VOA标准英语2014--Humans Driving Massive Animal Extinction

 

Humans Driving Massive Animal Extinction¹

Earth is in the midst of its sixth mass extinction of animal species  -- the first to be caused by humans -- in the past half-billion years, setting off a downward spiral in the environment and human health, which will accelerate unless action is taken, according to a new report in Science.

Co-author Hillary Young studies what happens when the big animals disappear. In her field work in Central Kenya, the University of California Santa Barbara researcher documents changes in four-hectare parcels of land, fenced to keep out giraffes and zebras and elephants.  

“We can measure things like the abundance of vegetation, the abundance of rodents², and the prevalence of disease in the wildlife species that are left behind,” she said.

Rapid decline

Rather quickly the fenced parcels fill with grasses and shrubs³, providing cover for rats which overwhelm the area and are vectors for human disease.

Young and her colleagues have coined a new term for this pattern of animal species loss. They call it defaunation.  

“We have lost more than 25 percent of all the vertebrates in the world - this is the number of individual animals in the world - and probably more than 45 percent of the invertebrate⁴ animals in the world," she observed. "On an average year, we’re probably losing 11,000 to 58,000 animal species. That’s just shocking to think about.”    

Beetles⁵, bugs⁶ and butterflys disappearing too

This loss is all the more surprising, Young says, because similar patterns are playing out across species worldwide. 

“We tend to think of extinction and species decline in the terms of giant pandas or polar bears, but what we find is that these small invertebrates⁷ - the beetles, the worms, the moths⁸ and the ladybugs - those animals are declining at rates that were equivalent if not greater than the large species,” she said.  

These are signs, Young says, that the sixth mass extinction is under way. The study affirms that humans are speeding it up by destroying wild lands and over-exploiting animals and resources. This, in turn, has triggered invasions of exotic species and climate change on a grand scale.

Animals protect vital human services

Young says conservation is not an esoteric luxury to keep wildlife around.

“Basic ecosystem⁹ functions like soil protection or water purification or carbon cycling to keep the soils rich and the atmosphere clean - all of those are services provided by animals, often these invertebrates that we don’t think about so much, but also the larger vertebrates," she said. "And what we find is that when we lose these animals, we see massive changes in these ecosystems¹⁰, functions in the systems that are impacted.”

As species die off, Young warns that defaunation can permanently¹¹ upset the trajectory¹² of life on Earth.  She says that loss, if left unchecked, will become a driver of global change rather than a consequence of it.   

“It is going to exacerbate¹³ climate change [and] water stress. It is going to increase human poverty and social conflict. These are themselves going to lead to more wildlife declines, and it’s going to create a downward spiral and we’re going to lose the opportunity to halt this spiral,” she said.

Young says slowing this planetary nightmare will require political will. She says immediately addressing habitat loss and over-exploitation of animals and resources would help in the short term, but in the long run, global action to curb¹⁴ climate change is imperative¹⁵.

1 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。

2 rodents   

n.啮齿目动物( rodent的名词复数 )

参考例句：

• Rodents carry diseases and are generally regarded as pests. 啮齿目动物传播疾病，常被当作害虫对待。 来自《简明英汉词典》
• Some wild rodents in Africa also harbor the virus. 在非洲，有些野生啮齿动物也是储毒者。 来自辞典例句

3 shrubs   

灌木( shrub的名词复数 )

参考例句：

• The gardener spent a complete morning in trimming those two shrubs. 园丁花了整个上午的时间修剪那两处灌木林。
• These shrubs will need more light to produce flowering shoots. 这些灌木需要更多的光照才能抽出开花的新枝。

4 invertebrate   

n.无脊椎动物

参考例句：

• Half of all invertebrate species live in tropical rain forests.一半的无脊椎动物物种生活在热带雨林中。
• Worms are an example of invertebrate animals.蠕虫是无脊椎动物的一个例子。

5 beetles   

n.甲虫( beetle的名词复数 )

参考例句：

• Beetles bury pellets of dung and lay their eggs within them. 甲壳虫把粪粒埋起来，然后在里面产卵。 来自《简明英汉词典》
• This kind of beetles have hard shell. 这类甲虫有坚硬的外壳。 来自《现代汉英综合大词典》

6 bugs   

adj.疯狂的，发疯的n.窃听器( bug的名词复数 )；病菌；虫子；[计算机]（制作软件程序所产生的意料不到的）错误

参考例句：

• All programs have bugs and need endless refinement. 所有的程序都有漏洞，都需要不断改进。 来自《简明英汉词典》
• The sacks of rice were swarming with bugs. 一袋袋的米里长满了虫子。 来自《简明英汉词典》

7 invertebrates   

n.无脊椎动物( invertebrate的名词复数 )

参考例句：

• Insects and worms are all invertebrates. 昆虫和蠕虫都是无脊椎动物。 来自辞典例句
• In the earthworm and many other invertebrates, these excretory structures are called nephridia. 在蚯蚓和许多其它无脊椎动物中，这些排泄结构称为肾管。 来自辞典例句

8 moths   

n.蛾( moth的名词复数 )

参考例句：

• The moths have eaten holes in my wool coat. 蛀虫将我的羊毛衫蛀蚀了几个小洞。 来自《简明英汉词典》
• The moths tapped and blurred at the window screen. 飞蛾在窗帘上跳来跳去，弄上了许多污点。 来自《现代英汉综合大词典》

9 ecosystem   

n.生态系统

参考例句：

• This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
• We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。

10 ecosystems   

n.生态系统( ecosystem的名词复数 )

参考例句：

• There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
• Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样，从雨林到半荒漠等不一而足。 来自辞典例句

11 permanently   

adv.永恒地，永久地，固定不变地

参考例句：

• The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
• The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。

12 trajectory   

n.弹道，轨道

参考例句：

• It is not difficult to sketch the subsequent trajectory.很容易描绘出它们最终的轨迹。
• The path followed by a projectile is called its trajectory.抛物体所循的路径称为它的轨道。

13 exacerbate   

v.恶化，增剧，激怒，使加剧

参考例句：

• WMO says a warming climate can exacerbate air pollution.世界气象组织说，气候变暖可能会加剧空气污染。
• In fact efforts will merely exacerbate the current problem.实际上努力只会加剧当前的问题。

14 curb   

n.场外证券市场，场外交易；vt.制止，抑制

参考例句：

• I could not curb my anger.我按捺不住我的愤怒。
• You must curb your daughter when you are in church.你在教堂时必须管住你的女儿。

15 imperative   

n.命令，需要；规则；祈使语气；adj.强制的；紧急的

参考例句：

• He always speaks in an imperative tone of voice.他老是用命令的口吻讲话。
• The events of the past few days make it imperative for her to act.过去这几天发生的事迫使她不得不立即行动。