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Question 19M.3.SL.TZ2.14b

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Date May 2019 Marks available [Maximum mark: 2] Reference code 19M.3.SL.TZ2.14b
Level SL Paper 3 Time zone TZ2
Command term Explain Question number b Adapted from N/A
b.
[Maximum mark: 2]
19M.3.SL.TZ2.14b

The photograph shows small, isolated Eucalyptus forest fragments in New South Wales, Australia, as part of a long-term experiment on habitat fragmentation.

[Source: Margules, C. (1992). The Wog Wog Habitat Fragmentation Experiment. Environmental Conservation, 19(4),
316–325 © Foundation for Environmental Conservation 1992, published by Cambridge University Press]

(b)

Explain the likely effects on biodiversity if a forest becomes fragmented.

 

[2]

Markscheme

a. reduction in diversity in fragmented forest as a whole ✔

b. greater diversity towards the edge ✔

c. new species appear/immigration of new/alien/invasive species ✔

d. local species decrease/emigrate
OR
unable to move between fragments ✔

e. faster species turnover than core forest ✔

Examiners report

Most candidates could state the abiotic effects that increased in a fragmented forest and were able to explain one effect of fragmentation on biodiversity. Few candidates gave an explanation in terms of the edge effect.