Table of Contents
Passage
At the intersection of land and sea, mangrove forests support a wealth of life, from starfish to people, and may be more important to the health of the planet than we ever realized.
A Mangroves live life on the edge. With one foot on land and one in the sea, these botanical amphibians occupy a zone of desiccating heat, choking mud, and salt levels that would kill an ordinary plant within hours. Yet the forests mangroves form are among the most productive and biologically complex ecosystems on Earth. Birds roost in the canopy, shellfish attach themselves to the roots, and snakes and crocodiles come to hunt. Mangroves provide nursery grounds for fish; a food source for monkeys, deer, tree-climbing crabs, even kangaroos; and a nectar source for bats and honeybees.
B As a group, mangroves can’t be defined too closely. There are some 70 species from two dozen families—among them palm, hibiscus, holly, plumbago, acanthus, legumes, and myrtle. They range from prostrate shrubs to 200-foothigh (60 meters) timber trees. Though most prolific in Southeast Asia, where they are thought to have originated, mangroves circle the globe. Most live within 30 degrees of the Equator, but a few hardy types have adapted to temperate climates, and one lives as far from the tropical sun as New Zealand. Wherever they live, they share one thing in common: They’re brilliant adapters. Each mangrove has an ultrafiltration system to keep much of the salt out and a complex root system that allows it to survive in the intertidal zone. Some have snorkel-like roots called pneumatophores that stick out of the mud to help them take in air; others use prop roots or buttresses to keep their trunks upright in the soft sediments at tide’s edge.
C These plants are also landbuilders par excellence. Some Aborigines in northern Australia believe one mangrove species resembles their primal ancestor, Giyapara, who walked across the mudflats and brought the tree into existence. The plants’ interlocking roots stop river-borne sediments from coursing out to sea, and their trunks and branches serve as a palisade that diminishes the erosive power of waves.
D Despite their strategic importance, mangroves are under threat worldwide. They are sacrificed for salt pans, aquaculture ponds, housing developments, roads, port facilities, hotels, golf courses, and farms. And they die from a thousand indirect cuts: oil spills, chemical pollution, sediment overload, and disruption of their sensitive water and salinity balance. Calls for mangrove conservation gained a brief but significant hearing following the 2004 Indian Ocean tsunami. Where mangrove forests were intact, they served as natural breakwaters, dissipating the energy of the waves, mitigating property damage, perhaps saving lives. Posttsunami, the logic of allowing a country’s mangrove “bioshields” to be bulldozed looked not just flawed but reprehensible. Bangladesh has not lost sight of that logic, putting a great premium on the ability of mangroves to stabilize shores and trap sediments. The vast tidal woodland they form is known as the Sundarbans——literally “beautiful forest.” Today, it’s the largest surviving single tract of mangroves in the world.
E Throughout the tropical world it’s the same: Mangrove forests are the supermarkets, lumberyards, fuel depots, and pharmacies of the coastal poor. Yet these forests are being destroyed daily. One of the greatest threats to mangrove survival comes from shrimp farming. At first glance, shrimp might seem the perfect export for a poor country in a hot climate. Rich countries have an insatiable appetite for it (shrimp has overtaken tuna to become America’s favorite seafood), and the developing world has the available land and right climate to farm it.
F A prime location for shrimp ponds, though, happens to be the shore zone occupied by mangroves, an unhappy conflict of interests that has a predictable outcome: The irresistible force of commerce trumps the all-too-removable mangrove. To compound matters, shrimp farmers typically abandon their ponds after a few crop cycles (to avoid disease outbreaks and declining productivity) and move to new sites, destroying more mangroves as they go.
G As serious as the threat from shrimp farming is to the world’s remaining mangroves, there looms a potentially more disastrous problem: rising sea levels. Standing as they do at the land’s frontiers, mangroves will be the first terrestrial forests to face the encroaching tides.
