1 . Regarded as the “loneliest tree in the world”, the Sitka spruce (云杉) on uninhabited Campbell Island lately has kept good company with a team of New Zealand researchers who believe it could help unlock secrets of climate changes.
The nine-meter-tall spruce holds the Guinness Record title for the “remotest tree” on the planet. It is the sole tree on the shrubby, windswept island, 700 kilometers south of New Zealand in the Southern Ocean. It’s the only tree for 222km around; its nearest neighbor grows on the Auckland Islands.
Although classified as an invasive species, for radiocarbon science leader at GNS Science, Dr. Jocelyn Turnbull, the tree could be a valuable tool to understand what is happening with the uptake of CO2 in the Southern Ocean. In order to measure CO2 concentrations, taking samples of the atmosphere is the best method, and can be complemented with radiocarbon dating samples of deep water. But it comes with limitations. “You can’t collect air that was there 30 years ago, because it is not there anymore,” Turnbull said, “So we came up with this idea of using tree rings. Plants, when they grow, take CO2 out of the air by photosynthesis (光合作用) and they use that to grow their structures and the carbon from the air ends up in the tree rings.”
This is helpful when there is an abundance of established trees, but those are a rarity in the Southern Ocean. Enter the Sitka Spruce - the south most tree, and the team could find it would offer up good data. “It’s grown a lot faster than anything else in that region and the rings are bigger and easier to separate out and get a record form.”
As for the tree’s lonely status: the description may be in the eye of the beholder. “To get to the tree you have to walk through elephant seals and sea lions, penguins and albatross,” Turnbull said. “The tree doesn’t look lonely …it looks quite content actually.”
1. What is special about the tree?| A．It measures nine meters wide. |
| B．It is the only tree on a vast land. |
| C．It grows on the Auckland Islands. |
| D．It owns the Guinness title for the “loneliest tree”. |
| A．CO2 builds up in the tree rings. |
| B．The Sitka spruce is a native species. |
| C．Samples from water are usually inaccessible. |
| D．Photosynthesis stops the plants absorbing air. |
| A．The tree coexists with a variety of animals. |
| B．The tree grows well because of suitable climate. |
| C．It’s unwise to use tree rings as an indicator of CO2. |
| D．It’s possible to measure previous CO2 concentrations directly. |
| A．Trees are of great significance to scientific research. |
| B．The “loneliest” tree in the world is not lonely at all. |
| C．Global warming has a far-reaching impact on creatures. |
| D．A remote Sitka spruce may help us learn about climate changes. |
2 . Plants do not suffer in silence when thirsty or stressed, according to a new study published today in Cell.
Plants that need water or have recently had their branches cut produce up to roughly 35 sounds per hour, the authors found. But well-watered and uncut plants are much quieter, making only about one sound per hour.
The reason why you have probably never heard a thirsty plant make noises is that the sounds are so high-pitched that very few humans could hear them. Some animals, however, probably can. Bats, mice and moths could possibly live in a world filled with the sounds of plants, and previous work by the same team has found that plants respond to sounds made by animals, too.
To overhear plants, Lilach Hadany at Tel-Aviv University in Israel and her colleagues placed tobacco and tomato plants in small boxes provided with microphones. The microphones picked up any noises made by the plants, even if the researchers couldn’t hear them. The noises were particularly obvious for plants that were stressed by a lack of water or recent cutting.
Plants do not have vocal cords (声带) or lungs. Hadany says the current theory for how plants make noises centers on their xylem (木质部) that transport water and nutrients from their roots to their branches and leaves. Water in the xylem is held together by surface tension, just like water moving through a drinking straw. If an air bubble (气泡) forms or breaks in the xylem, it might make a little popping noise; bubble formation is more likely during dry seasons. But the exact system requires further study, Hadany says.
The team produced a machine-learning model to check whether a plant had been cut or was water-stressed from the sounds it made, with about 70% accuracy. This result suggests a possible role for the audio monitoring of plants in farming and gardening.
To test the practicality of this approach, the team tried recording plants in a greenhouse. Pilot studies by the authors suggest that tomato and tobacco plants are not exception. Wheat, corn and wine grapes also make noises when they are thirsty.
1. What is the new research mainly about?| A．Plants can react to animals. | B．Plants can produce sounds. |
| C．Well-watered plants keep silent. | D．Branchless plants need watering. |
| A．They can create more bubbles. | B．They can feel less stressed. |
| C．They require less nutrient supply. | D．The y need lungs to breathe more. |
| A．Fruit growing. | B．Crop selection. |
| C．Water source protection. | D．Noise pollution test. |
| A．How Plants Are Thirsty | B．When Nature Expresses Itself |
| C．How Plants Cry for Their Needs | D．When Creatures Hear Each Other |
3 . It turns out our plants are just like us in some ways. We turn to medicines to relieve a minor flu or headache, and plants too have their ways of self-medicating. They protect themselves from environmental hazards like insects, drought and heat by producing salicylic acid (水杨酸). It is responsible for the anti-inflammatory action of aspirin, a drug which has been used by humans for centuries to counter pain and inflammation.
