1 . The California sea otter (海獭), once hunted to the edge of extinction, has staged a thrilling comeback in the last century. Now, scientists have discovered that the otters’ success story has led to something just as remarkable: the restoration of their declining coastal marsh (沼泽) habitat.

Elkhorn Slough, a coastal marsh within Monterey Bay, had been experiencing severe damage. The root cause was a growing population of shore crabs, which fed heavily on the marsh plants, weakening the structural integrity of the habitat. Coastal marshes like these are not only natural defenses against storm waves but also serve as important carbon storage areas and water-cleaning systems.

The conservation-driven comeback of the sea otter has been crucial. California’s coastlines were once alive with sea otters. Sadly, they were nearly wiped out at the hands of fur traders. In the 1980s, conservation efforts aided these otters in re-occupying large areas of their former range. Now, Elkhorn Slough has the highest concentration of sea otters in California, with a population of about 100. By naturally feasting on crabs, the otters have helped a significant regrowth of plant life. Brent Hughes, a scientist working alongside Angelini, led a three-year study. Their findings were clear: in areas with sea otters, crab numbers fell markedly. This led to a resurgence in plant growth, which in turn stabilized the soil and lowered the rate of soil washing away.

As the sea otter population continues to restore, their positive impact on coastal ecosystems is likely to increase. It not only showcases the sea otter as a central species—a species that has a significant effect on its natural environment—but also highlights the essential nature of top predators (捕食者) in preserving ecological harmony. “My honest reaction was—this could become a classic in the literature,” says scientist Lekelia Jenkins. She reveals marsh restoration also helps people by reducing flooding. “Suddenly, sea otters go from just cute things we like to something that can protect our livelihoods and our properties.”

2 . Humans have long gained pleasure from the smells of the natural world. For the most part, though, human beings are not their target market. For plants, fragrances are a way to interact with insects and other animals. Their attraction for people happens simply by chance.

In chemical terms, most natural fragrances are made up of volatiles — so called because of their tendency to change states suddenly. Volatiles evaporate easily, drifting into noses. In plants’ reproductive processes, smelly volatiles attract pollinators (授粉昆虫). But their natural applications are much more varied. If an insect chews through the leaves of some Bursera plants, out shoots a sticky, smelly liquid to trap it. Coyote tobacco plants are even more crafty: upon sensing the smell of hungry caterpillars, they produce volatiles that attract predators to kill the pests.

What is truly amazing is just how wily plants can be in using their scents for reproduction. White flowers often emit their scent at night to attract nocturnal pollinators such as moths. They produce a dilute nectar (稀释的花蜜) that encourages moths to keep moving, rather than linger at a single bloom—all the better to increase pollination. Other flowers change their fragrance after being successfully pollinated, as a signal for insects to go elsewhere.

But though “Scent” is a story of plants’ cleverness, it is also a tale of the human kind. People have long used fragrances for their own purposes, particularly for use in religious ceremonies: perfume recipes on the walls of an Egyptian temple in Edfu demonstrate just how long ingredients have been mixed in pursuit of the best blend. So highly prized were some scents that, to scare off competitors, Arab traders spread a legend about giant eagles that guarded cinnamon.

Eventually scientists no longer needed natural sources for fragrances. In 1866 a fragrance molecule was produced for the first time. Sixteen years later, Houbigant Parfum released Fougère Royale, the first “modern fantasy perfume” that creates an imaginary scent rather than copying a natural one. Nowadays fragrance–making is dominated by man–made compounds, which can be reliably and affordably produced in large quantities.

That has led to the mass production of smelly products, from toilet paper to toothpaste. Scent is accordingly big business. It is said that a world–famous fragrance and flavour manufacturer that claims people interact with its products up to 30 times a day, had sales of €3.8bn last year.

4 . The yogurt that’s past its sell-by date. The banana in your lunch that turned brown. The leftovers in the fridge that you forgot to eat. For most people, all that food goes right into the garbage can.

Eight to ten percent of global greenhouse gas emissions (放) are related to food waste, according to a report by the U. N.’s Intergovernmental Panel on Climate Change. “When you throw away an egg or a sandwich,” says Yvette Cabrera, food waste vice director at the Natural Resources Defense Council (N. R. D.C.) ,“you’ re also throwing away all the resources that went into producing those things.”

That includes not only all the water, land, and fertilizer (化肥) that went into producing that food, but also the massive amounts of fossil fuels used to power the farms, transport the food, and create the packaging.

10 . ...We spoke our own language. And my favorite: Safe. Safe meant cool. It meant hello. It meant don’t worry about it. Once, when trying a certain trick on the beam(横杆), I fell onto the stones, damaging a nerve in my hand,and Toby came over, helping me up: Safe, man, Safe. A few minutes later,when I landed the trick,my friends beat their boards loud, shouting: “Safe! Safe! Safe!” And that’s what mattered-landing tricks, being a good skater.