1 . A new report by a British-based plant protection group says almost 30 percent of the world’s tree species are at risk of extinction. The State of the World’s Tree report warns that 17,500 tree species are at risk of dying out. And 440 species have fewer than 50 individual trees left in the wild. The report was recently published by Botanic Gardens Conservation International (BGCI).
The report says the number of threatened tree species is double the number of threatened mammals, birds, amphibians and reptiles combined. In a statement, BGCI Secretary General Paul Smith said, “This report is a wake-up call to everyone around the world that trees need help.”
Among the most at-risk trees are species including magnolias and dipterocarps. These trees are commonly found in Southeast Asian rainforests. The report says oak and maple trees also face threats.
Trees help support the natural environment and are considered important for fighting global warming and climate change. The extinction of a single tree species could mean the loss of many others. “Every tree species matters, to the millions of other species that depend on trees all over the world,” Smith said.
The report shows that thousands of kinds of trees in the world’s top six countries for tree-species diversity are at risk of extinction. The greatest single number is in Brazil, where 1,788 species are at risk. The other five countries are Indonesia, Malaysia, China, Colombia and Venezuela.
The top three threats facing tree species are crop production, logging and farming. Most worryingly, climate change and extreme weather are also growing threats. The report adds at least 180 tree species are directly threatened by rising seas and severe weather. It notes that island tree species are more at risk than other trees because many islands have species of trees that can be found nowhere else.
1. What can we know about the world’s tree species?| A．They are in urgent need of protection. |
| B．There are 50 types of them unknown. |
| C．Most of them are in danger of dying out. |
| D．The number of them is higher than wild animals. |
| A．To attract readers to explore there. |
| B．To emphasize their special location. |
| C．To present wild animals’ important habitats. |
| D．To show the most threatened tree species there. |
| A．Their environmental benefits. | B．Their economic value. |
| C．Their characteristics. | D．Their evolution. |
| A．Confused. | B．Concerned. |
| C．Grateful. | D．Humorous. |
2 . There are not only strange animals in the world; there are also some crazy plants.
Cactuses grow in places that have very little rain. These plants don’t have leaves because plants lose water through their leaves. Cactuses want to keep water inside their bodies. If you are ever stuck in a desert, you can get water by cutting a cactus. The water is not very nice because it tastes bitter. Sharp thorns protect cactuses. This is why desert animals won’t eat them. Their roots are spread out very close to the top of the sand.
Venus flytraps got their name because they trap and digest small insects in their leaves. They grow in wet places where the soil does not have the right food for the plants, so the plants have to catch their own food. Venus flytraps are small plants that have little white flowers.
Mangrove trees are trees that are able to grow in salty water. As a mangrove gets taller, it grows roots from its branches. When it is fully grown, hundreds of roots hold the leaves above the salty water. Mangroves grow mainly in the shallow water of rivers, close to where the river runs into the sea. Trees do not need much salt and mangroves have special ways of releasing excess salt, to stop it damaging the tree. Other mangroves send the salt to be stored in the oldest leaves on the tree, so that when they drop off, the tree gets rid of all unwanted salt.
Plants are able to change so that they can live in certain environments.
1. What’s the tone of the article?| A．Terrifying. | B．Thrilling. | C．Serious. | D．Frightening. |
| A．Poisonous. | B．Costly. | C．Extra. | D．Bitter. |
| A．In a science fiction. | B．In a biology book. | C．In a fashion magazine. | D．In a novel. |
| A．Unique plants. | B．Wet plants. | C．Shallow plants. | D．Salty plants. |
3 . With no special equipment, no fences and no watering, two abandoned agricultural fields in the UK have been rewilded (重新野化), in large part due to the efforts of jays, which actually “engineered” these new woodlands. Researchers now hope that rewilding projects can take a more natural and hands-off approach and that jays can shed some of their bad reputations.
The two fields, which researchers have called the New Wilderness and the Old Wilderness, had been abandoned in 1996 and 1961 respectively. The former was a bare field, while the latter was grassland—both lay next to ancient woodlands. Researchers had suspected that the fields would gradually return to wilderness, but it was impressive to see just how quickly this happened, and how much of it was owed to birds.
