pioneer species (ants, spiders, rodents, small birds)

Question 6

secondary succession

Answer 6

• annuals (herbs and weeds)
• a year later, grasses and perennials
• forest gaps allow for climbers to occur

Question 7

intermediate species

Answer 7

• more fertile soil
• temperatures less extreme, there is more shade
• soil builds up, the plant species begin to develop to small non-woody herbaceous plants, small hardy woody plants, larger shrubs, etc…
• larger herbivores and carnivores can now develop

Question 8

climax community

Answer 8

• semi-stable end stage of succession
• state of transition
• environmental fluctuations:
• rainfall (drought or floods can kill of species and leave the succession to start again)
• overgrazing (a species becomes dominant)
• draining of wetlands (permanently changing the environment)
• climate change (affects successional end points)
• invasion by aliens (replaces the dominant species)