ecosystem dynamics - habitat destruction & conservation strategies

Question 1

habitat destruction

Answer 1

-destroyed due to urbanisation, manufacturing, agriculture, forestry, mining & fishing
-leads to habitat loss which reduces species richness and threatens biodiversity. when a habitat is lost its species of vulnerable to extinction

Question 2

urbanisation

Answer 2

-extreme modification of an ecosystem by humans to support a human population of gradually increasing density
-little recycling of matter between community & environment
-reduced biodiversity and are dominates by humans
-additional inputs of energy & matter are needed to maintain modern standards of living

Question 3

agriculture

Answer 3

-practice of farming, cultivating soil, growing crops, raising animals, preparation of plant & animal products for market
-20% of australia’s forests have been used for agriculture, 90% cleared in fertile areas in south eastern australia
-causes habitat destruction due to land clearing, especially to endangered species

Question 4

case study: carnaby’s cockatoo

Answer 4

-heavily affected by the growth of the greater perth metropolitain area
-environmental conservation management strategies are used by Perth Zoo, animals are bred for release
-Kaarkakin Black Cockatoo Conservation centre rescues and rehabilitates sick and injured cockatoos

Question 5

habitat fragmentation

Answer 5

-occurs when some parts of the habitat of the ecosystem are separated into isolated sections
-no interbreeding between subpopulations
-no sharing of genetic diversity, loss of resilience

Question 6

gondwana link program

Answer 6

-reconnects fragmented habitats across southwest australia
-if goal is reached 1000km of continuous habitat will be connected
-traditional land managers, organisations, farmers and conservation strategies have worked together to bridge gaps of cleared land

Question 7

land and soil degradation

Answer 7

-lead by overgrazing and hard hooves of animals
-shallow rooted plants have a higher frequency of growing in degraded land
-topsoil becomes more vulnerable to abiotic factors (e.g. wind, rain)
-pastoral grasses & fertilisers have lead to soil organisms suffering with less structural stability and topsoil maintenance

Question 8

dryland salinity

Answer 8

-over 1 mil hectares of agricultural land affected
-caused by removal of deep rooted, perennial, native vegetation

Question 9

salinity

Answer 9

-refers to the concentration of salt in soil
-if salinity is too high crops can no longer grow, making the soil infertile
-happens when natural vegetation is replaced with crops requiring irrigation

Question 10

steps leading to dryland salinity

Answer 10

1. human population increases, leading to increase food consumption
2. farming increases, with further clearing of deep-rooted trees
3. removal of deep-rooted native perennial species and planting shallow rooted annual crops. deep-rooted native plants remove water from underground aquafers, using in transpiration balancing input output. now transpiration and evaporation are prevented
4. watertable rises. salt from surrounding soil dissolves into water
5. water evaporates at soil surface, leaving behind salty, infertile soil