Using aerial data, the researchers monitored the two sites. After just 24 years, the New Wilderness had grown into a young, healthy wood with 132 live trees per hectare, over half of which (57%) were oaks. Meanwhile, the Old Wilderness resembled a mature woodland after 39 years, with 390 trees per hectare.
“This native woodland restoration was approaching the structure (but not the species composition) of long-established woodlands within six decades,” the researchers explained in the study.
Part of this reforestation was done by the wind, and researchers suspect that previous ground disturbance may have aided the woodland establishment—which is good news, as it would suggest that agricultural areas may be reforested faster than anticipated. However, animals—Eurasian jays, thrushes, wood mice, and squirrels—also played an important role in helping the forests take shape. This handful of species provided much of the natural regeneration needed for the forest to develop. Jays, in particular, seem to have done a lot of heavy lifting.
1. What does the underlined word “shed” in Paragraph 1 refer to?| A．Be opposed to. |
| B．Be ashamed of. |
| C．Get used to. |
| D．Get rid of. |
| A．The scale of the woodlands. |
| B．The diversity of the fields. |
| C．The rate of the changes. |
| D．The frequency of the wilderness. |
| A．The woodland restoration was approaching the structure of long-established ones. |
| B．Much of the wilderness of the fields was owed to birds. |
| C．Previous ground disturbance aided the woodland establishment. |
| D．How quickly the fields returned to wilderness over time. |
| A．The essential role of humans in the reforestation. |
| B．The factors that contribute to the reforestation. |
| C．The importance of woodland establishment. |
| D．The threats faced by a handful of wild animals. |
4 . Lichens (地衣)
Lichens look like splashes of paint left behind by a careless painter. Unlike many plants, they do not require soil to grow. They grow on trunk of trees in steaming tropical rain forests, on farmers’ fenceposts, on the bricks of big-city buildings, and on old gravestones. Lichens can tolerate extremes of climate. They grow on rocks in hot springs, on wind-swept mountaintops, and on stones in the driest deserts. In the Arctic, lichens are the principal source of food for reindeer. Whole mountainsides in Antarctica appear green and orange because of the presence of lichens; they are one of the few plants that can survive there. They are among the oldest of known plants. Recently, scientists discovered lichen fossils on a rock in a mine in southwest China that date back 600 million years.
When conditions become harsh, lichens become dormant (休眠). If there is not enough moisture, they simply dry up, but a short rain or even a heavy dew gives them new life. When growing on rock surfaces, lichens produce acids that dissolve (溶解) the minerals, contributing to the process of weathering by which rocks are slowly turned to soil. This property enables lichens to be pioneers. They appear on barren rock rubbed clean by glaciers, fires, lava flows, or floods, beginning the process of soil formation that allows mosses (苔藓) and other plants to later take root. But, despite their hardiness, lichens are extremely sensitive to airborne particles(颗粒). That’s why they serve as an early warning system for air pollution.
It is the acids lichens produce that give them their distinctive colors. Lichens are often spoken of in the same breath as mosses, and some lichens are even called mosses, but true mosses are all distinctively green, whereas lichens appear in many vivid colors. At one time, acids from lichens were used to make dyes, such as the purple dye, the blue dye, and the red dye, and they are sometimes still used that way today. Some lichens, such as oakmoss, contain oils that produce fragrant odors used in scented soaps, cosmetics and perfumes. Some lichens are also known to have antibiotic properties to kill bacteria.
So definite are the form, color, and characteristics of these organisms that for hundreds of years lichens were constantly under scientists’ microscope.
