食叶昆虫与叶子咀嚼伤痕-凯发k8官网

食叶昆虫与叶子咀嚼伤痕
文章来源:未知 文章作者:enread 发布时间:2014-05-04 06:53 字体: [ ] 
(单词翻译:双击或拖选)
observations of insects and their feeding marks on leaves in modern forests confirm indications from fossil leaf deposits that the diversity of chewing damage relates directly to diversity of the insect population that created it, according to an international team of researchers. "the direct link between richness of leaf-chewing insects and their feeding damage across host plants in two tropical forests 1(确认) the 2 assumptions of many paleobiological studies that rely on damage-type richness as a means to infer changes in relative herbivore(食草动物) richness through time," the researchers report in today's (may 2) issue of plos one.
 
studies of leaf chewing include observation of the leaves, but rarely include all the insects that actually made the marks. mónica r. carvalho, graduate student, cornell university and peter wilf, professor of geosciences, penn state, and colleagues looked at leaf predation(捕食) in two tropical forests in panama to test for a relationship between the richness of leaf-chewing insects and the leaf damage that the same insects induce.
 
using smithsonian tropical research institute 3-access cranes and working in the dark at almost 200 feet high in the treetops at new moon during two summers the researchers collected a total of 276 adult and 4 leaf-chewing insects of 156 species. while the largest category of insect was 5, leaf chewers among 6, stick insects and 7, as well as a few ants, were also collected.
 
the team also collected fresh leaves of the insects' host plants and placed the insects in feeding experiment bags with these leaves. they allowed adult insects to feed for two to three days and immature stages to feed until full 8 when possible. the researchers then classified the damage to the leaves into categories, in the same way they catalog fossil leaf-chewing damage.
 
"this is the first attempt to compare leaf-chewing damage 9 by many kinds of living insects on many kinds of plants throughout a large forest area, both to the culprit insects and to the leaf damage we see in the fossil record," said carvalho."we mounted 276 of the insects with their damaged leaves and deposited them in the stri insect collection."
 
this collection is the only known vouchered(收据,证人) collection of diverse, identified insects and their feeding damage on leaves of identified plant hosts.
 
the number of collected insect species correlated strongly with the number of damage types recorded in canopy leaves of 24 tree and liana species observed in the feeding experiments. this suggests that the number of types of damage seen in the fossil record is also related to the actual diversity of damage-making insects.
 
the researchers also compared the modern leaf data to fossil data from colombia, argentina, the great plains and the rocky mountains. they found that the distribution of chewing marks was the same across both modern and ancient settings, showing a striking 10 in how insects have divided up their leaf resources since at least the end of the age of 11.
 
"in the fossil record we frequently find a decrease in damage-type richness during cooling events and after extinctions and an increase in damage-type richness during warming events and post-extinction recovery," said wilf. "usually, insect body-fossils from these critical time 12 are absent or very rare, so we rely on the insect-damaged leaves to tell the story. these fossil studies have been considered tremendously important for understanding how 13 have responded, and will respond, to climate change and 14. we now have direct observational evidence that the fossil data represent changes in actual insect richness and no longer need to infer this through 15 alone."


点击收听单词发音收听单词发音  

1 d28f3305a883e5207d6097da0b7642f0     
v.证实( validate的第三人称单数 );确证;使生效;使有法律效力
参考例句:
  • other research validates that when it comes to chocolate, type does matter. 其他的研究也证实了不同种类的巧克力确实功效不同。 来自互联网
  • trouble shoots equipment, review and validates data and complete reports. 管理错误描述设备,审查并确认试验数据,完成试验报告。 来自互联网
2 5fyz8c     
adj.在下面的,含蓄的,潜在的
参考例句:
  • the underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
  • this word has its underlying meaning.这个单词有它潜在的含义。
3 rczya     
n.天篷,遮篷
参考例句:
  • the trees formed a leafy canopy above their heads.树木在他们头顶上空形成了一个枝叶茂盛的遮篷。
  • they lay down under a canopy of stars.他们躺在繁星点点的天幕下。
4 saaxj     
adj.未成熟的,发育未全的,未充分发展的
参考例句:
  • tony seemed very shallow and immature.托尼看起来好像很肤浅,不夠成熟。
  • the birds were in immature plumage.这些鸟儿羽翅未全。
5 e572d93f9d42d4fe5aa8171c39c86a16     
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 36b89ec2ea2ca37e7a20710c9662926c     
n.蚱蜢( grasshopper的名词复数 );蝗虫;蚂蚱;(孩子)矮小的
参考例句:
  • grasshoppers die in fall. 蚱蜢在秋天死去。 来自《简明英汉词典》
  • there are usually a lot of grasshoppers in the rice fields. 稻田里通常有许多蚱蜢。 来自辞典例句
7 7673bc2d84c4c7cba4a0eaec866310f4     
n.毛虫( caterpillar的名词复数 );履带
参考例句:
  • caterpillars eat the young leaves of this plant. 毛毛虫吃这种植物的嫩叶。
  • caterpillars change into butterflies or moths. 毛虫能变成蝴蝶或蛾子。 来自辞典例句
8 47nzh     
n.成熟;完成;(支票、债券等)到期
参考例句:
  • these plants ought to reach maturity after five years.这些植物五年后就该长成了。
  • this is the period at which the body attains maturity.这是身体发育成熟的时期。
9 cd6137b3bb7ad543500a72a112c6680f     
把…强加给,使承受,遭受( inflict的过去式和过去分词 )
参考例句:
  • they inflicted a humiliating defeat on the home team. 他们使主队吃了一场很没面子的败仗。
  • zoya heroically bore the torture that the fascists inflicted upon her. 卓娅英勇地承受法西斯匪徒加在她身上的酷刑。
10 iy2yt     
n.一贯性,前后一致,稳定性;(液体的)浓度
参考例句:
  • your behaviour lacks consistency.你的行为缺乏一贯性。
  • we appreciate the consistency and stability in china and in chinese politics.我们赞赏中国及其政策的连续性和稳定性。
11 87f9c39b9e3f358174d58a584c2727b4     
n.恐龙( dinosaur的名词复数 );守旧落伍的人,过时落后的东西
参考例句:
  • the brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
  • dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》
12 f46c9d8b430e8c86dea610ec56b7cbef     
n.[军事]间隔( interval的名词复数 );间隔时间;[数学]区间;(戏剧、电影或音乐会的)幕间休息
参考例句:
  • the forecast said there would be sunny intervals and showers. 预报间晴,有阵雨。
  • meetings take place at fortnightly intervals. 每两周开一次会。
13 94cb0e40a815bea1157ac8aab9a5380d     
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
14 bsnxk     
n.动乱,骚动;打扰,干扰;(身心)失调
参考例句:
  • he is suffering an emotional disturbance.他的情绪受到了困扰。
  • you can work in here without any disturbance.在这儿你可不受任何干扰地工作。
15 0xjx7     
n.减除,扣除,减除额;推论,推理,演绎
参考例句:
  • no deduction in pay is made for absence due to illness.因病请假不扣工资。
  • his deduction led him to the correct conclusion.他的推断使他得出正确的结论。
上一篇: 下一篇:
tag标签: leaf
发表评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
验证码:点击我更换图片
最新评论
网站地图