Questions 31-40
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
