小编为大家整理了2018年12月16日的
1. What is the discussion mainly about?
A. Effects of climate change on migratory animals
B. A strategy for protecting endangered species
C. Threats to aquatic habitats in the Pyrenees mountains
D. Ways to control the spread of invasive species
2. Why does a student mention the introduction of shrimp into a lake in Montana?
A. To point out a possible danger of assisted migration
B. To explain why certain species are good candidates for assisted migration
C. To suggest that assisted migration can benefit several species at the same time
D. To give an example of a new assisted migration program that is being considered
3. According to the professor, how did climate change affect the two butterfly
species that she discusses?
A. It dried up the water supply in their habitat.
B. It made them vulnerable to predators.
C. It caused a decrease in their food supply.
D. It made it hard for them to reproduce.
4. What does the professor imply about the biological costs of relocating wildlife?
A. The biological costs can be eliminated with careful planning.
B. The benefits almost always outweigh the biological costs.
C. It may be difficult for scientists to anticipate all of the biological costs.
D. There have been minimal biological costs involved to date.
5. What are two reasons that the Iberian desman may be a good candidate for
assisted migration to the Alps, Scotland, or Scandinavia?
Click on 2 answers.
A. Its current predators inhabit those areas.
B. It would be the only species of its kind in those areas.
C. It is unlikely to spread beyond those areas.
D. It would attract beneficial species to those areas.
6. What is the professor's opinion about the proposal to use assisted migration to
save the Iberian desman
A. She is surprised that it is controversial and believes that it will be beneficial if
closely followed.
B. She thinks that it will benefit the Iberian desman but will harm other species.
C. She appreciates that the researchers will proceed with it slowly.
D. She believes that efforts should have been made to rescue the Iberian desman
第一段: 教授开篇提到两个威胁很多动植物生存的因素:气候变化、栖息地的 毁坏,并问 Stephanie,怎么做才能拯救这些物种?Stephanie 回答说,可以停止 化石染料的使用,用太阳能跟风能。男同学补充,世界上有很多“种子银行”, 把种子收起来,不至于绝种。还有人在哺育濒临灭绝的动物。
第二段: 教授说,都是目前在用的方法,但他想介绍另一个越来越受关注的方 法:协助迁徙(assisted migration)。教授说“协助迁徙”是将整个物种从受威胁 的地方迁徙到一个新的、更适合居住的新环境的方法。Stephanie 提问,上次不 还讲了种虾吗?被野生动物管理员引进到蒙大拿州的一个湖里面,本以为这种虾 是湖里面鱼的好食物,但没想到虾进来后跟鱼抢食物吃,还搅乱了整个湖的食物 网。教授说,没错,另外就是物种有时候还会占据比我们预料还大的地区。正是 由于这些风险存在,所以这种方法才有争议
第三段:男同学问,有成功的案例吗?教授说有的。上世纪 90 年代,英格兰的 2 种蝴蝶的案例就是成功的。教授说,气候数据表明,蝴蝶的栖息地当时正经受 高温,这之间影响力它们的繁殖。所以,环保人士就用电能气候模型找到另一个 能让这些蝴蝶生存的地方。起初,一种蝴蝶往北挪了 35km,第二年,另一种蝴 蝶往北挪了 65km。随后的 20 年里,我们密切跟踪了这些蝴蝶,知道目前位置, 并未发现有什么消极影响。
第四段:Stephanie 问,那怎么决定哪种该迁徙,又怎么判断该往哪儿迁徙呢? 教授说,研究人员提出一组标准。首先、被迁徙的物种仅能是由于气候变化、栖 息地毁坏导致的高危物种。但是最关键的是迁徙后的“优”必须要超过生物成本 的“劣”。教授还说,但是问题在于这个成本只有在破坏产生了才看得到。
第五段:教授举例 Iberian desman。他说这个物种是一个半水生动物,生活在比 利牛斯山(Pyrenees Mountains)的急流中。研究人员认为,这个物种很适合迁 徙。原因有 2: a、 Iberian desman 仅在有限的地区里能发现。这意味着,靠它们自己无法迁徙 到一个新地区,而 Iberian desman 生活的溪流正在被污染。另外,那个地区有越 来越多的水力发电站,这导致了 Iberian desman 栖息地的碎片化。 b、 气候变化带来结果:高温、低降雨量。 教授说,综上,很多人想用“协助迁徙”帮助 Iberian desman 找到新的栖息地。 甚至有人认为欧洲的一些地区很适合:Alps、Scotland、Scandinavia 等
第六段:Stephanie 问,那风险呢?教授说 Iberian desman 现在生活地方的竞争对 手、天敌,在上面提到的那些候补地区里也找到了。另外,Iberian desman 从没 有扩张领地的迹象。所以,这些都表明,Iberian desman 的迁徙不会破坏生态平 衡。 第七段:男学生提问,那就决定做咯?教授说目前仅仅是提议阶段。但是这个方 法很有争议,即便是这个方案的提出者对此也很谨慎。教授说这么谨慎也是有原 因的,因为目前仅仅一个成功的案例。
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