The Eucalyptus Tree in Australia

Importance

• it provides 31. and food for a wide range of species
• its leaves provide 32. which is used to make a disinfectant

Reasons for present decline in number

A) Diseases

• (i) 'Mundulla Yellows'
  • Cause: lime used for making 33. was absorbed
  • trees were unable to take in necessary iron through their roots
• (ii) 'Bell-miner Associated Die-back'
  • Cause: 34. feed on eucalyptus leaves
  • they secrete a substance containing sugar
  • bell-miner birds are attracted by this and keep away other species

B) Bushfires
William Jackson's theory:

• high-frequency bushfires have impact on vegetation, resulting in the growth of 35.
• mid-frequency bushfires result in the growth of eucalyptus forests, because they:
  • make more 36. available to the trees
  • maintain the quality of the 37.
• low-frequency bushfires result in the growth of 38. rainforest', which is:
  • a 39. ecosystem
  • an ideal environment for the 40. of the bell-miner