H Loss of mangrove forests could prove catastrophic in ways only now becoming apparent. For more than 25 years Jin Eong Ong, a retired professor of marine and coastal studies in Penang, Malaysia, has been exploring a less obvious mangrove contribution: What role might these forests play in climate change? Ong and his colleagues have been studying the carbon budget of mangroves— the balance sheet that compares all the carbon inputs and outputs of the mangrove ecosystem—and they’ve found that these forests are highly effective carbon sinks. They absorb carbon dioxide, taking carbon out of circulation and reducing the amount of greenhouse gas. Mangroves may have the highest net productivity of carbon of any natural ecosystem, and as much as a third of this may be exported in the form of organic compounds to mudflats. Mangroves, it seems, are carbon factories, and their demolition robs the marine environment of a vital element.
I Ong’s team has also shown that a significant portion of the carbon ends up in forest sediments, remaining sequestered there for thousands of years. Conversion of a mangrove forest to a shrimp pond changes a carbon sink into a carbon source, liberating the accumulated carbon back into the atmosphere— but 50 times faster than it was sequestered. If mangroves were to become recognized as carbon-storage assets, that could radically alter the way these forests are valued, says Ong. If carbon trading becomes a reality—that is, if forest-rich, carbon-absorbing countries are able to sell so-called emissions credits to more industrialized, carbon-emitting countries—it could, at the least, provide a stay of execution for mangroves.
Questions
Questions 1-5 Complete the following summary of the paragraphs of Reading Passage, using no more than Three words from the Reading Passage for each answer. Write your answers in boxes 1-5 on your answer sheet.
Summary
Mangroves are outstanding 1 …………… who are able to live life in hard environment. There are two systems—2 …………… and 3 …………… enabling them to survive at the intersection of land and sea. Meanwhile, Mangroves have strategic importance. 4 …………… can be held by the roots, and the erosive power of waves can be reduced by their 5 …………… .
Questions 6-11 Do the following statements agree with the information given in Reading Passage 1? In boxes 6-11 on your answer sheet, write
TRUE if the sataement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
6 Mangroves are various and similar.
7 We can find mangroves in Singapore.
8 Mangroves had played an important role in the 2004 Indian Ocean tsunami and saved lives.
9 Bangladesh is mentioned to have spent a huge sum of money on the mangroves.
10 In order to avoid loss, shrimp farmers will cut down the amount of ponds regularly.
11 Shrimp farming will greatly influence the function of mangroves that holding the carbon.
Questions 12-13 Choose the correct letter, A-F. Write your answers in boxes 12-13 on your answer sheet.
Which TWO of the followings are NOT mentioned to have put mangrove survival in danger?
A increasing greenhouse gas
B too much sediment
C cut by human
D shrimp export
E rising sea levels
F shrimp farming
Answers
Below are the answers, key words and full explanations for the IELTS Reading passage Mangroves: Forests of the Tide (Passage 1, Questions 1–13).
Questions 1–5: Summary Completion (NO MORE THAN THREE WORDS)
1. Mangroves are outstanding __ who can live in a hard environment.
Answer: adapters
Key words: outstanding, hard environment
Explanation: “Wherever they live, they share one thing in common: They’re brilliant adapters.“
brilliant adapters = outstanding adapters.
Answer: adapters
2. & 3. Two systems — __ and __ — enable them to survive.
Answer: 2 = ultrafiltration system; 3 = complex root system
Key words: two systems, survive
Explanation: “Each mangrove has an ultrafiltration system to keep much of the salt out and a complex root system that allows it to survive in the intertidal zone.“
Answer: ultrafiltration system / complex root system
4. __ can be held by the roots.
Answer: river-borne sediments
Key words: held by the roots
Explanation: “The plants’ interlocking roots stop river-borne sediments from coursing out to sea.“
roots stop river-borne sediments = sediments held by the roots.
Answer: river-borne sediments
5. The erosive power of waves can be reduced by their __.
Answer: trunks and branches
Key words: erosive power of waves, reduced
Explanation: “their trunks and branches serve as a palisade that diminishes the erosive power of waves.“
diminishes the erosive power = reduces the erosive power.
