READING You should spend about 20 minutes on Questions 27-40, which are based on
PAS SAG E 3 Reading Passage 3 below.
The accidental rainforest
According to ecological theory, rainforests are supposed to develop slowly over millions ofyears. But
now ecologists are being forced to reconsider their ideas
When Peter Osbeck, a Swedish priest, stopped off luxuriant imported ones. And as botanist David
at the mid-Atlantic island of Ascension in 1 752 Wilkinson of Liverpool John Moores University in
on his way home from China, he wrote of 'a heap the UK pointed out after a recent visit to the island,
of ruinous rocks ' with a bare, white mountain in it goes to the heart of some of the most dearly held
the middle. All it boasted was a couple of dozen tenets of ecology. Conservationists ' understandable
species of plant, most of them ferns and some of concern for the fate ofAscension's handful ofunique
them unique to the island. species has, he says, blinded them to something
quite astonishing - the fact that the introduced
And so it might have remained. But in 1 843 British species have been a roaring success.
plant collector Joseph Hooker made a brief call on
his return from Antarctica. Surveying the bare earth, Today's Green Mountain, says Wilkinson, is ' a
he concluded that the island had suffered some fully functioning man-made tropical cloud forest'
natural calamity that had denuded it of vegetation that has grown from scratch from a ragbag of
and triggered a decline in rainfall that was turning species collected more or less at random from all
the place into a desert. The British Navy, which by over the planet. But how could it have happened?
then maintained a garrison on the island, was keen Conventional ecological theory says that complex
to improve the place and asked Hooker's advice. He ecosystems such as cloud forests can emerge
suggested an ambitious scheme for planting trees only through evolutionary processes in which
and shrubs that would revive rainfall and stimulate each organism develops in concert with others to
a wider ecological recovery. And, perhaps lacking fill particular niches. Plants co-evolve with their
anything else to do, the sailors set to with a will. pollinators and seed dispersers, while microbes in
the soil evolve to deal with the leaf litter.
In 1 845 , a naval transport ship from Argentina
delivered a batch of seedlings. In the following But that's not what happened on Green Mountain.
years, more than 200 species of plant arrived from And the experience suggests that perhaps natural
South Africa. From England came 700 packets rainforests are constructed far more by chance than
of seeds, including those of two species that by evolution. Species, say some ecologists, don't so
especially liked the place: bamboo and prickly much evolve to create ecosystems as make the best
pear. With sailors planting several thousand trees of what they have. 'The Green Mountain system is
a year, the bare white mountain was soon cloaked a man-made system that has produced a tropical
in green and renamed Green Mountain, and by the rainforest without any co-evolution between its
early twentieth century the mountain's slopes were constituent species,' says Wilkinson.
covered with a variety of trees and shrubs from all
over the world. Not everyone agrees. Alan Gray, an ecologist at
the University of Edinburgh in the UK, argues that
Modern ecologists throw up their hands in horror at the surviving endemic species on Green Mountain,
what they see as Hooker's environmental anarchy. though small in number, may still form the
The exotic species wrecked the indigenous framework of the new ecosystem. The new arrivals
ecosystem, squeezing out the island's endemic may just be an adornment, with little structural
plants. In fact, Hooker knew well enough what importance for the ecosystem.
might happen. However, he saw greater benefit in
improving rainfall and encouraging more prolific But to Wilkinson this sounds like clutching at
vegetation on the i sland. straws . And the idea of the instant formation of
rainforests sounds increasingly plausible as research
But there is a much deeper issue here than the reveals that supposedly pristine tropical rainforests
relative benefits of sparse endemic species versus from the Amazon to south-east Asia may in places
- T E ST 5 , R E A D I N G M O D U L E
be little more than the overgrown gardens of past arriving. But in their urgency to protect CndCfn H '
rainforest civilisations. ecologists are missing out on the study of it �tl' ; l l
enigma.
The most surprising thing of all is that no ecologists
have thought to conduct proper research into this 'As you walk through the forest, you see lots o r
human-made rainforest ecosystem. A survey of leaves that have had chunks taken out o f them hy
the island's flora conducted six years ago by the various insects. There are caterpillars and beetles
University of Edinburgh was concerned only with around,' says Wilkinson. ' But where did they come
endemic species. They characterised everything from? Are they endemic or alien? If alien, did they
else as a threat. And the Ascension authorities come with the plant on which they feed or discover
are currently turning Green Mountain into a it on arrival? ' Such questions go to the heart of how
national park where introduced species, at least the rainforests happen.
invasive ones, are earmarked for culling rather than
conservation. The Green Mountain forest holds many secrets.
And the irony is that the most artificial rainforest
Conservationists have understandable concerns, in the world could tell us more about rainforest
Wilkinson says. At least four endemic species have ecology than any number of natural forests.
gone extinct on Ascension since the exotics started
Questions 27-32
Do the following statements agree with the information given in Reading
Passage 3 ?
In boxes 27-32 on your answer sheet write
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
27 When Peter Os beck visited Ascension , he found no inhabitants on the island .
28 The natural vegetation on the island contained some species which were
found nowhere else.
29 Joseph Hooker assumed that human activity had caused the decline in the
island's plant life.
30 British sailors on the island took part in a major tree planting project.
31 Hooker sent details of his planting scheme to a number of different countries.
32 The bamboo and prickly pear seeds sent from England were unsuitable for
Ascension.
T E ST 5, R E AD I N G M O D U LE -
Questions 33-37
Complete each sentence with the correct ending A-G from the box below.
Tip Strip
• In sentence c:ompletion Write the correct letter A-G in boxes 33-37 on your answer sheet.
taskS using : a box.of
answers, 'the endings
. will often all be of the 33 The reason for modern conservationists' concern over Hooker's tree planting
same structure. You
. have to think about the programme is that
meaning to do the task,
not the g rammar. 34 David Wilkinson says the creation of the rainforest in Ascension is important
because it shows that
35 Wilkinson says the existence of Ascension's rainforest challenges the theory
that
36 Alan Gray questions Wilkinson's theory, claiming that
37 Additional support for Wilkinson's theory comes from findings that
A other rainforests may have originally been planted by man .
e many of the island's original species were threatened with destruction.
C the species in the original rainforest were more successful than the
newer arrivals.
o rainforests can only develop through a process of slow and complex
evolution.
E steps should be taken to prevent the destruction of the original
ecosystem .
F randomly i ntroduced species can coexist together.
G the introduced species may have less ecological significance than the
original ones.
T E ST 5 , R E AD I N G M O D U L E
Questions 38-40
Choose the correct letter, A, B, C or D.
Write your answers in boxes 38-40 on your answer sheet.
38 Wilkinson suggests that conservationists' concern about the island is
misguided because
A it is based on economic rather than environmental principles.
B it is not focusing on the most important question.
C it is encouraging the destruction of endemic species.
D it is not supported by the local authorities.
39 According to Wilkinson , studies of insects on the island could demonstrate
A the possibility of new ecological relationships.
B a future threat to the ecosystem of the island .
C the existence of previously unknown species.
D a chance for the survival of rainforest ecology.
40 Overall , what feature of the Ascension rainforest does the writer stress?
A the conflict of natural and artificial systems
B the unusual nature of its ecological structure
C the harm done by interfering with nature
D the speed and success of its development
T E S T 5, R E A D I N G M O D U L E