Researchers have found that plants’ salicylic acid, which is produced in chloroplasts (叶绿体), is usually generated in response to the stress caused by climate change. “It’s like plants use a painkiller for aches and pains, just like we do,” said plant biologist Wilhelmina van de ven from the University of California, River-side (U. C. R)
“We’d like to be able to use the finding to improve crop resistance (作物抗性),” said U. C. R.plant geneticist Jin-Zheng Wang. “That will be crucial for the food supply in our increasingly hot, bright world.”
Human skin produces ROS (Reactive oxygen species) (活性氧) in the absence of sunscreen. This causes freckles and burns. Similarly, environmental stresses result in the formation of ROS in plants which, at high levels, can cause death.
At low levels, however, ROS serves an essential function in plant cells. “ROS is a double-edged sword,” said Wang. “At non-lethal levels, ROS are like an emergency call to action, enabling the production of protective hormones ( 激素) such as salicylic acid.” The acid then acts to protect the plants’ chloroplasts, known to be the site of photosynthesis.
“With climate change, things like salicylic acid: helping plants stand up to stresses have become more common. So, being able to increase plants’ ability to produce it represents a step forward in challenging the impacts of climate change on everyday life,” said Katayoon Dehesh, UCR professor of molecular biochemistry.
“Those impacts go beyond our food. Plants being in trouble are a sign of what the future holds for us,” she continued. “Plants clean our air by removing the carbon dioxide from it while also offering us shade, and providing habitats for numerous animals. For humankind, the benefits of boosting plants’ ability to survive are becoming increasingly essential.”
1. What is the main function of salicylic acid in plants?| A．To secure plants. | B．To produce chloroplasts. |
| C．To relieve pain and inflammation. | D．To generate hormones. |
| A．Lack of sunscreen. | B．Chloroplastic acid. |
| C．Environmental stresses. | D．Use of Photosynthesis. |
| A．To explore the history and significance of aspirin in human medicine. |
| B．To invent a device that can make plants do self-medicating. |
| C．To compare the differences between plants and humans in self-medicating. |
| D．To improve crop resistance by increasing plants’ ability to produce salicylic acid. |
| A．Plants can be improved to resist environmental hazards. |
| B．Plants produce their own aspirin to cope with stress. |
| C．Plants and humans share some common features and needs. |
| D．Plants contribute to the well-being of humans and animals. |
4 . Imagine walking by a maple (枫树) tree that is no taller than a ruler. You may think that this is a special type of miniature tree, but it actually isn’t! Creating a tree like this is a form of art called bonsai. Bonsai are tiny trees grown in small pots. Bonsai can be any kind of tree. They just need to be planted in a small container and cultivated in a way that stunts their growth.
Cultivating, or taking care of, a bonsai tree requires patience and care. Pruning — removing branches, leaves, and roots — is an important part of raising bonsai. It keeps the trees small, and it also controls their shape. Pinching off new buds (嫩芽) and tying wire around branches help create a beautiful design. These processes allow the grower to control what shape the bonsai tree will take as it develops.
People who raise bonsai want their trees to look like they belong in nature. Even though it is contained in a pot, a bonsai tree should look similar to its larger counterpart (相对物，参照物). For example, the bonsai maple should have the same forked branches and vibrant leaves as the full-sized maple. This makes the bonsai a tiny copy of the full-sized maple that towers overhead.
Like other plants, bonsai need water and food from the soil. In order to keep bonsai the proper size, you need to carefully control the amount of water and fertilizer you provide. If you want to grow a bonsai, it is best to start with a species that grows in your area. Most bonsai do best when kept outdoors, so they need to be able to survive the weather. If kept indoors, the bonsai must be placed near a window. Interestingly, with proper care, bonsai can live for a hundred years or more.
1. Why does a bonsai tree need pruning frequently?| A．To control its size. |
| B．To help it grow well. |
| C．To save fertilizer and water. |
| D．To create a shape as designed. |
| A．One of a larger counterpart. |
| B．A tiny copy of the full-sized maple. |
| C．One looking like its counterpart in nature. |
| D．One with forked branches and vibrant leaver. |
| A．To keep the bonsai indoors. |
| B．To start with a native species. |
| C．To keep bonsai the proper size. |
| D．To control the amount of water. |
| A．Bonsai — a special hobby |
| B．How to be bonsai grower |
| C．What does bonsai refer to? |
| D．Why is bonsai so popular? |
5 . A new study reveals that trees can communicate and warn each other of danger. “For the first time, researchers have been able to visualize plant-to-plant communication,” said Masatsugu, senior author of the study.