Answer: trunks and branches
Questions 6–11: True / False / Not Given
6. Mangroves are various and similar.
Answer: FALSE
Key words: various and similar
Explanation: The passage stresses their diversity: “As a group, mangroves can’t be defined too closely. There are some 70 species from two dozen families … They range from prostrate shrubs to 200-foot-high timber trees.” It emphasises that they are too varied to be treated as “similar,” so the statement is contradicted.
can’t be defined too closely / 70 species with huge range contradicts “similar.”
Answer: FALSE
7. We can find mangroves in Singapore.
Answer: NOT GIVEN
Key words: Singapore
Explanation: The passage mentions Southeast Asia, the Equator, New Zealand and the Sundarbans, but Singapore is never named. There is no information about it.
Answer: NOT GIVEN
8. Mangroves played an important role in the 2004 Indian Ocean tsunami and saved lives.
Answer: NOT GIVEN
Key words: tsunami, saved lives
Explanation: “Where mangrove forests were intact, they served as natural breakwaters … mitigating property damage, perhaps saving lives.” The word “perhaps” makes the life-saving uncertain — it is not stated as a fact, so it cannot be confirmed.
“perhaps saving lives” is tentative, so “saved lives” is not confirmed.
Answer: NOT GIVEN
9. Bangladesh is mentioned to have placed great value on the mangroves.
Answer: TRUE
Key words: Bangladesh, great value
Explanation: “Bangladesh has not lost sight of that logic, putting a great premium on the ability of mangroves to stabilize shores and trap sediments.” Putting a great premium on them = placing great value on them.
putting a great premium on the mangroves = placing great value on them.
Answer: TRUE
10. To avoid loss, shrimp farmers will regularly cut down the number of ponds.
Answer: FALSE
Key words: avoid loss, cut down the number of ponds
Explanation: “shrimp farmers typically abandon their ponds after a few crop cycles … and move to new sites, destroying more mangroves as they go.” They abandon old ponds and build new ones (destroying more mangroves) — they do not reduce the number of ponds.
abandon ponds and move to new sites contradicts “cut down the number of ponds.”
Answer: FALSE
11. Shrimp farming will greatly affect the mangroves’ carbon-holding function.
Answer: TRUE
Key words: shrimp farming, carbon
Explanation: “Conversion of a mangrove forest to a shrimp pond changes a carbon sink into a carbon source, liberating the accumulated carbon back into the atmosphere — but 50 times faster than it was sequestered.“
changing a carbon sink into a carbon source = greatly affects the carbon-holding function.
Answer: TRUE
Questions 12–13: Multiple Choice — Which TWO are NOT mentioned as dangers to mangrove survival?
Answer: A (increasing greenhouse gas) and D (shrimp export)
Key words: NOT mentioned, danger
Explanation: The dangers the passage does mention are: cutting by humans / clearing for development (C), sediment overload / too much sediment (B), shrimp farming (F), and rising sea levels (E). It never lists increasing greenhouse gas (A) as a threat to mangroves — in fact mangroves reduce greenhouse gas — and it mentions shrimp as an export that drives shrimp farming, but shrimp export (D) itself is not named as a danger. So A and D are the two not mentioned.
greenhouse gas and shrimp export are not listed among the threats.
Answer: A and D
| Answer Key (Quick Reference) | |||
|---|---|---|---|
| Q | Answer | Q | Answer |
| 1 | adapters | 8 | NOT GIVEN |
| 2 | ultrafiltration system | 9 | TRUE |
| 3 | complex root system | 10 | FALSE |
| 4 | river-borne sediments | 11 | TRUE |
| 5 | trunks and branches | 12 | A |
| 6 | FALSE | 13 | D |
| 7 | NOT GIVEN | ||
Cambridge IELTS 1-21 Reading test solutions
