A.
Itseems biodiversity has become a buzzword beloved of politicians,conservationists protesters and scientists alike. But what exactly is it? TheConvention on Biological Diversity an international agreement to conserve and share the planet's biological riches, provides a good working definition:biodiversity comprises every form of life, from the smallest microbe to the largest animal orplant, the genes that give them their specific characteristics and the ecosystems of which they are a part.
B.
In October, the World Conservation Union (also known as theIUCN) published its updated Red List of Threatened Species, a rollcall of 11,167 creatures facing extinction – 121 more than when thelist was last published in 2000. But the new figures almost certainly underestimate the crisis. Some 1.2 million species of animal and 270,000 species of plant have been classified, but the well-being ofonly a fraction has been assessed. The resources are simply not available. The IUCN reports that 5714 plants are threatened, for example, butadmits that on1y 4 per cent of known plants have been assessed. And of course,there are thousands of species that we haveyet to discover. Many of these could also be facing extinction.
C.
It is important to develop a picture of the diversity of life on Earth now, so that comparisons can be made in the future and trends identified. But it isn't necessary to observe every single type of organism in an area to get a snapshot of the hea1th of the ecosystem.In many habitats there are species that are particularly susceptible to shifting conditions, and these can be used as indicator species.
D.
In themedia, it is usually large, charismatic animals such as pandas, elephants,tigers and whales that get all the attention when loss of biodiversity is discussed. However, animals or plants far lower down the food chain are often the ones vital for preserving habitats - in the process saving the skins of those more glamorous species. These are known as keystone species.
E.
By studying the complex feeding relationships within habitats species can be identified that have a particularly important impacton the environment. For example, the members of the fig family arethe staple food for hundreds of different species in many different countries so important that scientists sometimes call figs "jungleburgers". A whole range of animals, from tiny insects to birds and large mammals, feed on everything from the tree's barkand leaves toits flowers and fruits. Many fig species have very specific pollinators.There are several dozen species of fig tree in Costa Rica and a different type of wasp has evolved to pollinate each one. Chris Lyleof the Natural History Museum in London - who is also involved inthe Global Taxonomy Initiative of the Convention on Biological Diversity - points out that if figtrees are affected by global warming pollution disease or any other catastrophe,the loss of biodiversity will be enormous.
F.
Similarly,sea otters play a major role in the survival of giant kelpforests along the coasts of California and Alaska. These "marine rainforests" provide ahome for a wide range of other species. The kelp itself is the main food of purple and red sea urchins and in turn the urchins are eaten by predators particularly sea otters. They detach an urchin from the seabed then float to the surface and lie on their backs with the urchin shell on their tummy, smashing it open with astone before eating the contents. Urchins that are not eaten tend to spend their time in rock crevices to avoid the predators. This allows the kelp to grow - and it can grow many centimetres in a day. As the forests form, bitsof kelp break off and fall to the bottom to provide food for the urchins intheir crevices. The sea otters thrive hunting for sea urchins in the kelp and many other fish and invertebrates live among the fronds. The problems start whenthe sea otter population declines. As large predators they are vulnerable - their numbers are relatively small so disease or human hunters can wipe them out.The result is that the sea urchin population grows unchecked and they roam the sea floor eating young kelp fronds. This tends to keep thekelp very short and stops forests developing, which has a huge impacton biodiversity.
G.
Conversely key stone species can also make dangerous alien species: they can wreak havocif they end up in the wrong ecosystem. The cactus moth, whose caterpillar is a voracious eater of prickly pear was introduced to Australia to control the rampant cacti. It was so successful that someone thought it would be a good ideato introduce it to Caribbean islands that had the same problem.It solved the cactus menace, but unfortunately some of the moth shave now reached the US mainland-borne on winds and in tourists' luggage - where they are devastating the native cactus populations of Florida.
H.
Organisations like the Convention on Biological Diversity work with groups such as the UN and with governments and scientists toraise awareness and fund research. A numberof major international meetings - including the World Summit on Sustainable Developmentin Johannesburg this year - have set targets for governments around the world to show the loss of biodiversity. And the CITES meeting in Santiago last month added several more names to its list of endangered species for which trade is controlled. Of course, these agreement swill prove of limited value if some countries refuse to implement them.
I.
Thereis cause for optimism, however. There seems to be agrowing understanding of theneed for sustainable agriculture andsustainable tourism to conservebiodiversity. Problems such asillegal logging are being tackled throughsustainable forest ryprogrammes with the emphasis on minimising the use of rainforest hardwoodsin the developed world and on rigorous replanting of whatever trees are harvested. CITES is playing its part by controllingtrade in wood from endangered tree species. In the same waysustainable farming techniques that minimise environmental damageand avoid monoculture.
J.
Actionat a national level often means investing in public education and awareness.Getting people like you and me involved can be very effective. Australia andmany European countries are becoming increasingly efficient at recycling much oftheir domestic waste for example preserving natural resources and reducing the use of fossil fuels. This in turn has a direct effect on biodiversity by minimising pollution and an indirect effect by reducing the amount of greenhouse gases emitted from incinerators and landfill sites.Preserving ecosystems intact for future generations to enjoy isobviously important but biodiversity is not some kind of optionalextra. Variety may be "the spiceof life" but biological variety is alsoour life-support system.
Questions 14-20
Do the following statements agree with theinformation given in
Reading Passage 2
In boxes 14-20 on your answer sheet, write
TRUEIf the statement is true
FALSE If the statement is false
NOT GIVEN If the information is not givenin the passage
14 The term "biodiversity" consists of 1iving creatures and environment that they live in.
15 There are species that have not been researched because it’sun necessary to study all creatures.
16 It is not necessary to investigate all creatures in a certain place.
17 The press more often than not focuses on animals well-known.
18 There is a successful case that cactusmoth plays a positive role inthe US.
19 Usage of hardwoods is forbidden in some European countries.
20 Agriculture experts advise farmers toplant single crops in the field in terms of sustainable farming.
Questions 21-26
Summary
Complete the following summary of theparagraphs of Reading
Passage using no NO MORE THATN TWO WORDS fromthe Reading Passagefor each answer. Write your answers in boxes 21-26 answersheet.
Because of the ignorance brought by media peopletend to neglectsignificant creatures called 21______. Every creature has dietconnectionswith other such as 22 ______ which provide amajority of foods for other species.In some states of Americadecline in number of sea otters leads to the boom of23 ______ Animpressing case is that imported 24 ______ successfully tacklestheplant cacti in 25 ______. However, the operation is needed forthe government toincrease their financial support in 26 ______.
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