VOA常速英语2015--长期干旱影响加州的红杉

Long Drought Affecting California’s Sequoias 长期干旱影响加州的红杉

California is suffering under a historic four-year drought and scientists say even the state's famed sequoia¹ trees are feeling the pain. The National Park Service has started detailed² research to see how it can help the oldest living things on earth survive.

Slowly and painstakingly³, University of California tree biologist Anthony Ambrose climbs up a giant sequoia in California’s Sierra Nevada mountain range, the only place on earth where these magnificent trees live.

“It’s an amazing experience to be able to climb up into these things and know that it's been growing in this same spot for a thousand years or more,” he said.

Sequoias grow over 90 meters tall, their trunks are up to 15 meters wide and some of them are more than 3,000 years old.

Once-rich mountain streams have dwindled⁴ to trickles⁵ and the trees - that each need more than 3,000 liters of water a day - are now getting much less. Some of them are showing signs of thirst.

“We've observed some unusual and abnormal levels of foliage⁶ die-back, which haven't been observed in the park before,” Ambrose said.

Sensors⁷ installed in tree canopies⁸, examinations of seedlings⁹, data from individual trees and images collected by observational planes will help scientists measure the seriousness of the danger.

One possible solution would be to cut down less important species of trees that compete with sequoias for water.

“They'll have more water than they would have in a denser¹⁰ forest, more nutrients¹¹ and light and therefore be more resistant¹² and resilient to these hot droughts they're faced with in the future,” said Koren Nydick, who is with the National Park Service.

Scientists say that over thousands of years, sequoias have gone through many droughts, forest fires, insect infestations¹³ and other calamities¹⁴, so they will probably survive this drought, unlike many less-resilient California trees.

1 sequoia   

n.红杉

参考例句：

• The sequoia national forest is at the southern end of the sierra nevada range.红杉国家公园位于内华达山脉南端尽头处。
• The photo shows the enormous general Sherman tree in California's sequoia national park.照片显示的是加利福尼亚州红杉国家公园内巨大的谢尔曼将军树。

2 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

3 painstakingly   

adv. 费力地 苦心地

参考例句：

• Every aspect of the original has been closely studied and painstakingly reconstructed. 原作的每一细节都经过了仔细研究，费尽苦心才得以重现。
• The cause they contrived so painstakingly also ended in failure. 他们惨淡经营的事业也以失败而告终。

4 dwindled   

v.逐渐变少或变小( dwindle的过去式和过去分词 )

参考例句：

• Support for the party has dwindled away to nothing. 支持这个党派的人渐渐化为乌有。
• His wealth dwindled to nothingness. 他的钱财化为乌有。 来自《简明英汉词典》

5 trickles   

n.细流( trickle的名词复数 )；稀稀疏疏缓慢来往的东西v.滴( trickle的第三人称单数 )；淌；使)慢慢走；缓慢移动

参考例句：

• Trickles of sweat rained down my head and neck. 我颈上头上的汗珠，更同盛雨似的，一颗一颗的钻出来了。 来自汉英文学 - 中国现代小说
• Water trickles through an underground grotto. 水沿着地下岩洞流淌。 来自辞典例句

6 foliage   

n.叶子，树叶，簇叶

参考例句：

• The path was completely covered by the dense foliage.小路被树叶厚厚地盖了一层。
• Dark foliage clothes the hills.浓密的树叶覆盖着群山。

7 sensors   

n.传感器，灵敏元件( sensor的名词复数 )

参考例句：

• There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
• Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时，有很大变化。 来自辞典例句

8 canopies   

（宝座或床等上面的）华盖( canopy的名词复数 )； （飞行器上的）座舱罩； 任何悬于上空的覆盖物； 森林中天棚似的树荫

参考例句：

• Golf carts with bright canvas canopies wandered the raingreen fairways. 一场雨后显得愈加葱绿的高尔夫球场草地上，散放着一些带有色彩缤纷的帆布华盖的高尔夫小车。
• Rock permitted seven canopies, cornices floors, decorative glass, Ambilight, momentum magnificent, magnificent. 七檐佛殿背倚山岩，楼层飞檐翘角，殿顶琉璃装饰，流光溢彩，气势恢宏，蔚为壮观。

9 seedlings   

n.刚出芽的幼苗( seedling的名词复数 )

参考例句：

• Ninety-five per cent of the new seedlings have survived. 新栽的树苗95%都已成活。 来自《现代汉英综合大词典》
• In such wet weather we must prevent the seedlings from rotting. 这样的阴雨天要防止烂秧。 来自《现代汉英综合大词典》

10 denser   

adj. 不易看透的, 密集的, 浓厚的, 愚钝的

参考例句：

• The denser population necessitates closer consolidation both for internal and external action. 住得日益稠密的居民，对内和对外都不得不更紧密地团结起来。 来自英汉非文学 - 家庭、私有制和国家的起源
• As Tito entered the neighbourhood of San Martino, he found the throng rather denser. 蒂托走近圣马丁教堂附近一带时，发现人群相当密集。

11 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

12 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

13 infestations   

n.（害虫、盗贼等）群袭，出没，横行( infestation的名词复数 )

参考例句：

• The arrival of warm weather raises the specter of disease and increased rat infestations caused by rotting garbage. 天气转暖使人们担心垃圾腐烂会引起疾病传播和鼠群猖獗。 来自《简明英汉词典》
• Piperazine citrate is the drug of choice in the treatment of Ascaris infestations. 枸橼酸哌嗪治疗蛔虫感染是最好的药物。 来自辞典例句

14 calamities   

n.灾祸，灾难( calamity的名词复数 )；不幸之事

参考例句：

• They will only triumph by persevering in their struggle against natural calamities. 他们只有坚持与自然灾害搏斗，才能取得胜利。 来自《现代汉英综合大词典》
• One moment's false security can bring a century of calamities. 图一时之苟安，贻百年之大患。 来自《现代汉英综合大词典》