Ecosystems

Question 1

What is an ecosystem?

Answer 1

The combination of all the organisms (biotic factors) living in a community and all the non-living features (abiotic factors) with which they interact.

Question 2

What is a community?

Answer 2

A group of different populations in an area or habitat.

Question 3

What causes the distribution of different Australian ecosystems?

Answer 3

This distribution is caused by variations in biotic and abiotic factors found in each area.

Question 4

What are the main abiotic factors that affect organisms in terrestrial environments?

Answer 4

Rainfall, temperature, soil

Question 5

What are the main abiotic factors that affect organisms in aquatic environments?

Answer 5

Salt concentration, light availability, pressure,

Question 6

What are the two main types of aquatic environments? Provide examples.

Answer 6

Saltwater/ Marine environments. Eg. coral reefs

Freshwater environments. Eg. lakes

Question 7

Describe some of the features of deserts.

Answer 7

Annual rainfall is less than 250mm
High temp. during day (40), low during night (0).
Sandy, rocky soil
Sparse grasses, mice, insects, reptiles

Question 8

Describe some of the features of grasslands.

Answer 8

Annual rainfall 250-750mm
High/mild temp.
Grasses (eg. spinifex), kangaroos, snakes

Question 9

Describe some of the features of shrublands.

Answer 9

Annual rainfall 200-400mm
High temp.
Mallee trees, kangaroos, snakes

Question 10

Describe some of the features of woodlands.

Answer 10

Annual rainfall 400-750mm
High/mild temp.
Canopy cover 10-30%
Grasses, shrubs, eucalypt trees, birds, insects, wallabies

Question 11

Describe some of the features of temperate forests.

Answer 11

Annual rainfall greater than 750mm
Mild temp.
Canopy cover 30-70%
Eucalypt trees

Question 12

Describe some of the features of tropical rainforests.

Answer 12

Annual rainfall greater than 2500mm
Humid, mild/high temp.
Canopy cover 70-100%
Layers/strata develop (eg understory)
Birds, ferms, palms,

Question 13

How do abiotic factors present selection pressures on organisms?

Answer 13

An organism’s environment provides nutrients, water, shelter. Other organisms compete with it for these resources. This competition for abiotic factors means that species with favourable characteristics (adaptations) will survive and reproduce