1. What characteristic of lichens is mainly talked about in paragraph 1?| A．They grow only on rock surfaces. |
| B．They live primarily in cold places. |
| C．They have adapted to a wide variety of environments. |
| D．They live in remote locations far from human communities. |
| A．have their primitive structure |
| B．grow in areas before other plants do |
| C．are found in remote parts of the world |
| D．develop so early in the history of the planet |
| A．as a means of coloring clothing |
| B．as a type of medicine |
| C．as a source of food |
| D．as an ingredient in perfume |
| A．Lichens are important in Canada because of their abundance in the north. |
| B．Extracts of lichens were sold as herbal medicines to facilitate hair growth. |
| C．Glacier Park’s vast array of lichens indicate relatively good air quality. |
| D．A German botanist first found lichens are composed of two life forms. |
5 . The rapid pace of global warming and its effects on habitats raise the question of whether species are able to keep up so that they remain in suitable living conditions. Some animals can move fast to adjust to a swiftly changing climate. Plants, being less mobile, rely on means such as seed dispersal(传播) by animals, wind or water to move to new areas, but this redistribution typically occurs within one kilometre of the original plant.
When the climate in a plant’s usual range becomes hotter than it can tolerate, it must find new, cooler areas that might lie many kilometres away. One explanation for long-distance seed dispersal is through transport by migratory (迁徙的) birds. Such birds swallow seeds when eating fruit and can move them tens or hundreds of kilometres outside the range of a plant species.
Gonzáiez-Vary and colleagues report how plants might be able to keep pace with rapid climate change with the help of migratory birds. The authors analysed the fruiting times of plants, patterns of bird migration and the interactions between fruit-eating birds and fleshy-fruited plants across Europe. Plants with fleshy fruits were chosen for this study because most of their seed transport is by migratory birds, and because fleshy-fruited plants are an important part of the woody-plant community in Europe. The common approach until now has been to predict plant dispersal using models fitted to abiotic (非生物的) factors such as the current climate. Gonzáiez-Vary instead analysed an impressive data set of 949 different seed-dispersal interactions between bird and plant communities, together with data on entire fruiting times and migratory patterns of birds across Europe. The researchers also analysed DNA traces from bird wastes to identify the plants and birds responsible for seed dispersal.
1. How do species adapt to climate changes when it’s too hot?| A．All animals will move away across great distanced. |
| B．Some plants depend on migratory birds to carry seeds. |
| C．Some plants depend on animals, wind or water to move. |
| D．Plants’ seeds disperse to cooler places of several kilometres away. |
| A．Most of these can’t fit rapid climate change |
| B．Migratory birds like making nests in them |
| C．Migratory birds transport their seeds. |
| D．They are favoured by most birds. |
| A．To explain relations between fruit plants and migratory birds. |
| B．To clarify the reason why birds migrate in fruiting times. |
| C．To present a fact that migratory bird eats flesh fruits. |
| D．To show that fruits depend on migratory birds. |
| A．The advantage of fruit plants. |
| B．The destination of the bird migration. |
| C．The adaptation of fruit plants to the climate change. |
| D．The influence of climate change on plants and animals. |
6 . Covered in lush fur, the thickest in the animal kingdom, sea otters (海獭) can live their entire lives in the ocean, feeding heavily upon seafloor animals such as shellfish. They are often seen to eat clams(蛤), which bury themselves in meadows of eelgrass (大叶藻场), a wide-ranging plant species growing in water. Eelgrass meadows where sea otters dig for clams become partly bare, which is commonly a concern for ecologists.
As it turns out, the meadows with otters are healthier, with more eelgrass, according to a new study published in Science. That's because by gently disturbing the seabed, the otters make the plants flower and produce seeds. What's more, their digging provides more space and sunlight for seeds to settle and grow. The enhanced genetic diversity caused by sea otters could make eelgrass more adaptable to present and future threats.
The finding is a powerful example of how animals such as otters influence their ecosystems beyond predation (捕食), often in unseen and little-known ways, says study leader Erin Foster, a research associate at the Hakai Institute. It also means sea otters, an endangered species, are vital to their environments and give eelgrass, which is in danger worldwide, a better chance at staying healthy and surviving.
Seagrass habitats are also important for many fish, providing food for animals, absorbing, and filtering harmful pollution and bacteria from the water. "Genetic diversity typically strengthens the adaptability of species, and considering the challenges we're facing…this will be important for eelgrass meadows, and from this aspect, the impact the otters are having deserves our lasting concern," says Foster.
