VOA标准英语2012--Prehistoric Amber Reveals Natural Ancient Alliance

Prehistoric¹ Amber² Reveals Natural Ancient Alliance

Scientists say a piece of amber - recently found in India and dating back at least 52 million years - offers proof of the ancient relationship between fungi³ and flowering trees, which sustains modern forests.
The walnut-sized discovery is the first evidence that this relationship existed so long ago.
India’s Gujarat state was once the site of a tropical rainforest. It's where Paul Nascimbene's team found the eight-millimeter-long shard⁴ of amber, or petrified⁵ tree sap.
Nascimbene, a paleozoologist with the American Museum of Natural History in New York, says a tiny mass of mycorrhizal fungus⁶ and bits of tree root are visible inside the amber.
Together, they speak across the eons about one of the most abiding⁷ and important plant relationships on Earth.
“When plants colonized⁸ the land - because initially⁹ they were aquatic¹⁰, in the oceans - this partnership¹¹, or symbiosis¹², began between the mycorrhizae and pretty much 90 percent of all land plants," Nascimbene says. "And then there were different types of these partnerships¹³ that occurred.”
According to Nascimbene, there are two types of mycorrhizal symbiosis. In endomycorrhizae, the most common form, the fungi live symbiotically¹⁴ within the roots of a tree.
In ectomycorrhizae, the fungi live on the roots of their partner trees. This is the type that Nascimbene's team discovered entwined with roots and mixed with flowers inside the Indian amber.
“The one that we found, in a 52 million-year-old tropical rainforest biota¹⁵, was perhaps the earliest record of such a symbiosis with a flowering plant, a modern flowering plant," Nascimbene says.
That mycorrhyzal symbiosis has endured because it is important to the survival of both organisms - the fungus and the tree.
“Both organisms benefit because, in one sense, the surface area of the root is increased," Nascimbene says. "But also the fungus has the ability to leach¹⁶ important nutrients¹⁷ out of the soil. And that helps support the growth of the trees. Also, they are protected for some extent from drought… Essentially¹⁸, when you have the roots surrounded by the various stages of this fungus, you have a network which essentially creates a sort of microenvironment; the water doesn’t evaporate or dissipate from it as readily as [from] bare roots.”
The tree that produced the amber at the Gujarat fossil site was a dipterocarp, which is still the dominant¹⁹ family of hardwood trees in Southeast Asia. Although they are logged heavily, dipterocarp forests are thriving thanks largely to the mycorrhizal fungi.
And that, says Nascimbene, carries an important lesson for the global environment.
“There are a lot of people now on the planet, and there are a limited number of resources. So in order to plant and grow more trees, we have to be aware of the conditions that favor their growth. And in the case of the dipterocarps, these ectomycorrhizas are added to the soil in association with their roots when they are planted in order to allow the forest to develop properly. Otherwise as both a business - and as an ecology - it would fail.”
Nascimbene and his colleagues plan to continue digging for prehistoric mycorrhizae, and for further clues to the origins of the world’s forests.

1 prehistoric   

adj.（有记载的）历史以前的，史前的，古老的

参考例句：

• They have found prehistoric remains.他们发现了史前遗迹。
• It was rather like an exhibition of prehistoric electronic equipment.这儿倒像是在展览古老的电子设备。

2 amber   

n.琥珀；琥珀色；adj.琥珀制的

参考例句：

• Would you like an amber necklace for your birthday?你过生日想要一条琥珀项链吗？
• This is a piece of little amber stones.这是一块小小的琥珀化石。

3 fungi   

n.真菌，霉菌

参考例句：

• Students practice to apply the study of genetics to multicellular plants and fungi.学生们练习把基因学应用到多细胞植物和真菌中。
• The lawn was covered with fungi.草地上到处都是蘑菇。

