1 . Every August the clustered carline thistle (蓟) is one of the only plants that flower in most of Spain’s dry Mediterranean habitats, making it a dominant plant on the local bees and other pollinators. But how can the thistle survive, much less flower, when its neighbors are reduced to twigs and dust?
Spanish National Research Council evolutionary ecologist Carlo s Herrera had an amazing discovery when one day he peered into a thistle blossom to see how much nectar was inside and lightly touched the flower. He discovered that even after hours in direct sun, the flower heads were routinely five degrees cooler than their surroundings during the heat of the day, with the difference approaching 10 degrees for some flowers on the hottest days.
Sanna Sevanto, a physicist and plant physiologist at Los Alamos National Laboratory says that Herrera’s finding is exciting and could confirm a risky plant survival strategy that has, until now, only been theorized.
Sevanto and other scientists have documented that to perform photosynthesis (光合作用), leaves need access to carbon dioxide, which enters through tiny pores (毛孔) called stomata on the leaf’s surface. When stomata open to let carbon dioxide in, some water escapes; this causes evaporative cooling that lowers the leaf’s temperature slightly.
But for the Spanish thistles, evaporative cooling could be the goal rather than just a side effect of photosynthesis. Herrera suggests the plant could essentially be sweating: sacrificing precious water, so scarce in Spain’s dry summers, to prevent its delicate reproductive organs from overheating. She added that some flower species have stomata on their petals, which Sevanto says would be an easy route for releasing water. Opening stomata in a drought is a big gamble, though, and she notes that, so far, “we have not observed a plant that would do it to cool themselves.”
As heat waves become more frequent and intense with climate change, it’s increasingly important to study unusual adaptations that help plants survive heat stress. But ultimately, “whether these plants will have water enough to keep the system working,” Herrera says, “that’s another story.”
1. What was Herrera’s discovery about carline thistle in August?A.It was the only plant that blossomed. | B.It was the only plant that survived. |
C.It had little nectar in the flower. | D.It had lower temperature in the flower head. |
A.To cool the key organs. | B.To take in carbon dioxide. |
C.To accelerate photosynthesis. | D.To reduce water content in leaves. |
A.Advantage. | B.Risk. | C.Shift. | D.Evolution. |
A.Suspicious. | B.Positive. | C.Objective. | D.Unconcerned. |
2 . We are unavoidably linked to the ocean. Collectively, it covers about 71% of our world and is instrumental in the processes that keep us alive. While the rainforests may be referred to as “the lungs of the planet”, scientists say it’s actually the ocean that provides 50% — 80% of the oxygen we breathe. Besides, through a “conveyor belt” action, it helps regulate Earth’s climate by transporting heat away from the equator, towards the poles to cool. The ocean also proves itself essential in the fight against climate change too. It absorbs 50 times more carbon dioxide than our atmosphere-or rather, it’s not the ocean itself but what lives in it. And perhaps one of the most incredible forms is the humble seagrass.
Across the globe, there are more than 70 species of seagrass, growing in shallow and sheltered coastal areas and covering 300,000 square kilometres, which absorbs 10% of the ocean’s carbon each year and captures carbon up to 35 times faster than tropical rainforests. Seagrass builds its leaves and roots using carbon, which it extracts from water through the process of photosynthesis (光合作用) — and it holds on to it, even after death. Dead plant material decomposes (分解) slowly on the ocean floor, and this means that the carbon stored within is eventually buried under the seabed.
Significant as it is, seagrass is critically endangered. According to the U. N. Environment Programme, a seagrass area the size of a football pitch is destroyed every 30 minutes around the world. Fortunately, restoration missions are already underway, in places as far afield as Kenya, Mozambique, and the UK. But rising temperatures remain a twofold threat: an increase in storms that tear the shallow-rooted seagrass from its beds, and rising sea-levels that block out the sunlight.
However, seagrass is known to adapt to survive-and gene sequencing of the Zostera marina seagrass has shown it has done so on three separate occasions already. Could it be one of Earth’s great survivors that will save us all? Only time will tell.