1. What do we know about sea otters?| A．They live part of their lives underwater. | B．They mainly feed on sea animals like fish. |
| C．They eat clams beneath eelgrass meadows. | D．They become a new concern for ecologists. |
| A．By giving opinions. | B．By presenting reasons. |
| C．By clarifying concepts. | D．By comparing results. |
| A．To provide examples of sea otters' predation. |
| B．To show the urgency to protect the environment. |
| C．To highlight the role of otters in their ecosystems. |
| D．To warn against the potential risk of climate change. |
| A．Overestimated. | B．Noteworthy. | C．Temporary. | D．Unpredictable. |
7 . Seen any unseasonably early daffodils（水仙花）showing their faces yet? UK spring flowers are opening nearly a month earlier than they did before the mid-1980s, due to climate change.
That is the conclusion of a study of nearly 420,000 observations of the first flowering date of 406 plants from a UK citizen science project called Nature's Calendar. It has records dating back to 1753 from gardeners and naturalists, as well as bodies such as the UK's Royal Meteorological Society.
UIf Buntgen at the University of Cambridge and his team found that plants were opening their flowers 26 days earlier on average in the years after 1986 than they did before. They picked that year as it was the mid-point in the data set-where they had about the same number of observations before and after-because there were many more recent records than earlier ones.
The analysis included records of all plants, whatever time of year they flower, but most of them(like the daffodils) bloom in spring. “It is likely that the influence of climate change will be greater for spring-flowering plants, where the usual beginning of warmer temperatures that would cause flowering starts earlier,” says a spokesperson for the UK's Royal Horticultural Society.
There was a bigger advance in the dates of the first blooms for smaller plants, with those less than 20 centimeters high flowering an average of 32 days earlier in the years after 1986 than they had historically.
In any year, flower opening times were closely connected with the average temperature of the months from January to April. “If it's warmer, it's an earlier beginning. If it's cooler, it's a later one,” says Buntgen. The average maximum temperature across those four months rose by 1.1℃, comparing the period from 1950 to 1986 with the years after 1986.
“The change could hurt insects, birds and other wildlife that has evolved to sync with（同步）the flowering of certain plants,” says Buntgen.
1. What can we know about the study?| A．It dated back to 1753. |
| B．It was based on a large amount of data. |
| C．It was conducted by gardeners and naturalists. |
| D．It only covered records of plants blooming in spring. |
| A．It was in the middle of the data set. |
| B．It was a memorable day for Ulf Buntgen. |
| C．It was the first year to record flowering date. |
| D．It was in 1986 that spring flowers bloom earlier. |
| A．The influences of flowers’ early blooming. |
| B．Measures to be taken to stop climate change. |
| C．Further study to find the reason for flowers’ early blooming. |
| D．How creatures adapt to the change of flowers’ early blooming. |
| A．In a guidebook. |
| B．In a science fiction. |
| C．In a geography textbook. |
| D．In a science magazine. |
8 . Many gardeners do not begin to grow their plants from seeds. Instead, they buy young plants, also called seedlings or “starts”. These are plants that are grown in a nursery—a place where plants are grown and sold.
Many gardeners buy seedlings in containers for their gardens. Most nursery seedlings are either plants that last for one growing season or vegetables.
The first step is finding a good nursery. A good gardener will ask themselves whether the nursery grows its own plants, or buys them from larger growers.
Make sure the plants have been watered correctly. If not, the seedlings will have a hard time developing. If there are lots of half-dead or dried-out plants, it is often a sign to buy elsewhere.
Next, before buying a grouping of seedlings, feel the soil. In addition to being wet but not flooded, it should not be solid.
Look at the holes at the bottom of the container to see the roots. If the roots are too dense (密度大的), that is a sign not to buy the plant. Look to see if there has been damage from the wind or sun.
When you buy spring plants in cell containers, you should make sure all the plants in the group are healthy. If one out of four plants in a grouping is not healthy, the others might not be far behind.
| A．Damaged plants will take time to repair. |
| B．That is a sign that the soil has been dried out. |
| C．Lastly, always have a plan when buying plants. |
| D．Pay attention to the price when buying spring starts. |
| E．They come in plastic containers holding four to six plants. |
| F．A gardener should also know what kind of plants they are buying. |
| G．Nurseries that grow their own spring starts usually take good care of them. |
9 . If the grass looks greener after the skies have cleared, your eyes aren’t cheating you. “There are several reasons rain helps lawns green up,” said Jennifer Knoepp, a soil research scientist with the USDA Forest Service in Otto, North Carolina.
