1 . Amid rolling farms and green pasture 150 miles northwest of Sao Paulo, Brazil, two tropical forests bloom as one. The first consists of a single species, row after row of non-native eucalyptus (桉树), planted in perfect lines like carrots. The other is haphazard, an assortment of dozens of varieties of native saplings.
There’s no denying it: This forest looks ridiculous. The gangly (修长的) eucalyptuses shoot like witch fingers high above patches of stubby fig (矮壮的无花果树) and evergreen trees. Yet these jumbled 2.5-acre stands of native trees, ringed by fast-growing exotics, are among many promising efforts to resurrect the planet’s forests.
The eucalyptuses, says Pedro Brancalion, the University of Sao Paulo agronomist who designed this experiment, get big so quickly they can be cut after five years and sold to make paper or fence posts. That covers nearly half or more of the cost of planting the slow-growing native trees, which then naturally reseed ground that has been laid bare by the harvest. And this process doesn’t hamper natural regeneration.
You needn’t look far these days to find organizations trying to save the world by growing trees. Too often, tree-planting groups are so focused on getting credit for each seedling planted that they ignore what matters most: What kind of woodland is created? At what cost? And most importantly: How long will it last? Using the numbers of trees planted as a magic “proxy for everything,” Brancalion says, you “spend more money and get lower levels of benefits.” You can literally miss the forest for the trees.
Tree planting seems like a simple, natural way to counter the overwhelming crises of climate change and biodiversity loss. Trees provide wildlife habitats and slurp carbon dioxide from the atmosphere. No wonder trees are hailed as the ideal weapon. Yet for every high-profile planting operation, devastating failures have occurred. In Turkey, Sri Lanka, and Mexico, mass plantings have resulted in millions of dead seedlings or have driven farmers to clear more intact forest elsewhere. Trees that have been planted in the wrong places have reduced water yields for farmers, destroyed highly diverse carbon-sucking grassland soils, and allowed for invasive vegetation to spread. Simply reforesting the planet isn’t going to do much if we don’t also start cutting down on our emissions from the burning of coal, oil, and natural gas. Tree planting also can’t replace old-growth forests. Saving them is even more important than growing new forests.
So, what should we do?
To Brancalion, the answer is obvious: Restore native forests, mostly in the tropics, where trees grow fast and land is cheap. While that may require planting, it may also call for the clearing out of invasive grasses, the rejuvenation (使有活力) of soils, and crop yield improvements so that farmers will need less land for agriculture and more can be allowed to revert back to forests.
The combining of eucalyptus harvests with native plantings is just one more reminder that successful restoration must provide value to local communities. In many cases, if we let nature do the heavy lifting, Brancalion says, “the forest can regrow quite effectively.”
1. What can we learn from the first three paragraphs?A.The non-native eucalyptuses bring profits that can pay for planting native saplings. |
B.The non-native eucalyptuses compete with native saplings for water, nutrients, and light. |
C.The variety of trees being planted determines whether or not the restoration will succeed. |
D.Planting fast-growing exotics together with local trees does harm to the natural environment. |
A.emphasize the significance of protecting existing forests |
B.explain why tree planting is regarded as the ideal solution |
C.illustrate the serious problems planting campaigns can cause |
D.indicate the most important point tree-planting groups ignore |
A.clear more forest to improve crop yields for farmers |
B.combine harvests of fast-growing exotics with native plantings |
C.restore native forests in the tropics and clear out invasive grasses |
D.take into consideration the benefits of reforestation to local communities |
A.Plant trees—and time will tell. | B.Plant trees—but don’t overdo it. |
C.Plant trees—and save the world. | D.Plant trees—but mind the variety. |
In the 1400s and 1500s, Peru was the centre of the powerful ancient Inca Empire. The Inca emperor lived in the
Michael Jordan, known as “Air Jordan”, changed basketball with his graceful moves and jumps. His skills were impressive, but the
Tangshan started to revive itself and
3 . Ocean heat waves — defined as periods of extreme temperatures lasting five days or more — have become increasingly common in recent decades. In fact, as a new study published in Nature Climate Change finds, Earth’s number of annual ocean heat wave days increased by around 54 percent between 1987 and 2016, with abnormally high temperatures not only occurring more frequently, but also lasting for longer periods of time.
Underwater heat waves pose a significant threat to marine ecosystems, which are already at risk due to issues including overfishing and widespread plastic pollution. Sweeping through oceans much like wildfires blaze through forests on land, extreme temperatures exact damage on foundational organisms such as kelp forests, seagrass meadows and coral reefs. Given that these framework species provide shelter and food to many other ocean creatures, the study’s authors warn that such destruction will likely have cascading consequences for marine biodiversity.
