Ecologists Call for Action on Biodiversity Loss

In advance of the United Nations Conference on Sustainable Development in Rio de Janiero later this month, ecologists writing in the journal Nature are calling for renewed international efforts to curb¹ the loss of biodiversity. 

The paper summarizes more than 1,000 ecological² studies conducted since the first Earth Summit in Rio 20 years ago. 

Biodiversity loss impacts human health

Lead author and University of Michigan ecologist Bradley Cardinale says the 17 co-authors speak with a single voice: the loss of plant and animal diversity reduces the productivity and sustainability of earth’s ecosystems⁴.

“And in many instances it decreases their ability to provide services like food. It decreases the ability of ecosystems to produce wood, fodder⁵ that would be used to feed our livestock⁶. It reduces the ability of the ecosystems to protect us and our crops from certain kinds of pests and disease. And, it decreases the ability of nature to regulate certain aspects of our global climate.”

On the other hand, Cardinale says, the evidence shows that genetic⁷ diversity increases the yield of commercial crops and enhances the production of wood in tree plantations⁸. 

Forests with more tree species are more effective at absorbing carbon dioxide, a climate changing greenhouse gas. And, crops enhanced by genetic variation are better able to resist disease or attack by exotic species.

“We also know that the yield of fish out of our oceans tends to be more sustainable and stable through time, in fisheries that have a wide variety of fish species compared to parts of the ocean that don’t.”

Delicate balance

A bio-diverse ecosystem³ is often a delicate balance, and it doesn’t take much to upset it.  In her research, co-author Diane Srivastava has studied the cascading⁹ effects of extinction¹⁰. In one experiment, the University of British Columbia ecologist removed the ecosystem’s top predator¹¹ - a damsel fly larva - from a single bromeliad plant - with surprising results.

“We saw effects, of course, on the insects that that damsel fly larva consumed, which we expected," she says, "but what we didn’t expect is to see effects on the very tiny microscopic¹² organisms that were consuming the dead leaves in the system, you know, a completely different part of the food web.”

Cardinale says it is getting more difficult to sustain biodiversity, as more and more species go extinct. “But the real concern is that rates of extinction are about 1,000 times faster than what occurs naturally in the fossil record, and that rate of extinction is going up and the projection¹³ is if that rate continues we will be reaching the same level of the big five (earth) mass extinctions within about 250 to 400 years.”

The good news, Cardinale notes, is that we are not there yet.  There is still time to slow the loss of  biodiversity and protect the troves of animal and plant life that offer humans so much - from new ways of understanding the world and our place in it, to  miraculous new medicines and industrial materials. “If you essentially¹⁴ want to tell people how much species extinction is going to affect you - it’s going to affect your health or your pocketbook -we need to put a per dollar or per disease value on each species that goes extinct. And so the very obvious next step is translating these goods and services into economic value.”

Cardinale says that assessment¹⁵ is realistically about five years away. 

The report in the journal Nature directs a public warning to the international forum¹⁶ meeting in Rio that the loss of biodiversity is having a direct impact on human health and prosperity.

1 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。

2 ecological   

adj.生态的，生态学的

参考例句：

• The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
• Each animal has its ecological niche.每种动物都有自己的生态位.

3 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。

4 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

5 fodder   

n.草料；炮灰

参考例句：

• Grass mowed and cured for use as fodder.割下来晒干用作饲料的草。
• Guaranteed salt intake, no matter which normal fodder.不管是那一种正常的草料，保证盐的摄取。

6 livestock   

n.家畜，牲畜

参考例句：

• Both men and livestock are flourishing.人畜两旺。
• The heavy rains and flooding killed scores of livestock.暴雨和大水淹死了许多牲口。

7 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

8 plantations   

n.种植园，大农场( plantation的名词复数 )

参考例句：

• Soon great plantations, supported by slave labor, made some families very wealthy. 不久之后出现了依靠奴隶劳动的大庄园，使一些家庭成了富豪。 来自英汉非文学 - 政府文件
• Winterborne's contract was completed, and the plantations were deserted. 维恩特波恩的合同完成后，那片林地变得荒废了。 来自辞典例句

9 cascading   

流注( cascade的现在分词 )； 大量落下； 大量垂悬； 梯流

参考例句：

• First of all, cascading menus are to be avoided at all costs. 首先，无论如何都要避免使用级联菜单。 来自About Face 3交互设计精髓
• Her sounds began cascading gently. 他的声音开始缓缓地低落下来。

10 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。

11 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
• Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。

12 microscopic   

adj.微小的，细微的，极小的，显微的

参考例句：

• It's impossible to read his microscopic handwriting.不可能看清他那极小的书写字迹。
• A plant's lungs are the microscopic pores in its leaves.植物的肺就是其叶片上微细的气孔。

13 projection   

n.发射，计划，突出部分

参考例句：

• Projection takes place with a minimum of awareness or conscious control.投射在最少的知觉或意识控制下发生。
• The projection of increases in number of house-holds is correct.对户数增加的推算是正确的。

14 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。

15 assessment   

n.评价；评估；对财产的估价，被估定的金额

参考例句：

• This is a very perceptive assessment of the situation.这是一个对该情况的极富洞察力的评价。
• What is your assessment of the situation?你对时局的看法如何？

16 forum   

n.论坛，讨论会

参考例句：

• They're holding a forum on new ways of teaching history.他们正在举行历史教学讨论会。
• The organisation would provide a forum where problems could be discussed.这个组织将提供一个可以讨论问题的平台。