1. How does the seagrass help regulate Earth’s climate?A.It blocks out the sunlight. | B.It absorbs carbon dioxide. |
C.It provides most of the oxygen. | D.It transports heat towards the poles. |
A.Obtains. | B.Replaces. | C.Consumes. | D.Delivers. |
A.It is no longer endangered after restoration. |
B.It has saved the planet from climate change. |
C.It hasn’t been affected by rising temperatures. |
D.It is able to adapt to changes in its environment. |
A.The Fantastic World of Seagrass | B.The Uncertain Future of the Ocean |
C.Seagrass: The Ocean’s Unsung Hero | D.The Battle to Save Seagrass from Extinction |
3 . Tips For a Great Fall Garden
A fall garden can be a great place, which allows us to revel (陶醉) in the beauty and abundance of the season. Many gardeners seem to focus on summer so much that the garden can fade during the fall and not live up to its full potential.
Whether for production or for decoration, it is always a good idea to look first at native plants. Plants that are native to your area should always make up a high proportion of the plants you grow. Selecting plenty of native plants that bloom in the fall helps you to boost biodiversity and they look lovely and right at home.
Use and value fall leaves.When trees drop their colorful leaves, creating a great fall garden means making the most of those leaves as a resource to keep your garden looking good. To make the most of fall leaves, you can use them to protect the soil and overwintering plants, to enrich the soil and fill planters or containers.
Making a great fall garden is mostly about the plants you choose and the way you choose to garden. But gardens should not be entirely about hard work.
A.Choose native plants for a diverse fall garden. |
B.Make designs for forest gardening on a small scale. |
C.To help these gardeners, here are some tips for a great fall garden. |
D.Native plants for your area can become shopping lists for a fall garden. |
E.You can take steps to ensure you can fully enjoy the space in cooler seasons. |
F.You can even take on some arts and crafts projects to enjoy their colors and shapes. |
G.In cooler gardens, it is possible to grow year-round if you create an underco ver growing area. |
4 . Many people want to grow their own food in their own backyard, but they don’t know how to start. This article will teach you how to start!
Find out what plants to get. Get plants that can grow in your area, and make sure you plant them at the right time of the year.
Buy your plants and fertilizers. You can either get seeds or get plant seedlings. Go to your local nursery and see what they have. Get fertilizer as well.
Plant your plants in the garden. Use a hand shovel and dig a small hole big enough to put your plant in. Water your plant before you put it in so you can wet the root ball. Sprinkle(撒)in a little bit of fertilizer and put your plant in.
For seeds, stick your finger into the dirt where you want to plant the seed until the dirt reaches the second joint on your finger.
A.Learn how to start a garden. |
B.Plan out your garden wisely. |
C.Make sure to get the right fertilizer for your plants. |
D.Some plants that need acidity are tomatoes and blueberries. |
E.You should grow and water them in spring if you want to have a good start. |
F.Then surround the plant with dirt and make a small circle around it for water. |
G.If you plant them too early or too late, they could freeze and die before you can harvest vegetables. |
5 . Off Australia’s northern coast, the remains of ancient coral reefs (珊瑚礁) form the bedrock of wooded islands, which are home to diverse animals and plants, including mangrove (红树林) forests that blanket their coasts and serve as vital habitats and carbon storers. A recent survey shows that expanding seas might have led to a massive mangrove increase, researchers report November 1 in Proceedings of the Royal Society B.
Mangroves absorb carbon dioxide and store it as “blue carbon”, a term for carbon that is hidden away in ocean environments. “There’s a lot of interest in using mangrove blue carbon to lessen climate change,” says Kerrylee Rogers, an environmental scientist at the University of Wollongong in Australia. But there remain a lot of questions around their capacity to adapt to sea level rise.
In 2021,a team led by Wollongong environmental scientist Sarah Hamylton visited the Howick Islands to do a related research. They walked through the seawater to assess the plant diversity and measure individual trees. Using the measured widths and heights of several mangroves, the team calculated tree widths for the rest of the forest from the data to estimate the total mangrove quantity. The islands host nearly 54,000 metric tons of mangroves, the team estimates, which is roughly 10,000 more metric tons than there was in 1973.
The Howick Islands are uniquely suited to supporting mangroves as the ocean rises. At the end of the Last Glacial Maximum, around 12,000 years ago, water levels rose around northern Australia, and coral reefs grew upward to fill the space that had opened for them.
When sea levels fell thousands of years later, the exposed reefs became sediment (沉积物). With sea levels now rising again, the mixture of saltwater and sediment makes a perfect home for the salt-tolerant mangroves.
Rogers and Hamylton are now working on a bigger effort to study mangoves around Australia. “If we’re going to invest in mangroves to provide us blue carbon and to protect shorelines, we need to understand how dynamic they are,” Rogers says.