The idea of talking trees started to take root in the 1980s. Two scientists found that damaged trees began producing chemicals that made their leaves unappetizing and indigestible to discourage insects. The trees then sent chemical signals to one another through the air. Over the past four decades, scientists have observed this cell-to-cell communication in more than 30 plant species.
Past research shows plants communicate with their surroundings by releasing chemicals known as volatile (易挥发的) organic compounds. One class of these compounds are released when a plant is injured: green leafy volatiles. These are released by, as the name suggests, pretty much every green plant with leaves, and are produced when a plant experiences physical damage. An example of these compounds is the smell released from fresh-cut grass.
In the new study, Masatsugu and his colleagues manually damaged leaves and placed insects on tomato plants to trigger the release of various green leafy volatiles. After testing many of them, the team found it seemed to increase calcium ions (钙离子) inside cells. The calcium signaling is like a switch to turn on the defense responses from the plants.
With this new understanding, researchers say plants could be immunized against threats and stressors before they even happen. For instance, exposing healthy plants to insect-ridden plants or the associated green leafy volatiles could boost their genetic defenses, so farmers use less pesticides. The revelation could also help make plants more resilient (有复原力的) during a drought, signaling the plants to conserve more water.
1. What does the new research find?| A．Trees can inform other trees of potential threats. | B．Trees can make themselves attractive. |
| C．Trees will send signals first once damaged. | D．Trees will work together to trick insects. |
| A．They defend insects. | B．They kill insects. |
| C．Some of them can be smelt. | D．Some of them can be seen. |
| A．By protecting trees from insects. | B．By classifying green leafy volatiles. |
| C．By increasing calcium ions inside cells. | D．By causing the release of certain chemicals. |
| A．Its target. | B．Its process. | C．Its application. | D．Its background. |
6 . When most of us read the words “plant-based diet”, we tend to think of foods such as salads and grain. But there is another option — the newest super-food: seaweed. The brownish-green oceanic plant like matter that washes up on beaches is in fact edible. Nori, the papery sheets used to wrap sushi rolls, is likely the most well-known and enjoyed seaweed, but these large leafy algae (海藻) come in hundreds of colorful varieties. Seaweed helps to support other life in the ocean and to clean the water surrounding it. When out of the water, seaweed can bring more nutrition and minerals to our diets.
“Even though we try to eat healthily, we’re relying on land-based and soil-based agriculture for the most part,” said Sarah Redmond, founder and owner of Springtide Seaweed in Gouldsboro, Maine. “Seaweed is a really interesting alternative because it provides the nutrients that are really hard to find in other land plants.”
For humans, seaweed is a one-stop shop for our necessary nutrient needs. “Seaweed is an excellent source of dietary fiber and minerals,” said Mary Ellen Camire, professor of food science and human nutrition at the University of Maine.
Though nutrition varies slightly between green, brown and red varieties, across the board seaweed contains a number of vitamins, including B,C,E and K, omega-3 fatty acids, protein and 10 times more minerals than land-based plants, according to a recent study.
However, you don’t need to pile your plate high with seaweed. “Some brown seaweed is very high in iodine (碘),” Camire said. “It has so much iodine that consumers are advised to eat it no more than three times per week.”
Seaweed is just as beneficial to the planet as it is to our personal health. Seaweed pulls carbon dioxide out of the atmosphere and uses it to make more carbohydrates (碳水化合物). “We are not sure how much seaweed farming it would take to have a significant effect on global warming, but it helps,” Camire said.
Seaweed also consumes elements that can harm the ocean. It can also provide a place for smaller sea creatures to hide from their enemies, establishing environments that can help restore diverse ocean life in over-fished habitats.
1. What does the underlined word “edible” in paragraph 1 mean?| A．Fit to be eaten. | B．Large in size. | C．Hard to notice. | D．Good for health. |
| A．It can replace most vegetables and grain. | B．It provides people with important nutrition. |
| C．It attracts Mary Ellen Camire to agriculture. | D．It is bad for people’s health in the long run. |
| A．Choose seaweed low in iodine. | B．Combine seaweed with other foods. |
| C．Control the amount of seaweed you eat. | D．Remove brown seaweed from your plate. |
| A．By setting up new habitats for sea creatures. |
| B．By releasing friendly gases into the atmosphere. |
| C．By providing plenty of carbohydrates for fishers. |
| D．By using carbon dioxide to produce useful substances. |
7 . Theoretically some trees could live forever, according to a recent essay that reviews growing evidence on long-lived trees.
