Bristlecone Pine IELTS Reading Academic Passage with Answers
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| Uzbekistan | 16th June 2022 |
READING PASSAGE – 1
LONGAEVA: Ancient Bristlecone Pine
A. To understand more about the earth’s history, humans have often looked to the natural environment for insight into the past. The bristlecone pine (Pinus longaeva), of the White Mountains in California, has served this purpose greater than any other species of free on the planet. Conditions here are brutal: scant precipitation and low average temperatures mean a short growing season, only intensified by ferocious wind and mal-nutritious rocky. Nevertheless, bristlecone pines have claimed these barren slopes as their permanent home.
Evolving here in this harsh environment, super-adapted and without much competition, bristlecones have earned their seat on the longevity throne by becoming the oldest living trees on the planet. Results of extensive studies on bristlecone pine stands have shown that in fact such, environmental limitations are positively associated with the attainment of great age. This intriguing phenomenon will be discussed further on. [IELTSXpress.com]
B. But exactly how old is old? Sprouted before the invention of Egyptian hieroglyphs and long before the teachings of Jesus of Nazareth, Dethuselah is the oldest bristlecone alive at roughly 4,700 years. Although specimens of this age do not represent the species’ average, there are 200 trees more than 3,000 years old, and two dozen more than 4,000. Considering that these high ages are obtained in the face of such remarkable envnonmental adversity, the bristlecone pines have become the focus of much scientific examination over the past half century.
C. Perhaps most interested in the bristlecone pine are dendochronologists, or tree-ring daters. With every strenuous year that passes in the White Mountains, each bristlecone grows and forms a new outer layer of cambium that reflects a season’s particular ease or hardship. So while, growing seasons may expand or shrink, the trees carry on, their growth rings faithfully recording the bad years alongside the goods.
Through examining the annual growth rings of both living and dead specimens, taking thousands of core samples, and by processes of cross-dating between trees and other qualitative records, scientists have compiled a continuous tree-ling record that dates back to the last Ice Age between eight and ten thousand years ago. Among other linked accomplishments, this record has enhanced the dating process, helping to double-cheek and correct the radiocarbon-14 method to more accurately estimate the age of organic material.
D. Now more than ever the importance of monitoring the bristiecone is being realized. As our global climate continues to undergo its most recent and abrupt atmospheric change, these ancient scribes continue to respond. Since, the rings of wood formed each year reveal the trees’ response to climatic conditions during a particular growing seasons, in their persistence they have left US natural recordings of the past, markers of the present, and clues to the future.
E. The species’ name originates from the appearance of its unusual cones and needles. The bristlecone’s short, pale needles are also trademarks, bunching together to form foxtail-like bundles. As is the case of moat conifer needles, these specialized leaves cluster together to shelter the stomata so very little moisture is lost through them. This adaptation helps the bristlecone photosynthesize during particularly brutal months, Saving the energy of constant needle replacement and providing a stable supply of chlorophyll. For a plant trying to store so much energy, bristlecone seeds are relatively large in size.
They are first reproduced when trees reach ages between thirty and seventy-five years old Germination rates are generally high, in part because seeds require little to no initial stratification. Perhaps the most intriguing physical characteristic of a mature bristlecone, however, is its ratio of living to dead wood on harsh sites and how this relates to old age. In older trees, however, especially in individuals over 1,500 years, a strip-bark trait is adaptive. This condition occurs as a result of cambium dieback, which erodes and thereby exposes certain areas of the bole, leaving only narrow bands of bark intact F. The technique of cambial edge retreat has help promote old age in bristlecone pine, but that certainly is not the only reason.
Most crucial to these trees’ longevity is their compact size and slow rates of growth. By remaining in most cases under ten meters tall, bristlecones stay close to the limited water supply and can hence support more branches and photosynthesizing. Combined with the dry, windy, and often freezing mountain, slow growth guarantees the hrifltlecones tight, fibrous rings with a high resin content and structural strength. The absence of natural disaster has also safeguarded the bristlecone’s lengthy lifespan. Due to a lack of ground cover vegetation and an evenly spaced layout, bristlecone stands on the White Mountain peaks have been practically unaffected by fire. This lack of vegetation also means a lack of competition for the bristlecones.
G. Bristlecone pine’s restricted to numerous, rather isolated stands at higher altitudes in the southwestern United States. Stands occur from the Rocky Mountains, through the Colorado Plateau, to the western margin of the Great Basin. Within this natural range, the oldest and most widely researched stands of bristlecones occur in California’s White Mountains. Even just 200 miles away from the Pacific Ocean, the White Mountains are home to one of this country’s few high-elevation deserts.