1. What can be known about blue carbon?A.It is produced by ocean water. | B.It is massively present in the air. |
C.It is friendly environment. | D.It is nutritious for mangroves. |
A.To measure the size of mangroves. |
B.To figure out where to plant mangroves. |
C.To confirm whether local natural environment is polluted. |
D.To see how the mangroves respond to sea level rise. |
A.The diversity of ocean life. |
B.The increase of coral reefs. |
C.The combination of salt water and sediment. |
D.The formation of the bedrock of wooded islands. |
A.Climate Change Causes Sea Level Rise |
B.Sea Level Rise Helps Mangroves Boost |
C.Environment on Australia Islands Is Improving |
D.Climate Warming Poses Dangers To Mangroves |
6 . In early October, Travis Gienger transported an enormous pumpkin (南瓜) from his home in Minnesota to the World Championship Pumpkin Weigh-Off in California. His pumpkin set the record for the biggest one ever grown in North America. How do competitive growers get their pumpkins to grow to massive sizes?
Gienger, who teaches horticulture (园艺学) at Anoka Technical College, begins growing his pumpkins in mid-April, starting with seeds that he grows indoors for the first few weeks, when Minnesota’s soil is too frosty.
Depending on the variety, pumpkin plants can grow up to a dozen fruits on a single vine (藤曼) . But to maximize size, growers remove all but one or two of these pumpkins in order to decrease each individual fruit’s competition for resources.
But what exactly happens inside a pumpkin as it grows? Two factors drive natural growth: cell division and cell expansion. Cell division accounts for most of the growth at the beginning of a fruit’s life. This period lasts for about 20 days in pumpkin plants.
A.Biology has the answers. |
B.Genetics also influences pumpkin growth. |
C.The following tips will give you a head start. |
D.Once it warms up, the plants are transferred outside. |
E.When it stops, cell expansion will then come into play. |
F.Growers extend the growth period for as long as possible. |
G.Growers also remove the weeds in the area for the same reason. |
7 . How Gardeners Can Reduce Risk of Fire
If you are selecting plants for your garden, knowing which plants offer some fire resistance and which are more flammable (易燃的) can serve you well.
Quicker to catch fire
Plants like bamboo that produce flammable substances such as aromatic oils, resins (树脂), wax, or sap, are among the quickest to catch fire.
Trees with thin bark (树皮) that falls off are usually more flammable than those without. And fine-needled plants like pine, juniper, and spruce contain resins.
Many kinds of grasses are highly flammable. Their ability to catch fire increases when they are left to stand dry over winter or during periods without rain. Additionally, too much heat dries out the soil and under such conditions, many kinds of plants turn into a fire starter.
Native vs. non-native
As a group, native plants aren’t necessarily less flammable than introduced kinds of plants.
For the best fire resistance, choose trees that lose their leaves every year, like ash, and maple, rather than fine-needled trees.
What to look for in plants
The Washington State University Extension Service has published advice for choosing plants that are fire-resistant.
•High water content in leaves.
•Little or no seasonal gain of dead plant material.
•Open branching (they provide less fuel for fires).
•Fewer total branches and leaves.
A.Some plants are more flammable than others. |
B.Plants with water-filled leaves are slow to burn. |
C.But non-native plants often are a greater fire risk. |
D.Many plants have qualities that do not burn easily. |
E.All plants might catch fire under the right conditions. |
F.Their needle-like leaves increase the risk of fire when left on the ground. |
G.They will often catch fire even if they have been well-watered and cared for. |
8 . In a new study, researchers found that invasive insects in the United States could kill approximately 1.4 million urban trees by 2050, which would cost over $900 million to replace, reports Vishwam Sankaran for the Independent.
Hot spots predicted to have the most urban tree mortality (死亡率) were Milwaukee, Wisconsin; Chicago, Illinois; and New York, New York. The study, published in the Journal of Applied Ecology, is the first nationwide forecast of street tree mortality from invasive insects.
The emerald ash borer is an invasive beetle native to Asia. It was first detected in 2002 in southeastern Michigan, and experts suspect it was brought into the United States on wood packing material carried on cargo ships or airplanes traveling from Asia. Since then, the bug has been damaging ash trees. In the last two decades since the insect was first detected, numerous trees have been killed in North America.