4 shard   

n.（陶瓷器、瓦等的）破片，碎片

参考例句：

• Eyewitnesses spoke of rocks and shards of glass flying in the air.目击者称空中石块和玻璃碎片四溅。
• That's the same stuff we found in the shard.那与我们发现的碎片在材质上一样。

5 petrified   

adj.惊呆的；目瞪口呆的v.使吓呆，使惊呆；变僵硬；使石化(petrify的过去式和过去分词)

参考例句：

• I'm petrified of snakes. 我特别怕蛇。
• The poor child was petrified with fear. 这可怜的孩子被吓呆了。 来自《简明英汉词典》

6 fungus   

n.真菌，真菌类植物

参考例句：

• Mushrooms are a type of fungus.蘑菇是一种真菌。
• This fungus can just be detected by the unaided eye.这种真菌只用肉眼就能检查出。

7 abiding   

adj.永久的，持久的，不变的

参考例句：

• He had an abiding love of the English countryside.他永远热爱英国的乡村。
• He has a genuine and abiding love of the craft.他对这门手艺有着真挚持久的热爱。

8 colonized   

开拓殖民地，移民于殖民地( colonize的过去式和过去分词 )

参考例句：

• The area was colonized by the Vikings. 这一地区曾沦为维京人的殖民地。
• The British and French colonized the Americas. 英国人和法国人共同在美洲建立殖民地。

9 initially   

adv.最初，开始

参考例句：

• The ban was initially opposed by the US.这一禁令首先遭到美国的反对。
• Feathers initially developed from insect scales.羽毛最初由昆虫的翅瓣演化而来。

10 aquatic   

adj.水生的，水栖的

参考例句：

• Aquatic sports include swimming and rowing.水上运动包括游泳和划船。
• We visited an aquatic city in Italy.我们在意大利访问过一个水上城市。

11 partnership   

n.合作关系，伙伴关系

参考例句：

• The company has gone into partnership with Swiss Bank Corporation.这家公司已经和瑞士银行公司建立合作关系。
• Martin has taken him into general partnership in his company.马丁已让他成为公司的普通合伙人。

12 symbiosis   

n.共生（关系），共栖

参考例句：

• They live in a symbiosis with governments that they are financing.他们与他们服务的政府互利共存。
• The symbiosis between social values and political structure has produced extraordinary achievement.社会价值观念和政治结构的共生现象带来了非凡的成就。

13 partnerships   

n.伙伴关系( partnership的名词复数 )；合伙人身份；合作关系

参考例句：

• Partnerships suffer another major disadvantage: decision-making is shared. 合伙企业的另一主要缺点是决定要由大家来作。 来自英汉非文学 - 政府文件
• It involved selling off limited partnerships. 它涉及到售出有限的合伙权。 来自辞典例句

14 symbiotically   

参考例句：

• Lichen is a form in which green or bluegreen algae and a fungus live together symbiotically. 地衣是一种绿藻或蓝藻与一种真菌共生的形式。 来自辞典例句
• Different populations living together and interacting. Populations can interact as competitors, predator and prey, or symbiotically. 不同生物族群生活之间的互动，以相互竞争、食或共生的方式生活著。 来自互联网

15 biota   

n.生物区

参考例句：

• They have had serious effects upon the biota of stream.它们对河流中的生物群体产生严重影响。
• Historical biogeography attempts to reconstruct the biota history of the earth.历史生物地理学重建生物区系历史。

16 leach   

v.分离，过滤掉；n.过滤；过滤器

参考例句：

• Liquid water can leach soluble materials from the interface.液态水能够从界面溶解出可溶性物质。
• They believe that the humic materials are leached from decaying plant materials.他们认为腐植物料是从腐烂的植物体浸沥而来。

17 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》

18 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

19 dominant   

adj.支配的，统治的；占优势的；显性的；n.主因，要素，主要的人(或物)；显性基因

参考例句：

• The British were formerly dominant in India.英国人从前统治印度。
• She was a dominant figure in the French film industry.她在法国电影界是个举足轻重的人物。