Across the board, trees do not die so much as they are killed, write the authors of the review essay. Their killers are outer factors rather than old age alone. That is, there is no evidence that harmful genetic mutations (基因突变) occur over time or that trees lose their ability to continue to grow.
“Trees might live forever, but this does not happen,” says co-author Franco Biondi. “Tree killers include environmental risks such as droughts , wildfires, terrible weather and human behaviors such as woodcutting and fires set to clear forests for hunting or grassland.”
Tree longevity (长寿) interests researchers in part because trees and other plants remove carbon from the atmosphere, and older trees are thought to store more carbon than younger ones. The rings of old trees can also serve as an invaluable record of climate history, with wider rings indicating better years.
David Stahle, a geographer and tree longevity researcher at the University of Arkansas, takes issue with the belief that trees can possibly live forever. “The likelihood, all things being equal, that trees can live forever seems unlikely to me,” he says.
This hypothesis (假设) has become popular in the past 20 years as researchers continue to report having found little genetic evidence of aging in extremely old trees. And this is one of the review essay’s most important points. But evidence of aging could be out there and just not yet found.
1. What does the recent review essay mainly indicate?| A．There are a great variety of tree killers. | B．Trees could keep on surviving forever. |
| C．More trees die naturally than being killed. | D．Genetic mutations stop trees from growing. |
| A．Because the way trees grow rings is more interesting. |
| B．Because trees make clearer climate records than other plants. |
| C．Because older trees contribute more to the environment. |
| D．Because younger trees are less likely to have genetic mutations. |
| A．Doubtful. | B．Uninterested. | C．Reserved. | D．Favorable. |
| A．The assumption has been proved true. | B．Evidence of aging trees might exist. |
| C．Tree research has grown in the past 20 years. | D．Some key points disappear in the review essay. |
1. How does the woman feel at first?
| A．Curious. | B．Surprised. | C．Excited. |
| A．Flowers. | B．Mushrooms. | C．Trees. |
| A．Two. | B．Three. | C．Four. |
| A．On Thursday. | B．On Friday. | C．On Saturday. |
9 . Recent research confirms what our farming ancestors have known for centuries about hedges (树篱). They conserve precious soil by acting as windbreaks and absorbing rainwater that would otherwise wash it from the fields. And hedges store carbon, putting them in the front line of our bi d to tackle the climate crisis.
However, hedges have had a tough time in the poor countryside, with farmers encouraged to tear them down in pursuit of maximum production and larger field s to accommodate ever-larger machinery. What’s more, some hedges have been ignored. If left to their own devices, they’ll eventually become a line of trees. Some hedges each year lose their structures and fail to fulfil the primary duty as a barrier. Around a half of the nation’s hedges have disappeared in the past century.
There are signs that “the tide is turning”. The search for net zero has aroused many organizations’ interest in the humble hedge’s role as a carbon sink. The Climate Change Committee is recommending a 40 percent increase in hedges: an additional 200,000 km. Such recommendations are starting to drive policy. Cash-pressed farmers will be encouraged to create new hedges and improve their management of existing ones under the new Environmental Land Management Schemes, which will replace many of the existing agricultural support payments in coming years. Meanwhile, initiatives such as Close the Gap, led by the Tree Council, is providing funding and support to plug the gaps in existing hedges with new planting. There’s even an app to help time-pressed farmers do a quick survey to spot where their hedges need some help.
This is a good time for hedges. Take some of the most pressing challenges facing the countryside, and indeed, the world as a whole — the climate crisis, soil erosion (侵蚀), insect attack and wider biodiversity loss — and hedges are part of the solution.
1. What does recent research show about hedges?| A．They are unique landscapes in the rain. |
| B．They act as dividing lines between fields. |
| C．They have long been helpful to agriculture. |
| D．They are frequently washed away from the fields. |
| A．Their suffering. | B．Their production. |
| C．Their duties. | D．Their structures. |
| A．Puzzled. | B．Concerned. | C．Humble. | D．Indifferent. |
| A．Hedges: Ancient Resources |
| B．Hedges: Official Recommendations |
| C．Restoring Hedges: Bringing Benefits to the Environment |
| D．Researching Hedges: Originating from Farmers’ Request |
1. Why is the baobab’s trunk really fat?
| A．It is shaped by people. |
| B．It stores a large quantity of water. |
| C．It must be strong enough to support the tree. |
| A．About 12 metre. |
| B．About 15 metre. |
| C．About 30 metre. |
| A．Shops. |
| B．Wildlife habitats. |
| C．Bus shelters |