Data collected from 30,000 communities across the country was used to estimate tree mortality in the next 30 years. The researchers combined this data with a model that predicted the spread of 57 different invasive insect species. Their results show emerald ash borers alone could cause 90% of the estimated 1.4 million tree deaths. Ash borers are already predicted to “kill virtually all ash trees” in over 6,000 urban areas, according to Newsweek.
Less than 25% of 30,000 urban areas in the U.S. are expected to experience 95% of all street-tree mortality, reports Adam Barnes for the Hill. The areas that will experience the most tree loss include cities in the Midwest and East Coast. These locations are expected to have the most tree loss because large numbers of ash trees occupy the streets and parks in these areas, reported the Independent.
When it comes to how to save urban areas from becoming treeless, study author Emma Hudgins, a biologist at McGill University, says, “These results can hopefully provide a cautionary tale against planting a single species of tree throughout entire cities, as has been done with ash trees in North America. Planting various trees provides resilience against pest infestations (侵扰).”
1. What can we know about the emerald ash borer?A.It is an invasive beetle in Asia. |
B.It was first found by the Michigan people. |
C.It has killed numerous trees in America. |
D.They definitely enter the U.S. by cargo ships or airplanes. |
A.The purpose of the research. | B.The conclusion of the research. |
C.The significance of the research. | D.The process and result of the research. |
A.Pest infestations are taking place across the country. |
B.The insect’s invasion won’t spread equally in America. |
C.Tree loss is the main cause of environmental problems. |
D.Ash trees are being removed from many areas in the U.S. |
A.Getting different types of trees planted. |
B.Replacing foreign trees with local ones. |
C.Getting more trees planted in more areas. |
D.Planting trees resistant to pest infestations. |
A. chaos B. consume C. plentiful D. discharge E. evolutionarily F. extent G. freeze H. mechanism I. novel J. subsequently K. unstable |
Science in Images
Oyster mushrooms feature in cuisines around the world, but they should be off the menu for hungry worms -- which these delicious mushrooms will kill and eat. Now researchers finally know how they do it.
A study published in Science Advances details how oyster mushrooms use a particular poisonous substance to freeze and get rid of mushroom-eating roundworms called nematodes (线虫). The mushrooms, which grow on nutrient-poor dead wood, then
“Nematodes happen to be the most
The study team of geneticists, biochemists and biologists had previously found that oyster mushrooms release an unidentified poisonous substance that will somehow
For their new work, the researchers grew and analyzed samples of the mushroom’s tissue, finding no noticeable poison even when they broke it up. They reasoned that whatever was killing the worms must be a kind of
Before this study, “we underestimated the
10 . Keeping plants at home is a healthy and comfortable way of life. The following houseplants can create a most beautiful piece of green for your home.
Bird’s Nest Fern (蕨)The bird’s nest fern is a good choice for anyone with a house that wouldn’t support sun-loving species. It’s a hardy fern variety adapting to living on forest floors, where the air tends to be cool and damp. It likes to be misted as well, but this doesn’t always mean you need a misting bottle—spraying (喷洒) it in the sink or hanging it near a shower often works as well.
Chinese Money PlantThis is a flowering species that might be most appropriate for experienced plant gardeners looking for a new challenge. It prefers a moderate amount of indirect light, and tends to dry out slightly between watering sessions. It produces new plants easily without any input, directly from its root system. These can coexist in the same pot for a time.
Resurrection PlantThis native of the Mexican desert has adapted to surviving in extreme drought by curling (蜷缩) into a ball and remaining in seemingly lifeless state for years, if necessary. In this form, it can be transported by the wind across the dry landscape to areas with water. It will revive within hours in a shallow bowl of water, unfolding and transforming into a fresh and green moss (苔藓).
Snake PlantThis is a striking houseplant that can be an especially good option for new plant owners who you might not trust to keep a plant alive. It grows happily in almost any condition. While it prefers bright light, it doesn’t mind shade or even artificial light. Plus, thanks to its thick, fleshy leaves, it stores water with remarkable efficiency, which makes it survive without water in the earth.
1. What is special about the bird’s nest fern?A.It prefers shade. | B.It is sun-loving. |
C.It tends to grow in the sink. | D.It can return to life after death. |
A.Bird’s nest fern. | B.Chinese money plant. |
C.Resurrection plant. | D.Snake plant. |
A.They demand attentive owners. | B.They are very drought-tolerant. |
C.They will curl for self-protection. | D.They can store water for drought. |