To assess the effects of ocean heat waves, researchers led by ecologist Daniel Smale of Great Britain’s Marine Biological Association turned to 116 previously published academic studies. Reflecting on more than 1,000 ecological records and eight specific heat waves, the scientists identified regions and species that were the weakest to temperature increases. As Mary Papenfuss writes for the Huffington Post, areas of the Pacific, Atlantic and Indian Oceans topped the list, with the Caribbean’s coral reefs, Australia’s seagrass and California’s kelp forests causing particular concerns.
In terms of species, Pacific Standard’s Kate Wheeling adds, the team notes that immobile plants and animals were the hardest hit, while tropical fish and mobile invertebrates (无脊椎生物) were able to cope with the heat by moving to different habitats. Interestingly, John Timmer reports for Ars Technica, the researchers actually observed heightened levels of fish diversity during periods of above- average temperatures, likely due to the animals’ mass migration (迁徙) toward friendlier waters. The same trend did not prove true for sea-dwelling birds, however, as shifting habitats limited the avian creatures’ access to prey.
Although the researchers’ findings are most consequential for marine ecosystems. Pierre-Louis and Popovich explain that damage to ocean habitats will also affect humans who rely on fishing and fish farming.
“Certainly there’s going to be changes with climate change to marine communities, but it’s not like the oceans are going to become the dead sea. It’s just that, as a consequence of what we’re doing to the oceans, there’s going to be different marine communities in different places than what we’re used to. Obviously, that is a problem because we’re sort of set up for what the climate is now rather than what it is going to be in the future.”
1. “Species” in “these framework species” in Paragraph 2 refers to ________.A.wildfires | B.damages | C.organisms | D.temperatures |
A.The temperatures of wave heats nearly doubled in 2016. |
B.Living creatures can avoid heat wave damage by migration. |
C.Overfishing and plastic pollution are the main causes to ocean heat. |
D.The weakest regions are concluded from previous academic studies. |
A.People should stop fishing because of the climate change. |
B.People who take fishing for a living might earn lower profits. |
C.The researchers findings cannot help us protect the land ecosystems. |
D.Changes to ocean habitats would bring extremely bad results to the sea. |
A.Ocean Heat Waves Are Affecting Us |
B.Ocean Heat Waves Are Getting Worse |
C.Ocean Heat Waves Are Threatening Marine Life |
D.Ocean Heat Waves Are keys to Marine Biodiversity |
cause global warming, pick up, sharing cars, get stuck in a traffic jam, are addicted to, make excuses, protect the environment, do a lot of harm |
Many people often
Too many cars
1.说明活动意义并简述活动内容(如整理图书馆、打扫公共卫生区等);
2.提醒携带相关工具及其它注意事项。
注意:1.词数100字左右;
2.开头、结尾已给出,不计入总词数。
Hello, everyone.
_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
That’s all. Thank you.
The Burmese snub-nosed monkey (仰鼻猴) is a
In the past few years, the number of wild animals
Imprinting is a form of learning in
A series of water-conserving and recycling designs have been put into place
Around 90% of the snow
10 . Buck’s first day on the beach was a nightmare. Every hour was filled with shock or surprise. He had been suddenly removed from civilization and thrown into the heart of a primitive world. Here there was neither peace nor rest, nor a moment’s safety. It was essential to be constantly alert, for these dogs and men were not town dogs and men. They were savages, all of them, who knew no law but the law of Club and Tooth.
Buck had never seen dogs fight like these, and his first experience taught him an unforgettable lesson. He was fortunate that it was Curly who was the victim, not himself. Curly, in her friendly way, tried to make friends with a husky dog. The dog was the size of a full-grown wolf, but not half as large as Curly was. There was no warning: only a fast jump, a metallic cut of teeth, and a jump back. Curly’s face was ripped open from eye to mouth.
It was wolf fighting, to strike and jump away, but there was more to it than this. Thirty or forty huskies ran to watch. They surrounded the fighters in a silent, watching circle, all licking their lips. Curly rushed at the husky, who struck again and jumped away. He met her next rush with his chest in a strange way that knocked her over. She never got up again. This was what the watching huskies had waited for. They closed in on her, snarling and yelping. Curly was buried, screaming in pain, under the dogs’ bodies.
1. Why did Buck have to be ‘constantly alert’?A.He couldn’t fall asleep | B.He was worried about Curly |
C.He had to make sure he was always safe | D.He was in a lot of pain |
A.You must have a tooth and club in the wild | B.The strongest make the rules |
C.The weakest must survive in the wild | D.The tooth must fight the club |
A.Run at the enemy non-stop | B.First to strike wins |
C.Attack and step back | D.Wolves only use their paws to fight |
A.Dogs will always fight other dogs for food |
B.Buck wanted to help Curly, but he was afraid of the huskies |
C.The only way dogs can survive is by eating other dogs |
D.Only the strongest shall survive in the wild |