Located in the extreme eastern rain shadow of the Sierra Nevada, this region receives only 12.54 inches of precipitation per year and experiences temperatures between -20F and +50F. The peaks south of the Owens Valley, are higher up than they might appear from a distance. Although most summits exist somewhere around 11,000 feet, snow-capped White Mountain Peak, for which the range is named, stands at 14,246 feet above sea level. That said, to reach areas of pure bristlecone is an intense journey all to itself.
H. With seemingly endless areas of wonder and interest, the bristlecone pines have become subject to much research over the past half-century. Since the annual growth of these ancient organisms directly reflects the climatic conditions of a particular time period, bristlecones are of greatest significance to dendochronologists, or tree-ring specialists. Dating any tree is simple and can be done within reasonable accuracy just by counting out the rings made each year by the plant’s natural means of growth. [IELTSXpress.com]
By carefully compiling a nearly 10,000- year-old bristlecone pine record, these patient scientists have accurately corrected the carbon-14 dating method and estimated ages of past periods of global climate change. What makes this record so special to dendochronologists, too, is that, nowhere, throughout time, is precisely the same long-term sequence of wide and narrow rings repeated, because year-to-year variations in climate are never exactly the same.
I. Historically the bristlecone’s remote location and gnarled wood have deterred commercial extraction, but nothing on earth will go unaffected by global warming. If temperatures rise by only 6 degrees F, which many experts say is likely this century, about two-thirds of the bristlecones’ ideal habitat in the White Mountains effectively will be gone. Almost 30,000 acres of National Forest now preserves the ancient bristlecone, but paved roads, campsites, and self-guided trails have led only to more human impact.
In 1966, the U.S.F.S reported over 20,000 visitors to the Ancient Bristlecone Pine Forest, a figure which could exceed 40,000 today. Over the past hundreds of thousands of years, this species has endured in one of earth’s most trying environments; they deserve our respect and reverence. As global climate change slowly alters their environment, we as humans must do our part to raise awareness and lower our impact.[IELTSXpress.com]
Questions 1-4
The reading Passage has nine paragraphs A-I.
Which paragraph contains the following information?
Write the correct letter A-I, in boxes 1-4 on your answer sheet.
1. Human activity threats bristlecone pines habitat
2. Explanations for ring of bristlecone pines
3. An accountable recording provided from the past till now
4. Survived in hostile environment
Questions 5–7
Choose the correct letter, A, B, c or D.
Write your answers in boxes 5-7 on your answer sheet.
5. According to passage A, what aspect of bristlecone pines attracts author’s attention?
A. Brutal environment they live
B. Remarkable long age
C. They only live in California
D. Outstanding height
6. Why do we investigate Bristlecone pines in higher altitudes of California’s White Mountains?
A. Because oldest ones researched in this region
B. Because most bizarre ones are in this region
C. Because precipitation is rich in this region
D. Because sea level is comparatively high in this region
7. Why there are repeated patterns of wide and narrow rings?
A. Because sea level rises which affects tree ring
B. Because tree ring pattern is completely random
C. Because ancient organisms affect its growth
D. Because variation of climate change is different
Questions 8-13
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 8-13 on your answer sheet.[IELTSXpress.com]
The bristlecone’s special adaptation is benefit for photosynthesizing, and reserving the 8._________ of leave replacement and providing sufficient chlorophyll. Probably because seeds do not rely on primary 9._________ , Germination rate is high. Because of cambium dieback, only narrow 10._________ remain complete. Due to multiple factors such as windy, cold climate and 11._________ , bristlecones’ rings have tight and solid structure full of resin. Moreover, bristlecone stands are safe from fire because of little 12._________ plants spread in this place. The summits of Owens Valley is higher than they emerge if you observe from a 13_________
Practice LONGAEVA Ancient Bristlecone Pine IELTS Academic Reading Passage online or download a printable PDF copy.
Bristlecone Pine IELTS Reading PDF
Bristlecone Pine IELTS Reading Answers
1. I
2. C
3. D
4. A
5. B
6. A
7. D
8. ENERGY
9. STRATIFICATION
10. (BANDS OF) BARK
11. DRY (MOUNTAIN) AIR
12. GROUND COVER
13. DISTANCE
Bristlecone Pine IELTS Reading Answers Explanation
1. Human activity threats bristlecone pines habitat
Answer: I
Supporting Sentence: If temperatures rise by only 6 degrees F, which many experts say is likely this century, about two-thirds of the bristlecones’ ideal habitat in the White Mountains effectively will be gone.
