【推荐2】Antarctica is the most distant part of the world, but it is a center of scientific discovery and environmental change.

Early explorers were attracted there by the secret of Terra Australis. Others sought money from catching whales. Still others wanted to understand Earth’s pole in order to better sail the seas. I am a geologist (地质学家) who studies the timing and extent of past ice ages. I’ve been very lucky to conduct five season of research there under the protection of the Antarctic Treaty (条约), an international agreement that encourages scientific cooperation (合作) and environmental protection.

Antarctica is the only continent that was actually discovered, because it has no native human population. British explorer Sir James Cook sailed around the continent in 1772-1775, but saw only some outlying islands (离岛). Cook said that if there were any land, it would be “never to give way to the warmth of the sun.” But Cook also reported that Antarctic waters were rich with wildlife.

Today parts of the West Antarctica Ice Sheet are particularly close to collapse (坍塌). Recent research show sea level could rise by 1 meter by 2100 and 15 meters by 2500 if the greenhouse effect continues and the ice sheet experiences a rapid collapse, as it has in the past. Despite the environmental disaster in Antarctica, the continent also shows that nations can cooperate to find solutions. “I believe the Antarctic Treaty System is the world’s most important example of peaceful and scientific international cooperation. Thanks to it, 10% of Earth’s land surface is protected for wildlife.”

Yet in these bad environments, life finds a way to survive—showing that there are solutions to even the most difficult challenges. If Antarctica has taught me anything in 200 years, it’s that we can work together to deal with problems. As Ernest Shackleton once said, “Difficulties are just things to solve, after all.”

【推荐3】Last fall, the Great Salt Lake hit its lowest level since record keeping began. The lake sank to nearly six meters below the long-term average. The lake’s shrinking threatens to upend the ecosystem, disturbing the migration and survival of 10 million birds, including ducks and geese.

Duck hunters aren’t the only ones worried about the Great Salt Lake. The decades-long decline in lake level is raising alarm bells for millions of people who live in the region. The low lake level and increasing salts in the lake water threaten to destroy economic mainstays like agriculture, tourism and mining. Exposed salts can also reduce air quality and so threaten public health.

Saline lakes (咸水湖) are terminal lakes. They have no rivers flowing out of them. As water disappears, salts are left behind. At the same time, the people who live in these deserts use freshwater for crops, homes and industry. Residents get water from streams and rivers into canals, pipelines or reservoirs before it reaches the lakes. And as the lakes shrink, the salt in water increases.

Lake Poopo, a highland lake in Bolivia that used to stretch 90 kilometers long and 32 kilometers wide, is now a salty mud flat. The Aral Sea shared by Kazakhstan and Uzbekistan, once the world’s fourth largest lake, has at times in recent decades shrunk to a tenth of its historic 68,000-square-kilometer surface area. Some saline lakes, like Nevada’s Winnemucca Lake, dried up so long ago — the waters that fed it were led to agricultural fields — that most people have forgotten they were ever wet.

The good news is that people still have time to halt the Great Salt Lake’s decline by using less water. Cutting agricultural and other outdoor water use by a third to half through a combination of voluntary conservation measures and policy changes would allow the lake to refill enough to support the region’s economy, ecology and quality of life. If this succeeds, the Great Salt Lake can be a model for how to save other saline lakes around the world.

【推荐1】In hot countries the woods are not like our woods. They are great dark forests, where the trees grow so closely together, and are so tall, that if you looked up you could hardly see the sky.

Then there are a great many climbing plants, which twist themselves round and round the trunks and branches of the trees. They are called vegetable cables, because they are so much like ropes. They reach from one tree to another, and almost fill up the spaces between. Troops of monkeys run along the vegetable cables from one tree to another, or swing from the branches by their tails, making a noise all the time as if they are talking to each other. When night comes they roll themselves into a ball, gathered together as close as may be, to keep themselves warm.

Dangers of every kind lie in the forest. The poisonous snake may lie coiled among the bushes, or traces of the wild American tiger may be seen upon the path.

Then there are all sorts of wonderful birds, such as we never see in our country, except in cages. Birds, beasts, and insects live there, for the most part, undisturbed. It is their home; and on every side they are at work, hunting their prey, or escaping from danger. For though man seldom wages war upon them, these wild creatures of the forest are engaged in constant warfare with each other; and the weak are always using some plan to protect themselves from the strong.

There are a great many curious things to be seen in these South American forests.

【推荐2】Our world is full of sounds. Sound is so essential to life and survival that it made Tel Aviv University researcher Lilach Hadany ask: What if it wasn't just animals that could sense sound—what if plants could, too?

“Sounds are a natural resource-one that plants would be wasting if they didn’t take advantage of it as animals do,”said Hadany. If plants had a way of hearing and responding to sound, she figured, it could help them survive and reproduce.

Hadany's team started their study by investigating flowers. Evening primrose（夜来香）, which grows wild on the beaches and in parks around Tel Aviv, emerged as a good candidate, since it has a long bloom time and produces measurable quantities of nectar（花蜜）.

To test the primroses in the lab, Hadany's team exposed plants to five sound treatments: silence, recordings of a honeybee from four inches away, and computer generated sounds in low, intermediate（中等的）, and high frequencies. Plants given the silent treatment had no significant increase in nectar sugar concentration. The same went for plants exposed to high-frequency（158 to 160 kilohertz）and intermediate-frequency（34 to 35 kilohertz）sounds.

But for plants exposed to playbacks of bee sounds（0.2 to 0.5 kilohertz）and similarly low-frequency sounds（0.05 to 1 kilohertz）, the final analysis revealed an unmistakable response. Within three minutes of exposure to these recordings, nectar sugar concentration in the plants increased by 20 percent.

A sweeter treat for pollinators（传粉者）, their theory goes, may draw in more insects, potentially increasing the chances of successful cross-pollination. Indeed, in field observations, researchers found that pollinators were more than nine times more common around plants another pollinator had visited within the previous six minutes.

“We were quite surprised when we found out that it actually worked.” said Hadany.“But after repeating it in other situations, in different seasons, and with plants grown both indoors and outdoors, we feel very confident in the result.”

【推荐3】Trees are “social creature” that communicate with each other in cooperative ways that hold lessons for humans, too, ecologist Suzanne Simard says. Simard grew up in Canadian forests as a child of loggers before becoming an ecologist. She's now a professor of forest ecology at the University of British Columbia.

Trees are linked to neighboring trees by a network of fungi below the surface of the earth that resembles the nervous networks in the brain, she explains. In one study, Simard watched as a Douglas fir tree that had been injured by insects appeared to send chemical warning signals to a pine nearby. The pine tree then produced defense enzymes to protect against the insect.

“This was a breakthrough,” Simard says. The trees were sharing “information that actually is important to the health of the whole forest.”

In addition to warning each other of danger, Simard says that trees have been known to share nutrients at critical times to keep each other healthy. She says the trees in a forest are often linked to each other via an older tree she calls a “mother” or “hub” tree.

“In connecting with all the trees of different ages, the mother trees can actually ease the growth of these young trees,” she says. “The young trees will link into the network of the old trees and benefit from that huge resource capacity. And the old trees would also pass a little bit of carbon and nutrients and water to the young trees, at crucial times in their lives, that actually help them survive.”

The study of trees took on a new resonance for Simard when she suffered from breast cancer. During her treatment, she learned that one of the medicines she relied on was actually obtained from what some trees produce for their own mutual defense. She explains her research on cooperation in the forest, and shares her personal story in the new book Finding the Mother Tree: Discovering the Wisdom of the Forest.