男女羞羞视频在线观看,国产精品黄色免费,麻豆91在线视频,美女被羞羞免费软件下载,国产的一级片,亚洲熟色妇,天天操夜夜摸,一区二区三区在线电影

Global General

One scientist's hobby: recreating the ice age

(Agencies)
Updated: 2010-11-28 20:50
Large Medium Small

The project is being watched not only by climate scientists but by paleontologists and environmentalists who have an interest in "rewilding."

"This is a very interesting experiment," said Adrian Lister, of the Natural History Museum in London. "I think it's valid from an ecological point of view to put back animals that did formally live there," he told AP Television News. He disapproved of suggestions to rewild nonnative species -- for example, relocating elephants and rhinos to the American plains.

Zimov began the project in 1989, fencing off 160 square kilometers (40,000 acres) of forest, meadows, shrub land and lakes. It is surrounded by another 600 square kilometers (150,000 acres) of wilderness.

It is an offshoot of the Northeast Science Station, which he founded and where he has lived for 30 years. Already icebound by October, the park is 40 kilometers (25 miles) inland from the station, accessible only by boat in summer and by snow vehicles after the rivers freeze.

A 32-meter (105-foot) tower inside the park gives constant readings of methane, carbon dioxide and water vapor. The data feeds into a global monitoring system overseen by the US National Oceanic and Atmospheric Administration.

Zimov's research on permafrost, greenhouse gas emissions and mammoth archaeology has attracted world scientists to his laboratories, a small cluster of cabins and a tiny chapel on a rocky bluff above a channel of the Kolyma River. A 20-bed barge is used for field trips in summer, and a $100,000 hovercraft is on order. Zimov sometimes uses an old Russian tank to bring supplies from the Chinese border, 2,000 kilometers (1,200 miles) away.

Part of the station's attraction -- and deterrence -- is its remoteness. It is 6,600 kilometers (4,000 miles) and eight time zones east of Moscow. The nearby town of Chersky, with some 5,000 people, has few amenities, and the nearest city, Yakutsk, is a 4-1/2 flight. Many researchers, particularly Americans, prefer to work in Alaska or northern Canada, which are more accessible.

"Most of the Arctic is in Russia, and yet most of the Arctic research isn't," said Max Holmes, of Woods Hole Research Center in Massachusetts, director of the Polaris Project, which has sent undergraduates to the station for the last three summers.

Zimov started the park with a herd of 40 Yakutian horses, a semi-wild breed with a handsomely long mane that is raised by Yakuts and other native people for their meat. Short, sturdy and broad-backed, they survive harsh Siberian winters with the help of a furry hide, thick layers of fat and the ability to paw through a meter (3 feet) of snow to forage.

Of his first herd, Zimov said 15 were killed by wolves and bears, 12 died from eating wild hemlock that grows in the park, and two slipped through the perimeter and made their way back some 1,000 kilometers (600 miles) to their original pastures.

But he bought more. Now the horses have learned to avoid poisonous plants and to resist predators. Over the last three years, more colts were born and survived than horses lost.

The challenge is to find the right balance between grazers and predators, and how to help his animals get through their first winters.

His workers still give occasional buckets of grain to the horses to supplement their diet with salt. About half the horses come regularly to the cabin where a caretaker stays year-round. The other half are rarely seen except for their tracks.

Zimov also has had problems with the moose that he brought inside his enclosure. Moose still live in small numbers in surrounding forests, and the males jump back and forth over the 6-foot-high fence.

In September he traveled to a nature reserve on Wrangel Island, about five hours by boat across the East Siberia Sea, and brought back six 4-month-old musk oxen. One died a few weeks later. The others are kept in a small enclosure and fed hay until they can fend for themselves.

His objective is to see whether a thriving population of grazing animals will regenerate grasslands that disappeared long ago, which would slow and even halt the accelerating pace of permafrost thaw. So far, he says, the results are encouraging.

Today he has 70 animals in the park. He wants thousands to restock Siberia. To bring 1,000 bison from North America would cost $1 million, Zimov says, a small price to pay.

"If permafrost melts, 100 gigatons of carbon will be released this century," he said. "What's $1 million? One regular grant."

   Previous Page 1 2 Next Page  

主站蜘蛛池模板: 东阳市| 铁力市| 察隅县| 富锦市| 天长市| 泗洪县| 隆德县| 洪雅县| 临湘市| 宜昌市| 南宁市| 高台县| 舒兰市| 普兰县| 烟台市| 平阴县| 曲阜市| 忻州市| 五莲县| 泗洪县| 万全县| 凉山| 万全县| 金秀| 公安县| 永州市| 昔阳县| 镶黄旗| 新竹县| 龙井市| 新竹市| 玉山县| 平潭县| 陆川县| 安福县| 池州市| 武冈市| 大田县| 南京市| 专栏| 万源市| 宁德市| 漠河县| 宜昌市| 英吉沙县| 云浮市| 嘉荫县| 衡东县| 花垣县| 城固县| 华阴市| 石阡县| 中西区| 和林格尔县| 新泰市| 应用必备| 江西省| 昌平区| 肃北| 沂源县| 太原市| 内乡县| 大兴区| 双鸭山市| 大同县| 广饶县| 筠连县| 黑水县| 阳信县| 逊克县| 琼海市| 汉寿县| 梧州市| 长泰县| 商水县| 霸州市| 大兴区| 古丈县| 滨海县| 会宁县| 剑阁县| 利津县|