After it rains, there’s typically more water available in the soil for plants. When plants take up that water, they are also taking up nitrogen (氮) from the organic matter that’s in the soil. “As plants grow, their small roots die and new roots grow,” Knoepp said. When that happens, soil microbes (微生物) cause the dead roots to rot. This process is similar to adding fertilizers to your lawn, but only this action takes place underground and naturally, without your awareness. As rain runs into the soil, it activates the microbes to give off more nitrogen. The grass benefits from the freshly fallen rain because the water allows the roots to take up this “new” nitrogen as well as the nitrogen that the microbes have previously produced. At the same time, “the grass is very active with photosynthesis (光合作用)” when the sun returns, Knoepp explained.
Even though rain increases the nitrogen that’s available to your lawn in several ways, you can’t count on nitrogen from rain to meet all the fertilizer needs of your grass or your vegetable garden. Commercial fertilizers are still needed for a balanced fertilizer program, but Knoepp urges caution in applying them. While nitrogen is vital for good plant growth, be sure to follow package directions. Too much of a good thing can be harmful not only to plants but to nearby ponds, lakes, streams and rivers. After all, it’s not green streams but green lawns that homeowners want to see when the clouds depart and the sun returns.
1. What makes the grass look greener after the rain?| A．The cleanup of the rain. | B．Slower photosynthesis. |
| C．The appearance of new roots. | D．Increased absorption of nitrogen. |
| A．The production of nitrogen. | B．The process of plants’ growth. |
| C．The effects of photosynthesis. | D．The method of natural fertilizing. |
| A．Be careful not to overuse fertilizers. | B．Keep a commercial fertilizer program. |
| C．Collect as much rainwater as possible. | D．Take advantage of nitrogen from rain only. |
| A．Skeptical and critical. | B．Cautious and confident. |
| C．Objective and humorous. | D．Scientific and conservative. |
10 . Being highly connected to a strong social network has its benefits. Now a new study is showing the same goes for trees, thanks to their underground neighbors. The study is the first to show that the growth of adult trees is linked to their participation in fungal networks living in the forest soil. Though past research has focused on young trees, these findings give new insight into the significance of fungal networks to older trees — which are more environmentally beneficial for functions like capturing carbon.
“Large trees make up the main part of the forest, so they drive what the forest is doing,” said researcher Joseph Birch, who led the study. When they live in the forest soil, fungal networks act as a sort of highway, allowing water, nutrients and compounds to flow back and forth among the trees. The network also helps nutrients flow to resource - limited trees like family units that support one another in times of stress.
Cores taken from 350 Douglas firs (花旗松) showed that annual tree ring growth was related to the extent of fungal connections a tree had with other trees. They had much higher growth than those that had only a few connections. The research also showed that trees with more connections to many unique fungi had much greater growth than those with only one or two connections. “If you have this network that is helping trees grow faster, that helps capture more carbon year after year. These networks may help trees grow more steadily even as conditions become more stressful, and could even help protect them against death.” said Birch.
Birch hopes his findings lead to further studies in different kinds of forests in other geographical areas, because it's likely that the connections among trees change from year to year. He said, “Knowing whether fungal networks are operating the same way in other tree species could factor into how we reforest areas after harvesting them, and it could inform how we want to plant trees to preserve these networks.”
1. In what way do the new findings differ from the previous ones?| A．They confirm the benefits of fungal networks. | B．They demonstrate a new way to capture carbon. |
| C．They clarify misunderstanding of fungal networks. | D．They reveal the value of fungal networks to adult trees. |
| A．By fighting against diseases. | B．By bettering forest soil conditions. |
| C．By acting as the center of family units. | D．By maintaining the balance of resources. |
| A．Tree rings. | B．Fungal networks. | C．Douglas firs. | D．Cores from Douglas firs. |
| A．Geography. | B．Agriculture. | C．Reforestation. | D．Microbiology. |
