ecosystem dynamics - fire

Question 1

causes of fire

Answer 1

-only caused naturally from lightning and lava
-94% of bushfires are caused by humans
-caused by agricultural, accidental or arson

Question 2

immediate effects of fire

Answer 2

-loss of vegetation
-reduction of leaf litter
-decrease in animal numbers
the severity of impact depends on kind of fire (canopy vs understudy), intensity & scope

Question 3

impacts on interactions in community

Answer 3

-ash creating nutrient rich soil
-new open spaces offering more light availability
-vulnerable to effects of drying out in hot areas
-changes in amount of rain
-species of bottlebrush, hakeas, some acacia and eucalypts regenerate from seeds released due to the amount of fire

Question 4

fire damage

Answer 4

-stimulates regrowth in other species
-smoke particles signal growth in others
-new growth attracts mobile species such as wallabies, birds and small mammals and insects
-new growth supports species such as wombats & echidnas that survive in burrows
-fire is rapid & dramatic, but ecosystems can reestablish over time

Question 5

natural disturbances

Answer 5

followed by succession

Question 6

black saturday

Answer 6

-series of bushfires in victoria saturday 7th feb 2009, australias biggest loss of life from bushfire
-173 died 414 injured
-worst bushfire conditions ever in vic
-temperatures were mid to high 40, wind speeds 100km/hr+, 2 months of little to no rain, with intense heat wave day 1

Question 7

fire ignition causes

Answer 7

-fallen/clashing power lines
-deliberately lit (arson)
-lightning strikes
-sparks from power tools
-cigarette butts

Question 8

preventative measures (fire)

Answer 8

-keeping trees away from power lines
-removing leaves from gutters
-controlled burns
-fire breaks (areas where all fire fuels have been cleared)