Keywords: bristlecones, habitat, white mountains, temperature ieltsxpress
Keywords location: Paragraph I, line 2.
Explanation: If temperatures rise just 6 degrees Fahrenheit this century, roughly two-thirds of the bristlecones’ optimal habitat in the White Mountains will be lost. The old bristlecone is now protected on over 30,000 acres of National Forest. However, paved roads, campsites, and self-guided trails have only increased human influence.” This book recounts the misdeeds of humans and their destructive acts that have destroyed the environment over time. It also draws attention to future risks to our ecosystem and bristlecones. Hence, human activities present a threat.
2. Explanations for a ring of bristlecone pines
Answer: C
Supporting Sentence: With every strenuous year that passes in the White Mountains, each bristlecone grows and forms a new outer layer of cambium that reflects a season’s particular ease or hardship.
Keywords: white mountains, bristlecone, outer layer, growth ring
Keywords location: Paragraph C, lines 2 and 3
Explanation: It is mentioned in paragraph C that – Dendrochronologists, or tree-ring daters, are perhaps most interested in the bristlecone pine. Each bristlecone develops and forms a new outer layer of cambium with each rigorous year in the White Mountains, reflecting the ease or difficulty of the season. While growing seasons may lengthen or shorten, the trees continue to grow, their growth rings accurately chronicling the good and bad years.
3. An accountable recording provided from the past until now
Answer: D
Supporting Sentence: Since, the rings of wood formed each year reveal the trees’ response to climatic conditions during a particular growing season, in their persistence they have left US natural recordings of the past, markers of the present, and clues to the future.
Keywords: rings, climatic condition, natural recordings, past, future
Keywords location: Paragraph D, lines 2 and 3.
Explanation: As our global climate continues to experience its most recent and abrupt atmospheric shift, these ancient scribes continue to respond. The rings of wood generated each year show the trees’ response to climatic conditions during specific growing seasons. They have left natural recordings of the past, markers of the present, and pointers to the future in the United States.
4. Survived in a hostile environment
Answer: A
Supporting Sentence: Conditions here are brutal: scant precipitation and low average temperatures mean a short growing season, only intensified by ferocious wind and mal-nutritious rocky.
Keywords: brutal, ferocious wind, mal-nutritious, temperature, season
Keywords location: Paragraph A, lines 3 and 4
Explanation: Bristlecone pine (Pinus longaeva) of the White Mountains in California has served this duty better than any other tree species on the earth. The conditions are harsh. A short growing season is caused by a lack of precipitation and low average temperatures, which is exacerbated by violent wind and malnutrition stony soil. Despite this, bristlecone pines have made their permanent home on these bleak hillsides. Bristlecones have earned their place on the lifespan throne by becoming the world’s oldest living trees. It has evolved in this tough climate, super-adapted and without much competition
5. According to passage A, what aspect of bristlecone pines attracts author’s attention? ieltsxpress
Answer: B
Supporting Sentence: Results of extensive studies on bristlecone pine stands have shown that in fact such, environmental limitations are positively associated with the attainment of great age.
Keywords: bristlecone, environmental limitation, great age
Keywords location: Paragraph A, line 6.
Explanation: Bristlecones have earned their seat on the lifespan throne by becoming the longest living trees on the globe by evolving here in this tough environment. It is super-adapted, and without much competition.” Extensive research on bristlecone pine stands has revealed that such environmental constraints are positively related to the attainment of great age.
6. Why do we investigate Bristlecone pines in higher altitudes of California’s the White Mountains?
Answer: A
Supporting Sentence: Within this natural range, the oldest and most widely researched stands of bristlecones occur in California’s the White Mountains
Keywords: bristlecone, United States, Rocky Mountains, Colorado Plateau, Great Basin, White Mountai
Keywords location: Paragraph G, lines 1-3
Explanation: Bristlecone pine is only found in a few, relatively isolated stands at higher elevations in the southwestern United States. Stands can be found from the Rocky Mountains to the western edge of the Great Basin, as well as the Colorado Plateau. The oldest and most well-studied stands of bristlecones can be found in California’s the White Mountains. With temperatures ranging from -20 to +50 degrees Fahrenheit, this place, receives only 12.54 inches of rain per year. Even though most peaks are about 11,000 feet, the range’s namesake, snow-capped White Mountain Peak, lies at 14,246 feet above sea level.
