在线词典,在线翻译

啄木鸟医生

所属:听力板块 来源:普特英语听力 阅读:3665 次 评论:0 条 [我要评论]  [+我要收藏]

小编摘要:啄木鸟啄破死树或垂死的树的树皮(也作断枝讲),觅得吃木头的昆虫为食。有些物种也会在这些树上筑巢。

 Woodpeckers and Fungus 啄木鸟和真菌


W: Woodpeckers puncture the bark of dead or dying trees, also known as snags, to find the wood-boring insects that make up their diet, and some species also excavate cavities in these trees for their nests.

M: So where does the fungus come in?

W: Well, scientists observed that the snags woodpeckers excavate generally contain decayed wood, which is caused by wood-decay fungi. Right. And this led them to wonder whether woodpeckers are attracted to certain types of decay, or if they’re the ones actually spreading the fungus that causes the decay.

M: So what did come first?

W: Well, it turns out that the relationship between the two is pretty complex. When woodpeckers puncture bark, they provide a way for airborne fungal spores to infect the wood. They also act as vectors, unintentionally picking up fungal spores and other microbes from one snag and carrying them in their beaks to another. And not surprisingly, species of woodpeckers that nest in cavities carry a significantly larger number of these, which is synergistic, because the decay makes it easier for them to excavate.

So even though we still don’t know which came first, this also isn’t merely an intellectual exercise. Woodpeckers are pretty important ecologically because the sites they excavate are used for foraging, roosting, and nesting by many other species as well. And now that there’s debate over whether snags contribute to forest fires and should be removed, it’s especially important to study potential ramifications.


啄木鸟啄破死树或垂死的树的树皮(也作断枝讲),觅得吃木头的昆虫为食。有些物种也会在这些树上筑巢。

那么真菌是从哪来的呢?

恩,科学家们观察到啄木鸟啄洞的断枝通常包含由木腐菌造成的蛀木。是的。而且这引起观察家们思考:是某些类型的腐烂吸引了啄木鸟,还是说啄木鸟实际上传播了引起腐烂的真菌呢?

那么到底哪个在先?

恩,事实证明两者关系相当复杂。当啄木鸟啄树皮时,它们为空气传播的真菌孢子感染树木提供了方便,它们同时也是带菌者,无意中携带了真菌孢子和来自某根断枝的其他细菌,它们的喙载着这些细菌再传播给其他树木。毫不奇怪的是,那些在树洞里筑巢的啄木鸟携带着更大量的真菌,它们是协同作用着的,因为腐烂使得啄木鸟啄洞更容易了。

因此,即使我们不知道先有哪个,这也不仅仅是一种智力测验。从生态学的观点看,啄木鸟的角色相当重要,因为啄木鸟挖掘的树洞可以用于觅食,栖息,还可以被其他物种用来筑巢。既然人们关于断枝是否会导致森林火灾而应该被移除争论不休,那么研究一下可能出现的后果就特别重要了。

标签:听力文摘
3
2011-12-16 18:41 编辑:pliny
分享到:
关注海词微博:
发表评论:
表达一些您的想法吧!已有0条评论>>
登录,再发表评论
文明上网,理性发言!
您可能还感兴趣的文章:
  • [听力板块]身体,你怎么啦?

    每次生病了,家里人最多说的一句话就是“不吃药怎么行?”。可是,有的时候吃药不一定就对身体有好处,反而有可能会帮助病原体“攻击”我们的身体。今天我们来了解了解一种新的理论“达尔文医学
  • [听力板块]利刃特别在何处

    大家都知道锋利的刀刃的切割性能胜过钝刀,但您知道确切原因吗?刀刃的作用就是把人们用在刀把上的力集中起来。
>>精华推荐阅读
热门评论文章