23.1 - Ecosystems

Question 1

Define ecosystem

Answer 1

All living and non-living interacting components of an area

Question 2

State the biotic factors affecting ecosystems

Answer 2

• Predation
• Food supply
• Disease
• Competition

Question 3

Define community & population

Answer 3

Community – All population of living organisms in a habitat

Population - A group of interbreeding organisms from one species

Question 4

State the names of abiotic factors affecting ecosystems.

Answer 4

• Water availability
• Edaphic factors (soil)
• Oxygen availability
• Temperature
• Light

Question 5

How does light & temperature affect ecosystems?

Answer 5

Light

• Affects plants > required for photosynthesis
• Plants adapt to light conditions (e.g. larger leaves for low light levels)

Temperature

• Affects enzyme-controlled metabolic reactions
• Can trigger species migration if temp. changes
• Ectothermic animals develop faster as they don’t maintain internal temp. like endothermic animals

Question 6

How does O2 availability, water availability & edaphic factors affect ecosystems?

Answer 6

Water availability

• Lack of water = stress = fatality
• Keeps cells rigid, increasing hydrostatic skeleton for plants
• Required for photosynthesis

Oxygen availability

• In aquatic ecosystems – need fast flowing cold water to increase oxygen conc.

Edaphic factors (soil type)

• Clay – fine particles, easily waterlogged, forms clumps when wet
• Loam – different sized particles, retains water, doesn’t become waterlogged

Sandy – coarse, well-separated particles, free draining, doesn’t retain water and is easily eroded