7. Why there are repeated patterns of wide and narrow rings?
Answer: D
Supporting Sentence: What makes this record so special to dendrochronologists, too, is that, nowhere, throughout time, is precisely the same long-term sequence of wide and narrow rings repeated, because year-to-year variations in climate are never exactly the same.
Keywords: climate, narrow rings, dendrochronologist
Keywords location: Paragraph H, last line
Explanation: Dendrochronologists, or tree-ring specialists, value bristlecones the most. This is because their annual growth directly represents the climatic conditions of a certain historical time. Counting the rings formed each year by the plant’s normal development patterns is a simple approach to date any tree with fair accuracy. Because year-to-year climate variations are never exactly the same, dendrochronologists are not the same long-term sequence of wide and narrow rings duplicated.
Question 8:
Answer: Energy
Supporting Sentence: This adaptation helps the bristlecone photosynthesize during particularly brutal months, Saving the energy of constant needle replacement and providing a stable supply of chlorophyll.
Keywords: bristlecone, photosynthesize, energy, chlorophyll
Keywords location: Paragraph E, lines 4 and 5
Explanation: These specialised leaves cluster together to cover the stomata, resulting in extraordinarily little moisture loss, as mentioned in paragraph E. This change permits the bristlecone to photosynthesize even in the coldest months of the year, conserving energy and providing a continual supply of chlorophyll. For a plant that needs to store so much energy, bristlecone seeds are massive.
Question 9:
Answer: Stratification
Supporting Sentence: They are first reproduced when trees reach ages between thirty and seventy-five years old Germination rates are generally high, in part because seeds require little to no initial stratification.
Keywords: Germination, stratification, thirty, seventy-five
Keywords location: Paragraph E, line 6.
Explanation: According to paragraph E, they begin reproducing when trees reach the ages of thirty to seventy-five years. Because seeds require little to no early stratification, germination rates are often high. Because the germination rate in these cones is so high, this shows that the seeds of the Bristlecones do not rely on the initial/primary stratification ieltsxp ress
Question 10:
Answer: Bark
Supporting Sentence: This condition occurs as a result of cambium dieback, which erodes and thereby exposes certain areas of the bole, leaving only narrow bands of bark intact F.
Keywords: strip bark, cambium dieback, narrow bands, bark
Keywords location: Paragraph E, lines 8 and 9
Explanation: In paragraph E, it is said that- In older trees, particularly those over 1,500 years old, a strip-bark characteristic is adaptive. Cambium dieback causes this disease, which erodes and exposes specific regions of the bole, leaving only narrow strips of bark intact F. The practice of cambial edge retreat has aided in the promotion of old age in bristlecone pine, although it is far from the only reason.
Question 11:
Answer: Dry Air
Supporting Sentence: Combined with the dry, windy, and often freezing mountain, slow growth guarantees the hrifltlecones tight, fibrous rings with a high resin content and structural strength.
Keywords: dry, windy, freezing mountain, high resin
Keywords location: Paragraph F, line 3
Explanation: In paragraph F, it is said that the compact size and moderate growth rates of these trees are the most important factors in their lifetime. Bristlecones stay close to the limited water source by remaining under ten metres tall, allowing them to support more branches and photosynthesise. Slow development ensures the hrifltlecones tight, fibrous rings with a high resin content. It also ensureshe structural strength when combined with the dry, windy, and often hilly terrain.
Question 12:
Answer: Ground Cover
Supporting Sentence: Due to a lack of ground cover vegetation and an evenly spaced layout, bristlecone stands on the White Mountain peaks have been practically unaffected by the fire.
Keywords: ground cover, bristlecone, unaffected, lack of vegetation
Keywords location: Paragraph F, lines 5 and 6.
Explanation: According to paragraph F, the bristlecone’s lengthy longevity is attributable in part to the lack of natural disasters. Bristlecone stands on the White Mountain peaks have been almost fire-free due to a lack of ground cover flora and a uniformly spaced pattern. Because there isn’t much vegetation, the bristlecones don’t face much competition.
Question 13:
Answer: Distance
Supporting Sentence: The peaks south of the Owens Valley, are higher up than they might appear from a distance.
Keywords: Owens valley, white mountain, higher, summits
Keywords location: Paragraph G, lines 5 and 6 ielts xpress
Explanation: As stated in paragraph g, the peaks south of the Owens Valley are higher up than they appear from afar. Despite the fact that most peaks are about 11,000 feet, the range’s namesake, snow-capped White Mountain Peak, lies at 14,246 feet above sea level. As previously said, getting to pristine bristlecone ecosystems is a challenging task in and of itself.
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